Sublittoral Survey of Northern Ireland - Department of the Environment

Sublittoral Survey Northern Ireland 

May 2006 — May 2008 

A Review of the status of Northern Ireland 

Priority Species of Marine Invertebrates 

In partnership with

Research and Development Series 11/01 

A report commissioned by the Northern Ireland Environment Agency 

Sublittoral Survey Northern Ireland 

2006 — 2008 

A review of the status of Northern Ireland 

Priority Species of Marine Invertebrates 

Authors — Claire Goodwin, Bernard Picton, Joe Breen, Hugh Edwards & Julia Nunn 

Contractor — National Museums Northern Ireland 

NIEA contract number — CON 2/1 (227), CON 2/1 (244) 

This report should be cited as follows — 

Goodwin, C., Picton, B., Breen, J., Edwards H. and Nunn, J. (2011) Sublittoral Survey 

Northern Ireland (2006 – 2008). Northern Ireland Environment Agency 

Research and Development Series No. 11/01 

For further information on this report please contact — 

Joe Breen 

Northern Ireland Environment Agency, 

Conservation Science, 

Klondyke Building, 

Gasworks Business Park, 

Lower Ormeau Rd, 

Belfast, 

BT7 2JA 

The opinions expressed in this report do not necessarily reflect the current opinion or 

policy of the Northern Ireland Environment Agency.

Sublittoral Survey Northern Ireland Goodwin et al., 2011 

Contents 

Section Page 

1 Project Background 3 

2 Survey Methodology 5 

Survey Data 5 

Priority Species Data 5 

3 Survey Aims 6 

Rathlin Island 6 

The Skerries 7 

The Maidens 7 

Strangford Lough 7 

Carlingford Lough 8 

4 Results 9 

Rathlin Island 9 

The Skerries 15 

The Maidens 17 

Strangford Lough 19 

Carlingford Lough 21 

East Coast 21 

5 Recommendations for future work 22 

6 Acknowledgements 22 

7 Records of unusual species (other than NICP species) 25 

Porifera 25 

Cnidaria 34 

Crustacea 36 

Mollusca 37 

Bryozoa 41 

Echinodermata 42 

Tunicata 43 

Pisces 46 

8 References 48 

Appendix 1 Selection criteria for Northern Ireland Priority Species 51 

Appendix 2 Survey aims for NICP Marine Invertebrate Species 53 

Appendix 3 Dives undertaken during the SSNI project 56 

Appendix 4 Information pages for NICP marine invertebrate species 64 

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1. Project Background 

Sublittoral Survey of Northern Ireland 

Several marine invertebrate species are included in the Northern Ireland Conservation Priority 

(NICP) species list. However, prior to this project, very little was known about any of these 

species, and more information was urgently needed on their distribution and ecology in order to 

ensure their conservation. 

In June 1992, the ‘Convention of Biological Diversity’ or ‘Rio Convention’ was signed by 159 

governments at the Earth Summit. It was the first treaty to provide a legal framework for 

biodiversity conservation. It called for the creation and enforcement of national strategies and 

action plans to conserve, protect and enhance biological diversity. After consultation with over 300 

organisations the UK government launched ‘Biodiversity: the UK action plan’ in 1994. This 

outlined the UK plan for dealing with biodiversity conservation and included a list of UK 

Biodiversity Action Plan Priority Species. The criteria used to define these species are that they are 

globally threatened or have declined by at least 50% in the UK over the past 25 years. In June 

2007, a new UK Biodiversity Action Priority list was issued. This included 1149 species and 65 

habitats. 

Scotland, Wales and Northern Ireland are devolved from UK government, and consequently are 

responsible for implementing obligations that concern devolved matters. Powers on environmental 

regulation are among the policy areas devolved. All four countries have published strategies to help 

guide the implementation of biodiversity conservation, sustainable development and environmental 

concerns. In 2002 the ‘Northern Ireland Biodiversity Strategy’ was published and England 

followed with ‘Working with the Grain of Nature’ in the same year. In 2004, Scotland published 

‘Scotland’s biodiversity. It’s in Your Hands’ and the ‘Environment Strategy for Wales’ was 

published in 2006. 

Included in these strategies or created subsequently are local lists of Biodiversity Priority Species. 

All UK Biodiversity Action Priority Species are automatically included on these regional lists. 

However, provinces also develop their own lists which include additional species of local 

importance. There are two levels of designation: priority species (which require conservation 

action) and species of conservation concern (which require monitoring because they may need 

conservation action in the future). 

The draft lists of NICP species and Northern Ireland Species of Conservation Concern (SOCC) 

published in Northern Ireland Biodiversity Strategy Proposals in 1999 were reviewed by collating 

information supplied by experts on species groups and refining and applying the selection criteria. 

Following this, lists of NICP species (272 species) and SOCC (457 species) were published. 

The selection criteria for NICP species are that they fulfill any of the following criteria: 

UK Priority Species. 

Rapid decline in Northern Ireland (2% per year over the last 25 years). 

Declining (1% year) with Northern Ireland being a stronghold consisting of either:- 

>50% Irish population or 

>20% UK population/range. 

Rare (e.g. a small population and/or confined to one or two sites in Northern Ireland) with 

Northern Ireland being a stronghold consisting of either:- 

>50% Irish population or 

>20% UK population/range. 

Significant proportion (>20%) of the international population of a species (or well 

recognised subspecies) occurring in Northern Ireland. 

Published or proposed Irish Red Data Book species classed as either critically. 

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endangered, endangered or vulnerable. 

Red-listed species in either the Ireland or UK Birds of Conservation Concern (BOCC) lists. 

Table 1 – Northern Ireland Marine Invertebrate Conservation Priority Species 

Group Number of NICP Species 

Sponges 7 

Cnidarians 11 

Segmented worms 2 

Crustaceans 5 

Molluscs 9 

Bryozoans 1 

Echinoderms 9 

Acorn worms 1 

Tunicates 1 

Total 46 

The number of NICP species within different groups is shown in Table 1. A complete list of marine 

invertebrate NICP species, with selection criteria, is given in Appendix 1. Because of the relative 

paucity of information on marine species and the way the selection criteria operate, priority species 

lists are often heavily biased towards terrestrial groups. In the UK, BAP list marine species account 

for only 8% of the total list; whereas they represent approximately 22% of UK Biodiversity 

(Hiscock & Smirthwaite 2005). In Northern Ireland, they represent 33% of the priority species list. 

However, they are still under-represented as the terrestrial fauna of Ireland is impoverished due to 

recent glaciation and marine species represent >40% of Northern Irish biodiversity. 

Much of the information used to create the NICP species and SOCC lists derives from the Northern 

Ireland Sublittoral Survey (NISS) (Erwin et al. 1986, 1990). This diving survey of the marine life 

and habitats of the Northern Ireland Coast was carried out by the Ulster Museum between 1982 and 

1986. However, since this survey little sublittoral survey work has taken place in Northern Ireland, 

and consequently there is very little information on the current status of NICP species. 

In this survey, selected areas of the Northern Ireland coast were resurveyed to gain information on 

the current status of NICP species. Only marine invertebrate species were targeted, although 

records were made of algal species, where present, and interesting records were noted in the text. 

Although it is a marine invertebrate species, the acorn worm Glossobalanus sarniensis was not 

included in this study, as it is too small to be usefully targeted by dive surveys. Equally the 

honeycomb worm Sabellaria alveolata was not targeted, as it is primarily an intertidal species. 

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2. Survey methodology 

Data on the distribution of Northern Ireland Conservation Priority species were collected from 

sources including the Northern Ireland Sublittoral Survey (NISS) (Erwin et al. 1986). On the basis 

of this information, five areas of Northern Ireland coastline were selected for re-surveying during 

the 2006 and 2007 field seasons. These were chosen to target as many priority species as possible 

within the time given. Survey time allocated to each area was roughly proportional to the number 

of NICP species occurring there. The survey areas chosen were the Skerries, the Maidens, Rathlin 

Island, Carlingford Lough and Strangford Lough. In each area particular NICP species were 

targeted. By intensive survey work and focusing principally on the NICP species, a more detailed 

picture of their distribution, abundance and ecology could be obtained. 

The areas were surveyed by SCUBA diving. NISS sites with records of NICP species were 

revisited to establish if they were still present, and additional sites were surveyed where habitat 

information indicated that a NICP species may be present. On each dive, divers were asked to focus 

on recording particular NICP species. A JNCC phase 2 sublittoral habitat form was completed to 

give record of species and habitats at the site, and on most dives still photographs were also taken. 

Video was also taken on some dives. Samples were collected where necessary for identification or 

verification and specimens are held in the marine invertebrate collections of the Ulster Museum. 

Survey Data 

A Microsoft Access database was created. This includes information on dives, images and voucher 

specimens from the survey. It is possible to search the database by species and view a list of 

images, each identified with the location it was taken. Copies are held by museum and NIEA staff. 

Data sheets have been collated and passed to CEDaR where the data have been entered onto the 

database Marine Recorder. 

Priority Species Data 

A species page was produced for each NICP species. These can be found in Appendix 4. The page 

gives a species description, lists similar species, details why the species is on the NICP list, its 

distribution, Northern Ireland status prior to SSNI and findings and recommendations from the 

SSNI project. 

Table 2 – Organisation abbreviations used in this report 

Abbreviation Organisation 

BE Picton Records from B.E. Picton’s personal database from a variety of 

recreational and scientific dive surveys. 

BioMar BioMar Project data 

CCW* Countryside Council for Wales 

MBA* Marine Biological Association of the UK 

MCS* Marine Conservation Society 

MNCR* Marine Nature Conservation Review 

NISS Northern Ireland Sublittoral Survey 

PMSA* Pembrokeshire Marine Species Atlas 

Seasearch* Seasearch volunteer survey project (coordinated by the Marine 

Conservation Society) 

SNH* Scottish Natural Heritage 

* indicates data obtained from National Biodiversity Network Gateway. 

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Data on distribution were collated from many sources; any publications are referenced on the 

species page. Some distribution information was obtained from the National Biodiversity Network. 

Where possible the source dataset has been specified, and this is indicated with an acronym. The 

full names of these organisations are shown in Table 2. Most of the information on Northern 

Ireland distribution was obtained from the BioMar biotope viewer (Picton & Costello 1998) which 

combines data from the Northern Ireland Sublittoral Survey and the BioMar project, a survey of 

sublittoral species and habitats which took place in the Republic of Ireland between 1992 and 1996. 

Additional information was obtained from Bernard Picton’s personal records, CEDaR (the Centre 

for Environmental Data and Recording) which is the Northern Ireland Records Centre, and 

Seasearch Northern Ireland (a local branch of the national volunteer project which uses sports 

divers to collect information on sublittoral species and habitats). 

3. Survey Aims 

Of the five survey areas specified, two (Rathlin Island and Strangford Lough) are existing Special 

Areas of Conservation. The other areas (the Maidens, the Skerries, and Carlingford Lough) were 

identified as being of nature conservation importance in the Northern Ireland Sublittoral Survey, 

and may require designation in the future. 

In each area there were specific objectives, as detailed below. 

Rathlin Island 

East coast of Rathlin 

During fieldwork carried out by the museum team in summer 2005 it was noted that the east coast, 

previously a boulder strewn area with a rich associated hydroid and sponge fauna, appeared to have 

been significantly altered. Many of the boulders had apparently disappeared, and the previously 

abundant (locally rare) hydroid communities were greatly reduced. It is believed that the area was 

damaged by scallop dredging. This area is an important stronghold for a number of the NICP 

species; the hydroids Diphasia alata, D. nigra and Polyplumaria flabellata and the sponge Clathria 

barleei. The boulder area was previously rich in the squat lobster Munida rugosa and these, 

together with the starfish Anseropoda placenta and Astropecten irregularis, and the hermit crab 

Cestopagurus timidus may also have been impacted by dredging. 

Aims: 

Assess extent of damage to east coast communities. 

Gain information on the distribution of the hydroids Diphasia alata, D. 

nigra, Polyplumaria flabellata, Lytocarpia myriophyllum and Halecium 

plumosum. 

Gain information on the distribution of the sponge Clathria barleei, the squat 

lobster Munida rugosa, the starfish Anseropoda placenta and Astropecten 

irregularis, and the hermit crab Cestopagurus timidus. 

Anemones and corals 

The NICP species Arachnanthus sarsi (burrowing anemone) and Caryophyllia inornata (cup coral) 

are only known to occur in Northern Ireland on Rathlin Island. There is also one site at which the 

anemone Edwardsia timida has been recorded. 

The sea pen Virgularia mirabilis is also known to occur around Rathlin. 

Aims: 

Survey selected sites to establish the presence of these species. 

Other Species 

The nudibranch Cumanotus beaumonti is known to occur on sandy areas in Church Bay on Rathlin 

Island, and more information is needed on its distribution and status. 

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Aim: 

The Skerries 

Survey selected sites for this species. 

Horse Mussel beds 

The Skerries is one of four places that horse mussel Modiolus modiolus beds are known to occur in 

Northern Ireland. 

Aim: 

Survey beds and assess current status, specifically targeting associated NICP 

species, as detailed in the Strangford Lough proposal. 

Sponges 

The ‘Sponge Biodiversity of Rathlin Island’ project (Picton & Goodwin 2007a, b) resulted in the 

discovery of more than 30 undescribed species. It is believed that further populations of these may 

occur in the Skerries. Additional records would be useful in establishing the validity of the Rathlin 

Island species. 

Aim: 

Collect sponge material from sites in the Skerries, using similar methodology 

to the Rathlin project to establish if newly discovered species are present. 

Tunicates 

Several tunicate-dominated biotopes are present in this area. It is believed that new species may be 

present here. They include two species of Didemnum (yellow and brown), a Synoicum species, a 

polyclinid known as ‘the raspberry sea squirt’, and a sea-squirt called ‘the pin-head squirt’ on the 

NISS which has not been identified even to family level. These are known and recognisable from 

photographs, but new specimens need to be collected and carefully preserved. The specimens then 

would be studied using light and electron microscopy and fully described in the scientific literature. 

Aim: 

Collect specimens of these ascidian species. 

The Maidens 

The tidal and habitat conditions of the Maidens make them an important area for hydroids and 

sponges. Many species only occur here and on the east coast of Rathlin Island. However, currently 

the distribution, habitat preferences and abundance of these species is poorly known. The sponge 

Clathria barleei is only known in Northern Ireland from here and Rathlin Island. Although there 

are records from Rathlin from 1980-1990 this species was not found on the recent sponge survey 

(Picton & Goodwin 2007a, b): unlike many sponges it is a conspicuous and recognisable species 

underwater. 

Aims: 

Establish the distribution and conservation status of the NICP species 

Diphasia alata, D. nigra, Polyplumaria flabellata, Lytocarpia myriophyllum 

and Halecium plumosum. 

Obtain records of the target species: sponge Clathria barleei. 

Strangford Lough 

Modiolus beds 

Populations of many Modiolus bed associated species are likely to have been impacted by the 

damage to the beds in Strangford. Although the beds have been surveyed to assess damage and 

7


recovery, many of these may have been overlooked. NICP species associated with the beds are the 

sea cucumbers Paracucumaria hyndmani, Ocnus brunneus (formerly synonymised with O. planci), 

and Thyonidium drummondi, the mollusc Chlamys varia, the sponges Mycale (contarenii) and 

Mycale similaris, and the tunicate Pyura microcosmus. 

Aim: 

Survey areas with prior records for these species. 

Gravel communities 

Atelecyclus rotundatus (a crab), and Inachus leptochirus (a spider crab) have been previously 

recorded from gravel habitats in Strangford Lough. 

Aim: 

Sponges 

Survey selected sites to check status for these species. 

Strangford Lough is the type locality for several sponge species. Undoubtedly there are more 

sponges to be discovered in Strangford Lough if detailed collecting of the type used on the Rathlin 

Sponge Biodiversity project was employed. Mycale (contarenii) which occurs in Strangford Lough 

is a typical species on scallop shells (Aequipecten opercularis) and is slightly different in 

spiculation and very different in external appearance to Mycale contarenii from elsewhere. These 

two forms need to be carefully compared, including some DNA analysis, to examine whether the 

Strangford Lough scallop-associated species is a distinct (probably undescribed) species. 

Aim: 

Other taxa 

Populations of sponges to be checked using Rathlin collecting 

methodology 

Anemonactis mazeli – this burrowing anemone has only been recorded in Northern Ireland on one 

occasion; it is possibly nocturnal. 

Labidoplax media – this burrowing sea cucumber is only known to occur in two locations in the 

UK: the Shetlands and Strangford Lough. 

Edwardsia timida – this burrowing anemone is known from only a few localities in the Irish Sea 

and the North coast of France. 

Ocnus planci - this sea cucumber is known to occur in Carlingford Lough. However, its taxonomic 

status is currently unresolved. It has been suggested that it is conspecific with O. brunneus 

(McKenzie 1984) which occurs in Strangford Lough. Samples of O. brunneus will be collected in 

the course of survey work for genetic analysis, which should help resolve these problems. This 

could be carried out as part of the project, or subsequently passed on to an external contractor. 

Leptasterias muelleri – this is a species with predominantly a northern distribution in the UK, 

which may be vulnerable to climate change. 

Solaster endeca – known to be formerly present; a northern species which may be a good indicator 

of climate change. 

Tonicella marmorea – marbled chiton, a northern species which may be a good indicator of climate 

change. 

Aim: 

Resurvey selected sites to establish status of these species. 

Carlingford Lough 

Carlingford Lough is known to be an important location for Virgularia mirabilis, with the majority 

of the Northern Ireland populations occurring here. However, since these records were made during 

8


the Northern Ireland Sublittoral Survey (1982-85) there have been significant anthropogenic 

impacts on the lough, mainly dredging and fish farming, which may have damaged the populations. 

Specimens of the sea cucumber Ocnus planci were collected during previous surveys in 

Carlingford Lough, and were unusual in being much larger than the specimens from elsewhere in 

the British Isles (which are possibly a separate species, Ocnus brunneus). 

Aims: 

Survey sites at which the sea pen Virgularia mirabilis was known to occur to 

assess status. 

Collect samples of the sea cucumber Ocnus planci for molecular studies into 

its species status. 

4. Results 

Table 3 shows how the survey time was divided. Each area was allocated a survey time which was 

roughly estimated from the number of priority species which were to be surveyed. Belfast Lough 

and Larne Lough were dived when weather prevented diving on the Maidens. Dundrum Bay was 

surveyed to monitor priority habitats and collect records of priority species such as Astropecten 

irregularis. The East Antrim coast survey was included to monitor priority maerl and seagrass 

habitats and associated species. A list of dives is given in Appendix 3 and dive locations are shown 

in Figure 1. 

Table 3 – Survey time allocation during SSNI 

Site Proposed 

time (days) 

Actual time 

2006 

9 

Actual time 

2007 

Total Time 

SSNI (days) 

No. of 

dives 

Rathlin Island 15 7 10 17 80 

The Skerries 15 5 5 10 41 

Maidens 10 8 6 14 60 

Strangford Lough 15 3 21 24 99 

Carlingford Lough 5 0 2 2 7 

East Antrim Coast 0 4 1 5 19 

Dundrum Bay 5 1 3 4 9 

Belfast Lough 0 1 0 1 5 

Larne Lough 0 0 1 1 2 

Total time 60 29 49 78 322 

The findings for each NICP species are given in Appendix 4. The findings for each area 

are summarised below. 


Three main habitats of importance to NICP species are present on Rathlin Island: rocky 

reef habitats, sand and gravel habitats in Church Bay, and boulder slopes on the east coast. 

Rocky reef 

The rocky reef habitats on Rathlin include the sea cliffs on the north wall and the south 

coast, the latter including Damicornis Bay, a small bay of particular conservation


importance. These rocky habitats have been shown to be of particular importance for 

sponge species (Erwin et al. 1990; Picton & Goodwin 2007a, b), and are a stronghold for 

NICP sponge species including Microciona elliptichela. Further sponge samples were 

collected during SSNI. These included specimens of rare and recently described species 

(including Hymeraphia breeni and Ectyodoryx jenjonesae (Picton & Goodwin 2007a, b)) 

and what are believed to be further undescribed species. 

There was some concern over Microciona elliptichela as it was not recorded from Rathlin 

in the ‘Sponge Biodiversity of Rathlin Island’ survey in 2005 (Picton & Goodwin 2007b). 

This was the only location from which this species had been recorded in Northern Ireland. 

However, one record was made from Rathlin Island during SSNI, and three further 

specimens were taken from the Maidens. 

The cup coral Caryophyllia inornata is known in Northern Ireland only from Rathlin 

Island. One record was made of this species, consisting of several individuals (West of 

Derginan Point on the North Wall). 

A further area of bedrock reef, termed for lack of a prior name ‘Picton’s Reef’, was located 

by the survey on the east coast. This is a small table shaped reef (approximate position 55 o 

16.5’N, 06 o 10.3’W) with its base at ~37m and its top in 25m. It had abundant sponge and 

hydroid cover including the NICP hydroid species Polyplumaria flabellata and Diphasia 

alata. 

It was considered that there might be undamaged hydroid and sponge communities in the 

deeper areas on the east coast of Rathlin. There are some areas of steep boulder slope 

difficult to fish, and they are therefore likely to have escaped dredging damage. Two such 

areas were located with the help of multibeam sonar data from the Joint Irish Bathymetric 

Survey (JIBS) project. These were: ‘NE of Picton’s Reef’ (55 o 16.7’N, 06 o 10.0’W, dives 

070619/02, 070620/01, 070620/02) and ‘Slope East of Illancarragh Bay’ (55 o 16.14’N, 06 o 

10.14’W, dives 070621/02 and 070621/03). Unlike the shallower areas of the Rathlin coast 

level, these communities do not seem to have been damaged and a rich sponge and hydroid 

fauna was present. These communities are similar to those reported during NISS from 

shallower areas of the east coast. 

‘Slope East of Illancarragh Bay’ was a boulder slope of 45-60º angle composed of small 

and large rounded boulders from 38m to 45m+ (deeper areas not surveyed). The substrate 

was dominated by a hydroid, bryozoan and erect sponge turf including NICP species: the 

sponge Clathria barleei, the hydroids Diphasia nigra, D. alata and Polyplumaria 

flabellata and the anemone Parazoanthus axinellae were all present. 

‘NE of Picton’s Reef’ had two different habitats, of which the shallower (39-40m) was an 

area of gently sloping sediment composed of bedrock outcrops, small boulders, cobbles, 

pebbles and gravel. This substrate was dominated by a hydroid and bryozoan turf again 

including the NICP species Diphasia alata, D. nigra and P. flabellata. In slightly deeper 

water (40-42m, dive 070619/02), the substrate was a steep boulder slope with a hydroid 

and bryozoan turf including P. flabellata, Diphasia alata, D. nigra. The bryozoan 

Pentapora fascialis was abundant in this area – at least 8 colonies were seen on this dive. 

10


Figure 1 – SSNI dive locations 

11


Due to the small number of dives, it was not possible to establish how widespread these 

communities are. It is, however, apparent that these areas represent an important habitat for 

several rare NICP species. Although shallow areas of this habitat have apparently been 

damaged by dredging, it appears that communities in deeper water are still intact. The only 

other Northern Ireland location at which many of these species occur is the Maidens. 

Consequently, it is vital that the east coast of Rathlin is protected from further damage to 

ensure their favourable conservation status. We recommend that other areas adjacent to 

steeply sloping contours be surveyed in more detail. It is essential that appropriate 

conservation measures be put in place to prevent further damage by dredging. 

One fan shell Atrina fragilis was recorded from the east coast of Rathlin. It is possible that 

further specimens are present on this coast but, despite surveying the immediate area, none 

were found. The main surviving UK populations of this UK BAP species appear to be in 

Cornwall and Devon (those in the Salcombe estuary and Plymouth sound are particularly 

well documented), and the west coast of Scotland, and between John O’ Groats and the 

Shetland Isles. In the Republic of Ireland, it is only known recently from Galway Bay 

(1962, 1970s) and Valentia (1975). The only other recent Northern Ireland record is from 

the north coast of Northern Ireland in 1971, where an individual was taken during a 

trawling survey for the queen scallop Aequipecten opercularis (Nunn 2007a). 

The featherstar Antedon petasus and the seasquirt Synoicum pulmonaria were not recorded. 

Whilst the common featherstar Antedon bifida is widespread throughout Northern Ireland, 

the more robust species Antedon petasus has a more northerly range. During NISS, 

fourteen records were made, the majority from Rathlin Island. It was not recorded during 

SSNI; its disappearance could be linked to an increase in water temperature. Synoicum 

pulmonaria, the ‘tennis ball seasquirt’ is a distinctive seasquirt which was frequent on the 

east coast of Northern Ireland in the 1980s but was not found by the present survey. This 

species is common in the North Sea but confined to deeper colder water elsewhere in the 

Britain and Ireland. It is a northern species, distributed from the Arctic to the English 

Channel (Millar 1970). It is possible that the lack of recent records is due to increased 

water temperatures. 

Sand and gravel habitats in Church Bay 

In the relative shelter of Church Bay on the south coast of Rathlin Island sand and gravel 

habitats occur. NICP species the starfish Anseropoda placenta and Astropecten irregularis, 

the hermit crab Cestopagurus timidus and the slender sea pen Virgularia mirabilis had all 

been previously recorded from this area. Records were made of all these species, except 

Cestopagurus timidus. However, this species is very small and easily missed by diving 

surveys. 

An anemone thought to be Edwardsia timida was recorded from Church Bay in 1985 

(NISS, dive number 850703/06). However, re-examination of photographs from the dive 

indicates that this is a different, as yet unidentified, Edwardsia species. Neither this species 

nor E. timida were recorded, despite resurveying this area. 

A previously unrecorded area of sea grass (Zostera marina) was found and surveyed (55 o 

17.162’N, 06 o 11.679’W; dives 060608/04 and 060609/01) in Mill Bay on the east side of 

Church Bay. This is a priority habitat. It had originally been indicated that seagrass might 

be present in the area when some was obtained in a grab sample by Water Management 

Unit, Northern Ireland Environment Agency (WMU). Subsequently the location of the bed 

was established on a 2006 Seasearch dive. These dives were the first time the bed had been 

surveyed in any detail. The second survey dive was a night dive and an unusual, as yet 

12


undetermined, species of anemone was recorded (sample taken). 

The NICP nudibranch Cumanotus beaumonti was previously recorded from this habitat 

(previous Northern Ireland records are from Church Bay and offshore at Carlingford 

Lough). However, although its food source, the solitary hydroid Corymorpha nutans, was 

widespread within Church Bay and fairly abundant, no further records were made. 

Nudibranch populations are ephemeral, and it is possible the timing of the survey could 

have resulted in the species being missed or that populations were not present during 

2006/2007. 

The spotted burrowing anemone Arachnanthus sarsi, a NICP and UK BAP species, was 

previously known in Northern Ireland from only two individuals from Church Bay (East of 

Black Head and the White Cliffs). Several individuals were later seen on a night dive, 

which suggested the species might be nocturnal in this area. During the 2006 Rathlin 

survey, one record of A. sarsi was made during a night dive (White Cliffs, dive 

060608/05), close to these original records. During 2007, further records were made on 5 

dives, all at the White Cliffs (070611/07; 070614/02; 070618/05; 070613/06; 070618/06). 

Several of these dives were in the daytime, indicating that A. sarsi is not nocturnal on 

Rathlin Island as previously suspected. Elsewhere in the UK, it has also been recorded 

during daylight. On several dives more than one specimen was seen; on one dive 

(070618/06) three individuals were recorded. This indicates that populations on Rathlin 

may be comparable with the most abundant populations known within the UK, making it a 

UK stronghold for this species. The Rathlin population also represents the entirety of the 

Northern Ireland population. At present it is very vulnerable to damage by scallop 

dredging; currently Church Bay is regularly fished by scallop dredgers, particularly when 

poor weather prevents fishing elsewhere. There is no legislation currently in place to 

prevent this fishing. J. Breen (Northern Ireland Environment Agency (NIEA)) has been in 

discussions with local fishermen, and has succeeded in negotiating a voluntary ban on 

fishing here. However, this does not prevent boats from elsewhere fishing in this area. We 

recommend that a ban on bottom fishing with mobile gear be implemented as a matter of 

urgency. 

In addition to A. sarsi, records of two other anemones were made from the White Cliffs 

area. An anemone believed to be Halcampoides abyssorum was recorded during 2006 

(dive 060608/05). This species is known only from the UK from Lundy (Keith Hiscock) 

Havelet Bay, Guernsey (1987 Bernard Picton), and the west coast of Scotland (George 

Brown). 

Several specimens of an as yet unidentified Halcampoides anemone species were also 

recorded. These were frequent, with up to 20 being recorded on one dive. The species 

bears some similarities to H. elongatus which has been recorded from Pembrokeshire, 

Lundy, Mull and several sites on the west coast of Ireland (Gerd’s Hole, Ard Bay, Galway, 

Lettercallow Spit, Kilkieran Bay (BioMar, Bernard Picton pers. comm.)), and Port Erin 

Bay in the Isle of Man (Robert Lewis pers. comm.). However, it is smaller than H. 

elongatus, measuring 10-15cm in tentacle diameter rather than 20cm, and lacks the white 

marks at the base of the tentacles and dark brown lines across the disk which are 

characteristic of H. elongatus. Samples were taken and are being sent to a cnidarian 

specialist for identification. Unlike A. sarsi, this species does appear to be nocturnal as it 

was only recorded on night dives. 

13


Figure 2. Boulder habitat on 

east coast of Rathlin. Boulder 

surface covered by hydroids 

including the NICP species 

Polyplumaria flabellata. 

Figure 4. The rare anemone 

Halcampoides abyssorum in 

sand and gravel habitat in 

Church Bay, Rathlin. 

14 

Figure 3. Burrowing 

anemone Arachnanthus sarsi 

in sand and gravel habitat in 

Church Bay, Rathlin.


The Skerries 

The Skerries is one of four places in Northern Ireland from which there are records of 

horse mussel (Modiolus modiolus) beds, the others being Strangford Lough, Carlingford 

Lough and the outside of the Ards Peninsula (Erwin et al. 1986, 1990). These were last 

surveyed in 1979, but at that time were in good condition; clumps of Modiolus modiolus 

with a rich epifauna were recorded. Despite extensively resurveying these sites, no live 

specimens were found, although dead Modiolus shells were present and were dense at 

some sites. Locals have reported that this area had been extensively dredged since the 

NISS, and it is recommended that these claims are investigated. It is recommended that in 

view of the poor status of the Modiolus beds at the Skerries, the areas outside of the Ards 

Peninsula should be surveyed. 

It was expected that the sponge fauna of the area would be comparable to Rathlin, but the 

site was heavily silted and consequently the sponge fauna was not particularly rich. 

However, the area does merit further investigation in future projects, particularly as a new 

sewage outfall recently became operational. In the past, sewage was discharged at Ramore 

Head, very close to the Skerries, and this may have contributed to the silted conditions. 

Monitoring of any alterations in species composition at the site would be valuable, both in 

a local biodiversity and more general scientific context. 

An area of seagrass (Zostera marina) behind Great Skerry was resurveyed and found to be 

in good condition. Several shells of the fan mussel Atrina fragilis were found in the area 

between the Skerries and the shore. This is a UK BAP and NICP species with the only 

known currently living population present in Plymouth Sound. The comparatively large 

number of shells found indicates that live fan mussels may be present in this area, although 

the dense cover of hydroids and boulders would make them hard to locate. Fan mussels are 

known to be extremely vulnerable to bottom fishing, and it is essential that steps be taken 

to protect this area from such impacts in order to preserve any individuals that are present, 

and to create suitable habitat conditions for the growth of new settlers. 

A specimen of a nudibranch was taken that is a new species of Janolus. This had 

previously been photographed at St Kilda in Scotland, but it has not yet been possible to 

describe it. The tunicate Pycnoclavella aurilucens was recorded. This is a southern species 

which is very rare in Northern Ireland, with only two previous records which are also from 

the Skerries. The false cowrie Simnia patula was also recorded. There are only five 

previous records for this species for Northern Ireland. The spiny spider crab Maja 

brachydactyla (formerly M. squinado) was fairly common. This is a southern species, and 

has not been previously recorded from Northern Ireland. A trigger fish Balistes capriscus 

was sighted. This is also a warm water species not able to survive year round in British 

water but sometimes sighted during the summer. Although sightings are relatively common 

in more southerly parts of the UK such as Wales, there are very few sightings from 

Northern Ireland. Specimens of some tunicates were taken for taxonomic investigation. It 

was noted that tunicates seem to fluctuate seasonally and were much more abundant in 

spring than later in the year. 

15


Figure 6. The spiny spider crab 

Maja brachydactyla. Broad 

Sound, The Skerries, Portrush. 

16 

Figure 5. The burrowing 

anemone Halcampoides sp. 

Church Bay, Rathlin Island. 

Figure 7. A new species of 

nudibranch (Janolus sp.) 

The Skerries, Portrush.


The Maidens 

The tidal and habitat conditions of the Maidens make them an important area for hydroids. 

Many species only occur here and on the east coast of Rathlin Island; these include the 

priority species Diphasia alata, D. nigra, Polyplumaria flabellata, Lytocarpia 

myriophyllum and Halecium plumosum. Prior to this survey, the distribution and 

abundance of these species was poorly known. Whilst there were previous records of the 

other NICP hydroid species from the Maidens, the hydroid Diphasia nigra had only been 

recorded from Rathlin. All other above hydroid species were recorded - at some sites they 

were particularly numerous, forming dense hydroid forests (Figure 8). These populations 

are particularly important in view of the damage to the Rathlin hydroid/boulder 

communities on the east coast. Unlike the Rathlin communities, they are on bedrock or 

immediately adjacent to steep bedrock so are unlikely to suffer damage from mobile 

fishing gear. 

The sponge Clathria barleei was also present at several locations, confirming the Maidens 

as a Northern Ireland stronghold for this species. The only other location known from 

Northern Ireland is Rathlin Island. On Rathlin, it was originally recorded from boulders 

between 20 and 35m, a habitat which is believed to have been lost. It was found in SSNI to 

be present in deeper water off the east Rathlin coast. However, these populations remain 

vulnerable to dredge damage, and consequently the Maidens are an important additional 

site. 

Several other sponge species of note were also recorded from the Maidens. Three out of 

four specimens of the NICP sponge M. elliptichela collected during SSNI were from the 

Maidens. This species has only been recorded previously in Northern Ireland from Rathlin 

Island. It was originally described from Skagerrak, Sweden (2 specimens, Alander 1942), 

and the only other record is from deep water reefs at Mingulay (Van Soest 2006). The 

Maidens seem to be an important area for this rare species. 

Records were also made of several of the new species, newly described from the Sponge 

Biodiversity of Rathlin Island Project (Picton & Goodwin 2007a, b), including Ectyodoryx 

jenjonesae, Hymedesmia rathlinia, and Hymedesmia stellifera (Goodwin & Picton 2009). 

A previously undiscovered area of maerl bed was found in the centre of the Maidens NW 

of the Sheafing Rock (54 o 55.25’N, 005 o 43.96’W; dives 060816/06 and 060807/02). The 

substrate was up to 30% live maerl. The NICP algae Desmarestia dresnayi was frequent in 

the maerl and gravel sediment in this area. Previously the only known Northern Ireland 

population was at Altacarry Head on Rathlin Island. Carpomitra costata, another priority 

algae species was recorded from the Maidens. This has previously been recorded from 

Rathlin Island, the North Antrim coast and one site on the east coast of Northern Ireland 

(Carnlough), but records are very scarce. A rare red alga, Schmitzia hiscockiana was also 

recorded. The North Channel appears to be a stronghold for this species. 

Three unusual nudibranch species were recorded: one specimen of Caloria elegans was 

taken. This is the first record for Northern Ireland and the second for Ireland, with only 

five previous records for the British Isles. The two other species have both been identified 

as belonging to the genus Jorunna, and appear to be new species. 

The NICP sea pen Virgularia mirabilis was recorded in soft sediment near East Maiden 

lighthouse, and the policeman’s helmet anemone Mesacmea mitchellii was recorded from 

the same location. This is the first record for Northern Ireland for the latter, and only the 

third locality for Ireland. 

17


Figure 9. Sponge Clathria 

barleei. East of West Maiden. 

18 

Figure 8. ‘Hydroid Garden’ site 

to the west of West Maiden. 

Hydroids present include the 

priority species Polyplumaria 

flabellata and Diphasia alata. 

Figure 10. Nudibranch Caloria 

elegans.


As well as the main islands and charted rocks of the Maidens, submerged pinnacles were 

also surveyed. One of these was ‘Pin Head Pinnacle’ (54 o 56.372’N, 05 o 45.457’W, dive 

070824/03). This gently sloping bedrock mound is located south of Russell Rock. It was 

covered in a turf of bryozoans, erect sponges and hydroids: notable NICP species included 

the sponge Clathria barleei, and the hydroids Polyplumaria flabellata and Diphasia alata. 

The ‘pin head’ squirt, an apparently undescribed species of Pycnoclavella, was common, 

with colonies over much of the rock surface. The study of these less obvious sublittoral 

features should be encouraged in the future. 

The opisthobranch mollusc Colpodaspis pusilla was recorded apparently feeding on a ‘pin 

head’ ascidian. This species is found in many locations on the west coast of the British 

Isles, but elsewhere is known only from southern Norway. Their diet is currently unknown 

(Thompson 1988) so this observation provides important information on its ecology. 

Poor weather restricted survey work with diving only being possible on 11 days out of the 

four weeks proposed. In view of the number of significant findings it is recommended that 

further survey work be undertaken at the Maidens. 


The horse mussel beds in Strangford Lough have sustained damage since they were 

surveyed during the NISS, probably as a result of mobile fishing gear impact (Roberts et 

al. 2004). It was suspected that populations of many Modiolus bed associated species were 

impacted by the damage to the beds in Strangford Lough. NICP species associated with the 

beds are the sea cucumbers Paracucumaria hyndmani, Ocnus planci, and Thyonidium 

drummondi, the mollusc Chlamys varia, the sponges Mycale (contarenii) and Mycale 

similaris, and the tunicate Pyura microcosmus. Monitoring the Modiolus beds themselves 

was not a main target of the survey, but some records of Modiolus habitat were made. 

It was noted that the sea squirt Ascidiella aspera appeared to be less frequent than had been 

observed during the SLECI survey. It was suspected that colonisation by sea squirts could 

result from disturbance to the horse mussel beds. Therefore decreased numbers may 

indicate reduced disturbance and signal the start of recovery. It may be useful to monitor 

ascidian populations in the future to see if this is the case. 

The sea cucumber Thyonidium drummondi was a characteristic and moderately long-lived 

component of horse mussel beds in Strangford Lough until 20 years ago, but appears to 

have declined rapidly in recent years. This species is scarce and has undergone rapid 

decline, with Northern Ireland being the stronghold for the Irish population. It was not seen 

during the 2003 SLECI (Strangford Lough Ecological Change Investigation) fieldwork 

(Roberts et al. 2004), but there was one sighting in 2005 during a Seasearch dive. This 

species was recorded from three sites (dive 070523/01 SE Long Sheelah, 3 individuals 

seen; 070601/03 W of Sunk Rock (occasional); 070606/06 SE Black Rock (frequent)). At 

the latter site, where the species was most frequent, the habitat was not Modiolus bed, 

which all prior Northern Ireland records had been associated with. The substrate was sandy 

mud sediment with abundant burrowing brittlestars (Amphiura sp.). Further surveys of this 

type of habitat for T. drummondi should be encouraged. Elsewhere, the species is thought 

to occur in a variety of habitats including mud, muddy sand and gravel (Southwood & 

Campbell 2006). 

Strangford Lough is an important area for sponges. It is the type locality for several sponge 

species, and is a stronghold for the NICP species Mycale cf. contarenii and Mycale 

similaris. Many of theses species are associated with the Modiolus beds. The numbers of 

19


sponges seem to have decreased in recent years (Roberts et al. 2004). This has been 

attributed to loss of substrate from damage to the Modiolus beds and increased 

sedimentation (Roberts et al. 2004). 

Specimens of the SOCC sponge Myxilla cf. rosacea were collected: this sponge is possibly 

a distinct species from Myxilla rosacea, which occurs on other areas of the Northern 

Ireland coast: differing in texture, colour and spicule size. Specimens were collected from 

Strangford Lough, and from Rathlin, the Skerries and the Maidens. 

The NICP sponge Mycale cf. contarenii is probably an undescribed species. The sigmas 

are different in size and shape from Mycale contarenii and can be used to positively 

identify this species. It grows into a cushion covering queen scallop (Aequipecten 

opercularis) shells in undisturbed horse mussel beds, and can be considered to be an 

indicator of healthy status of these beds. Whilst many sponges were collected, no 

specimens of this species were obtained. Very few specimens of A. opercularis were 

observed, and this may explain the absence of the sponge. Aequipecten has been fished in 

Strangford Lough since 1970 using otter trawls (Roberts et al. 2004) and some areas of the 

Lough have been heavily impacted by this fishery (Service & Magorrian 1997). It was 

observed in the 2003 SLECI survey that numbers of A. opercularis were low, and it was 

hypothesised that this might be attributed to recruitment failure due to the removal of 

hydroids and bryozoans by repeated disturbance and increased siltation (Roberts et al. 

2004). 

Several specimens of the NICP sponge Mycale similaris were collected from Strangford 

Lough. This species is associated with the horse mussel beds, and there was some concern 

that it might decrease in abundance due to damage to these. However, unlike other 

associated sponge species, populations appear to have increased rapidly in recent years 

(Roberts et al. 2004). It cannot currently be considered threatened. It is now common 

throughout the Lough in a variety of habitats, and has been found recently (2006) on the 

shore at Ballyhenry Island. The current status of this species is not clear, but it may be a 

useful indicator to monitor health of the horse mussel beds. There are no other recent 

records from Northern Ireland and few records of this species from the UK. 

Numerous specimens of the NICP sponge Iophon hyndmani were present in the sponge 

samples from tide swept areas in the southern part of Strangford Lough, growing as thin 

crusts on rocks. Strangford Lough is the type locality for this species. The Strangford 

Lough populations were associated with horse mussel (Modiolus modiolus) beds, forming 

extensive, conspicuous, bushy growths on Chlamys varia. The shells provide a substrate 

for the sponge to attach to in muddy areas which would otherwise be impossible for it to 

colonise. It was observed in 2003 that Iophon hyndmani had decreased in numbers and was 

now ‘almost absent’ from the Lough (Roberts et al. 2004). Damage to the horse mussel 

beds has resulted in a loss of habitat and may account for its disappearance from this area. 

However, this species was found, during the ‘Sponge Biodiversity of Rathlin Island’ 

(Picton & Goodwin 2007a, b) and this project, to be common on Rathlin Island. 

Consequently, it would appear that Northern Ireland populations of this species are not 

threatened, despite the habitat loss in Strangford Lough. We recommend that its status on 

Rathlin continues to be monitored as the bushy growth form may be a good indicator of the 

ecological health of the Modiolus beds. Taxonomically this is a difficult species to identify, 

so genetic work may be useful in confirming that the Rathlin and Strangford populations 

are the same species: the species Iophon ingalli and I. pattersoni (Bowerbank 1866) are 

currently synonymised with I. hyndmani, but this requires further investigation, ideally 

using molecular methods, and they may turn out to be distinct species. 

20


Two NICP species are associated with gravel communities in Strangford: Atelecyclus 

rotundatus (a crab), and Inachus leptochirus (a spider crab). Sites at which there were 

previous records of these species were resurveyed, but no further records were obtained. 

Inachus leptochirus is difficult to distinguish from other small spider crabs in the field, 

being identified primarily by a white ventral tubercule on the male which is not visible 

unless the animal is captured. This may account in part for the lack of records. 

The burrowing NICP anemone Anemonactis mazeli was known from only one site in 

Northern Ireland: Bird Island Passage in Strangford Lough. Despite revisiting this site and 

searching for it in other areas it was not relocated. The habitat at the Bird Island Passage 

site seems to have altered considerably. It was originally described as ‘flat sea bed covered 

with shells (Venerupis; Chlamys) fine muddy sand on surface and oozy mud beneath.’ 

(NISS). There is now no sand layer on the mud surface and only occasional shells are 

present. 

The burrowing NICP anemone Edwardsia timida has intertidal populations at Ballyhenry 

Island. These were investigated by digging a few holes on the shore and the anemones 

were found to be present in considerable numbers; as many as three or four in a single 

spade full of muddy gravel. Not all parts of the shore had specimens, so the distribution 

may be very patchy and disturbance to the shore should be minimised, but at present the 

populations are healthy. 

One of the survey objectives was to collect samples of the sea cucumber Ocnus brunneus 

for molecular comparison with samples of Ocnus planci from Carlingford Lough. O. 

planci is a NICP species; it has been synonomised with O. brunneus in the past and 

molecular taxonomy would be useful in clarifying its species status. Sites at which the 

species has been recorded, one sublittoral and one shore site at the Dorn were revisited. 

However, no individuals were seen and consequently it was not possible to obtain samples. 

Carlingford Lough 

Beds of Virgularia mirabilis recorded during NISS were revisited. These appear to be in 

good condition: dense populations of Virgularia mirabilis were present at all the sites 

which were resurveyed. At one site, the sea slug Stiliger bellula was recorded (Rostrevor 

Bay, dive 070508/01). This is a Northern Ireland SOCC, and had only previously been 

recorded once from Northern Ireland, in 1984, from a site close by in Rostrevor Bay. 

A deep hole, south of Killowen Bank in the shipping channel of Carlingford Lough was 

resurveyed, as records of clumps of Modiolus modiolus were made from this site during 

NISS (dive 070509/01, 54 o 3.74’N, 006 o 11.013’W). This site is steep sided hole (16-36m 

in depth). No Modiolus clumps were recorded, but some dead shell was present. 

Specimens of Ocnus planci were collected for comparison with the Strangford Lough 

populations. 

East Coast 

Although not part of the initial survey plan, the east coast (Larne to Fair Head) has a 

number of priority habitats such as maerl and seagrass beds. It was identified as an area of 

key importance by the NIEA staff, and so the survey plan was modified in order to include 

some sites from this area. A seagrass (Zostera marina) bed in Red Bay was resurveyed and 

found to be in good condition. The burrowing anemone Edwardsia claparedi was found in 

21


association, although the related NICP species Edwardsia timida was not present. A large 

population of the sea cucumber Leptopentacta elongata was also found in Red Bay. The 

only place this species was previously known from in Northern Ireland was Strangford 

Lough. The rare nudibranch Lomanotus genei was also recorded. This is the fourth record 

for Northern Ireland. The mollusc Philine pruinosa was recorded from Red Bay. There are 

only two previous records for this species from Northern Ireland, one from Rathlin Island 

and one from Strangford Lough. Several dives were performed to check for the presence of 

live or fossil maerl and samples collected for morphological analysis by a Department Of 

Agriculture (Northern Ireland) (DARDNI) project. The NICP ‘goosefoot’ starfish Anseropoda 

placenta was recorded from one location (Ballygalley Head). 

5. Recommendations for further work 

These are general recommendations; there are further specific recommendations for particular areas 

in earlier sections. 

Continuation of general marine survey work 

By comparison with our terrestrial biodiversity, the marine biodiversity of Britain and Ireland is 

poorly known. Despite revisiting areas which had previously been extensively sampled, a number 

of significant new discoveries were made by this survey. These included species over 1cm in size 

which are completely new to science - this would be very unusual with terrestrial species in 

Europe. It is important that such general survey work continues, rather than solely targeting species 

defined as biodiversity priorities. 

Some of the most interesting findings of the survey were of species not listed as Northern Ireland 

Conservation Priority species. Fortunately the scope of the project was sufficiently flexible to allow 

for the investigation of these. Several new species were recorded including three new species of 

nudibranch: two Jorunna spp. and one Janolus sp. On Rathlin, two species of the burrowing 

anemone Halcampoides were found. It is believed that these may be new species as currently only 

one species is known from the British Isles. The sponge Ectyodoryx (Lissodendoryx) jenjonesae, 

which was first described from Rathlin in 2005, was found to be common on the Maidens as well 

as several other rare sponges. The conspicuous nudibranch Okenia elegans is thought to be rare in 

the British Isles, but was recorded at several locations during the survey; records of other rare 

species made during the project will increase knowledge of their distribution and ecology. 

The Ulster Museum/Northern Ireland Environment Agency partnership resulted in very successful 

surveys, and could provide a cost effective partnership for continuing this work in the future. 

Investigation of poorly known marine invertebrate groups 

In order to develop a meaningful conservation strategy it is essential to have a good taxonomic 

framework. The need for study of poorly known groups and the development of taxonomic 

capacity has been recognised in the UK Biodiversity Strategy, Ireland’s National Biodiversity 

Strategy and the Northern Ireland Biodiversity Strategy. The biodiversity of some marine groups, 

notably Porifera (sponges), Cnidaria (sea anemones and hydroids), and Ascidiacea (sea squirts), 

has been insufficiently studied. They are under-represented on both national and local biodiversity 

priority lists as there is insufficient data on them for them to meet the selection criteria. As this 

work demonstrates, in these groups some relatively common, visually distinctive, species have yet 

to be named. 

Ascidians are one such group. Several species, for example the ‘raspberry sea squirt’, a polyclinid 

ascidian and the ‘pin head’ squirt are readily identifiable in the field, but as yet do not appear to 

have been described or given a scientific name. Two other sea squirts are also candidate new 

22


species; a yellow didemnid sea squirt was frequent in the circalittoral on Rathlin Island and an 

additional orange didemnid species was also observed. Samples of these species were collected 

during SSNI, but as yet it has not been possible to formally describe them. 

Use of marine species to monitor climate change 

Changes in species abundances and ranges may indicate climate change. The anemone Mesacmea 

mitchellii was recorded from the Maidens. This is the first time this southern species has been 

recorded in Northern Ireland. A trigger fish Balistes capriscus was sighted at the Skerries. This 

species used to be rarely recorded in Britain and Ireland with only one or two sightings a year, but 

since the mid eighties has become fairly common on the southern and western coasts (Dipper 

2001). There are several recent records from Wales and Donegal. There have been previous 

sightings near to the Skerries, with records as far back as 1976, but these are by no means frequent. 

The number of sightings seem to be increasing and becoming further north with recent sightings as 

far north as the Hebrides (http://www.glaucus.org.uk/Triggerf.htm). The spiny spider crab Maja 

brachydactyla was sighted at several Skerries sites. This crab is common on the west coast of 

Ireland, but these were the first records for Northern Ireland. The southern sponges Hexadella 

racovitzai, Styloptilon ancoratum and Axinella damicornis have also all become more common 

since the 1980s. At the same time, there seems to have been a decline in species with a more 

northerly distribution: the large feather star Antedon petasus was not recorded during this survey, 

although several records were made from Rathlin and the east coast during NISS. The purple 

sunstar Solaster endeca also seems to have declined in numbers; during NISS it was present 

throughout Northern Ireland and was frequent in Strangford Lough. During this survey, very few 

records were made. Monitoring some of these key, readily identifiable, species may be helpful in 

determining if climate change is affecting species distributions. 

Additional survey of the Maidens 

The Maidens plateau is an area of great biological significance. The area was last surveyed during 

the Northern Ireland Sublittoral Survey (1982-86). This survey made several interesting discoveries 

and indicates that the area merits further investigation. Work during SSNI was restricted due to 

poor weather; out of a proposed four weeks (20 days) of survey it was only possible to spend 12 

days on the Maidens. We recommend that further survey work is carried out. This is particularly 

important in view of the proposed inclusion of the area in a new SAC. 

The Maidens are the Northern Ireland stronghold for several NICP species including the sponge 

Clathria barleei, and the hydroids Diphasia nigra and Polyplumaria flabellata. Several of the new 

sponge species originally described from Rathlin are now also known from the Maidens, having 

been collected during SSNI. At least three undescribed species of ascidian are also known to be 

present, including the distinctive ‘pin head squirt’. Two undescribed species of a nudibranch, 

Jorunna sp., were collected, as well as the rare nudibranch Caloria elegans. One individual of the 

anemone Mesacmea mitchellii was found during SSNI. This is the only record from Northern 

Ireland, and further work is needed to establish if a population is present. 

The habitats present are, as yet, not fully understood. Maerl was discovered in the centre of the 

Maidens during SSNI, together with the rare alga Desmarestia dresnayi. Several low-lying 

pinnacles lie off the main Maidens islands. These have not yet been fully surveyed. Multi-beam 

sonar is now becoming available for this area, a technology unavailable during NISS, and would 

help identify interesting survey sites. 

23


Areas under particular threat 

It was noted during the survey that several habitats had been badly impacted by dredging. These 

included the east coast of Rathlin, particularly the hydroid and sponge communities on the boulder 

areas; sand and gravel habitats in Church Bay, and the inside of the Skerries, notably the horse 

mussel communities. We recommend that immediate action be taken to protect these areas from 

further damage. 

Suggested changes to the Northern Ireland Conservation Priority species lists 

Most of the species on the original list are still threatened. However, there are two exceptions; 

Halecium plumosum and Iophon hyndmani. Halecium plumosum was recorded from all coasts of 

Rathlin (Lochgarry, White Cliffs, Picton’s Reef, Illancarragh Bay), from Russell’s Rock on the 

Maidens, Carlingford Lough and from two sites in Strangford Lough. At several of these sites it 

was common. In view of these findings, it cannot be classified as rare in Northern Ireland and 

could be removed from the NICP list. The sponge Iophon hyndmani was found to be present on 

Rathlin Island, the Maidens, the Skerries and Dundrum Bay. It was known that this species was 

characteristic of the horse mussel beds in Strangford Lough, and it was placed on the priority list 

because of the damage which had occurred to these populations. It was observed in 2003 that 

Iophon hyndmani had decreased in numbers and was now ‘almost absent’ from the Lough (Roberts 

et al. 2004). However, these new records show that the species is reasonably common in other 

areas of Northern Ireland, and consequently the Northern Ireland populations of this species are not 

threatened, except in the case of the habitat loss in Strangford Lough. This species can no longer be 

considered to be rare and could be removed from the NICP list. 

6. Acknowledgements 

This project is a partnership between Northern Ireland Environment Agency and National 

Museums Northern Ireland. We are grateful to the support of these organisations for this work. The 

project was funded by the NIEA directorate research and development series through the CEDaR 

initiative. The CEDaR initiative brings together resourced and the expertise of scientists from the 

National Museum Northern Ireland’s Department of Natural Sciences and the NIEA conservation 

science team. We are greatly indebted to the programme for the support of this and other similar 

initiatives. We would like to specially thank Damian McFerran (CEDaR) and Mark Wright (NIEA) 

for their assistance with this project. 

24


7. Records of unusual species 

(except Northern Ireland Conservation Priority species) 

This list includes Northern Ireland Species of Conservation Concern (SOCC), which are indicated 

with this acronym in the text. Other species included are those newly discovered in Northern 

Ireland waters, and species whose populations appear to have changed significantly since the 

Northern Ireland Sublittoral Survey. 

Porifera 

Recently several new species of sponge have been described from Northern Ireland (Picton & 

Goodwin 2007a, b; Goodwin & Picton 2009). Currently Northern Ireland is the only location in the 

world from which these are known. These species should be given consideration for Priority 

Species status. 

Stelletta grubii Schmidt, 1862 (SOCC) 

Recorded from the north coast and Damicornis 

Bay on Rathlin. There are few recent records 

for the British Isles: recently recorded from 

County Donegal (Mulroy Bay and St John’s 

Point) and the Aran Islands in Ireland. There are 

records from 20 sites on the west coast of Wales 

(Moore 2002). 

Stryphnus ponderosus (Bowerbank, 1866) 

(SOCC) 

Eight records, all from the north wall of Rathlin 

Island. This species occurs on vertical of 

overhanging rock surfaces and is fairly common 

on the north wall of Rathlin (Ackers et al. 

2007). It is not common elsewhere in the British 

Isles; there are only scattered records from the 

west coast of Ireland, Wales, the Isle of Man, 

the Channel Islands and Scotland. It may be 

rare as a result of its specific habitat 

preferences. However, targeted sponge sampling in other areas of the UK is needed to give an 

accurate indication of its distribution. 

Tethya hibernica 

Heim, Nickel, Picton & Brümmer, 2007 

This species was described from Rathlin Island 

during the 2005 BSP funded ‘Sponge 

Biodiversity of Rathlin Island’ project (Heim, 

Nickel, Picton & Brümmer, 2007; Picton & 

Goodwin 2007a, b), during which five 

specimens were collected from Damicornis Bay 

on Rathlin Island. A further two specimens 

were collected during SSNI, also both from 

25


Damicornis Bay. It is only known from the type locality (Rathlin Island). The genus Tethya was 

revised in the early 20 th century by Burton (1924) and Topsent (1918). Several species were 

synonymised into T. aurantium, and until recently it was believed that all European specimens 

were of this species (Ackers et al. 2007; Sarà 1987). See Picton & Goodwin 2007a for further 

details. 

Hymeraphia breeni 

Picton & Goodwin, 2007 



Biodiversity of Rathlin Island’ project (Picton 

& Goodwin 2007a, b). During SSNI, a further 

record was made from Rathlin. It is not 

currently known from any other location. 

Hymeraphia elongata 





& Goodwin 2007a, b). It is only known from 

the type specimen; no further specimens were 

collected during SSNI. 

Mycale lingua (Bowerbank, 1866) (SOCC) 

This species was only previously known in Northern Ireland from one record on the north wall of 

Rathlin. It is a large and conspicuous sponge and should have been recorded if present. Despite 

many survey dives near to the site of the original record, it was not recorded during SSNI. This 

species is a deep water species, ranging between 30 and 2460m, and has a northern distribution. 

Biemna varianta (Bowerbank, 1858) (SOCC) 

Recorded during SSNI from the ‘Outer Lee’s’ 

wreck in Strangford Lough. There are previous 

Northern Ireland records from Lee’s Wreck and 

Green Island in Strangford Lough. 

This is not known from many other locations in 

the British Isles. Most UK records from the 

coast of Wales, other scattered records from 

Shetland, St Kilda, and the east coast of 

England (PMSA, MNCR, CCW, MarLIN). 

There are several records from the west coast of 

Ireland (BioMar). 

26


Lissodendoryx (Ectyodoryx) jenjonesae 





& Goodwin 2007a, b), during which fifteen 

specimens were collected. During SSNI eleven 

further specimens were collected, all from the 

Maidens. This is a species which, unlike many 

other crustose sponge species, may be easily 

recognised in situ: the raised rims to the pore 

sieves and the thick form of the crust are 

distinctive. 

Hymedesmia (Hymedesmia) cohesibacilla 

Goodwin & Picton, 2009 




& Goodwin 2007a; Goodwin & Picton 2009), 

during which three specimens were collected. 

During SSNI, a further specimen was collected 

from the Maidens. 

Hymedesmia (Hymedesmia) cratera 





& Goodwin 2007a, b; Goodwin & Picton 2009), 

during which one specimen was collected. 

Hymedesmia (Hymedesmia) peachii 

Bowerbank, 1882 




& Goodwin 2007a, b; Goodwin & Picton 2009), 

during which two specimens were collected. 

During SSNI two further specimens were 

collected, both from the Maidens. This species 

is rarely recorded but widely distributed from 

northern British Isles to the Mediterranean. The 

type locality is Wick, NE Scotland. 

27


Hymedesmia (Hymedesmia) rathlinia 




Biodiversity of Rathlin Island’ project (Picton & 

Goodwin 2007a; Goodwin & Picton 2009), 

during which twelve specimens were collected. 

During SSNI a further specimen three 

specimens were collected from Rathlin and four 

from the Maidens. Several further photographic 

records were made from both the Maidens and 

Rathlin. During the same period this species was 

recorded from St John’s Point in Donegal. 

This species is conspicuous and easily 

recognisable in the field. 

Top: H. rathlinia is typically covered in silt in 

situ with just the oscules protruding. 

Bottom: H. rathlinia beneath an overhang, with 

no silt. 

Hymedesmia (Hymedesmia) stellifera 





Goodwin 2007a, b; Goodwin & Picton 2009), 

during which two specimens were collected. 

Two further specimens were collected during 

SSNI from the Maidens. These specimens are 

listed as paratypes in the species description. H. 

stellifera is also present in the Firth of Lorn in 

Scotland. 

Hymedesmia (Hymedesmia) umbelliformis 





Goodwin 2007a, b; Goodwin & Picton 2009), 

during which one specimen was collected. 

28


Hymedesmia (Stylopus) crami 






during which one specimen was collected. No 

further records from SSNI. 

Hymedesmia (Stylopus) hibernica 

Stephens, 1916 

This species was recorded from Rathlin Island 



& Goodwin 2007a, Goodwin & Picton 2009), 

during which one specimen was collected. No 

further records were made during SSNI. 

Hymedesmia (Stylopus) primitiva 

Lundbeck, 1910 

This species was recorded from Rathlin Island 




during which six specimens were collected. 

During SSNI six further specimens were 

collected from the Maidens and two from 

Rathlin. It appears to be one of the more 

common Hymedesmia species in the area. 

Hymedesmia (Stylopus) sp. 

Several specimens of Hymedesmia (Stylopus) 

have been collected during SSNI. The 

taxonomy of this sub-genus is currently 

confused with some species having been 

recently (possibly erroneously) synonomised. 

The samples collected during SSNI should help 

elucidate the taxonomy of this subgenus. 

29


Plocamiancora arndti Alander, 1942 (SOCC) 

This species appears to be reasonably common 

on Rathlin Island and the Maidens; 34 records 

were made during SSNI. It was first described 

from Sweden, and is thought to have a restricted 

distribution in the British Isles: other than 

Northern Ireland it is known only from the west 

coast of Scotland. There were previous Northern 

Ireland records from Rathlin Island and 

Carnlough Bay in Antrim (NISS; Picton & 

Goodwin 2007a, b). Despite sponges from the 

Maidens having been sampled during NISS there were no prior records from this area. However, 

sponges were not a priority during this general survey and this may be due to low sampling effort. 

Targeted sponge sampling in other areas of the UK is needed to give an accurate indication of its 

distribution. 

Styloptilon anchoratum (Cabioch, 1968) 

This species was first described from the UK 

and Ireland from Rathlin Island, during the 2005 

BSP funded ‘Sponge Biodiversity of Rathlin 

Island’ project (Picton & Goodwin 2007a, b), 

during which 31 specimens were collected. 

It was originally described from Roscoff, France 

(Cabioch 1968). There were previously 

unidentified specimens in Ulster Museum 

collection from Skomer Island, Wales, Ardnoe 

Point, Sound of Jura, Ballyhenry Island, 

Strangford Lough, Rathlin Island and North Water, Mulroy Bay. During SSNI four further 

specimens were taken from Rathlin and eight from the Maidens. 

Clathria (Microciona) laevis 

(Bowerbank, 1866) 

This species was first recorded from Northern 

Ireland during the 2005 BSP funded ‘Sponge 


Goodwin 2007a, b), during which one specimen 

was collected. No further records were made 

during SSNI. This species was first described by 

Bowerbank (1866) from Shetland. Recorded by 

Stephens (1917) from the West coast of Ireland 

and Vosmaer (1935) and Burton (1959) from 

Iceland. Also from the Skager Rak (fairly common) and Väderö Fjord (common 50-70m) in 

Sweden (Alander 1942). 

Antho (Antho) brattegardi 

van Soest & Stone, 1986 

This species was first recorded from the UK and 



and Goodwin 2007a, b), during which ten 

specimens were collected from Rathlin Island. It 

was originally described from Norway from one 

specimen (van Soest & Stone, 1986) but has 

30


since been recorded from offshore reefs at Mingulay (Van Soest, 2006). During SSNI there were 

three further records from Rathlin and two from the Maidens. 

Antho (Antho) granditoxa 



as a result of the 2005 BSP funded ‘Sponge 


Goodwin 2007a, b), during which six specimens 

were collected. A further specimen was 

collected from Rathlin during SSNI. Rathlin is 

the only location from which it is currently 

known. 

Plocamionida tylotata Brøndsted, 1932 

This species was first recorded from the UK and 



and Goodwin 2007a, b), during which one 

specimen was collected from Damicornis Bay, 

Rathlin Island. During SSNI two further 

specimens were collected, both from the 

Maidens. This species is also known from the 

Faeroes and the Swedish west coast. 

Spongionella pulchella (Sowerby, 1806) 

(SOCC) 

Recorded from Farganlack point on Rathlin and 

three sites in the Maidens (SE East Maiden, SE 

Allen’s Rock, NW Allen’s Rock). There are 

previous Northern Ireland records from the 

Maidens, Rathlin and the North Antrim Coast 

and the species appears to be widespread but 

local around the west coast of Ireland. This 

species is rarely recorded in the UK. 

Hexadella racovitzai Topsent, 1896 

A Mediterranean species, with very few records 

from the Atlantic (Roscoff, Canary islands, 

Azores and Skomer). First recorded from the 

British Isles from the Aran Islands, Galway 

(Morrow & Picton 1996) and has since also 

been recorded from Kerry Head shoals, Kerry; 

Aran Islands, Galway and Rathlin Island (Picton 

& Costello 1998). There are recent unpublished 

records from Plymouth (K. Hiscock, S. Sharrock 

pers. comm.). During the 2005 BSP funded 

‘Sponge Biodiversity of Rathlin Island’ project 

(Picton & Goodwin 2007a, b) seven specimens were recorded, from Damicornis Bay and West of 

Derginan Point on the north wall. During SSNI it was recorded again from the same areas on 

Rathlin. However, it was not sighted elsewhere in Northern Ireland. 

31


Amphilectus lobatus (Montagu, 1818) (SOCC) 

This is listed in the species of conservation 

concern list as Mycale ovulum but the taxonomy 

has been recently revised. It has previously been 

recorded from Carlingford Lough, Islandmagee 

and Strangford Lough in Northern Ireland (BE 

Picton). There are also records from Milford 

Haven in Wales (BE Picton). 

During SSNI it was recorded and one specimen 

was collected from Zara shoal in Strangford 

Lough. In Northern Ireland this species appears 

to be confined to habitats with strong water flow in Carlingford Lough entrance and Strangford 

Narrows. 

Axinella damicornis (Esper, 1794) 

Prior to 2005 there were only Northern Ireland 

records for this species from Rathlin Island, 

Damicornis Bay (also known as O’Byrne Bay) 

(three from August 1989 and one 850906/02) 

and two from the Skerries (870412/01 N of 

Large Skerries, 870606/01 NW of Little 

Skerries). During the 2005 BSP funded ‘Sponge 


Goodwin 2007a, b) it was noted that it was 

common in, but almost confined to, Damicornis 

Bay (see picture bottom right). It was also 

recorded from the north wall. During SSNI it 

was recorded from Damicornis Bay, the White 

Cliffs, Picton’s Reef on the east coast and two 

sites on the north wall on Rathlin, and three 

records were made from the Skerries. 

This species is a southern species: uncommon 

on west coast of British Isles and Atlantic coasts 

of France, common in the Mediterranean. There 

are records from Scilly Isles, Channel Isles, 

Wales (Pembrokeshire and Bardsey Island 

(Moore 2002)), Devon and Lundy in UK. It is 

possible that the increase in abundance in Northern Ireland is related to climate change. 

There are previous Irish records from the west and north coasts only: Skerries, Portrush, Antrim; 

Tory Island, St. John’s Point, Donegal Bay, Donegal; Clare; Stags of Broadhaven, Achill Island, 

Mayo; Kilkieran Bay, Slyne Head, Skerd Rocks, Mannin Bay, Galway; Kerry Head Shoals, Kerry; 

Lough Hyne, Cork. 

It is not clear why this species is so abundant in Damicornis Bay. This may indicate that unusual 

hydrogeographic conditions are found here. As well as A. damicornis many other unusual species 

are found in this small bay, including several of the newly described Rathlin sponge species. 

32


Axinella dissimilis (Bowerbank, 1866) 

(SOCC) 

Recorded during SSNI from Rathlin (Picton’s 

Reef and Slope East of Illancarragh Bay on the 

east coast, Damicornis Bay on the south coast, 

and Duncan’s Bay and West of Derginan point 

on the north wall), the Maidens (Russell’s Rock 

and NW of West Maiden), and the Skerries 

(East and NW of Black Rock, NW of Large 

Skerrie, N of the Stork). 

This sponge has a southern distribution and is 

consequently not very common in Northern Ireland. There are recent records from SW Britain as 

far as Anglesey and along the west coast of Ireland around to Rathlin (there is one MNCR record 

from off Fleetwood but this is doubtful). There are verified Scottish records from Mull and Loch 

Scridain (MNCR, Ackers et al. 2007), although there are several other records from the Scottish 

west coast which require verification (Seasearch). A. dissimilis can be confused with other large, 

yellow, branching sponges such as Haliclona oculata and Raspailia hispida. The Maidens records 

represent an increase in its range in Northern Ireland. This could be related to climate change. 

Axinella pyramidata Stephens, 1916 

This species was recorded from Damicornis Bay, 

Rathlin Island during the 2005 BSP funded 

‘Sponge Biodiversity of Rathlin Island’ project 

(Picton & Goodwin 2007a, b). There was one 

specimen from 1989 already in the Ulster 

Museum collection but this had not been 

identified to species. 

During SSNI another individual was recorded 

from this bay and a further record was made 


It was originally described from County Kerry and there are few other records. It has been recorded 

from the Faeroes (Brondsted 1928), and Roscoff (Cabioch 1968). Also reported by Burton from 

the West coast of Africa but this record is doubtful. A West coast of France record of A. alba 

(Descatoire 1966) may also be this species. 

Axinella parva Picton & Goodwin, 2007 




& Goodwin 2007a, b), during which four 

specimens were collected. There is also one 

specimen from 1989 from the same site in the 

museum’s collection, which was previously 

unidentified. During SSNI two further 

specimens were collected from Rathlin and one 


Phakellia rugosa (Bowerbank, 1862) (SOCC) 

This species was not recorded. It is a rare species and there was only one prior Northern Ireland 

record from the Maidens. 

33


Myxilla cf. rosacea (Lieberkühn, 1859) 

(SOCC) 

Specimens of the SOCC sponge Myxilla cf. 

rosacea were collected: this sponge is possibly a 

distinct species from Myxilla rosacea which 

occurs on other areas of the Northern Ireland 

coast, differing in colouration, surface 

appearance, and the shape of the tornote ends. 

Four specimens were collected from Strangford 

Lough, and one each from Rathlin, the Skerries 

and the Maidens. Further work is needed to 

determine if these two varieties are separate 

species. 

Tamarisca tamarisca (Linnaeus, 1758) 

(SOCC) 

This hydroid was recorded from Damicornis 

Bay on Rathlin Island (060608/01). It is only 

found patchily around the British Isles and the 

only previous Northern Ireland records were 

from Castle Head on the north wall of Rathlin 

Island and Clough on the outer Ards Peninsula. 

Cnidaria 

Alcyonium hibernicum (Renouf, 1931) 

(SOCC) 

This tiny, pink dead men’s finger was only 

known from two sites in Northern Ireland; the 

underside of the archway on the north cliffs of 

Rathlin Island and the wreck of the ‘Hunsdon’ 

just outside Strangford Lough. The Rathlin 

population was revisited during the survey and 

appears to be undisturbed and in good condition. 

Other patches were found 200m west of the 

known site. There are scattered records of this 

species throughout western Britain and Ireland (Devon and Cornwall, Wales, Western Ireland, 

Scotland: MarLIN). It was suggested in the past that A. hibernicum is the same species as the 

Mediterranean Alcyonium (=Parerythropodium) corallioides Pallas, 1766. However, molecular 

evidence confirms that is a distinct species (McFadden 1999). 

34


Parazoanthus anguicomus (Norman, 1868) 

(SOCC) white trumpet anemone 

Thirty records were made of this species from 

the Maidens and Rathlin Island. Parazoanthus 

anguicomus is found at scattered locations 

around Scotland and in deep water around 

northern Europe, south to Lundy Island and 

Brittany. Most previous Northern Ireland 

records were from Rathlin with only two from 

the Maidens (NISS). 

Aureliania heterocera (Thompson, 1853) 

(SOCC) Emperor or Imperial anemone 

Seven records were made during the survey: 

from the Maidens, SE of Long Sheelah in 

Strangford Lough, and Rathlin Island. The five 

Rathlin records were from the south side of 

Rathlin; two from the White Cliffs and two 

from Damicornis Bay. It appears that these soft 

sediment areas may be a stronghold for the 

species. 

Stomphia coccinea (Mueller, 1776) 

(SOCC) swimming anemone 

This species was not found during the survey 

work. There is a recent record from a Seasearch 

dive from the north coast of Islandmagee 

(Goodwin 2007c). Within Ireland this species 

had only recently been recorded from Northern 

Ireland; 29 records, spread over the coast from 

the Outer Ards Peninsula to the Skerries, were 

made during NISS. It is a northern species, 

widespread throughout cold temperate and subarctic 

regions of the northern hemisphere. Most 

British records are from the east and west coasts of Scotland. SSNI did not target the habitat of this 

species, but it seems likely that it has become much rarer since NISS. 

Halcampoides abyssorum Danielssen, 1890 

One specimen was recorded from the White 

Cliffs (dive 060608/05). This is a tentative 

identification as no specimen has been 

examined. The genus Halcampoides is poorly 

known and in need of a worldwide revision. 

Known from the UK from Lundy (Keith 

Hiscock), Havelet Bay, Guernsey (1987 

Bernard Picton), and the west coast of Scotland 

(George Brown). 

35


Halcampoides sp. 

This Halcampoides species was frequent in the 

White Cliffs area of Church Bay on Rathlin. It 

appears to be nocturnal: it was only recorded on 

night dives. It is similar in appearance to 

Halcampoides elongatus which has been 

recorded from Wales and the west coast of 

Ireland (Gerd’s Hole Ard Bay, Galway, 

Lettercallow Spit, Kilkieran Bay: BioMar, 

Bernard Picton) Port Erin Bay in the Isle of Man 

(Rupert Lewis). However, it is smaller than H. 

elongatus, measuring 10-15cm in tentacle 

diameter rather than 20cm and lacks the white marks at the base of the tentacles and dark brown 

lines across the disk which are characteristic of H. elongatus. Samples were collected and are being 

sent to a cnidarian specialist for identification. 

Mesacmea mitchellii (Gosse, 1853) 

Policeman’s Helmet Anemone 

This anemone was recorded from one site on the 

Maidens. This species is only known from one 

other site in Ireland, Kilkieran Bay in County 

Galway. It is locally frequent on the south and 

southwest coast of the British Isles, and occurs 

north to mid Scotland (Manuel 1988). There are 

recent records from Lundy, Skomer Island and 

the Lleyn Peninsula (Wales), and North Devon 

(MNCR, Seasearch, CCW BMD and CCW 

PMSA, MarLIN). 

Homarus gammarus (Linnaeus, 1758) 

Lobster (SOCC) 

Records were made of lobsters from the 

Skerries, Rathlin Island and Strangford Lough. 

An extremely large individual was recorded 

from Strangford Lough (070601/03). Claw size 

was estimated as 50cm. 

Crustacea 

36


Maja brachydactyla Balss, 1922 

Spiny spider crab 

This species was formerly synonymised with 

Maja squinado, which is now thought to be 

restricted to the Mediterranean (Neumann 

1988). It is a southern species. It had not been 

previously recorded from Northern Ireland but 

is relatively widespread on the west coast of 

Ireland with records from Mayo around to 

Wexford (Picton & Costello 1998). During 

SSNI records were made from three sites on the 

Skerries. During the same period, additional 

records from Northern Ireland were made on Seasearch dives from the Skerries and the Tun’s Bank 

at the mouth of the Foyle (Goodwin 2007b; Goodwin 2008a) 

Corystes cassivelaunus (Pennant, 1777) 

Masked Crab (SOCC) 

One record was made of this species from Red 

Bay (060614/01). It can be fairly common in 

mobile sandy areas and the lack of records 

during the SSNI may be attributed to the fact 

that these were not often surveyed. During the 

SSNI survey period records were made by 

Seasearch divers from the Tun’s Bank and 

Rathlin Island (see Goodwin 2007a; Goodwin 

2008a, b). 

Mollusca 

Simnia patula (Pennant 1777) Egg Cowrie 

Previously recorded from Northern Ireland from 

the Skerries, Rathlin Island, Shamrock Pinnacle 

(NW Rathlin) and Strangford Lough (Picton & 

Costello 1994; CEDaR). Fairly widespread on 

west coast of Ireland. Recorded from two sites at 

the Skerries. 

Philine pruinosa (Clark, 1827) 

opisthobranch mollusc 

Recorded from Red Bay. There were only two 

previous records for this species from Northern 

Ireland, one from Rathlin Island (1992 - Bernard 

Picton) and one from Strangford Lough (2004 - 

Julia Nunn). It is uncommon but occurs all 

around the British Isles, except for south-east 

England and more widely from the 

Mediterranean to Norway (Thompson 1988). 

37


Philinoglossa helgolandica Hertling, 1932 (SOCC) 

This tiny shell-less mollusc is a constituent of sublittoral shelly gravel meiofaunal communities. It 

is known only from Strangford Lough in Northern Ireland. Not recorded during SSNI. 

Stiliger bellula (Orbigny, 1837) a sacoglossan sea slug (SOCC) 

This inconspicuous species of sacoglossan was recorded from Rostrevor Bay (Dive 070508/01). It 

is a Northern Ireland SOCC and had only previously been recorded once from Northern Ireland, in 

1984, from a site close by in Rostrevor Bay (Nunn 2007e). It is found from Norway to the 

Mediterranean in sheltered, muddy, locations including Zostera beds. It is very rare in the British 

Isles with only five reported sightings (from Ireland, SW England and Yorkshire, in addition to 

Carlingford) (Seaward 1982). 

Lomanotus genei Verany, 1846 

a nudibranch mollusc 

This species is distributed from the west coast of 

Scotland to the Mediterranean but is rare and 

sporadic in occurrence (Picton and Morrow 

1994). It feeds on the common hydroid 

Nemertesia ramosa. There are recent records 

from the Arran in Scotland (Ferris 2006), Loch 

Linnhe in Scotland and Oban (Anderson, J. 

http://www.scottishnudibranchs.co.uk/lomanotu 

s-genei.html), Start Point in Devon (Rudman 

2007a), and Baltimore Harbour, Donegal Bay, Rathlin Island and the Skerries (Picton & Costello 

1998). Recorded from Ballygalley Head (Antrim Coast), Damicornis Bay on Rathlin Island (two 

individuals mating in 2007). The spawn of this species was recorded from the White Cliffs on 

Rathlin and Damicornis Bay (2006). 

Dendronotus sp. a nudibranch mollusc 

Several unusually coloured variants of the 

common sea slug Dendronotus frondosus were 

recorded. It is believed that these may represent 

a group of cryptic species rather than a single 

species. 

Okenia elegans (Leuckart, 1828) 

Yellow skirt sea slug 

This distinctive sea slug is rare in the British 

Isles. It has been recorded in the British Isles 

from scattered localities in SW England, 

Skomer Island and neighbouring 

Pembrokeshire, Bardsey Island in North Wales, 

the Saltees in County Wexford, St Kilda, 

Strangford Lough and the Skerries in Portrush 

(Ellis et al. 1995; Goodwin 2008b; Moore 2002; 

Picton & Morrow 1994; Rudman 2007b). It 

feeds on the ascidian Polycarpa rustica and may 

sometimes be seen with just its gills emerging from the test of the ascidian. It is known more 

widely from the Mediterranean and the Bay of Biscay. Thirteen records were made during SSNI. 

38


The majority of these were from Rathlin Island – six from Damicornis Bay, 2 from the White 

Cliffs, 2 from Picton’s Reef, 1 from NW Bull Point and 1 from SE Lochgarry. Two additional 

records were made from the Skerries and 1 from Torr Head. 

Thecacera pennigera (Montagu, 1813) 

a nudibranch mollusc (SOCC) 

This nudibranch feeds on the bryozoan Bugula plumosa. It is very rare in Northern Ireland, having 

been last recorded in 1986 (records from the Skerries between 1982 and 1985) and populations 

elsewhere are known to fluctuate. Not recorded during SSNI. 

Jorunna sp. nov. A. a nudibranch mollusc 

Spotty Jorunna 

Records were made of this species, presumed to 

be a new species, from NE Maiden and 

Russell’s Rock in the Maidens; Damicornis 

Bay, Duncan’s Bay, Picton Reef on Rathlin; 

and North of the Storks on the Skerries. It 

appears to feed on the sponge Haliclona 

urceolus. It is in the process of being described. 

Jorunna sp. nov. B. a nudibranch mollusc 

Lemon Yellow Jorunna 

This appears to be another undescribed species 

of Jorunna. It was found on three occasions at 

the Maidens, possibly feeding on the sponge 

Hymedesmia jecusculum. 

Janolus sp. nov. 


This was recorded twice, from SE of little 

Skerrie and from the Tun’s bank. It had 

previously been recognised as a probable new 

species after being first recorded from St Kilda 

(Picton & Morrow 1994). However, at this time 

there was not enough material to properly 

describe it. It differs from the common Janolus 

cristatus (del Chiaje, 1841) in that the cerata 

(back projections) are slightly roughened, there 

are white rings round the tips of the cerata rather than solid white ends, and it has no dark line of 

digestive tract running up the cerata. 

39


Hero formosa Lovén, 1841 


Not recorded during SSNI. This species has been recorded from Strangford Lough. Two specimens 

were dredged in 10m off Island Taggart, on weed in September 1954, two specimens off 

Killyleagh, 12m, in August 1964, and one specimen off Island Taggart, March 1966 (Queen’s 

University Belfast). The only other known record is from the wreck of ‘The Bangor’ in May 1988 

(J. Nunn) in 31m. It has not been seen since 1988. It is only known elsewhere in the island of 

Ireland from off Dingle Bay (1890, c. 150m) and Sherkin Island, County Kerry (August 1995, 

32m). It is defined as Nationally Scarce in Great Britain, with most recent records from the Isle of 

Man, the west coast of Scotland and the Rockall Trough (Nunn 2007c). 

Cuthona concinna (Alder & Hancock, 1843) 


Cuthona concinna is mainly found in Strangford 

Lough with a few scattered records elsewhere in 

Northern Ireland. It was first recorded in the Lough 

in May 1977, and most recently seen there in June 

2006 (Nunn 2007b). It is a northern species found 

elsewhere predominantly in Scotland, living in the 

shallow sublittoral. There are scattered records from 

elsewhere in Britain (mainly western Scotland), the 

most southerly being at Skomer MNR. Northern 

Ireland currently holds the entire Irish population, which is scarce. As a northern species, its 

populations may be vulnerable to climate change (Nunn 2007b). During SSNI it was recorded from 

Lee’s wreck in Strangford Lough and Duncan’s Bay on the north coast of Rathlin Island. 

Caloria elegans (Alder & Hancock, 1845) 


The first record for Northern Ireland and the 

second for Ireland; there are only five previous 

records for the British Isles. 

It was originally described from Torbay and has 

also been found at Lundy, Lough Swilly in 

Donegal, and off the Lleyn peninsula in Wales 

in 1984, (Picton 1979; Picton & Morrow 1994; 

Moore 2002). There is a more recent record 

from Cardigan Bay in 1995 by Dr Bill 

Sanderson in CCW (MarLIN). There is one record from near Whitby on the NE English coast 

(MNCR); it has not been possible to check this but the record seems unlikely, given the southern 

distribution of the species. Caloria elegans is common in the Mediterranean, where it was formerly 

known as Caloria maculata (Picton & Morrow 1994). 

40


Aeolidiella alderi (Cocks, 1852) 


This nudibranch was recorded for the first time 

in Northern Ireland, in Bird Island Passage, 

Strangford Lough (dive 070530/02). It is a 

southern species, known from a few records on 

the west coast of Ireland as far north as Mulroy 

Bay. Unlike most nudibranchs it has direct 

development, with small juveniles emerging 

from the eggs and no planktonic phase, so 

would be expected to spread slowly in response 

to climate change. 

Pecten maximus (Linnaeus, 1758) (SOCC) 

King Scallop 

This species is common, particularly on the 

east and southeast coasts of Northern Ireland. 

Wild stocks of the king scallop are thought to 

be declining, mainly due to overfishing, and 

damage to the benthic communities which act 

as nursery grounds (Nunn 2007d). Many 

records during SSNI, widespread over all areas 

surveyed. 

Reteporella couchii (Hincks, 1878) 

Recorded during SSNI from Damicornis Bay on 

Rathlin Island. There were no previous records 

from Northern Ireland. This is a poorly known 

species with a predominantly southern 

distribution, although it has been recorded from 

Norway and the Faeroes (Hayward & Ryland 

1999). 

Bugula turbinata Alder, 1857 (SOCC) 

Recorded during SSNI from Limestone and 

Hadd rock in Strangford Lough. There were 

previous records from the Skerries and 

Strangford Lough. This is a southern species, 

reaching up to the Clyde on the west coast of 

Britain (Hayward & Ryland 1998). 

Bryozoa 

41


During the 2007 Rathlin Survey Dr J. Porter and S. Tompsett, bryozoan specialists from the 

University of Aberystwyth joined the team for a week’s survey. Preliminary results indicate that 

species present on Rathlin Island are: Aetea anguina, Alcyonidium diaphanum, Amphiblestrum 

flemingii, Bicellariella ciliata, Bugula flabellata, Bugula plumosa, Bugula purpurotincta, Bugula 

simplex, Buskea dichotoma, Caberea ellisii, Callopora lineata, Cellaria fistulosa, Cellaria sinuosa, 

Cellepora pumicosa, Celleporella hyalina, Crisia aculeata, Crisia denticulata, Crisia eburnea, 

Crisidia cornuta, Disporella hispida, Electra pilosa, Escharoides coccinea, Flustra foliacea, 

Microporella ciliata, Omalesecosa ramulosa, Palmiskenia skenei, Parasmittina trispinosa, 

Phaeostachys spinifera, Porella compressa, Reteporella couchii, Schizomavella linearis, 

Scrupocellaria reptans, Scrupocellaria scruposa, Securiflustra securifrons, Tubulipora sp. 

Echinodermata 

Luidia sarsi Duben & Koren, 1846 (SOCC) 

Two records during SSNI from the White Cliffs 

on Rathlin and Red Bay (video of this 

specimen). There are two previous records, from 

the White Cliffs, Rathlin and Glenarm Bay (B.E. 

Picton. Lives on muddy sand, recorded from all 

round the British Isles (Southwood & Campbell 

2005). Its habitat makes it vulnerable to damage 

from dredging. There are few previous Irish 

records - it was recorded from Cork, Kerry and 

Donegal during the BioMar survey (Picton & 

Costello 1998). It has a more northerly distribution than the similar seven armed starfish Luidia 

ciliaris, occurring from Norway to the Mediterranean but in deep colder water in the south. 

Amphiura securigera (Duben & Koren, 1844) - a brittlestar (SOCC) 

This species occurs sporadically around western coasts of the British Isles in gravel (Southwood & 

Campbell 2005). It was recorded during the Northern Ireland Sublittoral Survey from the Outer 

Ards coast (2 records). No records were made during this survey but the Ards peninsula was not 

surveyed. 

Leptopentacta elongata 

(Duben & Koren, 1845) sea cucumber 

A population of this small white sea cucumber 

was found in Red Bay. The only other Northern 

Ireland location for this species is Strangford 

Lough. It is found all around the British Isles, 

usually in mud associated with the sea pen 

Virgularia mirabilis. Elsewhere it is widely 

distributed from the Mediterranean to Norway. 

42


Porania pulvillus (O.F. Müller, 1776) 

(SOCC) Crimson Cushion Starfish 

During the NISS this was found to be most 

common on Rathlin Island (records from the 

White Cliffs, Damicornis Bay and around 

Picton’s reef on the east coast). Also recorded 

from East of Torr Head and Murlough Bay on 

the east Antrim coast and several sites on the 

Maidens. This reflects the distribution found 

during SSNI. An entirely white individual was 

recorded from Damicornis Bay, Rathlin. 

Asterina phylactica Emson & Crump, 1979 (SOCC) 

This small cushion star was recorded during the Northern Ireland Sublittoral Survey from 

Strangford Lough. It is most common on rock pools on exposed shores but may also be found 

sublittorally (Southwood & Campbell 2005). It was not found during this survey but intertidal sites 

were not examined. 

Tunicata 

Pycnoclavella sp. 

Pin Head Squirt 

During SSNI recorded from Rathlin (Lochgarry, 

Strangford Lough (Klondyke Shoal, Neil Reef, 

SE Dunnyneil Island) the Maidens (W of the 

Bushes, W of West Maiden, and Pin Head 

Pinnacle). There are previous records from 

Murlough Bay and Fair Head in Country Antrim 

(NISS) and Pembrokeshire (PMSA). 

Although small, this species is distinctive when 

seen in the field due to the white cross shaped 

marking on its head, from which its name derives. In some areas it was found to be very abundant, 

particularly on a formerly unnamed pinnacle west of the Maidens, which we have termed Pin Head 

Pinnacle in its honour. So far it has not been possible to find a scientific name for this species and it 

is likely that it is a new species of Pycnoclavella. Several samples were collected during SSNI and 

these are being sent to an expert in this group for identification. 

Pycnoclavella aurilucens Garstang, 1891 

Recorded from east of Black Rock on the Skerries. This colonial ascidian is rarely recorded in 

Britain. Millar (1970) reported that it was known only from Plymouth. However during NISS it 

was recorded from the Skerries and during BioMar it was found to be widespread on the west coast 

of Ireland (Picton & Costello 1998). 

43


Archidistoma aggregatum Garstang, 1891 

(SOCC) 

Recorded during SSNI from Derginan point 

and Farganlack point on Rathlin. Found from 

Plymouth and Salcombe in southern England 

north to the Irish Sea and North Channel. 

Probably under-recorded due to its 

inconspicuous appearance and small size. 

There are scattered previous Northern Ireland 

records along the north-east coast from 

Islandmagee to the Skerries. The Northern 

Ireland records represent the majority of the 

Irish populations; in the Republic it is only recorded from Kerry Head and the Saltee Islands 

(BioMar). 

Synoicum incrustatum (M Sars, 1851) 

(SOCC) 

Recorded from the Skerries and Duncan’s Bay 

on Rathlin. All the Skerries records were from 

April, despite most of the sampling of this area 

being later in the year. It seems that this species 

may be seasonal, early season sampling would 

be important for the future assessment of 

distribution and abundance. 

Sidnyum sp. Raspberry sea squirt 

This sea squirt is found in kelp forest habitats on 

Rathlin Island, at the Skerries, Portrush, and in 

Strangford Lough. It has not been possible to 

match with any described species, but appears to 

be a species of Sidnyum. 

Red didemnid squirt 

This sea squirt was observed at a number of 

sites in Strangford Lough in 2007 and 2008. It is 

consistently red in colour, forming patches 1- 

3cm in extent with rounded edges. The anatomy 

of this species needs to be investigated in order 

to attempt an identification. The external 

appearance is similar to Didemnum 

pseudofulgens, but that species has not been 

reported from Great Britain or Ireland and was 

described originally from Banyuls-sur-Mer on 

the French Mediterranean coast. 

44


Brown didemnid squirt 

This sea squirt is another member of the family 

Didemnidae which is frequently encountered in 

sponge rich habitats on Rathlin Island. There are 

a series of marks around the cloacal openings 

and the colony is brown or orange in colour. 

Lissoclinum sp. 

yellow didemnid 

This sea squirt is consistently present in sponge 

rich habitats on Rathlin Island, showing a 

preference for limestone substrata. It has large 

cloacal openings and large inhalent openings. 

The colour is a pale lemon yellow. Preliminary 

dissection of a specimen suggests that it may be 

a species of Lissoclinum. 

Boltenia echinata (Linnaeus, 1767) (SOCC) 

Recorded from Derginan point, Rathlin and the 

Maidens (Allen’s Rock and West Maiden). This 

species is inconspicuous and is likely to be 

under-recorded. There are sparsely scattered 

previous records from Northern Ireland between 

Dundrum Bay and Rathlin Island. There are no 

records from the Republic of Ireland. 

45


Pisces 

This survey focused on marine invertebrate species, so a full account of the fish species is not 

given. 

Parablennius ruber (Valenciennes, 1836) 

Red or Portuguese Blenny 

During 2006 a record was made on a Seasearch 

dive of the Red Blenny from the Skerries 

(Goodwin 2007b). The Ulster Museum held 

unpublished records of this species dating back 

as far as the 1980s. As part of SSNI, records 

were collated and notes provided on field 

identification characteristics (Goodwin & 

Picton 2007). The species has recently been 

revalidated as separate from the tompot blenny 

P. gattorugine and this, together with confusion about the field identification characteristics which 

distinguish the two species, is likely to have resulted in it being under-recorded. 

Callionymus reticulatus Valenciennes, 1837- Reticulated dragonet, Callionymus maculatus 

Rafinesque, 1810- spotted dragonet, Callionymus lyra Linnaeus, 1758 - common dragonet 

There is some confusion in the identification of these species. There is a lack of awareness amongst 

biologist of the identification characteristics of the spotted and reticulated dragonets, there are 

currently no good guides to field identification characteristics for these species, and consequently 

these species may be under recorded. 

The following descriptions are mainly from Picton & Morrow (2007). 

The common dragonet (top left) has a 

rather flattened head and body and when 

viewed from above the head is almost 

triangular in shape. The pelvic fins are 

large and are held expanded. The eyes are 

close together and on top of the head. 

There are two dorsal fins, the first is 

triangular shaped and in males the first fin 

ray is very long. Females and immature 

males are usually pale brown with a series 

of six darker blotches along the sides and 

three conspicuous saddle-like markings 

across the back. Males have numerous blue spots and stripes on their bodies and fins. This is the 

largest of the dragonet species with females growing to 20cm in length and males growing to 

30cm. 

The reticulated dragonet (middle left) has a 

similar body shape to the common dragonet but 

tends to be much smaller, 8-10cm in length 

compared with 20-30cm. Both males and 

females have numerous pale blue spots on their 

sides and four dark saddle-like markings across 

the back. The saddle markings are surrounded 

by a clearly defined darker outline. The first 

dorsal fin is short with three rays. 

46


The spotted dragonet (bottom left). Male fish have four dark spots interspersed with pearl spots on 

the membranes between each ray of the dorsal fin. Females have two rows of dark spots on the 

second dorsal fin. Females up to 11cm in length, Males up to 14cm (Lythgoe & Lythgoe 1991). 

Dipper (2001) states that the common dragonet 

is widespread and abundant all around Britain 

and Ireland whereas the reticulated dragonet is 

more restricted and occurs on the south and west 

coast of Britain and in the Irish Sea, and the 

spotted dragonet generally lives in water deeper 

than 70m. 

During SSNI the common dragonet was 

recorded from Strangford Lough, Carlingford 

Lough and Red Bay. The reticulated dragonet 

from Rathlin (Lochgarry, Damicornis Bay, 

White Cliffs), the Skerries, Red Bay and 

Strangford Lough. There were two records of the spotted dragonet from N of West Rock and Bird 

Island Passage in Strangford Lough. However, these are tentative records based on our current 

understanding of identification characteristics. The reticulated and common dragonets are 

particularly hard to distinguish and these identifications may need to be reassigned in the future. 

Balistes capriscus Linnaeus, 1758 

Grey trigger fish 

One record was made of this species at the Skerries (060824/01 East Broad Sound). This species 

used to be rarely recorded in Britain and Ireland, with only one or two sightings a year, but since 

the mid eighties has become fairly common on southern and western coasts (Dipper 2001; Reeds 

2008). There are several recent records from Wales and Donegal. There have been infrequent 

sightings near to the Skerries, with records as far back as 1976. The number of sightings seems to 

be increasing and becoming further north, with recent sightings as far north as the Hebrides 

(http://www.glaucus.org.uk/Triggerf.htm). 

47


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50


Appendix 1 – Selection criteria for Northern Ireland Priority species (Marine Invertebrates) 

Rate of decline: rapid decline (2% per year over the last 25 years), decline (1%/year). 

Rarity: 

Rare (e.g. a small population and/or confined to one or two sites in Northern Ireland) with Northern 

Ireland being a stronghold consisting of either: >50% Irish population or >20% UK population/range. 

Scarce – JNCC definition is a species occurring in 16-100 hectads (10 km squares) throughout. 

UK and Irish population columns denote the proportion represented by Northern Ireland population; S 

indicates >50% Irish population/range or >20% of the UK population/range. R indicates that the UK or Irish 

population is restricted to Northern Ireland. 

Species 

(taxonomic order) 

Common name Group 

51 

UK 

priority 

Rate of 

decline 

Rarity 

UK 

population 

Hymerhabdia typica a sponge Porifera Rare R R 

Eurypon coronula a sponge Porifera Decline Rare S S 

Mycale (contarenii) a sponge Porifera Rapid decline Scarce 

Mycale similaris a sponge Porifera Increasing Scarce S S 

Iophon ingalli 

(hyndmani) 

Spanioplon 

armaturum 

a sponge Porifera Rapid decline Scarce 

a sponge Porifera Rapid decline Scarce 

Clathria barleei a sponge Porifera Decline Rare S S 

Microciona 

elliptichela 

a sponge Porifera Rare R R 

Halecium plumosum a hydroid Cnidaria Rare S S 

Lytocarpia 

myriophyllum 

Polyplumaria 

flabellata 

a hydroid Cnidaria Rapid decline Rare 

lacy hydroid Cnidaria Decline Scarce S S 

Diphasia alata a hydroid Cnidaria Decline Scarce S S 

Diphasia nigra black hydroid Cnidaria Decline Rare S S 

Virgularia mirabilis slender sea pen Cnidaria Decline Scarce 

Arachnanthus sarsi spotted burrowing 

anemone 

Parazoanthus 

axinellae 

yellow cluster 

anemone 

Irish 

population 

Cnidaria Yes Decline Rare S S 

Cnidaria Rare S 

Anemonactis mazeli a burrowing anemone Cnidaria Decline Rare S S 

Edwardsia timida worm anemone Cnidaria Rare S 

Caryophyllia inornata southern cup coral Cnidaria Rare S 

Sabellaria alveolata honeycomb worm Annelida Decline Scarce 

Sabellaria spinulosa honeycomb worm Annelida Decline Scarce


Species Common name Group UK 

52 

priority 

Rate of 

decline 

Palinurus elephas crawfish Crustacea Yes Decline 

Rarity 

UK 

population 

Cestopagurus timidus a hermit crab Crustacea Decline Rare S S 

Inachus leptochirus a spider crab Crustacea Decline S S 

Munida rugosa long clawed squat 

lobster 

Irish 

population 

Crustacea Rapid decline S 

Atelecyclus rotundata circular crab Crustacea Decline S 

Tonicella marmorea chiton Molluscs Decline Scarce S 

Erato voluta egg cowrie Molluscs Rare S S 

Palio dubia a nudibranch mollusc Molluscs Rare S 

Eubranchus doriae a nudibranch mollusc Molluscs Rare S 

Cumanotus beaumonti a nudibranch mollusc Molluscs Rare S S 

Modiolus modiolus horse mussel Molluscs Rapid decline Scarce 

Atrina fragilis fan mussel Molluscs Yes Rapid decline? Rare 

Ostrea edulis native oyster Molluscs Yes Decline Scarce 

Chlamys varia variegated scallop Molluscs Rapid decline 

Pentapora foliacea potato crisp bryozoan/ 

ross coral 

Astropecten 

irregularis 

Bryozoa Rapid decline Scarce 

sand starfish Echinoderms Rapid decline 

Anseropoda placenta goosefoot starfish Echinoderms Rapid decline 

Solaster endeca purple sunstar Echinoderms Decline S 

Leptasterias muelleri northern starfish Echinoderms Decline Scarce S 

Paracucumaria 

hyndmani 

Hyndman’s sea 

cucumber 

Echinoderms Decline Rare S S 

Ocnus planci a sea cucumber Echinoderms Decline Rare S S 

Thyonidium 

drummondi 

Leptosynapta 

bergensis 

Labidoplax media a burrowing sea 

cucumber 

Glossobalanus 

sarniensis 

red sea cucumber Echinoderms Rapid decline Scarce S 

a sea cucumber Echinoderms Rare S 

Echinoderms Decline Scarce S S 

acorn worm Chordata Rare S 

Pyura microcosmus a sea squirt Chordata Rapid decline Scarce


Appendix 2 - Survey aims for NICP marine invertebrate species 

Where species do not fall into the proposed survey areas no location is given. Work proposed for each 

species is detailed; more information can be found in the work plan for the relevant survey area(s). 

Species name 

(taxonomic order) 

Porifera 

Description 

Occurrence in 

proposed survey 

areas 

53 

Proposed action 

Hymerhabdia typica sponge Rathlin Distribution and status established by sponge 

project. 

Eurypon coronula sponge Strangford Lough Search for more specimens. 

Mycale (contarenii) sponge Strangford Lough, 

Modiolus beds 

Mycale similaris sponge Strangford Lough, 

Modiolus beds 

Iophon ingalli 

(hyndmani) 

Spanioplon 

armaturum 

Survey populations to examine if they have been 

adversely affected by Modiolus bed damage. 



sponge Rathlin Distribution and status established by sponge 

project. 

sponge Strangford Lough, 

Rathlin 

Abundant on Rathlin, check Strangford Lough 

populations. 

Clathria barleei sponge Rathlin, Maidens Although previously recorded on Rathlin there 

were none found on the recent sponge survey – 

may have been damaged by dredging on east coast. 

Establish distribution in Maidens. 

Microciona 

elliptichela 

Cnidaria 

sponge Rathlin Distribution and status established by sponge 

project. 

Halecium plumosum a hydroid Rathlin, Maidens Establish distribution and population status – there 

is currently little information on this species. 

Lytocarpia 

myriophyllum 

Polyplumaria 

flabellata 

a hydroid Rathlin Establish distribution. Assess damage to 

populations, east side of Rathlin. 

lacy hydroid Rathlin, Maidens Establish distribution. Assess damage to 

populations, east side of Rathlin. 

Diphasia alata a hydroid Rathlin, Maidens Establish distribution. Assess damage to 

populations, east side of Rathlin. Write action plan. 

Diphasia nigra black hydroid Rathlin Establish distribution. Assess damage to 

populations, east side of Rathlin. Write action plan. 

Virgularia mirabilis sea pen Carlingford Lough, 

Strangford Lough, 

Rathlin 

Arachnanthus sarsi a cerianthid 

anemone 

Parazoanthus 

axinellae 

Yellow cluster 

anemone 

Anemonactis mazeli a burrowing 

anemone 

Edwardsia timida a burrowing 

anemone 

Caryophyllia 

inornata 

southern cup 

coral 

Rathlin, white cliffs on 

gravel 

Main NI populations in Carlingford Lough; may 

have been affected by dredging and fish farming. 

Check status, look for other populations. 

Only one known population in Northern Ireland, 

check status. 

Rathlin Collate survey data – existing data probably 

sufficient for Rathlin. Possible Skerries sites? 

Strangford Lough Only recorded on one occasion. Obtain more 

records. 


Rathlin? 

Rathlin, Skerries (right 

habitat present but no 

records) 

Little known about habitat – may be nocturnal. 

Survey areas of known populations to check status. 

Resurvey Rathlin record site as identification not 

confirmed. 

None observed during Rathlin sponge survey – 

check population status and distribution


Species name 

(taxonomic order) Description 

Annelida 

Sabellaria alveolata Honeycomb 

worm 

Sabellaria 

spinulosa 

Crustacea 

Honeycomb 

worm 

Occurrence in 


areas 

Records from north 

coast of possible reef. 

Palinurus elephas Crawfish Rathlin, Strangford 

Lough 

Cestopagurus 

timidus 

54 


Survey sites at which previously recorded. 

Intertidal species. Will not be covered in this 

survey. 

Collect anecdotal information from divers to gain 

more information on distribution. 

a hermit crab Rathlin East coast Rathlin Island, check for populations. 

Inachus leptochirus spider crab Strangford Lough, 

elsewhere, on gravel 

Munida rugosa squat lobster Rathlin, Strangford 

Lough 

Atelecyclus 

rotundatus 

Mollusca 

a crab Strangford Lough, 

elsewhere, on gravel 

Tonicella marmorea chiton Lees wreck, 


Erato voluta Egg cowrie 

Myxas glutinosa Glutinous snail 

Chlamys varia Variegated 

scallop 

Palio dubia nudibranch 

Cumanotus 

beaumonti 


Modiolus beds 

May have been impacted by scallop dredging. 

Rathlin populations may have been affected by 

dredging on east coast – should be resurveyed. 

May have been impacted by scallop dredging. 

Survey populations. 

nudibranch Rathlin, on sand Survey populations. 



Eubranchus doriae nudibranch Skerries Skerries; check distribution and populations. 

Modiolus modiolus Horse mussel Strangford Lough, 

Skerries 

Atrina fragilis Fan mussel 

Ostrea edulis Native oyster 

Bryozoa 

Pentapora foliacea Ross coral Rathlin, Skerries, 

Maidens 

Monitor associated species in Strangford Lough 

and Skerries 

Establish distribution, write action plan.


Species name 

(taxonomic order) Description 

Echinodermata 

Astropecten 

irregularis 

Anseropoda 

placenta 

Occurrence in 


areas 

starfish Rathlin, Strangford 

Lough 

55 


Main populations are in Dundrum Bay. 

starfish Rathlin, Maidens Survey populations to examine if they have been 

adversely affected by scallop dredging. 

Solaster endeca starfish Strangford Lough Establish distribution – may be good indicator of 

climate change so knowledge of distribution 

important for long term monitoring. 

Leptasterias 

muelleri 

Paracucumaria 

hyndmani 

starfish Strangford Lough – also 

occurs on shore 

sea cucumber Strangford Lough, 

Modiolus beds 

Ocnus planci sea cucumber Carlingford Lough, 


Modiolus beds 

Thyonidium 

drummondi 

Leptosynapta 

bergensis 

Labidoplax media burrowing sea 

cucumber 

Tunicata 

sea cucumber Strangford Lough, 

Modiolus beds 

sea cucumber Strangford Lough, in 

gravel 

Pyura microcosmus sea squirt Strangford Lough, 

Modiolus beds 

Survey populations – can be partly surveyed 

from shore. 





Resolve taxonomy of NI populations. 



Establish distribution. 

Strangford Lough, mud Survey populations. Only known from 

Strangford Lough and lochs in the Shetlands in 

the UK. 


adversely affected by Modiolus bed damage.


Appendix 3 - Dives undertaken during the SSNI project 

Dives are arranged by survey area, site name and then dive date. The Dive number is a unique dive identifier 

consisting of the date backwards followed by a number indicating order on day (e.g. 061021/01 indicates the 

first dive on 21st October 2006). 

Dive 

Number 

Site Name Survey Area Latitude Longitude 

061021/01 Chirripo, Black Head Belfast Lough 54˚ 45.929’N 5˚ 40.719’W 

060810/01 Chirripo, E of Black Head Belfast Lough 54˚ 45.929’N 5˚ 40.719’W 

060810/02 Chirripo, E of Black Head Belfast Lough 54˚ 45.929’N 5˚ 40.719’W 

060810/04 N of Cloghan Jetty Belfast Lough 54˚ 44.514’N 5˚ 42.379’W 

060810/03 S of Black Head Belfast Lough 54˚ 45.705’N 5˚ 41.430’W 

070509/01 Hole N of no. 18 buoy Carlingford Lough 54˚ 03.74’N 6˚ 11.013’W 

070508/04 N of Killowen Bank Carlingford Lough 54˚ 04.076’N 6˚ 10.72’W 

070509/02 NW of Killowen Bank Carlingford Lough 54˚ 04.27’N 6˚ 11.938’W 

070508/01 Rostrevor Bay Carlingford Lough 54˚ 04.881’N 6˚ 12.992’W 

070508/02 S of Killowen Bank Carlingford Lough 54˚ 03.393’N 6˚ 10.127’W 

070508/03 S of Killowen Bank Carlingford Lough 54˚ 03.501’N 6˚ 10.037’W 

070509/03 SW of Stalka Rock Carlingford Lough 54˚ 02.604’N 6˚ 08.146’W 

070522/04 Mid Dundrum Bay Dundrum Bay 54˚ 11.659’N 5˚ 50.126’W 

070524/02 Mid Dundrum Bay Dundrum Bay 54˚ 12.513’N 5˚ 45.945’W 

070522/01 NE Annalong Dundrum Bay 54˚ 07.852’N 5˚ 48.675’W 

070522/02 NE Annalong Dundrum Bay 54˚ 07.254’N 5˚ 46.277’W 

070522/03 NE Roaring Rock Dundrum Bay 54˚ 09.129’N 5˚ 51.99’W 

070521/02 NW of St John’s Point Dundrum Bay 54˚ 14.011’N 5˚ 41.675’W 

060619/01 S St John’s Point Dundrum Bay 54˚ 12.216’N 5˚ 40.210’W 

070524/01 SW St John’s Point Dundrum Bay 54˚ 12.643’N 5˚ 43.24’W 

070521/01 W of St John’s Point Dundrum Bay 54˚ 13.416’N 5˚ 41.835’W 

060613/01 Cushendun Bay East Antrim 55˚ 07.893’N 6˚ 01.529’W 



060613/04 E of Ballygalley Head East Antrim 54˚ 53.947’N 5˚ 49.734’W 

060616/04 E of Drumnagreagh Point East Antrim 54˚ 56.827’N 5˚ 53.807’W 

060615/01 E of Torr Head East Antrim 55˚ 11.844’N 6˚ 03.558’W 

060616/01 Maerl bed, Red Bay East Antrim 55˚ 07.703’N 6˚ 01.4896’W 

060615/02 Murlough Bay East Antrim 55˚ 12.836’N 6˚ 06.853’W 

060613/03 N Ballygalley Head East Antrim 54˚ 54.192’N 5˚ 50.730’W 

060615/04 NE Torr Head East Antrim 55˚ 11.999’N 6˚ 03.6138’W 

060615/03 NW Torr Head East Antrim 55˚ 12.080’N 6˚ 04.563’W 

060614/01 Red Bay East Antrim 55˚ 03.6967’N 6˚ 02.6224’W 




56



070823/01 NE end of Lough Larne Lough 54˚ 50.022’N 5˚ 46.589’W 

070823/02 NE end of Lough Larne Lough 54˚ 49.897’N 5˚ 46.398’W 

060816/01 Annika’s pinnacle Maidens 55˚ 00.5322’N 5˚ 42.585’W 

060816/02 Annika’s pinnacle Maidens 55˚ 00.5322’N 5˚ 42.585’W 

070814/03 Between W and E Maiden Maidens 54˚ 55.759’N 5˚ 44.001’W 

070816/01 Cliffs E of Brown’s Bay, Islandmagee Maidens 54˚ 51.453’N 5˚ 44.547’W 

070817/03 E East Maiden Maidens 54˚ 55.705’N 5˚ 43.501’W 

060807/04 E of East Maiden Maidens 54˚ 55.734’N 5˚ 43.536’W 

060815/01 E of The Highlandman Maidens 54˚ 57.237’N 5˚ 43.843’W 

060818/03 E of the Highlandman Maidens 54˚ 57.258’N 5˚ 43.922’W 

060817/06 E of the Sheafing Rock Maidens 54˚ 55.276’N 5˚ 43.635’W 

060814/01 E of West Maiden Maidens 54˚ 55.768’N 5˚ 44.218’W 

060814/02 E of West Maiden Maidens 54˚ 55.768’N 5˚ 44.218’W 

060809/01 Larne Lough [Maidens] 54˚ 50.352’N 5˚ 46.945’W 



060815/06 N East Maiden Maidens 54˚ 55.897’N 5˚ 43.677’W 

070817/04 N East Maiden Maidens 54˚ 55.858’N 5˚ 43.769’W 

060807/03 N of East Maiden Maidens 54˚ 55.871’N 5˚ 43.605’W 



060815/04 NE East Maiden Maidens 54˚ 55.766’N 5˚ 43.552’W 

060818/06 NE of West Maiden Maidens 54˚ 55.907’N 5˚ 44.525’W 

060807/01 NE The Sheafing Rock Maidens 54˚ 55.239’N 5˚ 43.918’W 

060807/02 NE The Sheafing Rock Maidens 54˚ 55.253’N 5˚ 43.961’W 

070813/01 NE W Maiden Maidens 54˚ 55.978’N 5˚ 44.146’W 

060808/01 NNE East Maiden Maidens 54˚ 56.410’N 5˚ 43.431’W 

060808/02 NNE East Maiden Maidens 54˚ 56.410’N 5˚ 43.431’W 

060814/05 NNW East Maiden Maidens 54˚ 55.850’N 5˚ 43.787’W 

060808/03 NNW The Sheafing Rock Maidens 54˚ 55.273’N 5˚ 43.916’W 

060818/01 NW Allen’s Rock Maidens 54˚ 57.156’N 5˚ 44.628’W 

060818/02 NW Allen’s Rock Maidens 54˚ 57.166’N 5˚ 44.624’W 

060818/04 NW of West Maiden Maidens 54˚ 55.866’N 5˚ 44.551’W 

060816/06 NW the Sheafing Rock Maidens 54˚ 55.253’N 5˚ 43.955’W 

070813/02 NW West Maiden Maidens 54˚ 55.869’N 5˚ 44.546’W 

070824/03 Pin Head Pinnacle, Maidens Maidens 54˚ 56.372’N 5˚ 45.457’W 

070824/04 Pinnacle SE Highlandman Maidens 54˚ 57.044’N 5˚ 43.232’W 

060614/05 Russell’s Rock Maidens 54˚ 57.282’N 5˚ 44.995’W 





57



070824/01 Russell’s Rock, Maidens Maidens 54˚ 57.291’N 5˚ 45.008’W 

070824/02 Russell’s Rock, Maidens Maidens 54˚ 57.298’N 5˚ 44.986’W 

060816/04 S of West Maiden Maidens 54˚ 55.721’N 5˚ 44.322’W 

060816/05 S of West Maiden Maidens 54˚ 55.720’N 5˚ 44.364’W 

070817/01 S West Maiden Maidens 54˚ 55.716’N 5˚ 44.33’W 

060815/03 SE Allen’s Rock Maidens 54˚ 56.790’N 5˚ 43.898’W 

060815/05 SE East Maiden Maidens 54˚ 55.642’N 5˚ 43.544’W 

060815/02 SE of the Highlandman Maidens 54˚ 57.185’N 5˚ 43.820’W 

060817/04 SE of West Maiden Maidens 54˚ 55.727’N 5˚ 44.261’W 

060817/05 SE of West Maiden Maidens 54˚ 55.735’N 5˚ 44.241’W 

070820/01 SE The Saddle Maidens 54˚ 55.549’N 5˚ 43.537’W 

070820/02 SE The Sheafing Rock Maidens 54˚ 55.153’N 5˚ 43.722’W 

070814/01 SE West Maiden Maidens 54˚ 55.715’N 5˚ 44.295’W 



070813/03 W of the Bushes Maidens 54˚ 55.399’N 5˚ 44.06’W 

070813/04 W of the Bushes Maidens 54˚ 55.54’N 5˚ 43.938’W 

060818/05 W of West Maiden Maidens 54˚ 55.775’N 5˚ 44.436’W 

070814/04 W West Maiden Maidens 54˚ 55.8’N 5˚ 44.46’W 

060607/02 Archway, Ruecallan Rathlin Island 54˚ 55.897’N 5˚ 43.677’W 




060605/02 Church Bay, White Cliffs Rathlin Island 55˚ 17.454’N 6˚ 14.290’W 

060601/03 Damicornis Bay Rathlin Island 55˚ 17.447’N 6˚ 15.204’W 













070611/01 Derginan Point Rathlin Island 55˚ 18.462’N 6˚ 16.166’W 

070620/05 Duncan’s Bay Rathlin Island 55˚ 18.793’N 6˚ 14.885’W 




58



060608/02 E of Farganlack Point Rathlin Island 55˚ 18.720’N 6˚ 15.168’W 

070621/04 East of Kinrea Rathlin Island 55˚ 18.679’N 6˚ 13.864’W 

060531/02 East of Portnaminnan Rathlin Island 55˚ 17.196’N 6˚ 10.390’W 

070620/04 Kinrea, Rathlin Rathlin Island 55˚ 18.798’N 6˚ 14.317’W 

060602/01 Loch Garry, SE of Doon Point Rathlin Island 55˚ 15.956’N 6˚ 10.411’W 

060531/01 Lochgarry wreck Rathlin Island 55˚ 15.933’N 6˚ 10.399’W 



060608/04 Mill Bay Rathlin Island 55˚ 17.161’N 6˚ 11.679’W 

060609/01 Mill Bay Rathlin Island 55˚ 17.161’N 6˚ 11.679’W 

060601/02 NE Doon Point Rathlin Island 55˚ 16.393’N 6˚ 10.363’W 

070619/02 NE Picton’s Reef Rathlin Island 55˚ 16.651’N 6˚ 09.989’W 



060609/03 NW Drake, Church Bay Rathlin Island 55˚ 17.380’N 6˚ 13.162’W 

060601/01 Picton’s Reef Rathlin Island 55˚ 16.480’N 6˚ 10.295’W 








060605/01 Ruecallan Rathlin Island 55˚ 18.478’N 6˚ 16.127’W 



070414/01 Ruecallan Archway Rathlin Island 54˚ 55.897’N 5˚ 43.677’W 

070613/04 SE Lochgarry wreck Rathlin Island 55˚ 15.953’N 6˚ 10.397’W 




060605/03 SE White Cliffs, Church Bay Rathlin Island 55˚ 17.368’N 6˚ 14.141’W 

070621/02 Slope east of Illancarragh Bay Rathlin Island 55˚ 16.137’N 6˚ 10.141’W 

070621/03 Slope east of Illancarragh Bay Rathlin Island 55˚ 16.144’N 6˚ 10.148’W 

060608/03 West of Derginan Point Rathlin Island 55˚ 18.214’N 6˚ 16.596’W 








59


060531/03 White cliffs Rathlin Island 55˚ 17.578’N 6˚ 14.399’W 

060531/04 White Cliffs Rathlin Island 55˚ 17.583’N 6˚ 14.345’W 












070201/01 Red Bay Maerl Red Bay 55˚ 06.021’N 6˚ 01.792’W 

070201/02 Red Bay Maerl Red Bay 55˚ 06.153’N 6˚ 01.822’W 

070202/01 Red Bay Maerl Red Bay 

070803/01 1st Pinnacle E Black Rock Skerries 55˚ 13.489’N 6˚ 36.918’W 

070803/02 2nd Pinnacle E Black Rock Skerries 55˚ 13.527’N 6˚ 36.603’W 

070802/02 300m SE Little Skerrie Skerries 55˚ 13.174’N 6˚ 38.422’W 

070802/01 600m S Great Skerrie Skerries 55˚ 13.09’N 6˚ 37.919’W 

070801/03 Bay S Great Skerrie Skerries 55˚ 13.362’N 6˚ 37.504’W 

060823/06 Broad Sound Skerries 55˚ 12.987’N 6˚ 38.654’W 

060824/02 Broad Sound Skerries 55˚ 12.998’N 6˚ 38.590’W 

060821/05 E Broad Sound Skerries 55˚ 13.074’N 6˚ 38.400’W 



060825/01 E of Black Rock Skerries 55˚ 13.525’N 6˚ 36.534’W 



060823/01 N Large Skerrie Skerries 55˚ 13.478’N 6˚ 37.731’W 

070731/03 N Mid Skerrie Skerries 55˚ 13.464’N 6˚ 38.288’W 

070731/01 N of Great Skerrie Skerries 55˚ 13.502’N 6˚ 37.549’W 

060823/04 N of The Stork Skerries 55˚ 13.464’N 6˚ 35.304’W 

060823/03 NE Black Rock Skerries 55˚ 13.506’N 6˚ 37.176’W 

060824/06 NE Broad Sound Skerries 55˚ 13.171’N 6˚ 38.575’W 

070802/04 NE Foyle entry marker Skerries 55˚ 15.742’N 6˚ 50.652’W 

070731/02 NE Great Skerrie Skerries 55˚ 13.486’N 6˚ 37.306’W 

070801/02 NE Great Skerrie Skerries 55˚ 13.495’N 6˚ 37.423’W 

060823/02 NE Large Skerrie Skerries 55˚ 13.482’N 6˚ 37.414’W 

070430/01 North Side of Great Skerrie Skerries 55˚ 13.465’N 6˚ 38.000’W 

070430/02 North Side of Great Skerrie Skerries 55˚ 13.465’N 6˚ 38.000’W 

070801/01 NW Great Skerrie Skerries 55˚ 13.469’N 6˚ 37.824’W 

060822/03 NW Large Skerrie Skerries 55˚ 13.437’N 6˚ 38.061’W 

60


060822/04 NW Large Skerrie Skerries 55˚ 13.474’N 6˚ 37.957’W 

060822/01 NW of Black Rock Skerries 55˚ 13.522’N 6˚ 37.148’W 

060822/02 NW of Black Rock Skerries 55˚ 13.514’N 6˚ 37.207’W 

070802/03 NW Portstewart point Skerries 55˚ 11.728’N 6˚ 44.094’W 

060821/01 S coast of Large Skerrie Skerries 55˚ 13.354’N 6˚ 37.598’W 

060821/02 S coast of Large Skerrie Skerries 55˚ 13.353’N 6˚ 37.525’W 

060821/04 SE Little Skerrie Skerries 55˚ 13.141’N 6˚ 38.315’W 

060821/03 SW coast of Large Skerrie Skerries 55˚ 13.325’N 6˚ 37.819’W 

070801/04 SW Great Skerrie Skerries 55˚ 13.353’N 6˚ 38.012’W 

060823/05 W Broad Sound Skerries 55˚ 12.923’N 6˚ 38.703’W 




070731/04 W Ramore head, Portrush Skerries 55˚ 12.635’N 6˚ 39.800’W 

070725/02 Ballywhite Bay Strangford Lough 54˚ 23.834’N 5˚ 35.219’W 

070530/01 Bird Island Passage Strangford Lough 54˚ 28.704’N 5˚ 34.557’W 




070330/02 Black Rock, Navigation Position Strangford Lough 

070322/02 Bouldery spit, Ballyhenry Strangford Lough 

070726/02 Colin Rock Strangford Lough 54˚ 25.597’N 5˚ 35.976’W 

070426/01 Dive refresher training, Portaferry Strangford Lough 

070904/01 E Abbey Rock Strangford Lough 54˚ 25.595’N 5˚ 35.071’W 

070906/02 E Black Rock Strangford Lough 54˚ 25.677’N 5˚ 36.99’W 

070905/05 E Green Island Strangford Lough 54˚ 27.786’N 5˚ 36.675’W 

070531/01 E Limestone Rock Strangford Lough 54˚ 25.231’N 5˚ 36.136’W 

070907/03 E Limestone Rock Strangford Lough 54˚ 25.155’N 5˚ 35.988’W 

070727/01 E Long Sheelah Strangford Lough 54˚ 27.017’N 5˚ 35.012’W 

070907/02 E Neil Reef Strangford Lough 54˚ 24.154’N 5˚ 36.57’W 

070903/02 E Roe Island Strangford Lough 54˚ 28.441’N 5˚ 36.825’W 

070328/04 Harbour, Mooring check Strangford Lough 

070329/01 Hoskyn’s Waypoint, Navigation position Strangford Lough 

070329/04 Kircubbin Port, Navigation position Strangford Lough 

070329/03 Kircubbin Starboard, Navigation position Strangford Lough 

070726/04 Klondyke Shoal Strangford Lough 54˚ 24.193’N 5˚ 36.259’W 

070723/01 Long Sheelah Strangford Lough 54˚ 27.27’N 5˚ 35.66’W 

070727/04 Marfield Bay Strangford Lough 54˚ 24.376’N 5˚ 35.225’W 

070906/03 Marlfield Bay Strangford Lough 54˚ 24.213’N 5˚ 35.295’W 

070605/02 N Abbey Rock Strangford Lough 54˚ 25.678’N 5˚ 35.254’W 

070531/02 N Limestone Rock Strangford Lough 54˚ 25.276’N 5˚ 36.362’W 

070604/01 N Long Sheelah Strangford Lough 54˚ 27.026’N 5˚ 35.377’W 

61




070727/03 N of Kate’s Pladdy Strangford Lough 54˚ 24.743’N 5˚ 34.963’W 

070601/02 N Sunk Rock Strangford Lough 54˚ 26.127’N 5˚ 36.307’W 

070723/04 N West Rock Strangford Lough 54˚ 28.562’N 5˚ 35.097’W 

070726/03 Neil Reef Strangford Lough 54˚ 24.185’N 5˚ 36.504’W 

070606/02 NW Kate’s Pladdy Strangford Lough 54˚ 24.823’N 5˚ 35.193’W 

070905/01 NW Long Sheelah Strangford Lough 54˚ 26.989’N 5˚ 35.91’W 

070724/01 NW McLaughlin Rock Strangford Lough 54˚ 23.976’N 5˚ 36.915’W 

070605/05 Ringburr Point Strangford Lough 54˚ 25.427’N 5˚ 34.872’W 

070907/01 Routen Wheel Strangford Lough 54˚ 21.707’N 5˚ 32.497’W 

070605/03 S Abbey Rock Strangford Lough 54˚ 25.481’N 5˚ 35.187’W 

070606/05 S Black Rock Strangford Lough 54˚ 25.511’N 5˚ 37.22’W 

070906/01 S Black Rock Strangford Lough 54˚ 25.494’N 5˚ 37.233’W 

070601/05 S Colin Rock Strangford Lough 54˚ 25.467’N 5˚ 35.955’W 

070724/02 S Klondyke Shoal Strangford Lough 54˚ 23.969’N 5˚ 36.334’W 

070724/03 S Klondyke Shoal Strangford Lough 54˚ 23.895’N 5˚ 36.322’W 

070724/05 S Limestone Rock Strangford Lough 54˚ 24.894’N 5˚ 36.148’W 

070724/04 S Pinnacle E of Dunnyneil Strangford Lough 54˚ 24.357’N 5˚ 36.347’W 

070904/04 S Selk Rock Strangford Lough 54˚ 24.606’N 5˚ 37.654’W 

070904/03 S Town Rock, Quoile Strangford Lough 54˚ 23.416’N 5˚ 38.379’W 

070601/01 Scott’s Hole Strangford Lough 54˚ 27.035’N 5˚ 36.703’W 

070606/04 SE Black Rock Strangford Lough 54˚ 25.622’N 5˚ 37.117’W 

070606/06 SE Black Rock Strangford Lough 54˚ 25.611’N 5˚ 37.17’W 

070904/02 SE Dunnyneil Island Strangford Lough 54˚ 24.476’N 5˚ 36.69’W 

070328/01 SE Hadd Rock Strangford Lough 54˚ 27.223’N 5˚ 35.558’W 




070531/05 SE Limestone Pladdy Strangford Lough 54˚ 24.902’N 5˚ 36.631’W 

070531/03 SE Limestone Rock Strangford Lough 54˚ 25.119’N 5˚ 36.072’W 

070726/01 SE Limestone Rock Strangford Lough 54˚ 25.092’N 5˚ 35.983’W 

070523/01 SE Long Sheelah Strangford Lough 54˚ 26.774’N 5˚ 35.257’W 

070723/02 SE of Hadd Rock Strangford Lough 54˚ 27.189’N 5˚ 35.687’W 

070725/01 Selk Rock, Ballyhenry Island Strangford Lough 54˚ 23.678’N 5˚ 34.725’W 

070903/03 Selk Rock, Ballyhenry Island Strangford Lough 54˚ 23.642’N 5˚ 34.705’W 

061025/01 Selk Rock Strangford Lough 54˚ 23.642’N 5˚ 34.705’W 





070330/03 Strangford Harbour Strangford Lough 54˚ 23.642’N 5˚ 34.705’W 

070606/03 SW Ringburr Point Strangford Lough 54˚ 25.144’N 5˚ 35.14’W 

62


070905/03 The Drop Off Strangford Lough 54˚ 23.435’N 5˚ 34.883’W 

070906/04 The Drop Off Strangford Lough 54˚ 23.494’N 5˚ 34.992’W 

070330/01 Tipp, Navigation position Strangford Lough 

070605/01 Turbine Site, Narrows Strangford Lough 54˚ 22.098’N 5˚ 32.775’W 

070605/04 Unnamed pinnacle, W of Round Island Strangford Lough 54˚ 26.016’N 5˚ 35.469’W 

070531/04 W Dunnyneil Island Strangford Lough 54˚ 24.654’N 5˚ 37.277’W 

070905/04 W Hadd Rock Strangford Lough 54˚ 27.348’N 5˚ 36.081’W 

070328/03 W of Brown Rock Pladdy Strangford Lough 54˚ 25.776’N 5˚ 37.092’W 

070727/02 W Slave Rock Strangford Lough 54˚ 27.728’N 5˚ 35.161’W 

070601/03 W Sunk Rock Strangford Lough 54˚ 25.99’N 5˚ 36.452’W 

070601/04 W Sunk Rock Strangford Lough 54˚ 26.02’N 5˚ 36.438’W 

070418/01 Walters Rock, Portaferry Strangford Lough 

070329/02 West Sand Rock, Navigation position Strangford Lough 

070328/02 WNW of Jane’s Rock Strangford Lough 54˚ 26.984’N 5˚ 35.872’W 

060620/01 Lee’s wreck Strangford Lough 54˚ 23.360’N 5˚ 34.388’W 




060622/02 NE Cloghy Point Strangford Lough 54˚ 21.246’N 5˚ 32.656’W 

060621/02 Strangford Harbour Strangford Lough 54˚ 22.701’N 5˚ 34.127’W 

060623/01 Turbine site Strangford Lough 54˚ 22.137’N 5˚ 32.750’W 

060623/02 Turbine site Strangford Lough 54˚ 22.137’N 5˚ 32.750’W 

060622/01 Turbine site, Strangford Narrows Strangford Lough 54˚ 22.137’N 5˚ 32.750’W 

060621/01 Zara shoal Strangford Lough 55˚ 22.820’N 5˚ 33.770’W 

63


Appendix 4 Information on current status of Northern Ireland Conservation Priority Species 

Phylum Species (taxonomic order) Common name Page 

Porifera Hymerhabdia typica a sponge 65 

Eurypon coronula a sponge 66 

Mycale cf. contarenii Queen scallop sponge 67 

Mycale similaris orange mycalid sponge 69 

Iophon hyndmani a sponge 71 

Spanioplon armaturum Scallop cushion sponge 73 

Clathria barleei a sponge 75 

Microciona elliptichela a sponge 77 

Cnidaria Halecium plumosum a hydroid 79 

Lytocarpia myriophyllum a hydroid 81 

Polyplumaria flabellata Lacy hydroid 83 

Diphasia alata a hydroid 85 

Diphasia nigra Black hydroid 87 

Virgularia mirabilis Slender sea pen 89 

Arachnanthus sarsi Spotted burrowing anemone 91 

Parazoanthus axinellae Yellow cluster anemone 94 

Anemonactis mazeli a burrowing anemone 96 

Edwardsia timida a worm anemone 98 

Caryophyllia inornata Southern cup coral 100 

Annelida Sabellaria spinulosa Honeycomb worm 102 

Crustacea Palinurus elephas a crayfish 104 

Cestopagurus timidus a hermit crab 106 

Inachus leptochirus Leach’s Spider Crab 108 

Munida rugosa Long clawed squat lobster 110 

Atelecyclus rotundatus Circular crab 112 

Mollusca Tonicella marmorea a chiton 114 

Erato voluta Egg cowrie 116 

Palio dubia a sea slug 118 

Eubranchus doriae a nudibranch mollusc 120 

Cumanotus beaumonti a sea slug 122 

Modiolus modiolus Horse mussel 124 

Atrina fragilis Fan mussel 126 

Ostrea edulis Native oyster 128 

Chlamys varia Variegated scallop 130 

Bryozoa Pentapora fascialis var. foliacea Ross Coral/Potato crisp bryozoan 132 

Echinodermata Astropecten irregularis Sand starfish 134 

Anseropoda placenta Goosefoot starfish 136 

Solaster endeca Northern sunstar 138 

Leptasterias muelleri Northern starfish 140 

Paracucumaria hyndmani a sea cucumber 142 

Ocnus planci a sea cucumber 144 

Thyonidium drummondii Red sea cucumber 146 

Leptosynapta bergensis a sea cucumber 148 

Labidoplax media a sea cucumber 149 

Tunicata Pyura microcosmus a sea squirt 151 

64


Hymerhabdia typica Topsent 1892 - a sponge 

Description 

Thin yellow encrusting sponge with a ‘mealy’ appearance to the surface. Forms extensive sheets to 

20cm across. The oscules are regularly distributed, and have transparent chimneys of tissue (these 

collapse if the sponge is disturbed). Spicules: tylostyles 500-800 by 3-13μm, rhabdostyles and 

centrotylote oxeas 120-300 by 4-5μm. 

Similar species 

There are many similar crusts but the surface and oscule appearance may be characteristic. 

Requires microscopic examination of the spicules to confirm identification. 

Why is this species a priority in Northern Ireland? 

Rare – 100% of UK and Irish populations from Northern Ireland. 

Threats/causes of decline 

Distribution 

Primarily a southern species; known from Mediterranean, Azores and Roscoff. Occurs from 15m 

into deep water. Not known from elsewhere in the UK. 

Previously known Northern Ireland distribution 

Prior to the Sponge Biodiversity of Rathlin Island Project, this species was known only from 

Damicornis Bay on Rathlin Island. During this project further records were made from Damicornis 

Bay, the White Cliffs and the North Coast. 

Findings and recommendations from SSNI 

One additional record was obtained during SSNI from the east coast of Rathlin. 

Rathlin Island remains the only UK location from which this species is known. Continued 

monitoring of the Rathlin sponge communities is necessary to monitor its status. 

References 

Ackers, R.G., Moss, D. Picton, B.E., Stone, S.M.K. & Morrow, C.C. 2007 Sponges of the British Isles 

(Sponge V), 1992 edition reset with modifications. Marine Conservation Society/Ulster Museum, Belfast 

Picton. B.E. & Goodwin, C.E. 2007 Sponge Biodiversity of Rathlin Island. Project Report. Ulster Museum, 

Belfast 

Picton, B.E. & Goodwin, C.E. 2007 Sponge Biodiversity of Rathlin Island. Journal of the Marine Biology 

Association of the United Kingdom 87 (6): 1441-1458 

Soest, R.W.M. van, Picton, B. & Morrow, C. 2000 Sponges of the North East Atlantic (CD-ROM). Windows 

Version 1. Expert Centre for Taxonomic Identification. University of Amsterdam 

65


Eurypon coronula (Bowerbank, 1869) - a sponge 

Description 

This is a thin encrusting sponge, distinguished from similar species by details of its spicules. It has 

only been reported on a few occasions worldwide, but sponges are a neglected group of animals so 

this rarity is probably not a true reflection of the status of this species. 


This sponge is easily confused with other red encrusting sponges. No photographs of this species 

are known to exist and therefore the external appearance is unknown. The spicule complement is 

distinctive. 

Distribution 

The type locality for this species is Shetland. 


Strangford Lough, a single record. 


This species has only been found once in Northern Ireland, in Bird Island Passage in 1985. 

Threats/Causes of decline 

The only known locality for this species has been badly impacted by the decline in Horse Mussel 

beds in Strangford Lough due to trawling for queen scallops during the 1980s. 


Despite searching in the original locality, this species was not rediscovered. It is small and not easy 

to distinguish from other red encrusting sponges, but the habitat in Bird Island Passage has become 

heavily silted. It is likely to be present somewhere in the Lough, and more sampling for sponges 

will probably locate further populations. 

References 

Ackers, R.G., Moss, D. Picton, B.E. Stone, S.M.K. & Morrow, C.C. 2007 Sponges of the British Isles 




66


Mycale cf. contarenii - Queen scallop sponge 

Description 

This sponge is probably an undescribed species. It grows into a cushion covering queen scallop 

(Aequipecten opercularis) shells in undisturbed horse mussel beds, and can be considered to be an 

indicator of healthy status of these beds. It has also been found on queen scallops in the west coast 

of Scotland. It forms cushions or sheets on hard substrata. It is purple to pink in colour, with large 

exhalent canals leading to an osculum which is normally in the middle of the upper surface of the 

scallop shell. Internally there is a silica spicule skeleton consisting of subtylostyles with large and 

small anisochelae, toxa and sigma spicules. The sigmas are different in size and shape from Mycale 

contarenii and can be used to positively identify this species. 


There are other sponges which have a similar external appearance. Therefore microscopic 

examination of the spicules is necessary to confirm identification. Other Mycale species can be 

distinguished by the size range of the spicules and the form of the skeleton. It differs in external 

appearance and details of its spicule skeleton from Mycale contarenii (Martens, 1824) to which it is 

closest. 


Scarce, and has undergone rapid decline in Northern Ireland (2% per year over the last 25 years). 


In rapid decline, possibly due to physical impact of bottom fishing gear in its habitat. The target for 

the fishery is the queen scallop, Aequipecten opercularis, which lives in more open muddy patches 

between the horse mussel clumps, but requires stable biogenic reefs for successful recruitment. 

Queen scallop numbers are now very low compared with the situation 30 years ago, and sponges 

have been particularly affected by the changes. Sponges may be very vulnerable to increased 

siltation which clogs their feeding mechanisms and may in turn protect the bivalves from starfish 

predation. Thus healthy sponge populations may be an important indicator of health of these 

communities. It is unclear whether direct impact from trawling has disrupted the mussel beds and 

encouraged predatory starfish or whether smothering by stirred-up bottom sediments is more to 

blame for their decline. 

Distribution 

Grows into a cushion covering queen scallop (Aequipecten opercularis) shells in undisturbed horse 

mussel beds and can be considered to be an indicator of healthy status of these beds. Known from 

Strangford Lough in Northern Ireland and on the west coast of Scotland. 

67



Only present in Strangford Lough. 


Establish appropriate management on suitable historical sites. Monitor numbers present in horse 

mussel beds in Strangford Lough. Investigate taxonomy and biology of this species. 

References 



Picton, B.E. 2007 Mycale contarenii – Queen Scallop Sponge. Northern Ireland Priority Species Reports 

[online]. Cultra: National Museums Northern Ireland [cited 15/02/2008]. Available from: 

http://www.habitas.org.uk/priority/species.asp?item=655 



68


Mycale similaris (Bowerbank, 1874) 

- orange mycale sponge 

Description 

This sponge forms substantial cushions or sheets on hard substrata. It is orange in colour with large 

exhalent canals leading to several large osculae. It is soft in consistency with a transparent 

membrane at the surface and around the osculae. Internally there is a silica spicule skeleton 

consisting of subtylostyles with small and large anisochelae, toxa, trichodragmata and sigma 

spicules. The size and shape of the trichodragmata can be used to positively identify this species. 


Similar in appearance to several other Mycale species, but the colour is quite distinctive and 

appears to be quite consistent between individuals. In Northern Ireland, most Mycale species are 

rare on the open coast, apparently being more common in sheltered locations. 


Rare - confined to a small population of one or two sites in Northern Ireland, with Northern Ireland 

being a stronghold consisting of over 50 per cent of the Irish population and over 20 per cent of the 

UK population. 


This species was a characteristic and moderately long-lived component of horse mussel (Modiolus 

modiolus) beds in Strangford Lough until 20 years ago, but unlike other sponges from this habitat it 

appears to have increased rapidly in recent years. It is now common throughout the lough in a 

variety of habitats and has been found recently (2006) on the shore at Ballyhenry Island. The 

current status of this species is not clear, but it would be a useful indicator to monitor the health of 

the horse mussel beds. Investigation is required to elucidate details of its biology. Investigations in 

2003 confirmed that the horse mussel beds have declined considerably in the past 30 years, but this 

sponge species seems to have increased significantly and cannot currently be considered 

threatened. There are no other recent records from Northern Ireland and few records of this species 

from the UK. 

Distribution 

Originally described from specimens collected in Strangford Lough by Professor Dickie of Queen’s 

College Belfast. Recent records from Strangford and the Firth of Lorne Scotland. Also previously 

69


recorded from the Mediterranean coast of France. 


Only known from Strangford Lough. 


Monitor populations in relation to Modiolus beds in Strangford Lough. 

References 



Picton, B.E. 2007 Mycale similaris– Orange mycalid sponge. Northern Ireland Priority Species Reports 





70


Iophon hyndmani (Bowerbank, 1858) – a sponge 

Description 

Irregularly branching pale yellow sponge, typically in sheltered waters, encrusting sessile 

organisms such as shells and hydroids. There is also a flattened encrusting form which has a 

distinctive surface appearance with radiating channels around oscules forming a star-like pattern on 

its surface. Becomes dark when preserved. 


Could be confused with other sponges, particularly other encrusting species and the branching 

sponge Iophon nigricans. A sample should be taken, and the spicules examined under a light 

microscope to confirm identification. 


Strangford Lough is the type locality for this species. The Strangford Lough populations are 

associated with horse mussel (Modiolus modiolus) beds; the shells provide a substrate for the 

sponge to attach to in muddy areas which would otherwise be impossible for it to colonise. Damage 

to the horse mussel beds has resulted in a loss of habitat. Its status on other areas of the Northern 

Ireland coast is uncertain, and Strangford Lough may be the Northern Ireland stronghold for this 

species. 


Damage to Modiolus modiolus beds resulting in loss of substrate. May be affected by alteration in 

sedimentation regimes; increased sediment load may result in the sponge being smothered. 

Distribution 

Common and widely distributed from Norway to the Mediterranean. Recent records from Northern 

Ireland, the west coast of Ireland and Scotland. Type locality is Strangford Lough. 


All Northern Ireland coasts, but particularly common in Strangford Lough and on Rathlin Island. 

Prior to the Rathlin Sponge Biodiversity Project its status on Rathlin was uncertain, but sampling 

for this showed it to be extremely common on all Rathlin coasts. 


Further samples were collected from Rathlin Island. Specimens were also collected from the 

Maidens, the Skerries and Dundrum Bay. In Strangford Lough it was recorded from Klondyke 

71


Shoal, Marfield Bay, and off Ballyhenry Island. The Strangford Lough populations used to be 

associated with horse mussel (Modiolus modiolus) beds, forming extensive, conspicuous, bushy 

growths on Chlamys varia. The shells provided a substrate for the sponge to attach to in muddy 

areas which would otherwise be impossible for it to colonise. Damage to the horse mussel beds has 

resulted in a loss of habitat, and may account for its disappearance from these areas. It was 

observed in 2003 that Iophon hyndmani had decreased in number and was now ‘almost absent’ 

from the Lough (Roberts et al. 2004). 

However, the species is reasonably common on Rathlin, and at the Maidens and the Skerries, so the 

Northern Ireland populations of this species are not threatened, despite the habitat loss in 

Strangford Lough. In view of the recent discovery of populations in these other locations, this 

species can no longer be considered to be rare and could be removed from the NICP list. 

Rathlin appears to be particularly important for this species, and we recommend that its status on 

Rathlin continues to be monitored. We recommend that its status in Strangford Lough continues to 

be monitored as the bushy growth form may be a good indicator of the ecological health of the 

Modiolus beds. Taxonomically this is a difficult species to identify, so genetic work may be useful 

in confirming that the Rathlin and Strangford populations are the same species: the species Iophon 

ingalli and I. pattersoni (Bowerbank, 1866) are currently synonomised with I. hyndmani, but this 

requires further investigation and they may turn out to be distinct species. 

References 



Picton, B. & Goodwin, C. 2007 Sponge Biodiversity of Rathlin Island. Project report for EU BSP and EHS. 

Department of Zoology, Ulster Museum, Belfast 

Roberts, D., Davies, C. Mitchell, A., Moore, H., Picton, B., Portig, A., Preston, J., Service, M., Smyth, D., 

Strong, D. & Vize, S. 2004 Strangford Lough Ecological Change Investigation (SLECI). Report to 

Environment and Heritage Service by the Queen’s University, Belfast 



72


Spanioplon armaturum (Bowerbank, 1866) 

- Scallop Cushion Sponge 

Description 

This sponge forms cushions or sheets on hard substrata. It is grey in colour with a semi-transparent 

surface and large exhalent canals leading to osculae where the feeding currents emerge. When 

growing on Chlamys varia, these osculae are usually few in number and grow adjacent to the 

opening of the scallop shell, possibly thereby benefiting by a symbiotic relationship where the 

scallop and sponge support each other’s feeding currents. Internally there is a silica spicule 

skeleton consisting of tornotes, styles and microspined straight acanthostyle spicules. The latter are 

very distinctive and can be used to positively identify this species. Encrusting specimens were redescribed 

by Burton under the name Hymedesmia stephensi, but examination of Burton’s material 

in the Natural History Museum, London confirms the synonymy. 


There are other encrusting sponges which could be confused with this species. Examination of the 

spicules is necessary to confirm identification. 


Scarce, and has undergone rapid decline (2% per year over the last 25 years). 


In rapid decline possibly due to physical impact of bottom fishing gear on its habitat. The target for 

the fishery is the queen scallop, Aequipecten opercularis, which lives in more open muddy patches 

between the horse mussel clumps, but requires stable biogenic reefs for successful recruitment. 

Both queen scallop and variegated scallop numbers are now very low compared with the situation 

30 years ago, and sponges have been particularly affected by the changes. Sponges may be very 

vulnerable to increased siltation which clogs their feeding mechanisms and may in turn protect the 

bivalves from starfish predation, so healthy sponge populations may be an important indicator of 

health of these communities. It is unclear whether direct impact from trawling has disrupted the 

mussel beds and encouraged predatory starfish or whether smothering by stirred up bottom 

sediments is more to blame for their decline. 

Distribution 

Found in sheltered conditions on Modiolus communities and on very exposed bedrock (shore- 

50m). Norway, St Kilda, S. England, Ireland, west coast of France and Spain, Mediterranean. 

73



This was thought to be a species primarily confined to horse mussel beds in Northern Ireland where 

it used to be present in densities of several specimens per 10m 2 . Living Chlamys varia are now 

much rarer in these beds, so there are fewer suitable hosts for the sponge. Investigations in 2003 

confirmed that the horse mussel beds have declined considerably in the past 30 years and this 

species in particular seems to have become rare; it was not seen during the 2003 SLECI fieldwork. 

During the 2005 Sponge Biodiversity of Rathlin Island project, nine further specimens were 

collected from Rathlin Island. The species appears to be present all around the coast of Rathlin. 

There is also one record from Murlough Bay, County Antrim. 


This species was not recorded during SSNI. Previously it was only known from Northern Ireland in 

association with the horse mussel beds in Strangford Lough. 

In light of the damage that has occurred to the beds, the Rathlin Island population may now be the 

Northern Ireland stronghold. In the light of the importance of Rathlin for this and other priority 

sponge species, we recommend that a programme to monitor its sponge communities is established. 

References 



Picton, B.E. 2007 Spanioplon armaturum – Scallop cushion sponge. Northern Ireland Priority Species 

Reports [online]. Cultra: National Museums Northern Ireland [cited 15/02/2008]. Available from: 


Picton, B.E. & Goodwin, C.E. 2007 Sponge Biodiversity of Rathlin Island. Project Report. Ulster Museum, 

Belfast 





74


Clathria barleei (Bowerbank, 1866) - a sponge 

Description 

Pale yellow, beige or green flattened 

sponge, usually forming a fan shape; 

diameter up to 20cm, attached by a stalk 

to the substrate. It may also form a thin 

crust (see lower right). Pores are 

conspicuous on the surface and the 

consistency is compressible (these 

characters should enable its distinction 

from axinellid sponges). It has a ladderlike 

skeleton of styles echinated by 

acanthostyles. Microscleres are thin 

toxa and palmate chelae. The 

spiculation can be variable and one or 

more of these spicule categories may be 

absent. 


Axinella infundibuliformis may sometime be confused with this species as it occasionally grows in 

a similar flattened form. However, it has a much less porous surface and has a firm, rather than 

compressible, texture. If a sample is taken the identity can be easily be confirmed by examination 

of the spicules. 


Northern Ireland populations declining. Rare with Northern Ireland population representing >50% 

Irish population and >20% UK population. 


A northern species and Northern Ireland populations may be affected if water temperatures 

increase due to climate change. Occurs on boulder habitats which are vulnerable to disturbance 

from dredging. 

Distribution 

A northern deepwater species distributed from the Arctic to the Atlantic coasts of France. Usually 

occurs in deep water >40m. Recent records from deep water communities in Rockall and 

Mingulay, the west coast of Scotland (Insh Island, Loch Sunart, Sound of Mull), Ireland (the Aran 

Islands, Donegal Bay, Kenmare Bay and Achill Island) and Northern Ireland. 

75



Only known from Rathlin Island and the Maidens. There is only one record from Rathlin, from 

boulder habitat 32-36m BCD. There are five previous records from the Maidens, all from bedrock, 

between 21 and 35m BCD. 


Not recorded from Rathlin Island, but seven records were made from the Maidens (Russell Rock (2 

records), Annika’s pinnacle, NW Allen’s Rock, N of East Maiden (2 records), and Pin Head 

Pinnacle. The sponge and hydroid communities on Rathlin’s east coast have been adversely 

affected by dredging. In view of the importance of the Maidens for this and other priority species, 

we recommend the area be further investigated and consideration given to its designation as an 

SAC. 

References 





Soest, R.W.M. van 2006 Report on the Porifera of Mingulay. In C. Maier (ed.). Biology and ecosystem 

functioning of cold water coral bioherms at Mingulay (Hebrides), NE Atlantic, pp. 25-29. Cruise Report, 

BIOSYS 2006 Cruise 64PE250 on R/V Pelagia Oban-Oban 7-23 rd July 2006. Royal Netherlands Institute for 

Sea Research, the Netherlands 

76


Microciona elliptichela (Alander, 1942) - a sponge 

Description 

Thinly encrusting mustard yellow sponge. Requires examination of spicules to confirm 

identification: can be distinguished from other similar species as it possesses distinctive 

‘cleistochelae’ or closed chelae which are circular in form. 


May be confused with other encrusting species, but can be separated from these by microscopic 

examination of the spicules. 


This species is was until recently only known from Northern Ireland in the UK. Classified as rare 

(e.g. a small population and/or confined to one or two sites in Northern Ireland) with Northern 

Ireland being a stronghold consisting of either >50% Irish population and >20% UK population. 


Not known. 

Distribution 

Originally recorded from 400m in the Skager Rak, Sweden (2 specimens). Until recently the only 

other record was from Rathlin Island, Northern Ireland, but recently it has also been recorded from 

deep water reefs at Mingulay. 


Only previously known from Rathlin Island (one record from the White Cliffs). 


This species was originally known in Northern Ireland from only one record from Rathlin Island. 

Despite intensive sampling this species was not recorded during the Sponge Biodiversity of Rathlin 

Island Project. During SSNI, one sample was taken from Rathlin and three further samples from 

the Maidens. This indicates that the Maidens may be the Northern Ireland stronghold for this 

species. We recommend that further sampling on the Maidens be undertaken to establish the status 

of this species. In view of the importance of the Maidens for this and other priority species we 

recommend the area be further investigated and consideration given to its designation as an SAC. 

References 



Alander, H. 1942 Sponges from the Swedish west-coast and adjacent waters. Henrik Struves Boktryckeri, 

Göteborg 

77


Picton. B.E. & Goodwin, C.E. 2007 Sponge Biodiversity of Rathlin Island. Project Report. Ulster Museum, 

Belfast 



Soest, R.W.M. van 2006 Report on the Porifera of Mingulay. In C. Maier (ed.). Biology and ecosystem 

functioning of cold water coral bioherms at Mingulay (Hebrides), NE Atlantic, pp. 25-29. Cruise Report, 

BIOSYS 2006 Cruise 64PE250 on R/V Pelagia Oban-Oban 7-23rd July 2006. Royal Netherlands Institute for 

Sea Research, the Netherlands 

78


Halecium plumosum Hincks 1868 - a hydroid 

Description 

Forms a straggly colony similar to Sertularia argentea. A stout central stem with a loosely pinnate 

arrangement of gently curving side branches. The branches may be forked at the end, giving the 

colony a bushy appearance. 


There is some debate as to whether this species and H. sessile Norman, 1867 are separate species. 

It has been proposed that H. plumosum as described by Hincks (1868) is merely a large growth 

form of H. sessile (Cornelius 1975, 1995). The similarity between H. sessile and H. plumosum was 

also noted by Storm (1882) and Christiansen (1972). After Cornelius’ revision of the Haleciidae, 

the two species are regarded as synonyms and H. plumosum should now be referred to as H. sessile. 

However, we believe that further work is necessary to confirm this, and consequently have retained 

the original name here. 

Cornelius (1975) noted that the mode of branching, structure of the hydrothecae, manner of 

hydrothecal renovation and possession of and annular thickening of H. sessile and H. plumosum 

were similar (although this was not based on examination of the type specimens and needs 

confirmation). The main difference between the species is in the growth form; Hincks (1868) 

describes H. plumosum as tall and slender with branches tapering to a point, attaining a length of up 

to 6 inches. H. sessile is described as a slender irregularly branching colony up to 1 ½ inches in 

length. H. plumosum was originally described from Ireland (from a specimen held by Trinity 

College Dublin), and H. sessile from deepwater in the Minch. Cornelius (1995) notes that larger 

specimens, as described by Hincks (1868) are seldom reported, whereas this is the dominant 

growth form encountered in Northern Ireland. We recommend that the taxonomy of H. sessile and 

H. plumosum be revised, including re-examination of the type specimens and molecular and 

taxonomic analyses of fresh material, preferably from the type locality. There is a re-description of 

H. sessile in Ramil & Vervoort (1992). 

Habitat 

This hydroid is usually found in the circalittoral zone, in areas of moderate tidal streams, attached 

to bedrock, boulders, shells and wrecks. 


Rare with the Northern Ireland population comprising >50% Irish population and >20% UK 

population. 

79



Not known. 

Distribution 

Records from the west and northern coasts of Scotland, including Loch Moidart, Loch Tarbert and 

North Solway (MNCR, B.E. Picton); Loch Eribol (Seasearch), Pembrokeshire (PMSA, B.E. 

Picton), Calf of Man, Isle of Man (B.E. Picton), Donegal Bay (B.E. Picton). 


Records from the Lochgarry off Rathlin Island, Co. Antrim and Russell Rock, Maidens (BioMar). 


The species was re-recorded at the NISS sites, and records from several additional locations were 

made. H. plumosum was recorded from all coasts of Rathlin (Lochgarry, White Cliffs, Picton’s 

Reef, Illancarragh Bay), from Russell’s Rock on the Maidens, Carlingford Lough and from two 

sites in Strangford Lough. At several of these sites it was common. In view of these findings it 

cannot be classified as rare in Northern Ireland, and could be removed from the NICP list. 

In view of the uncertain taxonomic status of this species, we recommend that the taxonomy of H. 

sessile and H. plumosum be revised, including re-examination of the type specimens and molecular 

and taxonomic analyses of fresh material, preferably from the type locality. 

References 

Christiansen, B.O. 1972 The hydroid fauna of the Oslo Fjord in Norway. Norwegian Journal of Zoology 20: 

279-310 

Cornelius, P.F.S. 1975 A revision of the species of Lafoeidae and Haleciidae (Coelenterata: Hydroida) 

recorded from Britain and nearby seas. Bulletin of the British Museum (Natural History) Zoology 28 (8): 376- 

426 

Cornelius, P.F.S. 1995 North-West European Thecate Hydroids and their Medusae. Part 1: Laodiceidae to 

Haleciidae. Synopses of the British Fauna (New Series). R.S.K. Barnes & J.H. Crothers (eds), no. 50. Field 

Studies Council 

Hincks, T. 1868 A history of the British Hydroid zoophytes. Two volumes. London 

Picton, B.E. & Morrow, C.C. 2007 Halecium plumosum. [In] Encyclopedia of Marine Life of Britain and 

Ireland: http://www.habitas.org.uk/marinelife/species.asp?item=D5300 

Ramil, F. & W. Vervoort 1992 Report on the Hydroidea collected by the “BALGIM” expedition in and 

around the Strait of Gibraltar: 1-262, figs 1-68, tables 1-83 Zoologische Verhandelingen 277: 3–262 

Storm, V. 1882 Bidrag til Kundskab om Trondhejmsfjordens Fauna. IV. Om de I Fjorden forekomme 

hydroide Zoophyter. Kongelige Norske Videnskabernes Selskabs Skrifter (1881) 1: 1-21 

80


Lytocarpia myriophyllum (Linnaeus, 1758) - a hydroid 

Description 

A tall feather like colony with the branches angled approx 60 degrees to the stem, giving a vshaped 

form. There are bract-like structures on the main stem. Colony height can be up to 300mm 

in the British Isles, reportedly up to 1m in the Mediterranean (Cornelius 1995). The worm-like 

caudofoveate mollusc Nematomenia banyulensis is frequently found coiled round the base of the 

stems of this species. 


None; a much larger hydroid than Gymnangium montagui or the Aglaophenia species, which are 

other feather shaped hydroids found in the NE Atlantic. 

Habitat 

Normally found in deep water, below 25 metres, in semi-sheltered sites with moderate tidal 

streams. Occurs mainly below 80m in Brittany, recorded down to 1200m in the South Atlantic and 

1592m near the Strait of Gibraltar (Cornelius 1995). Found on substrates from gravel to silt 

(Cornelius 1995). 


Rare - a small population and/or confined to one or two sites in Northern Ireland) with Northern 

Ireland being a stronghold consisting of >50% Irish population and >20% UK population. Has 

undergone rapid decline in Northern Ireland (2% per year over the last 25 years). 


The main threat to this species is scallop dredging which, since 1986, has altered the habitat where 

the main populations live. 

Distribution 

Widespread in eastern North Atlantic Ocean, from Guinea Bissau and Liberia north to northern 

Norway and Iceland, on American coasts from Davis Strait to New England, and around the 

Falkland Islands and Magellan Straits. Also reported from the Pacific but this might be a different 

sub-species (Cornelius 1995). 

All coasts of the British Isles apart from the eastern English Channel and southern North Sea 

(Cornelius 1995). Most recent records from the western coasts of the British Isles, but distribution 

very localised. Frequent amongst islands in SW Scotland (Loch Linnhe, Loch Sunart, Loch 

Seaforth, Loch Craignish, Loch Crinan, Firth of Lorn), also present in the Outer Hebrides (BE 

81


Picton, MNCR). Elsewhere in Britain recorded from the Scilly Isles (B.E. Picton, MNCR), Isle of 

Man (MBA), Skomer, Wales (Seasearch), and Celtic Sea (Hartley, 1979). Present all around 

Ireland, but most records from Northern Ireland, and County Cork and Kerry (BioMar), others 

from Galway and Dublin (BioMar, B.E. Picton). 


Recorded from the South Down Coast (Strangford Lough to Carlingford Lough), the Maidens and 

Rathlin Island. The majority of the records are clustered on the south and east coasts of Rathlin 

Island. 


Recorded during SSNI from the Maidens, and the east and south coasts of Rathlin. 

We recommend that the east coast of Rathlin be protected from further dredge damage by the 

creation of a mobile gear exclusion zone around the SAC. In view of the importance of the 

Maidens for this and other priority species, we recommend the area be further investigated and 

consideration given to its designation as an SAC. 

References 

Cornelius, P.F.S. 1995 North-West European Thecate Hydroids and their Medusae. Part 2: Sertulariidae to 

Campanulariidae. Synopses of the British Fauna (New Series). R.S.K. Barnes & J.H. Crothers (eds), no. 50. 

Field Studies Council 

Hartley, J.P. 1979 On the offshore Mollusca of the Celtic Sea. Journal of the Conchological Society of Great 

Britain & Ireland, London 30: 81-92 



Picton, B.E. & Morrow, C.C. 2007 Lytocarpia myriophyllum. [In] Encyclopedia of Marine Life of Britain 

and Ireland: http://www.habitas.org.uk/marinelife/species.asp?item=D5660 

82


Polyplumaria flabellata G O Sars, 1874 – Lacy hydroid 

Description 

A fan-like hydroid with irregularly branching main stems, and regular side branches arising in 

opposite pairs from the main stem. The main stem and secondary branches bear short, regular 

tertiary branches. The hydrothecae are arranged on the upper edge of the tertiary branches. They 

are tubular in shape with a smooth outer margin, and are surrounded by four smaller, defensive 

polyps, one on either side, and one above and below. The gonothecae are arranged on short 

pedicels. They are roughly oval shaped, and have a wide aperture. The capsule tapers towards the 

base and is surrounded by four small, defensive polyps, located in the basal region. Typically 

70mm with side branches 10mm in length. Colonies produce gonothecae in early summer and 

presumably release planktonic larvae. No other details known. 


One similar species exists in almost the same habitat, but is more common. It is Polyplumaria 

frutescens (formerly Schizotricha frutescens). It differs in not having the regular, opposite, 

secondary branching of the colony and having longer tertiary branches bearing the polyps. 

Habitat 

Offshore into deepwater, occurs from approximately 30m to at least 1378m (Cornelius 1995). 


Declining and scarce with Northern Ireland being a stronghold consisting of over 50 per cent of the 

Irish population and over 20 per cent of the UK population. 




Distribution 

Records few and patchy, despite its distinctive appearance. Cornelius (1995) stated that this might 

be a true reflection of its distribution. Widespread in the Eastern Atlantic from Morocco and the 

Azores to Norway and Iceland. Most records from the western British Isles; historically recorded 

from Scotland, the Shetlands, Plymouth, Scilly and the North Sea, but probably rare in the latter 

(Cornelius 1995). Recent records from Coverack (Devon), Sound of Mull and Sarn-y-bwch 

Cardigan Bay (MNCR), Scilly Isles and Brittany (B.E. Picton). The Cardigan Bay record is very 

shallow for this species (11.4-12m), but the original form was checked to rule out errors in data 

processing and the species is listed. This site would merit resurveying. 

83



Populations of this species occur on the east coast of Rathlin Island and at the Maidens near Larne, 

on the Antrim coast. It was recently recorded in 2005 from East Maiden and West Maiden during a 

Seasearch survey (Goodwin 2007). The main stronghold for this species in Northern Ireland was 

the east coast of Rathlin Island where it was quite common in 30-50m depth attached to boulders 

on a stable gravel seabed. This area has changed considerably since 1986, and when visited in 2005 

by divers and a Remote Operated Vehicle (ROV) it was found that the boulders have mostly been 

removed, presumably by scallop dredging activities (Picton & Goodwin 2007). 


Several records were made from the east coast of Rathlin. The areas where this species was most 

abundant were Picton’s Reef and a deepwater boulder slope (40-50m). It was also recorded from 

Damicornis Bay on the south coast. Several records were made from the Maidens. At some sites 

this species together with Diphasia spp. formed dense hydroid forests. 





References 




Erwin, D.G., Picton, B.E., Connor, D.W., Howson, C.M., Gilleece, P. & Bogues, M.J. 1990 Inshore Marine 

Life of Northern Ireland. Ulster Museum & HMSO, Belfast 

Goodwin, C.E. 2007 Isle of Muck and Maidens Survey, a Seasearch survey summary report. Seasearch 

Northern Ireland. Available from: 

http://www.seasearch.co.uk/NorthernIreland/Muck%20and%20Maidens%202005-2006%20Seasearch% 

20NI.pdf 

Picton, B.E. 2007 Polyplumaria flabellata – a hydroid. Northern Ireland Priority Species Reports [online]. 

Cultra: National Museums Northern Ireland [cited 15/02/2008]. Available from: 



Association of the United Kingdom 87(6): 1441-1458 

Picton, B.E. & Morrow, C.C. 2007 Polyplumaria flabellata. [In] Encyclopedia of Marine Life of Britain and 


84


55.0N 

2006-7 SSNI records 

2005 Rathlin BSP records 

Previous records 

Diphasia alata (Hincks 1855) – a hydroid 

6.5W 6.0W 

Species description 

A reddish brown hydroid. The colony is pinnate 

with the main stem straight and thick, and the side 

branches alternate. The side branches increase in 

length towards the colony’s base, giving a 

triangular outline to the apex of the colony. The 

hydrothecae are arranged in opposite pairs and are 

attached to the side branches for about two-thirds of their length. The outer rim of the hydrotheca is 

smooth and flared, and there is a single, rounded opercular flap. Both the male and female 

gonothecae are small, quadrangular in shape and taper towards the base. Each ‘corner’ of the 

capsule forms a projection which curves inwards towards the centre of the theca. The colour of the 

colony in life is a distinctive chocolate brown. A colony is typically 100-130mm in height by 

60mm in width. Colonies produce gonothecae in early summer and presumably release planktonic 

larvae. No other details known. 


Several other smaller Diphasia species exist in almost the same habitat. Diphasia pinaster has a 

main stem hardly differentiated from the side branches and Diphasia alata is dark brown in life. 

Why is it a priority in Northern Ireland? 

Rapid decline with Northern Ireland being both the Irish and UK stronghold. Rare - confined to a 

small population of one or two sites in Northern Ireland. 




Distribution 

In the UK, known from scattered records from Shetland, Hebrides, Firth of Lorn, Argyll, Cornwall 

and Devon (Cornelius 1995). Widely distributed across Europe from Norway to the Azores, 

including the Western Mediterranean (Cornelius 1995). Cornelius (1995) speculates that there may 

be few records because the depth range it inhabits is mostly deeper than the range of SCUBA but 

shallower than that sampled by offshore studies. 


Populations of this species occur on the east coast of Rathlin Island and at the Maidens near Larne, 

on the Antrim coast. The main stronghold for this species in Northern Ireland was the east coast of 

Rathlin Island where it was quite common in 30-40m depth attached to boulders on a stable gravel 

seabed. This area has changed considerably since 1986. Scallop dredging damage was first noted in 

85


1986. When visited in 2005 by divers and a Remote Operated Vehicle (ROV), it was found that the 

boulders have mostly been removed, presumably by scallop dredging activities (Picton & Goodwin 

2007). 


The sites on the east coast of Rathlin at which this species was originally recorded have largely 

been altered by dredging and at many of these it is no longer present. However, it is still present on 

the east coast in other locations. The majority of records from this survey are from an area of 

bedrock midway along the coast termed “Picton’s reef”, around the Lochgarry wreck, and on a 

steeper deeper area of boulder slope 40-50m in depth offshore of the Lochgarry. There are also 

several sites on the Maidens at which this species is abundant. 





References 


Campanulariidae. Synopses of the British Fauna (New Series), R.S.K. Barnes & J.H. Crothers (eds), no. 50. 


Erwin, D.G., Picton, B.E., Connor, D.W., Howson, C.M., Gilleece, P. & M.J. Bogues 1990 Inshore Marine 


Picton, B.E. 2007 Diphasia alata – a hydroid. Northern Ireland Priority Species Reports [online]. Cultra: 

National Museums Northern Ireland [cited 15/02/2008]. Available from: 




Picton, B.E. & Morrow, C.C. 2007 Diphasia alata. [In] Encyclopedia of Marine Life of Britain and Ireland: 

http://www.habitas.org.uk/marinelife/species.asp?item=D6370 

86


Diphasia nigra (Pallas, 1766) - Black hydroid 

Description 

The hydroid stage is a very large (to around 20cm). The colony is branched in one plane, giving a 

robust, feather-like form. It is yellow or straw-coloured in life. Cornelius (1995) states that it is 

sometimes said to be deep red, but this is probably an artifact of preservation. When preserved or 

dried it turns black, which is the origin of its latin name. The main stem is un-branched; regular 

side branches arise from this alternately in a single plane. The hydrothecae are arranged in opposite 

pairs and are attached to the stem and side branches for about four-fifths of their length. The outer 

rim of the hydrotheca is smooth and flared and there is a single, rounded opercular flap. Both the 

male and female gonothecae are large, quadrangular in shape and taper towards the base. Each 

‘corner’ of the capsule forms a projection which curves inwards towards the centre of the theca. 

Typically 70mm with side branches 10mm in length. Colonies produce gonothecae in early 

summer and presumably release planktonic larvae. No other details known. 


Several other smaller Diphasia species exist in almost the same habitat. Diphasia pinaster has a 

main stem hardly differentiated from the side branches and Diphasia alata is dark brown in life. 


Rapid decline with Northern Ireland being both a UK and Irish stronghold. Rare - confined to a 

small population at one or two sites in Northern Ireland. 




Distribution 

Known from a restricted area of the temperate North-East Atlantic. There are very few records 

from the UK and Ireland. Recorded from SW England (Pallas 1766; Hincks 1868; Marine 

Biological Association 1957), NW France (Teissier 1965) and Brittany (Fey 1969; unpublished 

records B. Picton 1986). It was recorded from the Netherlands in the 18 th and 19 th centuries but 

authentic material is lacking and it has not been recently recorded (Cornelius 1979). Occurs mainly 

in deep water; records from c. 80m in the western English Channel (Cornelius 1979), although 

there are records from slightly shallower water between 30m and 50m from Brittany and Rathlin 

(B. Picton, unpublished data). ROV footage from deepwater off the Scillies showed communities 

of hydroids (including possibly D. nigra, together with D. alata and possibly D. rosacea, also P. 

flabellata and P. frutescens) (Paul Somerfield pers. comm.). The species has recently been 

recorded from several sites in the Firth of Lorn during the Ulster Museum ‘Sponge UK’ project. 

There are records of D. nigra from Northumberland on the MNCR survey database which have 

87


been transposed onto the National Biodiversity Network. However in the original report (Connor 

1989) Thuiaria fusca is listed but there is no record of D. nigra. T. fusca (now Selaginopsis fusca) 

was briefly erroneously synonomised with D. nigra by Cornelius, probably resulting in erroneous 

entry of these species records into the database as D. nigra. Consequently these records should be 

re-allocated to Selaginopsis fusca. 


This species was known from only two records, both on the east coast of Rathlin east of the 

Lochgarry wreck. One of these sites is 38-42m, the other 46-50m in depth; in both cases the 

hydroids were attached to boulders on a stable gravel seabed. This area has changed considerably 

since 1986, and when visited in 2005 by divers and a Remote Operated Vehicle (ROV) it was 

found that the boulders have mostly been removed, presumably by scallop dredging activities 

(Picton & Goodwin, 2007) and this hydroid was not seen. 


Dives during the SSNI failed to obtain records from the sites on Rathlin’s east coast where it was 

originally recorded. However, it was present in deeper water (>40m) on a steeper boulder slope 

which appear not to have been damaged and also on Picton’s Reef, a bedrock outcrop midway up 

the coast. Four further records were made from the Maidens: NW of W Maiden, W of East Maiden, 

NE of E Maiden and SE of the Sheafing Rock. 





References 

Connor, D.W. 1989 Marine Biological Survey of Berwick to Beadnell including the Farne Islands. Marine 

Nature Conservation Review. Nature Conservancy Council. Peterborough 

Cornelius, P.F.S. 1979 A revision of the species of Sertulariidae (Coelenterata, Hydroida) recorded from 

Britain and nearby seas. Bulletin of the British Museum (Natural History) (Zoology Series) 34: 243-321 




Fey, A. 1969 Peuplements sessiles de l’archipel de Glénan. I. Inventaire: hydraires. Vie Milieu. (B) 20:387- 

413 

Hincks, T. 1868 A history of the British Hydroid zoophytes. Two volumes. London 

Pallas, P.S. 1766 Elenchus zoophytorum. The Hague, F. Varrentrapp, pp. i-xxviii, 1-451 

Marine Biological Association 1957 Plymouth Marine Fauna, third edition. Plymouth, England. 

Picton, B.E. 2007 Priority species account for Diphasia nigra, a hydroid. 




Teissier, G. 1965 Inventaire de la Faune Marine de Roscoff. Cnidaires-cténaires. Roscoff, France 

88


Virgularia mirabilis (O F Müller, 1776) - Slender sea pen 

Description 

Forms elongated, very slender colonies with narrow ‘leaves’ bearing polyps. Colour yellowish or 

whitish; capable of luminescence in darkness. Up to 600mm long with central stem only a few mm 

thick. All sea-pens possess an internal calcareous skeletal rod (axis): in this species it is round in 

section and often protrudes from the top of the colony. 


Only the tall sea pen Funiculina quadrangularis is similar, but its polyps are not arranged in 

‘leaves’, and its axis is square in section. 

Habitat 

Lives embedded in mud or fine sand, into which it can withdraw. Occurs in sheltered localities in 

depths greater than about 5m. 


This species is a component of the BAP habitat ‘mud habitats in deep water’ (mud deeper than 20- 

30m). It is easily killed by any type of bottom-fishing, and has been eradicated in many areas 

where it was previously abundant. 


Organic pollution and trawling for Nephrops norvegicus are thought to be the human activities 

most likely to affect the biotope of which this species is a component (Hughes 1998). However, 

Virgularia mirabilis is less likely to be damaged by trawling than other sea pens, as it is able to 

withdraw rapidly into the sediment. It can also re-anchor in the sediment if dislodged by trawling 

(Hughes 1998; Tuck et al. 1998). Sea pens may also move to avoid fishing gear. Eno et al. (1996) 

found that sea pens bent away from lobster pots dropping on top of them in a passive response to 

the pressure wave travelling ahead of the dropping pot. 

Distribution 

Generally distributed around western Europe and in the north Atlantic, also in the Mediterranean. 

Occurs on all coasts of Britain and Ireland, locally abundant in sea lochs and other sheltered inlets; 

major UK populations on west coast of Scotland where these habitats abound (MNCR, Hill & 

Wilson 2000; Greathead et al. 2007). 

89



Recorded from all NI coasts, but main Northern Ireland populations in Strangford Lough and 

Carlingford Lough (BioMar, Seasearch, Professional survey data). The populations in Strangford 

Lough are reported to be some of the best examples of seapen biotope in the UK (Hughes 1998), 

but most of the seapens we observed were very small and the individuals very scattered. 


The populations in Carlingford Lough were resurveyed and found to be in good condition. Several 

records were also made from Strangford Lough, although populations are less dense here. Around 

Black Rock in Strangford it was observed that in shallow water all individuals were very small 

(


Arachnanthus sarsi Carlgren, 1912 

– Spotted burrowing anemone 

Description 

A large cerianthid anemone (the column measures approximately 20cm by 1.5cm). Approximately 

30-34 tentacles, each ~10cm in length, surround the edge of the disk. These are distinctively 

marked with greyish spots on a brown background. The labial (central) tentacles are much shorter 

and point inwards and upwards to form a cone. 

It has been proposed by Carlgren (1912) and Picton and Manuel (1985) that A. sarsi is the adult 

stage of A. albida Sars 1846, a cerianthid anemone known only from its larval form; see Picton and 

Manuel (1985) for discussion. There have been records of A. albida in the plankton of western 

regions since 1841 (Picton & Manuel 1985), as well as from Valencia Harbour (Fowler 1897, in 

Browne 1899) and more recently from Teelin Harbour in Donegal (B. McCullough pers. comm.). 

There are no observations confirming the link between the larval phase and the adult (Picton & 

Manuel 1985); molecular work would be useful in determining this relationship. 


The only other species of cerianthid anemone recorded in Northern Ireland is the common 

burrowing anemone Cerianthus lloydii Gosse. This is much smaller in size and the tentacles do not 

have the distinctive colouring present in A. sarsi. 

Habitat 

Most previous records have been from muddy gravel or mud (Picton & Manuel 1985; Picton & 

Costello 1998). Some of the SSNI records were from less muddy substrate (sand/gravel mixes). 

The anemones live in a tube which runs vertically into the substratum for about 25cm, then 

horizontally for at least 40cm (Picton & Manuel 1985). 

There are reports of one individual from Shetland, which was monitored on regular survey visits, 

disappearing from view between September and May the following year (L. Ruthven pers. comm.). 

This indicates that A. sarsi may hibernate in a similar manner to some species of holothurians. As 

this could have implications for survey of populations, it merits further investigation. 

Why is it a priority in Northern Ireland? 

Declining in Northern Ireland. Rare with Northern Ireland populations comprising 50% Irish 

population and >20% UK population. Recently added to the UK BAP species list (June 2007). 


This species is vulnerable to damage if its habitat is disturbed. Mobile fishing gear is likely to have 

a significant impact. 

91


Distribution 

Originally described from Norway in 1901 from a damaged dredged specimen, lacking the 

uppermost part of the body (Carlgren 1912). It was recorded for the first time since the original 

description from Scotland in 1981 (Picton and Manuel 1985), and has since been recorded from 

other locations on the west coast of Scotland, Lundy and from Rathlin Island, Northern Ireland. 

There are probable records from Lundy Island (I. Reach pers. comm.); 3-5 individuals were 

recorded, situated under the jetty (probably nocturnal as not observed on frequent dives in the 

daytime at the same site). However, it was not possible to collect samples or photograph the 

individuals to confirm identification. On subsequent visits the anemones were not observed and 

seem to have been eliminated by sediment scouring. The location would seem quite southerly given 

the known distribution of A. sarsi. An as yet unidentified Arachnanthus species was recorded from 

Ushant by B.E. Picton (unpublished data). It is similar in form to A. sarsi but much smaller and 

white in colour. 

Records for Arachnanthus sarsi from the UK and Ireland 

Record Country Date Position 

Malin Beg Harbour, 

Donegal 

E of Black Head, 


White Cliffs, S Coast, 


Ireland 11/84 54° 39.78’N 

08° 47.24’W 

Northern Ireland 10/06/83 55° 17.40’N 

06° 15.32’W 

Northern Ireland 04/07/85 55° 17.57’N 

06° 14.38’W 

Meall Eatharna, Coll Scotland 24/06/81 56° 37.40’N 

06° 30.50’W 

Rubha Deireas, Lunga Scotland 13/07/82 56° 13.00’N 

05° 42.80’W 

E of Eilean Dubh Scotland 16/07/82 56° 13.00’N 

Beag, Firth of Lorn 

05° 42.76’W 

Soay Sound, Skye Scotland 25/07/82 57° 10.10’N 

06° 10.50’W 

Loch Seaforth, Lewis Scotland 29/07/88 57° 57.3’N 

06° 42.5’W 

Canna, Hebrides Scotland 20/06/93 57° 03.5’N 

06° 29.1’W 

Village Bay, Hirta, St Scotland 24/08/85 57° 48.570’N 

Kilda 

08° 33.890’W 

Eilean Dubh Mor Scotland Jun-00 ~56° 13’N 

(just NW of Lunga) 

05° 43’W 

Eilean Dubh Beag, Scotland 06/05/91 56° 14.005’N 

Firth of Lorn 

05° 43.604’W 

Lunna Ness, Shetland Scotland 12/08/98 60° 24.1’N 

01° 07.1’W 

* Subsequently revisited and photographed by C. & L. Ruthen. 

92 

Depth 

(metres) Recorder 

9-10 B.E. Picton 

20-24 C.M. Howson 

35-39 B.E. Picton, C.M. 

Howson 

36 B.E. Picton 


10-18 B.E. Picton 

28 G. Brown 

25-40 MNCR (C. Maggs) 

26.5-34.5 MNCR (F. Fortune) 


R. Holt 

20 J. Anderson 

21 J. Moore, B. 

James* 


Known from two records from the White Cliffs on the south side of Rathlin Island. Both records 

were taken on night dives, indicating that this species might be nocturnal. 


Several more records were made of this species on the south coast of Rathlin. The initial records 

were made during a night dive (2006), but subsequently it was also recorded during the day, 

indicating that it is not nocturnal. Elsewhere in the UK it has also been recorded during daylight. 

The Rathlin population represents the entirety of the Northern Ireland population. At present it is


very vulnerable to damage by scallop dredging; currently Church Bay is regularly fished by scallop 

dredgers, particularly when poor weather prevents fishing elsewhere. There is no legislation 

currently in place to prevent this fishing. J. Breen (NIEA) has been in discussion with local 

fishermen and has succeeded in negotiating a voluntary ban on fishing here. However, this does not 

prevent boats from elsewhere fishing in this area. We recommend that a ban on fishing be 

implemented as a matter of urgency. 

References 

Carlgren, O. 1912 Ceriantharia. Danish Ingolf-Expedition 5 (3): 1-76 

Browne, E.T. 1899 Part 1. The Pelagic fauna. [In] The Fauna and Flora of Valencia Harbour on the West 

Coast of Ireland. Proceedings of the Royal Irish Academy (Series III) 5: 667-693 

Picton, B.E. & Costello, M.J. 1998 BioMar biotope viewer: a guide to marine habitats, fauna and flora of 


Picton, B.E. & Manuel, R.L. 1985 Arachnanthus sarsi Carlgren, 1912: a re-description of a cerianthid 

anemone new to the British Isles. Zoological Journal of the Linnean Society 83: 343-349 

Picton, B.E. & Morrow, C.C. 2007 Arachnanthus sarsi. [In] Encyclopedia of Marine Life of Britain and 


Wilson, E. 1999 Arachnanthus sarsi. A sea anemone. Marine Life Information Network: Biology and 

Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the 

United Kingdom [cited 11/01/2007]. Available from: 

http://www.marlin.ac.uk/species/Arachnanthussarsi.htm 

93


Parazoanthus axinellae (Schmidt, 1862) 

- Yellow cluster anemone 

Description 

This sea anemone is colonial, forming encrustations of variable thickness and shape. Each polyp 

has a serrated parapet and pointed tentacles of moderate length; the wall and base may be encrusted 

with sand. There are up to 34 tentacles, polyps are up to 20mm tall. The colour is usually yellow, 

often orange around mouth. 


Parazoanthus axinellae and the white cluster anemone P. anguicomus are distinguishable by 

tentacle numbers, size and colour. Parazoanthus axinellae forms discrete clumps while 

Parazoanthus anguicomus tends to form more extensive sheets. Larger and different in colour from 

the ginger tiny anemone Isozoanthus sulcatus and the sandy creeplet anemone Epizoanthus couchii. 

Habitat 

Found in open coast rocky habitats attached to rocks, also on sponges and other organic substrates 

(Manuel 1988), often on vertical faces or beneath overhangs, from 6-100m depth. 



Ireland being a stronghold consisting of >20% UK population/range. 


A southern species at the northern extent of its range in Northern Ireland, it could be affected by 

climate change. 

Distribution 

A southern species, common in the Mediterranean and southern coast of Europe and extending into 

the British Isles (Manuel 1988). Quite common on the south-west coasts of Britain: records from 

Lundy, the Scilly Isles, Pembrokeshire and the Bardsey peninsula in Wales, and the north and south 

coasts of Devon and Cornwall. The eastern UK limit appears to be Lyme Bay in Dorset (MNCR, 

Seasearch, MBA, PMSA, CCW). Also known from a few locations on the west coast of Ireland 

(Donegal Bay, Achill Island, the Aran Islands, and Kinsale Head, Cork (BioMar)). Records from 

Rathlin Island and Scotland represent the northern extent of its range in the British Isles. In 

Northern Ireland, it is known only from Rathlin Island (BioMar). There are two Scottish records 

one from St Kilda (MNCR), and one from Sgeirean Dubha, Firth of Lorn (Seasearch). 

94



Only known from Rathlin Island, from a few sites on the north-west coast (Ruecallan, Derginan 

Point, Farganlack Point). 


Recorded from sites on the north coast where previously known to occur. One new record from 

east coast (east of Illancarragh Bay, a deepwater (40-50m) steep boulder slope with a rich sponge 

and hydroid community). This east coast site is vulnerable to dredging damage. We recommend 

that the east coast of Rathlin be protected from further dredge damage by the creation of a mobile 

gear exclusion zone around the SAC. 

References 

Manuel, R.L. 1988 British Anthozoa (Coelenterata: Octocorallia & Hexacorallia). Synopses of the British 

Fauna (New Series), D.M. Kermack & R.S.K. Barnes (eds), no. 18. Linnean Society of London and The 

Estuarine and Brackish-water Sciences Association, Leiden 



Picton, B.E. & Morrow, C.C. 2007 Parazoanthus axinellae. [In] Encyclopedia of Marine Life of Britain and 


95


Anemonactis mazeli Jourdan, 1880 

– a burrowing anemone 

Species description 

This burrowing sea anemone has a fairly elongate column with a rounded base, sometimes 

encrusted with sand. There are 20 stout, cylindrical tentacles, each with a constriction near the tip, 

forming a terminal knob. The disc has dark radial lines on cream or orange background; the 

tentacles are translucent, cream or orange, more or less speckled with cream or brown. Other 

variations probably occur. Size is up to 60mm across tentacles, column up to 120mm in length. It is 

unlikely to be confused with other species. However there is a possibility that the specimen 

collected in Strangford Lough and those from Scandinavia are a different species to the ones from 

Plymouth southwards. 


Can be distinguished from other anemones by the distinctive form of its tentacles. 

Habitat 

Burrows in sand or mud, always offshore from 5-1000m depth. 


Declining, and Rare with the Northern Ireland record comprising >50% Irish population and >20% 

UK population. 


Not known. 

Distribution 

Occasional in English Channel, Irish Sea, and off southwest Ireland. Also from Scandinavia, Bay 

of Biscay, and the Mediterranean (Manuel 1988). 


One previous record from Northern Ireland from Bird Island Passage, Strangford Lough (Picton, 

1985). 


The site within Bird Island Passage where an individual was originally recorded was resurveyed. 

However, no further records were made from here or elsewhere. The habitat at the Bird Island 

passage site appears to have altered substantially since the original record was made in 1980. The 

habitat was then described as a ‘Flat sea bed covered with shells (Venerupis; Chlamys) fine muddy 

96


sand on surface and oozy mud beneath.’ The survey dives in 2007 recorded soft mud with some 

dead shell, there was no layer of sand and the site appeared very heavily silted. It is possible that 

this site has been affected by the damage to the horse mussel beds and eutrophication of the lough. 

References 

Erwin, D.G., Picton, B.E., Connor, D.W., Howson, C.M. Gilleece, P. & M.J. Bogues 1986 The Northern 





Picton, B.E. 1985 Anthozoans (Coelenterata: Anthozoa) new to Ireland and new records of some rarely 

recorded species. Irish Naturalist’s Journal 21 (11): 484-488 

Picton, B.E. & Morrow, C.C. 2007 Anemonactis mazeli. [In] Encyclopedia of Marine Life of Britain and 


Wilson, E. 2004 Anemonactis mazeli. A sea anemone. Marine Life Information Network: Biology and 



http://www.marlin.ac.uk/species/Anemonactismazeli.htm 

97


Edwardsia timida de Quatrefages, 1842 

- a worm anemone 

Description 

This burrowing sea anemone has an elongated and worm-like column which is divided into a 

scapus and scapulus. The scapus has a soft, adherent cuticle and a naked rounded base. There are 

16-32 tentacles, arranged in three cycles with four in the primary cycle. The colour of the disc, 

tentacles and scapulus is translucent pale orange, usually patterned with opaque white or cream, 

tentacles plain or with white tips. The column is up to 70mm long and 5mm diameter, span of 

tentacles to 40mm (see Manuel 1977 for re-description). It is oviparous with the eggs hatching into 

planula larvae which develop into small anemones in two months. 


There are several other small burrowing anemones but all the others have fewer than 20 tentacles 

apart from Edwardsiella carnea, but this species lives in rock crevices or borings in limestone and 

is not buried free in gravel. 

Habitat 

Burrows in sand or gravel in the infralittoral and shallow sublittoral. Where present may be 

abundant. 


Rare - confined to a small population of one or two sites in Northern Ireland with Northern Ireland 

being a stronghold consisting of over 20 per cent of the UK population/range. 


Damage to habitat. 

Distribution 

Recorded from Loch Creran, Loch Feochan, and Loch Tarbert in Scotland; the Calf of Man on the 

Isle of Man; Plas Newydd in the Menai Straits (MNCR data); and the Scilly Isles (Manuel 1988). 

The type locality is Northern France. 


In Northern Ireland, this species is found only in Strangford Lough - originally reported from 

Ballyhenry Island by Williams (1954). There is another record on the BioMar database from 

Church Bay, but re-examination of the photographs indicate that it is a different, as yet 

unidentified, Edwardsia species. The only other Irish locality at Malahide (Dixon 1886) has been 

severely altered and the species has not been found there for many years. 

98



Attempts were made to locate the Ballyhenry Island populations while diving in order to obtain 

photographs of them in their natural state. However, the sites where they occur are behind a large 

rock, known locally as Selk Rock, and proved difficult to access while diving. Several samples 

were obtained during a subsequent shore collection from this area. The habitat is very variable, 

ranging from fine mud to sandy gravel. E. timida appeared to be most frequent in muddy gravel 

amongst boulders. Other species present included Halcampa chrysanthellum, another burrowing 

sea anemone. The population appears to be in good condition. Sites in Church Bay on Rathlin were 

dived to look for E. timida, including the sites at which the unidentified Edwardsia species was 

recorded, but no further records were made. 

The Ballyhenry Island site is currently used for fieldwork on Queens University Field Courses. The 

impact of this work on the E. timida at the site should be examined and if necessary measures 

should be taken to restrict this. However, this fieldwork has been ongoing at the site for many years 

and does not yet seem to have had any effect. 

References 

Dixon, G.Y. 1886 Notes on two Irish specimens of Edwardsia timida (Quatrefages). Scientific Proceedings 

of the Royal Dublin Society 5: 100-106 



Erwin, D.G., Picton, B.E., Connor, D.W., Howson, C.M., Gilleece, P. & Bogues, M.J. 1990 Inshore Marine 


Manuel, R.L. 1977 A re-description of Edwardsia beautempsi and E. timida (Actinaria: Edwardsidae). 

Cahiers de Biologie Marine 18: 483-497 




Picton, B.E. 2007 Edwardsia timida – worm anemone. Northern Ireland Priority Species Reports [online]. 





Picton, B.E. & Morrow, C.C. 2007 Edwardsia timida. [In] Encyclopedia of Marine Life of Britain and 


Williams, G. 1954 The fauna of Strangford Lough and neighbouring coasts. Proceeding of the Royal Irish 

Academy 56: 47-54 

99


Caryophyllia inornata Duncan, 1878 

- Southern cup coral 

Description 

A solitary cup coral. The polyp is usually brown but may be white or red. It is usually taller than it 

is broad: up to 18mm tall and 12mm across. The corallum is parallel-sided with protruding septa at 

rim. The tentacles are short and have prominent knobbed tips. 


This cup-coral could easily be mistaken for a 

small Devonshire cup-coral, Caryophyllia 

smithii. However, its tentacles are much 

shorter in relation to its column and it is much 

smaller in size. It could also be confused with 

a jewel anemone, Corynactis viridis. 

C. inornata, bottom right, C. smithii top left and 

top right. 

Habitat 

Usually found on vertical or overhanging rock faces, often in small groups. May also occur in small 

caves where it is out of the light. 


Rare in Northern Ireland. Rare in UK, with the Northern Ireland population comprising > 20% of 

the total UK population. 


Not known. 

Distribution 

This is a frequent species in the Azores and occurs along the Atlantic coasts of France, Spain and 

Portugal and in the Mediterranean Sea. It is only known comparatively recently from the UK; it is 

noted as a new addition to the British anthozoan fauna by Manuel (1988). It is infrequently 

reported but fairly widespread on the western coasts of the British Isles. Records from Scotland 

(Loch Crinan, Loch Sunart and Maen Mellt (MNCR, B.E. Picton); Wales (Bardsey Island and 

Lleyn peninsula (MNCR), Skomer (B.E. Picton); several locations in Devon (MNCR, Seasearch); 

100


Lundy Island (Seasearch) and Lough Hyne, Cork (B.E. Picton). 


One record from the roof of a small cave near Ruecallan, North Wall of Rathlin in 1992 (B.E. 

Picton). 


Recorded from west of Derginan Point, Rathlin (dive 070618/03). The north wall of Rathlin is the 

only known location for this species in Northern Ireland and consequently would merit further 

monitoring. 

References 




Picton, B.E. & Morrow, C.C. 2007 Caryophyllia inornata. [In] Encyclopedia of Marine Life of Britain and 


101


Sabellaria spinulosa Leuckart, 1849 - Honeycomb worm 

Description 

Small tube-building polychaete worm. Can form dense subtidal aggregations which create reefs 

several centimetres thick raised above the surrounding seabed. These persist for many years and 

form a stable hard substrate on otherwise mobile sediment, enabling a wide range of epibenthic and 

crevice fauna to become established. However, in the majority of its range, S. spinulosa does not 

form reefs but is solitary or in small groups encrusting hard substrate and kelp holdfasts. In 

favourable conditions, extensive thin crusts can be formed. However, these tend to be seasonal 

features which are broken up by winter storms; as such they do not provide a stable biogenic 

habitat and are therefore not considered true reefs. 


Solitary specimens may be confused with other worm species. When forming aggregations, the 

colony form is distinctive. There is an intertidal species Sabellaria alveolata which also forms 

similar reefs. 


This species is scarce and is declining in Northern Ireland (1% year). The reefs which are 

sometimes formed by this species are a UK BAP Habitat. 


The greatest threat is considered to be physical disturbance from fishing activities and aggregate 

extraction. 

Distribution 

The species is common all around Britain and Ireland, and the rest of the north-east Atlantic, in the 

subtidal and sublittoral fringe. Requires some hard substrate to allow initial colonisation (cobbles, 

pebbles or gravel) and a good supply of sand grains for tube building, put into suspension by water 

movement (tidal or wave action). The crust colony forms are common on the west Wales coast and 

Berwickshire and North Northumberland coast. There are two main reef biotopes: CR.MCR.CSab: 

circalittoral Sabellaria reefs (on rock), with a few records spread all around coast of England and 

one record from the Foyle, and SS.SBR.PoR.SspiMx: Sabellaria spinulosa on stable circalittoral 

mixed sediment (present all around the coast of England but most common in the Wash). Whilst 

both these biotopes may encompass thin layers of Sabellaria spinulosa overlying the substrate, true 

reef habitats consist of a much thicker more stable layer, although the exact definition is as yet 

poorly defined (Hendrick & Foster-Smith, 2006). 

102



There are three NISS records of this species from offshore Londonderry, and one from Isle O’Valla 

Strangford Lough (littoral). However, the majority of these are records of individuals or small 

colonies rather than true reefs. There are also several records obtained from grab surveys by NIEA 

(Water Management Unit) during the course of their monitoring surveys: however, these are 

mainly of individual worms and therefore would not indicate the presence of reefs. Only NISS 

records are shown on the map above. 

Sabellaria spinulosa reefs are mentioned in the Northern Ireland Sublittoral Survey Report ‘Low 

lying pitted bedrock outcrops from mobile sand off Magilligan Strand in 23-29m. The rock, 

probably of limestone, and accompanying boulders, are colonised by the reef building calcareous 

tube worm Sabellaria’. 


Sites at which Sabellaria spinulosa was previously recorded during NISS, around the Londonderry 

coast, were resurveyed (dives 070802/03 and 070802/04). Sabellaria spinulosa was recorded at one 

site (dive 070802/04, Entrance to Foyle). It was recorded as Frequent but was present as an 

encrusting patch rather than a true reef form. 

References 

Anon. 1999 Sabellaria spinulosa UK Biodiversity Group Tranche 2 Action Plans - Volume V: Maritime 

species and habitats (October 1999, Tranche 2, Vol. V, p.145) 

Connor, D.W., Allen, J.H., Golding, N., Howell, K.L., Lieberknecht, L.M., Northern, K.O. & Reker, J.B. 

2004 The marine habitat classification for Britain and Ireland version 04.05. JNCC, Peterborough, ISBN 1 

861 07561 8 (internet version) 

Erwin, D.G., Picton, B.E., Connor, D.W., Howson, C.M. Gilleece, P. & M.J. Bogues 1990 Inshore Marine 


EHSNI (2005) Northern Ireland Habitat Action Plan Sabellaria spinulosa Reefs. Environment and Heritage 

Service Northern Ireland, Belfast 

Hendrick, V.J. & Foster-Smith, R.L. 2006 Sabellaria spinulosa reef: a scoring system for evaluating 

‘reefiness’ in the context of the Habitats Directive. Journal of the Marine Biological Association of the 

United Kingdom 86: 665-677 

Jones, L.A., Hiscock, K. & Connor, D.W. 2000 Marine habitat reviews. A summary of ecological 

requirements and sensitivity characteristics for the conservation and management of marine SACs. Joint 

Nature Conservation Committee, Peterborough (UK Marine SACs Project report) 

103


Palinurus elephas (Fabricius, 1787) - Crayfish 

Description 

The crayfish is larger than the lobster, growing to about 600mm in length. It has long antennae but 

small hook-like claws. It is orange in colour. 


The only other UK crustacean of a similar size is the lobster (Homarus gammarus) but this has 

large, robust claws. 


This is a UK BAP species (on new list, 2007). Prior to this, it was a component of the offshore 

rocky reef priority habitat action plan. Declining in Northern Ireland. 


Traditionally crayfish have been caught by potting, but over the last 40 years tangle netting has 

been used. Tangle net fishing can severely deplete populations (Hepper 1977; Hunter et al. 1996). 

Diving for crayfish eliminated the species from shallow water around Cornwall in the 1960s 

(Hepper 1977). Taking the species on SCUBA is no longer economically viable (Hunter et al. 

1996). In the UK, the species is primarily taken as bycatch rather than as a targeted fishery (Hunter 

et al. 1996). 

Distribution 

Crayfish are found on open exposed rock faces and rocky seabed in the circalittoral and infralittoral 

zones in waters up to 200m deep (Goñi & Latrouite 2005). The species is gregarious with adults 

favouring neighbouring individual shelters, although up to 10 individuals will share (Mercer 1973). 

They migrate into deeper waters over winter, migrating back onshore before reproducing in the 

spring (Mercer 1973; Andsell and Robb 1977). They are omnivorous, changing their food 

preference as a function of abundance of benthic organisms (Goñi et al. 2001). 

Occurs in the Atlantic from above 26°N on the coast of Africa to Norway (occasional records 

only). Found over the entire western basin of the Mediterranean but absent in the eastern basin 

(Hunter 1999). In the British Isles, it is usually confined to exposed western coasts, although there 

have been incidental records from the east coast of Scotland (Ansell & Robb 1977). In the UK, it 

has been found in Devon and Cornwall, Wales, and the west coast of Scotland (MNCR, Seasearch). 

On the west coast of Ireland it is widespread, occurring from Ballycotton Bay around the western 

coast to northern Donegal (BioMar). 


Recorded from the south and west coasts of Rathlin Island, Kinbane Head in County Antrim, and 

Shamrock Pinnacle offshore from Rathlin Island. 

104



Crayfish were seen in small numbers on the NW side of Rathlin Island. In view of their general 

decline we recommend consultation with the Fisheries Division of DARD (NI) and proposal of 

restrictions on taking of crayfish by any method within Rathlin Island SAC. 

References 

Ansell, A.D. & Robb, L. 1977 The spiny lobster Palinurus elephas in Scottish waters. Marine Biology 43: 

63-70 

Goñi, R. & Latrouite, D. 2005 Biology, ecology and fisheries of Palinurus spp. of European waters: 

Palinurus elephas (Fabricius, 1787) and Palinurus mauritanicus (Gruvel, 1911). Cahiers de Biologie Marine 

46: 127-142 

Goñi, R., Quetglas, A. & Reñones O. 2001 Diet of the spiny squat lobster Palinurus elephas of the marine 

reserves of Columbretes Islands. Journal of the Marine Biological Association of the United Kingdom 80:1-3 

Hepper, B.T. 1977 The fishery for crawfish, Palinurus elephas, off the coast of Cornwall. Journal of the 

Marine Biological Association of the United Kingdom 57: 925-941 

Hunter, E. 1999 Biology of the European spiny lobster, Palinurus elephas (Fabricius, 1787) (Decapoda, 

Palinuridae). Crustaceana 72 (6): 545-565 

Jackson, A. & Marshall, C. 2007 Palinurus elephas. European spiny lobster. Marine Life Information 

Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological 

Association of the United Kingdom [cited 14/09/2007]. Available from: 

http://www.marlin.ac.uk/species/Palinuruselephas.htm 

Mercer, J.P. 1973 Studies on the spiny squat lobsters (Crustacea: Decapoda: Palinuridae) of the west coast 

of Ireland, with particular reference to Palinurus elephas Fabricius, 1787, 331pp. Ph.D. thesis, University 

College, Galway 



Picton, B.E. & Morrow, C.C. 2005 Palinurus elephas. [In] Encyclopedia of Marine Life of Britain and 

Ireland: http://www.habitas.org.uk/marinelife/species.asp?item=S24140 

105


Cestopagurus timidus (Roux, 1830) - a hermit crab 

Description 

Small hermit crab with a body (shield) length of 1.6-2.7mm. The claws are the same length, but the 

right is much thicker than the left; both claws are covered with fine hairs (Ingle 1993). The claws 

have patches of blue and white annulations on them (Ingle & Christiansen 2004). 


Difficult to distinguish from other hermit crabs in the field; requires microscopic examination to 

confirm identification. 


Rare and declining in Northern Ireland. Northern Ireland populations represent >50% Irish 

population and >20% UK population. 


A rare species likely to be adversely impacted by bottom fishing using scallop dredges or aggregate 

extraction. 

Distribution 

Occurs from 0-70m in various habitats including amongst algae and seagrasses, on rock, and on 

coralline substrates (Ingle & Christiansen 2004). Widespread in the Mediterranean, with a few 

records from North-eastern Atlantic (northern France, Isles of Scilly, County Donegal, and the 

Clyde in Scotland; also occurs southwards as far as the Canary Islands) (Ingle 1993). The Scottish 

record is currently thought to be the most northerly (Ingle 1993). There are, however, four records 

from a UKOOA industry survey from grabs taken NE of Shetland (1978-1979) (Kingston et al. 

2004). It has not been possible to verify these. 


Only two records, both from the east coast of Rathlin Island (SE Doon Point and Ushet Point) 

(BioMar). Both the Northern Ireland records are from areas of muddy gravel with cobbles and 

boulders between 24 and 30m (BioMar). 


Not found during SSNI despite resurveying Rathlin sites. This small inconspicuous crab is difficult 

to find during dive surveys unless effort is devoted to searching for hermit crabs. 

References 

Ingle, R.W. 1993 Hermit crabs of the Northeastern Atlantic Ocean and Mediterranean Sea, an illustrated 

key. Natural History Museum Publications. Chapman and Hall, London 

106


Ingle, R.W. & Christiansen, M.E. 2004 Lobster, mud shrimps and anomuran crabs. Synopses of the British 

Fauna (new series), J.H. Crothers & P.J. Hayward (eds), no. 55. The Linnean Society of London. Cambridge 

University Press, Cambridge 

Kingston, P., Harris, D., Ambrose, P. & Moore, C. 2004 UK Benthos database. Produced for UKOOA, 

Centre for Marine Biodiversity and Biotechnology, School of Life Science, Heriot-Watt University, 

Edinburgh 

107


Inachus leptochirus Leach, 1817 

- Leach’s spider crab 

Description 

Small spider crab, carapace length up to 30mm. Broad rostrum with narrow u-shaped incision. 

Each protogastric region has a tubercule. The chelipeds are larger in males. The carapace is 

greyish-yellowish brown, the chelipeds and walking legs lighter. The body and legs are covered 

with small, hook like, setae and are often covered with an encrusting growth of epifauna and 

epiflora (Ingle 1996). Males of I. leptochirus and I. phalangium are easily distinguished by a 

prominent white tubercule present on the ventral surface, but females and immature individuals are 

more difficult to identify; this may account for some doubtful records (Clark 1986). Both sexes of 

I. leptochirus may be distinguished from I. phalangium and other Inachus species by the shape of 

the cleft in the rostrum (a distinctive u-shaped cleft not found in other species in the genus) and the 

number and position of tubercules on the carapace (Moyse & Smaldon 1990). However, neither of 

these characteristics is immediately apparent in the field, which may have resulted in it being 

under-recorded. 


May be confused with other Inachus and Macropodia species, not easily identified in the field. 


Declining (1% year) with Northern Ireland being a stronghold consisting of >50% Irish population 

and >20% UK population/range. 


Associated with Modiolus beds and may have been affected by the deterioration in this habitat. 

May be vulnerable to damage from dredging. 

Distribution 

Reported from 27-166m on stony and shelly substrates and Modiolus beds (Ingle 1996). Ovigerous 

crabs and larvae may be found throughout the year. Distributed from Mauritania to Norway in the 

Atlantic; also occurs in Mediterranean (Clark 1986). Most British Isles records are from the Irish 

Sea, western coasts of Scotland and Ireland, and English Channel (Clark 1986). Recorded from two 

sites (Flamborough headland and Seahouses) in the North Sea (MNCR). Lack of records for the 

North Sea may be due to failure to sample hard grounds which are the preferred substrate for this 

species (Hartnoll 1963). 

108



Present all Northern Ireland coasts. Majority of records from cobble, pebble and gravel substrates, 

but recorded from a variety of coarse sediments (sand and gravel, cobbles, sand with shell 

fragments, maerl, mud with cobbles), and from Modiolus beds in Strangford Lough (Picton & 

Costello 1998). Several records from around Ballygalley Head; recorded as common from one site 

(site 850522/01) (Picton & Costello 1998). 


The Ballygalley sites were not surveyed in SSNI as they lay outside target areas, and these habitats 

were not targeted by the present survey. Although several spider crabs were sampled, the majority 

of these were subsequently identified as Inachus phalangium and Macropodia rostrata. 

References 

Clark, P.F. 1986 North East Atlantic Crabs; an atlas of distribution. Marine Conservation Society, 

Hertfordshire 

Hartnoll, R.G. 1963 The biology of Manx spider crabs. Proceedings of the Zoological Society of London 141 

(3): 423-496 

Ingle, R.W. 1996 Shallow-water Crabs. Synopses of the British Fauna, R.S.K. Barnes & J.H. Crothers (eds), 

no. 25 (2 nd edition). The Linnean Society of London. Cambridge University Press, Cambridge 

Moyse, J. & Smaldon, G. 1990 Chapter 10. Crustacea III Malacostraca Eucarida. In P.J. Hayward & J.S. 

Ryland (eds), The Marine Fauna of the British Isles and North-West Europe. Volume 1, pp. 489-552 



109


Munida rugosa (Fabricius, 1775) 

- Long Clawed Squat Lobster 

Description 

A fairly small squat lobster (carapace length approx 30mm). The chelipeds are very long in 

comparison with the carapace. This together with the rostrum shape and the colouration of the 

carapace distinguishes it from other squat lobster species. The rostrum is a single, untoothed, spine 

and is flanked by two shorter supra-orbital spines. The carapace is orange with darker red stripes 

running transversely across it. 


Could be confused with other squat lobster species; the length of the chelipeds relative to the 

carapace is distinctive. 


Rapid decline in Northern Ireland (2% per year over the last 25 years). Northern Ireland is a 

stronghold, consisting of >50% Irish population. 


Munida rugosa has been landed by fishermen on a largely opportunistic scale, which has been 

attributed to a possible overlap in habitats, principally at boundaries between the mud substratum 

of Nephrops norvegicus and the gravel substratum of Munida species (Pothanikat 2005). This 

fishery is a potential threat to the species. 

Distribution 

Around the coasts of Northwest Europe, species of the genus Galathea are distributed in 

rocky/gravely subtidal areas (Zariquiey Alvarez 1968). M. rugosa is reported from rock, stone, 

gravel and sand substrates (Ingle & Christiansen 2004). In Northern Ireland, it typically occurs 

under boulders, which may be lying on sand or gravel. The four main North-eastern Atlantic 

Munida species range from 30m (M. rugosa, the shallowest dwelling species of the four) down to 

1400m (M. tenuimana, the deepest water species) (Rice & Saint Laurent 1986). Munida rugosa 

may be found from LWST to 576m (Ingle & Christiansen 2004). 

Fairly common, present on all British coasts, apart from the eastern English Channel and southern 

North Sea. Wider distribution is from Portugal to Norway; also occurring in the Mediterranean 

(Moyse & Smaldon 1990). Particularly common on the west coast of Scotland (NBN Gateway). 

Only known from a few sites in the Republic of Ireland, mainly on the south coast (BioMar). 

110



Widespread and fairly common in Northern Ireland; particularly on Rathlin Island and in 

Strangford Lough. 


Several records, mainly from Rathlin Island and Strangford Lough. Not rare but may be declining 

due to fishing pressure and continued monitoring recommended. 

References 

Ingle, R.W. & Christiansen, M.E. 2004 Lobster, mud shrimps and anomuran crabs. Synopses of the British 

Fauna (new series), J.H. Crothers & P.J. Hayward (eds), no. 55. The Linnean Society of London. Cambridge 

University Press, Cambridge 

Picton, B.E. & Morrow, C.C. 2007 Munida rugosa. [In] Encyclopedia of Marine Life of Britain and Ireland. 

http://www.habitas.org.uk/marinelife/species.asp?item=S24950 

Pothanikat, R.M.E. 2005 The behaviour and ecology of Munida rugosa and Munida sarsi. Ph.D. Thesis, 

Queen’s University of Belfast, 245pp. 

Rice, A.L. & Saint Laurent, M. de 1986 The nomenclature and diagnostic characters of four north-eastern 

Atlantic species of the genus Munida Leach: M. rugosa (Fabricius), M. tenuimana G. O. Sars, M. intermedia 

A. Milne Edwards and Bouvier, and M. sarsi Huus (Crustacea, Decapoda, Galatheidae). Journal of Natural 

History 20: 143-163 

Zariquiey Alvarez, R. 1968 Crustáceos Decápodos Ibéricos. Investigación Pesquera, Barcelona 32:1-510 

111


Atelecyclus rotundatus (Olivi, 1792) 

– Circular crab 

Description 

Small crab reddish-brown (carapace up to 40mm) with nearly circular carapace. The carapace has 

short, transverse grooves on its surface and has hairy margins. It bears 9-11 teeth on each side; 

these are often alternating in size and have tubercules on their margins. There are three further teeth 

between the eyes; the middle is longer than those on either side. The chelipeds are equal in size and 

have black claws; the walking legs are slightly flattened with hairy margins. 


May be confused with other crab species of similar size, but the rounded carapace and black claws 

on the chelipeds should help in its identification. 

Habitat 

Reported from 12-91m on sand and gravel; also in deep water down to 795m (Clark 1986; Ingle 

1996). 


Recent decline. Northern Ireland is a stronghold, consisting of >50% of the Irish population. 


Vulnerable to habit disturbance from fishing. 

Distribution 

Known from Gabon to Norway in the North-east Atlantic, also the Mediterranean (Clark 1986). 

Present on all coasts of the British Isles (Ingle 1996, Rowley 2007). 


Present all Northern Ireland coasts but not common. 


Not recorded during SSNI, but small and easily missed during dive surveys. 

References 

Clark, P.F. 1986 North East Atlantic Crabs; an atlas of distribution. Marine Conservation Society, 

Hertfordshire 

112


Ingle, R.W. 1996 Shallow-water Crabs. Synopses of the British Fauna (2 nd edition). R.S.K. Barnes & J.H. 

Crothers (eds), no. 25. The Linnean Society of London. Cambridge University Press, Cambridge 

Rowley, S.J., 2007 Atelecyclus rotundatus. Circular crab. Marine Life Information Network: Biology and 



http://www.marlin.ac.uk/species/Atelecyclusrotundatus.htm 

113


Tonicella marmorea (O Fabricius, 1780) – a chiton 

Description 

A large, broadly oval ‘limpet-like’ chiton, up to 4cm in length. The eight arched shell plates are 

smooth (covered with numerous minute granules) and glossy, light red to dark brick red or chestnut 

brown in colour with variable white or fawn marbling. Adjacent valves may have contrasting 

colours. The fleshy girdle around the edge is broad, thin and smoothly leathery, reddish-brown with 

a fringe of tiny, flattened spines (red, green or purple in colour, sometimes banded). 


There are several similar species: Callochiton septemvalvis, Tonicella rubra and pink forms of 

Lepidochitona cinerea. Tonicella marmorea is distinguished by having a smooth, broad girdle, not 

coarsely granular, scaly or with tufts of bristles. The shell valves are smooth and glossy, and 

normally a rich chestnut red/brown colour (not pink), and marbled with white. 


Northern Ireland currently holds the entire Irish population, which is thought to be declining and is 

scarce. It is a northern species found elsewhere predominantly in Scotland, where it can occur in 

high densities in sea lochs, and northern England. 


The major threat to this species is thought to be climate change. Tonicella marmorea is a northern 

species at the southern limits of its range in Northern Ireland. 

Distribution 

Lives under stones and boulders in muddy gravel, close to low water on the shore or sublittorally, 

in areas of shelter from current or wave action, rarely on the open coast. It is a herbivorous grazer 

of microalgae. In the sublittoral, it is usually on silty muddy bedrock or large boulders. 

An Atlantic-Boreal species occurring in the Arctic Ocean, on the coasts of Norway, Sweden, 

Greenland, Britain and the Atlantic coast of North America. Within the British Isles it is restricted 

to the north, only extending as far south as Northumberland and North Wales. 


Tonicella marmorea was found commonly throughout Strangford Lough in the late 1980s and early 

1990s, with up to a dozen animals found at any single site. Since that date, anecdotal evidence 

suggests that while single animals may still occasionally be found at most sites, there are 

substantially reduced populations. 

114


Found all around the coast of Northern Ireland from Carlingford Lough to Rathlin Island. It is 

particularly common in Strangford Lough. 


Not recorded during the survey. This species is mainly found in shallow water or on shore, where 

SSNI did not conduct much survey work. 

References 

Jones, A.M. & Baxter, J.M. 1987 Molluscs: Caudofoveata, Solenogastres, Polyplacophora and Scaphopoda. 

Synopses of the British Fauna, no. 37. The Linnean Society of London and The Estuarine & Brackish-water 

Sciences Association. 

Hayward, P.J. & Ryland, J.S. (eds) 1995 Handbook of the marine fauna of north-west Europe. Oxford 

University Press 

Nunn, J. 2007 Tonicella marmorea – greater marbled chiton. Northern Ireland Priority Species Reports 





Seaward, D.R. 1990 Distribution of the marine molluscs of north west Europe, 114pp. Nature Conservancy 

Council, Peterborough for Conchological Society of Great Britain & Ireland 

115


Erato voluta (Montagu, 1803) - egg cowrie 

Description 

Small, translucent, glossy, white gastropod up to 12mm high. The shell has 3-4 whorls, the last of 

which occupies 80-85% of the shell. The pinkish outer lip is thick and turned in with 15-18 ridgelike 

teeth on its inner edge. The mantle edge is drawn out to form lobes which cover the shell but 

are withdrawn if the animal is disturbed. This is speckled with brown, red, orange and yellow. It 

lives on hard substrates, with pockets of sediment, and associates with ascidians which form its 

food. 


There are three similar species in Northern Ireland waters: Simnia patula, Trivia arctica and T. 

monacha. Simnia patula is yellow, with a mantle of yellow striped with black, and is found on dead 

men’s fingers Alcyonium digitatum. Trivia spp. have ridged shells (unlike Erato) except for 

juveniles. The juveniles have very thin shells, with no spire in mature shells, whereas Erato voluta 

has a thick shell and a short spire. 


This species is rare in Northern Ireland, being confined to only two sites off Rathlin Island, and has 

not been seen since 1984. It has only certainly been found elsewhere in Ireland in Galway Bay. It is 

rare in the rest of the UK. 


Possible threats to Erato voluta are unknown, as so little is known about the biology and ecology of 

this species. 

Distribution 

From the Mediterranean to Norway, depths of 20-100m off most shores of the British Isles apart 

the east coast between the Humber and Isle of White. However, it is rarely found. 


Erato voluta has only been found living off the coast of Rathlin Island in Northern Ireland, in 

waters deeper than 20m, during the summer months of 1983 and 1984. Shells have been found on 

the strands at Portstewart and Magilligan. 


This species was not found during SSNI. It is a very small mollusc and would have been easily 

overlooked by divers. 

116


References 

Graham, A. 1988 Molluscs: prosobranch and pyramidellid gastropods. Synopses of the British Fauna (new 

series), no. 2 (second edition). The Linnean Society of London and The Estuarine & Brackish-water Sciences 

Association 



Nunn, J. 2007. Erato voluta - egg cowrie. Northern Ireland Priority Species Reports [online]. Cultra: 







117


Palio dubia (M Sars, 1829) - a sea slug 

Description 

The body of this nudibranch sea slug is brownish to olive green with numerous rounded white or 

yellow tubercles. There are short white papillae on either side of the gills. It may grow to 29mm 

length. It feeds on the bryozoan species Eucratea loricata (Hamel, Sargent & Mercier 2008) and 

Bowerbankia. The larvae show a specific settlement preference for the bryozoan E. loricata 

(Hamel, Sargent & Mercier 2008). 


Frequently confused with Palio nothus. Palio dubia differs from P. nothus in having rounded rather 

than conulate tubercles on the body, and an even rather than blotchy green colouration. 


This species is very rare in Northern Ireland, and has not been seen since the original record was 

made in 1978. It is the only record for the island of Ireland since the late 19 th /early 20 th century. 

Due to confusion with the closely related P. nothus, it is not possible to be certain of those early 

records. 


Threats to this species are unknown, as there is little knowledge of the current populations in 

Britain and Ireland. As egg laying has been observed to occur at between 6 and 7˚C (Hamel, 

Sargent & Mercier 2008), it is possible that spawning could be prevented by increased water 

temperatures. Its main food source, the bryozoan Eucratea loricata is widespread in Northern 

Ireland and common in some areas such as Strangford Lough and inside the Skerries. 

Distribution 

Sublittoral from 10-100m. A northern species in Britain and Ireland, with animals known only 

certainly from west Scotland and off Northumberland. Elsewhere it is known from the French 

Atlantic coast and in the northwest Atlantic from the Arctic to Connecticut, the north-east Pacific 

and the White Sea in Russia (Hamel, Sargent & Mercier 2008). 


Only found in Northern Ireland at one site, the wreck of the ‘Chirripo’ off Black Head, Belfast 

Lough in 15m. 

118



This species was not found during SSNI. Nudibranch populations can be ephemeral, so continued 

monitoring is needed to establish the status of this species. It is a species which might be expected 

to disappear from Northern Ireland waters if sea temperatures are increasing. 

References 

Hamel, J., Sargent, P., Mercier, A. 2008 Diet, reproduction, settlement and growth of Palio dubia 

(Nudibranchia: Polyceridae) in the north-west Atlantic. Journal of the Marine Biological Association of the 

United Kingdom 88: 365-374 

Nunn, J. 2007 Palio dubia - a nudibranch mollusc. Northern Ireland Priority Species Reports [online]. 




London 



Seaward, D.R. 1990 Distribution of the marine molluscs of north-west Europe, 114pp. Nature Conservancy 


Thompson, T.E. 1988 Molluscs: benthic opisthobranchs. Synopses of the British Fauna (new series), no. 8 

(second edition). The Linnean Society of London and The Estuarine & Brackish-water Sciences Association 

Thompson, T.E. & Brown, G.H. 1984 Biology of opisthobranch molluscs. Volume II. The Ray Society, 

London 

119


55.0N 

Eubranchus doriae (Trinchese, 1874) 

- a nudibranch mollusc 

2006-7 SSNI records 

2005 records 

Previous records 

7.0W 6.5W 6.0W 

Description 

A small nudibranch, up to 12mm in length. The body is translucent white, with scattered brown or 

green pigment on the back and cerata. The cerata have 2-3 rows of tubercles giving an irregular 

knobbly appearance. The tip of each ceras is covered by a pale patch, and encircled by a browncoloured 

ring. The rhinophoral and oral tentacles are smooth; the tips of these tentacles are white 

with a sub-terminal brown band. Feeds on the hydroid Kirchenpaueria similis. 


There are two similar species: Eubranchus exiguus and E. vittatus. Eubranchus doriae may be 

easily distinguished from E. vittatus by the presence of tubercles on the cerata. Eubranchus exiguus 

has few cerata, which are urn-shaped, and is usually found on Obelia sp. attached to kelp. 


This species is Rare in Northern Ireland, being only found at the Skerries and Fair Head. It is 

elsewhere in the Republic of Ireland from Mulroy Bay, Co. Donegal south down the west coast, to 

Lough Hyne, Co. Cork. It lives in mainly on the south and western coasts of Britain, although it has 

been found as far north as St Kilda, and elsewhere the Atlantic coast of France and the 

Mediterranean. It is probably under-recorded. 



Britain and Ireland. 

Distribution 

There are few records for this species but it appears to be widespread around the southern and 

western coasts of British Isles: records from Lundy Island, Sussex, Mulroy Bay in County Donegal, 

and St Kilda. 


This species has only been found off the Skerries (near Portrush) and Fair Head in Northern 

Ireland, in depths of 18-31m between 1982 and 1985 in July and August. 


This species was not found during the survey, despite resurveying sites at which it was previously 

found. Nudibranch populations can be ephemeral, so continued monitoring of these sites would be 

120


needed to establish the status of this species. 

References 

Nunn, J. 2007 Eubranchus doriae – a sea slug. Northern Ireland Priority Species Reports [online]. Cultra: 



Picton, B.E. & Costello, M.J., 1998 BioMar biotope viewer: a guide to marine habitats, fauna and flora of 



London 








London 

121


Cumanotus beaumonti (Eliot, 1906) - a sea slug 

Description 

Cumanotus beaumonti is a translucent, gold flecked, nudibranch up to 25cm in length. It has 

numerous long, smoothly tapered, cerata. The animals are vigorous swimmers, moving through the 

water by repeated violent vertical movements of the cerata or flexing of the body. 


There are no closely similar species. 

Habitat 

Feeds on the solitary hydroid Corymorpha nutans, and may be found either on this species or 

crawling over sand near to populations (Picton 1991). 


The species is Rare in Northern Ireland, which holds the only known sites for the island of Ireland, 

and the majority of the population for the UK. It is only known with certainty elsewhere from 

Norway, western Scotland and Plymouth. 



Britain and Ireland. 

Distribution 

This species is scarce. It was originally described from Plymouth and found at the same time in 

Norway. There are recent records from Northern Ireland and the west coast of Scotland. 


This species has only been found off Rathlin Island in 8-15m (16 specimens), south-east of Kilkeel 

in 20m, and off Cranfield Point, Carlingford Lough in 20m, all in May and June 1985 (Picton & 

Costello 1998). 


Sites in Church Bay, Rathlin Island, at which there were previous records were revisited. Although 

populations of Corymorpha nutans were found and appeared to be numerous and in good condition 

Cumanotus beaumonti was not recorded. Nudibranch populations can be ephemeral, so continued 

monitoring of these sites is needed to establish the status of this species. 

122


References 

Nunn, J. 2007. Cumanotus beaumonti – sea slug. Northern Ireland Priority Species Reports [online]. Cultra: 



Picton, B.E. 1991 Cumanotus beaumonti (Eliot, 1906), a nudibranch adapted for life in a shallow sandy 

habitat? Malacologia 32: 219-221 

Picton, B.E. & Costello, M.J. 1998. BioMar biotope viewer: a guide to marine habitats, fauna and flora of 



London 








London 

123


Modiolus modiolus (Linnaeus, 1758) - horse mussel 

Lower left: Horse mussel community in Strangford 

Lough 

Description 

Large brown mussel (younger specimens may 

be bluish); the shells reach 10cm long by 12- 

18 years, but can be up to 22cm. The shell is 

irregularly oval, the umbones are anterior but 

subterminal, with the anterior margin 

projecting beyond them. 


There are many similar species: Mytilus edulis; Modiolus barbatus, Modiolus adriaticus, 

Modiolula phaseolina, Modiolarca tumida and Musculus discors. All these species are very 

difficult to distinguish when juvenile. Modiolus barbatus has serrations on its spines, and has not 

been found in N.I. waters; Modiolarca tumida and Musculus discors have raised ribs on their 

shells; the umbones (or beaks) are blunter in Modiolus modiolus than Mytilus edulis, and are not 

quite anterior due to extension of the shell margin; Modiolus adriaticus is light-yellow in colour 

with prominent reddish rays or zigzags. It can be reasonably assumed that any specimen of mussel 

longer than c. 12cm in Northern Ireland is likely to be Modiolus modiolus. 


The horse mussel community is one of the most diverse in Strangford Lough and has been 

identified as being of major importance to the Lough’s conservation interest. The community is 

dependent on the survival of mature, long-lived mussels living together in closely knit clumps to 

provide a substrate for attachment of epifauna and protection for infauna. The viability of the 

population itself is dependent on slow but continuous recruitment provided by the present 

population, and on the physical structure of the community to provide secure sites for larval 

settlement and growth, so that some individuals at least escape predation (Brown, 1989). In the last 

10 years, a rapid decline in the extent and loss of integrity of the horse mussel reefs has been 

identified, such that both the species and its community are now considered scarce in Northern 

Ireland. Similar reefs of horse mussel are absent from the Republic of Ireland, and only exist in a 

few areas in Britain such as the Isle of Man, off the Welsh coast, and the west coast of Scotland, to 

more than 200m. 

124



This species has a high sensitivity to substratum loss; smothering; desiccation; increase in 

emergence routine; changes in water flow; increase in temperature or wave exposure; abrasion and 

physical disturbance; decrease in salinity; synthetic compound contamination; extraction of the 

species or other species. There is low recoverability to all these physical factors. 

The commercial species the queen scallop Aequipecten opercularis is closely associated with the 

horse mussel reefs. Juvenile A. opercularis may attach to horse mussels prior to becoming freeliving 

adults. They are therefore important nursery grounds, but are also therefore a target fishery. 

Recent diving and remote studies using side-scan sonar confirm that certain areas of Strangford 

Lough have been heavily impacted by trawling; in particular that part occupied by the horse 

mussel/variegated scallop community. The horse mussel is also considered to be a northern species, 

which may therefore already be under stress due to climate change. 

Distribution 

Elsewhere the species is distributed from the Arctic to France down to 2000m. Although it is a 

widespread and common species, true beds forming a distinctive biotope are much more limited 


In Northern Ireland, there were formerly extensive mature beds or reefs in Strangford Lough 

(1970s, 1980s). Most of these beds have now been damaged extensively. Beds have also been 

found in Carlingford Lough, inside the Skerries and off Millisle/Ballywalter on a variety of 

sedimentary habitats. 


Strangford Lough is currently being investigated with the intention of restoring the horse mussel 

bed habitats. 

In addition to the populations in Strangford Lough, the beds previously recorded on the inside of 

the Skerries were resurveyed. Despite doing many survey dives in the vicinity of previous records 

of horse mussel beds these communities were not found. There were records of large areas of dead 

shell and some records of individual horse mussels. There is anecdotal evidence of recent trawling 

in this area which may have impacted on the beds. 

Horse mussel beds on the outside of the Ards Peninsula are anecdotally reported as being in good 

condition with extensive beds present east of Ballyferris point between the 20 and 30m contour 

lines. This is in the area of a previous record from 1984 (54° 34.93’N, 005° 27.36’W). It is 

imperative these beds are surveyed to assess their condition; they are under immediate threat from 

mussel spat dredgers which operate all along this coast. 

References 

Brown, R.A. 1989 Bottom trawling in Strangford Lough: problems and policies. In C.C ten Hallers & A. 

Bijlsma (eds), Proc. North Sea Meeting, Rotterdam pp. 117-127. Amsterdam 

Brown, R.A. & Seed, R. 1977 Modiolus modiolus (L.) - an autecological study. In B.F. Keegan, P. Ó Céidigh 

& P.J.S. Boaden (eds), Biology of Benthic Organisms pp. 93-100. Pergamon Press, Oxford 



Nunn, J. 2007. Modiolus modiolus – horse mussel. Northern Ireland Priority Species Reports [online]. 







Tebble, N. 1966 British Bivalve seashells. The British Museum (Natural History), London 

UK Biodiversity Group Tranche 2 Action Plans - Volume V: Maritime species and habitats (October 1999, 

Tranche 2, Vol. V, p153) http://www.ukbap.org.uk/UKPlans.aspx?ID=37 

125


Atrina fragilis (Pennant, 1777) - Fan mussel 

Description 

One of the largest bivalve molluscs found in Europe, reaching up to 48cm in length (growth rate of 

3-4cm per year), with the largest individuals being at least 10 to 12 years old. The shell is brittle, 

equivalve and triangular in outline with prominent gapes, tapering to a point. It is light yellowishbrown 

or dark brown in colour, occasionally with black patches, and a sculpture of concentric lines 

and 8 to 12 radiating ribs, sometimes with fluted spines. The colour inside is similar to the outside, 

but glossy. The pointed end of the shell (1/3 to 2/3 of shell length) is buried vertically in the 

substrate so only the top section of the shell is visible. 


There are no other UK bivalve species which grow to this size. 

Habitat 

It has been recorded from a variety of soft sediment habitats, from soft mud to gravel. 


This species is a UK priority species, has experienced rapid decline in Northern Ireland, only seen 

living once in 2007 since 1971, and is considered to be rare in Northern Ireland. It is legally 

protected from intentional killing, injuring or taking; possession or sale under the Wildlife Order 

(NI), 1985. 


It is sensitive to substratum loss; smothering; changes in temperature, water flow, wave exposure; 

abrasion and physical disturbance; displacement and extraction of species – with a low 

recoverability to all these. Although fan mussels can repair considerable damage to the edge of 

their shells, they are unable to re-burrow if dislodged from the sediment. The main threat is thought 

to be the use of trawls and dredges in fishing, both of which disturb the seabed and damage fan 

mussels, often removing them from the sediment. Further threats include gravel and sand 

extraction. 

Distribution 

The fan mussel is distributed south from Britain on the continental shelf to the Iberian Peninsula 

and the Mediterranean down to 600m. Historically this species was common around Britain and 

Ireland, being frequently caught by fishermen and during biological dredging surveys. It was often 

caught in aggregations. However, most records from the 20th century are of isolated individuals. 

The species is now thought to be scarce. Seaward (1982) mapped the records of A. fragilis for the 

126


British Isles according to sea areas. A. fragilis has been recorded off Shetland, Orkney, the east 

coast of Scotland in the Moray Firth, down the west coast of Scotland, off the north and west coasts 

of Ireland, the Irish Sea (Dublin Bay, Liverpool Bay and the Bristol Channel), the Scilly Isles, the 

Channel Isles and along the south coast of England. In Scottish waters, A. fragilis appears to be 

most commonly encountered amongst the Western Isles, particularly around Mull. In the southwest 

of England, it is thought that A. fragilis has largely disappeared from inlets where it was once 

common. The main surviving UK populations appear to be from Cornwall and Devon (those in the 

Salcombe estuary and Plymouth sound are particularly well documented), and the west coast of 

Scotland, and between John O’ Groats and the Shetland Isles. In the Republic of Ireland, it is only 

known recently from Galway Bay (1962, 1970s) and Valentia (1975). 


Only known recently from off the north coast of Northern Ireland during a trawling survey for the 

queen scallop Aequipecten opercularis in 1971, close to and west of Rathlin Island to Magilligan, 

in depths to 64m+, and off Rathlin Island in 2007 (SSNI). Shells have been found on Portstewart, 

Downhill and Magilligan strands. There are several other historical records from the North Coast. 


Several shells were found during dives on the inside of the Skerries. A young, clean, shell (~ 20cm 

in length) was also found on a Seasearch dive during the same period, indicating that living 

populations may still be present in this area. Most of the shells were damaged with large portions of 

the upper shell missing. This indicates that they may have been disturbed by fishing gear. No living 

fan mussels were found, but these are likely to be difficult to locate in the boulder and sand habitat. 

There is anecdotal evidence that fishing has recently taken place here. We would recommend that 

the site be protected from future dredging which would disturb any individuals present. Further 

surveys could help determine if living fan mussels are present. 

A live individual was found near to the Lochgarry wreck. This was present in sand and boulder 

habitat on the port side of the wreck near to the bow, about 3 metres away from the wreck. The area 

around it was surveyed but no further individuals were recorded. The east coast of Rathlin has been 

impacted by scallop dredgers, and it is likely that this individual was protected by the proximity of 

the wreck. This individual should be monitored in the future. Surveys of areas around wrecks with 

suitable soft sediment (for example in Belfast Lough) should be undertaken. The Marine 

Conservation Society run a publicity campaign to promote the reporting of fan mussel sightings 

(http://www.mcsuk.org/mcsaction/wildlife-protection/fanshell+survey) and this should be 

promoted amongst the fishing and diving communities. It has been demonstrated that live 

specimens are able to survive being moved and re-planted into the sediment, so culture and 

transplantation for restoration of populations is theoretically possible. 

References 

Anon. (1999) Fan Mussel (Atrina fragilis). UK Biodiversity Action Plan. Originally published in: UK 

Biodiversity Group Tranche 2 Action Plans - Volume V: Maritime species and habitats (October 1999, 

Tranche 2, Vol. V, p63). Available from: http://www.ukbap.org.uk/UKPlans.aspx?ID=123 

Nunn, J. 2007 Atrina fragilis – fan mussel. Northern Ireland Priority Species Reports [online]. Cultra: 

National Museums Northern Ireland [cited 15/02/2008].Available from: 






Solandt, J.L. (2003). The fan shell Atrina fragilis- a species of conservation concern. British Wildlife 14 (no. 

6): 423-427 


Woodward, F.R. 1985 The fan mussel, Pinna fragilis Pennant in Scotland. Glasgow Naturalist 21: 63-69 

127


Ostrea edulis Linnaeus, 1758 - native oyster 

Description 

The shell is solid, oval or pear-shaped, or circular when young, up to 100mm in length. It is inequivalve 

with the lower valve convex and the upper flat. The left, upper, valve has coarse 

concentric, scale like, sculpture and numerous irregular ribs. The lower, right, valve is coarsely 

sculpted but does not have ribs. The oyster is usually attached to the surface by this valve. Colour 

off-white, yellow or cream. 


There is only one similar species in Northern Ireland, the introduced Portuguese oyster Crassostrea 

gigas. Ostrea edulis has 10 fine ribs on the left valve only, and a white, off-white or cream 

adductor muscle scar. Both valves of Crassostrea gigas have 6-7 prominent ribs, and the adductor 

muscle scar is deep purple or brownish. 


Extensive oyster beds are known to have existed in Carlingford Lough for several hundred years; 

there were beds of oysters in Lough Foyle and Strangford Lough, but most stocks crashed during 

late 19 th or early 20 th century, and oyster fishing ceased - suspected to be result of over-fishing. 

The species was therefore considered to have declined, and to be scarce. Between 1997 and 1999, 

the EU funded a project to re-establish a sustainable native oyster fishery in Strangford Lough, 

using seed and adult broodstock from a disease free population in Lough Foyle. This has increased 

the prevalence of the species in this area. 


The dramatic reduction in stock abundance seen in the middle of the last century is attributed 

mainly to over-exploitation following the increased demand that accompanied improved rail 

transport. Unusually cold winters in the 1930s and 40s resulted in severe oyster mortalities and are 

thought to have contributed to the decline. Exotics such as the slipper limpet Crepidula fornicata, 

the American oyster drill Urosalpinx cinerea were introduced with the American oyster 

Crassostrea virginica around 1900 and have been harmful to stocks, although neither of these is 

were present in Northern Ireland prior to the early 21 st century. The parasitic protozoan Bonamia 

ostreae has caused massive mortalities in France, from whence it was introduced, and in the 

Netherlands, Spain, Iceland and England. The species is also sensitive to substratum loss, 

smothering, pollution and synthetic chemicals such as TBT. TBT (tri-butyl tin) anti-fouling paints 

used on ships and leisure craft in the early 1980s causes stunted growth and probably affects 

reproductive capacity. 

128


Distribution 

Associated with highly productive estuarine and shallow coastal water habitats with sediments 

ranging from mud to gravel. Its natural range extends from the Norwegian fjords to Morocco and 

the Mediterranean. Along with other oyster species, it is also cultivated in North America, 

Australasia and Japan. Stock abundance was probably greatest in the 18th and 19th centuries, when 

there were large offshore oyster grounds in the southern North Sea and the Channel producing up 

to 100 times more than today’s 100-200 tonnes. During the 20th century its abundance declined 

significantly in European waters. The main UK stocks are now located in the rivers and flats 

bordering the Thames Estuary, The Solent, River Fal, the west coast of Scotland and Lough Foyle. 


There are two main populations in Northern Ireland; in the Foyle and in Strangford Lough. The 

Lough Foyle populations were replenished by the release of spat by DARD in the 1970s and now 

provides an annual yield of 80-200 tonnes from five beds on the west side of the Lough. Ostrea 

edulis was common in Strangford until the 19 th century but populations crashed. By the late 1990s 

the species was rare, with no natural oyster beds reported for over 100 years and populations 

estimated at around 100,000 individuals. Commercial restocking in the late 1990s led to an increase 

in numbers and by 2002 the estimated population was 1 million; however, by 2004 there had been a 

decline of >300,000 oysters (Smyth 2007). Numbers have continued to decline: this is 

predominantly due to unregulated fishing (Smyth 2007). 


Ostrea edulis was seen in moderate numbers amongst Modiolus modiolus in the small areas where 

this species is still present. Continued monitoring is recommended. 

References 

Anon. 1999 UK Biodiversity Group Tranche 2 Action Plans - Volume V: Maritime species and habitats 

(October 1999, Tranche 2, Vol. V, p153). Available from: http://www.ukbap.org.uk/UKPlans.aspx?ID=37 



Kennedy, R.J. & Roberts, D. 1999 A survey of the current status of the flat oyster Ostrea edulis in Strangford 

Lough, Northern Ireland, with a view to the restoration of its oyster beds. Biology and Environment: 

Proceedings of the Royal Irish Academy 99: 79-88 

Nunn, J. 2007 Ostrea edulis – native oyster. Northern Ireland Priority Species Reports [online]. Cultra: 




Nature Conservancy Council, Peterborough for Conchological Society of Great Britain & Ireland. 


Council, Peterborough for Conchological Society of Great Britain & Ireland. 

Smyth, D. 2007 The impacts of stock enhancement strategies on Ostrea edulis in Strangford Lough. 

Unpublished Ph.D. Thesis, Queen’s University Belfast 


129


Chlamys varia (Linnaeus, 1758) - Variegated scallop 

Description 

Small (under 6.5cm) scallop with variable colouration (from off-white to yellow, orange, red or 

deep purple). The ears on its valves are un-equal, the anterior is at least twice as long as the 

posterior and bears a distinct rounded notch. The shell is ribbed and the margin of the shell is 

distinctly corrugated. 


There are several similar small scallops – this species can be distinguished from Palliolum spp. as 

it has strong ribs on the shell rather than fine lines, Chlamys distorta has distorted valves and 

Aequipecten opercularis has equally sized ears. 

Habitat 

This species cannot inhabit wave-exposed areas. It lives attached by a byssus, often associated with 

kelp holdfasts, but normally under or on boulders. Formerly it was co-dominant with Modiolus 

modiolus in horse mussel beds to the north of the Long Sheelah in Strangford Lough, with more 

than 100 individuals per m 2 . 


This species is common in Northern Ireland only from Strangford Lough where it is close to the 

northern edge of its range. The horse mussel community of which it is significant part in Strangford 

Lough, has been heavily impacted by fishing gear, causing a rapid decline in that habitat. Numbers 

are probably now less than 1% of the population in 1983. 


The major threat to the variegated scallop is the impact of commercial fishing gear on the horse 

mussel/variegated scallop community in Strangford Lough. 

Distribution 

Common off all British coasts from the lower shore to 100m. More widely known from Denmark 

to the west coast of Africa; also known from the Mediterranean. 


The majority of Northern Ireland records are from Strangford Lough where it is common on the 

low water zone on shores and also occurs sublittorally. Sublittoral populations are strongly 

associated with the horse mussel beds. Outside Strangford there are scattered sublittoral records 

130


from all coasts. In these areas it is not present on the shore as it cannot tolerate wave exposed 

conditions. 


Chlamys varia is now quite scarce in the remaining areas of Modiolus beds, where it used to be codominant 

in the beds to the North of Long Sheelah. As it is short-lived compared with Modiolus 

modiolus, but also a more southern species, it is likely to be a good indicator of recovery of the 

beds. It is recommended that this species is monitored as an important component of Strangford 

Lough Modiolus beds. 

References 

Hayward, P.J. & Ryland, J.S. (eds) (1995) Handbook of the marine fauna of north-west Europe. Oxford 


Nunn, J. 2007 Chlamys varia – Variegated Scallop. Northern Ireland Priority Species Reports [online]. 








131


Pentapora fascialis var. foliacea (Pallas, 1766) 

Ross coral or Potato crisp bryozoan 

Description 

Consists of large cabbage-like colonies composed of flat brittle plates, orange in colour. This is the 

largest bryozoan to be found around our coasts, growing to 40cm or more across. The colony 

consists of a series of brittle plates joined to each other to form a domed or hemispherical colony. 

Small colonies start by encrusting the rock and then growing a series of upright plates. On close 

examination it is easy to see that the plates are composed of thousands of small square cells. 

Planktonic larvae are released at intervals from the colony. Individual colonies grow quite rapidly 

and probably last for five to ten years. Analysis of one colony from the Bristol Channel showed a 

growth rate of approximately 2cm per year (Pätzold et al. 1987). The largest known colony was 

reported by Hincks (1880) from off the Eddystone lighthouse; this exceeded 2m in diameter and 

30cm in height. 

The main issue with the taxonomy of this species is whether the two morphological forms are 

separate species. Colonies formed from flat leaf-like plates ‘foliaceous laminae’ are present in both 

the Atlantic and the Mediterranean seas growing on hard surfaces, typically in tide swept localities. 

A second form with dichotomic branches is apparently present only in the Mediterranean, typically 

growing as an epizooan on gorgonians. The species was first described by Pallas (1766) as Eschara 

fascialis with two varieties fascialis and lamellosa. Ellis and Solander (1786) named the species 

Millepora foliacea, with two varieties lamellosa and porosa. Gautier (1962) considered the forms 

two separate species Hippodiplosia fascialis and H. foliacea. In 1968 Hastings and Ryland 

described a single species Pentapora foliacea which was the name adopted for the Marine Species 

Directory (Picton & Howson 2000). Since 1999, a single species (Pentapora fascialis) with two 

morphotypes (foliacea and fascialis) has been recognised (Hayward & Ryland 1999). 

A genetic study is currently ongoing between researchers at Heriot-Watt University and in the 

Mediterranean to try and resolve the species status (J. Porter pers. comm.). 


No other species in the area form upright lamellate colonies. 

Habitat 

Can be seen on open seabed in areas with moderate current. Often abundant between 25 and 35m; 

on southern coasts in areas of hard substrate with fast current may reach densities of one colony per 

m2 (Hayward & Ryland 1999). Important habitat, providing refuge from current for many small 

fish and invertebrate species. 

132



Rapid decline in Northern Ireland (2% per year over the last 25 years). Scarce. 


Apparently declining due to damage to the very fragile colonies by mobile fishing gear. In Skomer 

Island some studies have shown that this species is also vulnerable to damage by ropes attached to 

lobster pots. Heavy recreational diving activity has been shown to affect P. fascialis colony form 

and densities (Sala et al. 1996). 

Distribution 

Occurs off rocky western coasts of Britain and Ireland from the Hebrides southward and along the 

central English Channel. A narrow, branched form (currently treated as a morphotype, but 

previously considered to be a distinct species) is present in the western Mediterranean and in the 

Adriatic (Hayward and Ryland, 1999). Common on the southern coast of the British Isles, but 

becomes much rarer towards the north. 


Most NI records from the North Coast (Rathlin Island, the Skerries, offshore of the Giant’s 

Causeway) but one record from a pinnacle east of the Maidens. 


Records from 6 sites, all from Rathlin Island. Three of these sites were on the east coast of Rathlin. 

This area has been impacted by dredging in the past, and this would damage P. fascialis colonies. 


creation of a mobile gear exclusion zone around the SAC. 

References 

Ellis, J. & Solander, D., 1786 The natural history of many curious and uncommon zoophytes, collected by the 

late John Ellis, systematically arranged and described by the late Daniel Solander. Benjamin White and Son: 

London. 

Gautier, Y.V. 1962 Recherches écologiques sur les Bryozoaires chilostomes en Mediterranée occidentale. 

Recl. Trav. Stn. Mar. Endoume 38: 1-434 

Hastings, A.B. & Ryland, J.S. 1968 Characters of the polyzoan genera Pentapora and Hippodiplosia, with 

redescriptions of P. foliacea (Ellis & Solander) and H. verrucosa Canu. Journal of the Linnean Society 

(Zoology) 47: 505-514 

Hayward, P.J. & Ryland, J.S. 1979. British Ascophoran Bryozoans. Synopses of the British Fauna (New 

Series). Barnes, R.S.K. & Crothers, J.H. eds. No. 14. published for the Linnean Society of London and The 

Estuarine and Brackish Water Sciences Association. Academic Press 

Hayward, P.J. & Ryland, J.S. 1999 Cheilostomatous Bryozoa, part 2 Hippothooidea – Celleporoidea. 

Synopses of the British Fauna (New Series), R.S.K. Barnes & J.H. Crothers (eds), no. 14 (second edition). 

Linnean Society of London and The Estuarine and Costal Sciences Association. Field Studies Council, 

Shrewsbury 

Hincks, T. 1880 A history of the British Marine Polyzoa. John van Voorst: London 

Pallas, P.S. 1766 Elenchus zoophytum sistens generum adumbrations generaliores et specierum cognitarum 

succintas descriptions cum selectis auctorus synonymis. Petrum can Cleef, Hagae-Comitum 

Pätzold, J., Ristedt, H. & Wefer, G. 1987 Rate of growth and longevity of a large colony of Pentapora 

foliacea (Bryozoa) recorded in their oxygen isotope profiles. Marine Biology 96: 535-538 

Picton, B.E. & Howson, C.M. (eds) 2000 The species directory of the marine fauna and flora of the British 

Isles and surrounding seas. Ulster Museum and The Marine Conservation Society, Belfast and Ross-on-Wye. 

CD-ROM Edition 

Picton, B.E. & Morrow, C.C. 2007 Pentapora foliacea. [In] Encyclopedia of Marine Life of Britain and 

Ireland: http://www.habitas.org.uk/marinelife/species.asp?item=Y3510 

Sala, E. Garrabou, J. & Zabala, M. 1996 Effects of diver frequentation on Mediterranean sublittoral 

populations of the bryozoan Pentapora fascialis. Marine Biology 126: 451-459 

133


Astropecten irregularis (Pennant 1777) – Sand starfish 

Description 

A rigid star-shaped starfish with 5 short tapering arms. At the edge of each arm there is a double 

series of large square plates and a horizontal row of long pointed spines. The dorsal surface appears 

finely granular and is sand coloured, often with purple tips to the arms and a purple spot at the 

centre of the disc. 5-15cm across. 


The spines projecting from its arms and the flattened form of its arms distinguish it from other local 

starfish species. 

Habitat 

Usually on clean sand or sandy mud, where it may be buried just below the surface. It may emerge 

to feed at dawn and dusk. 


Rapid decline in Northern Ireland. 


Lives on sandy sea beds where it may be vulnerable to scallop dredging and other bottom fishing. 

Distribution 

Widely distributed from Northern Norway to Morocco and the Cape Verde Islands (Southwood 

and Campbell 2006). Common all round the British Isles apart from central and eastern parts of 

channel (Southwood and Campbell 2006), majority of records appear to be from the western coasts 

of Britain (CCW, JNCC, MBA, MCS, SNH). 

Previously known Northern Ireland Distribution 

Majority of records from SE Down coast, including Dundrum Bay. One record from Strangford 

and one from Rathlin Island (south coast). 


Records from Church Bay and the White Cliffs on Rathlin Island, and Dundrum Bay. During the 

SSNI period this species was also recorded several times from Church Bay by Seasearch divers 

(Goodwin 2006, 2008). 

134


It appears that Church Bay on Rathlin is an important habitat for this species and because of this, 

and its importance to other priority and rare species, we recommend that the area is protected from 

dredging and other disturbance immediately. 

References 

Goodwin, C.E. 2006 Rathlin Survey 4-9th June 2005, a Seasearch survey summary report. Seasearch 


http://www.seasearch.co.uk/NorthernIreland/Rathlin%202005%20Seasearch%20NI.pdf 

Goodwin, C.E. 2008 Rathlin Survey 2007, a Seasearch survey summary report. Seasearch Northern Ireland. 

Available from http://www.seasearch.co.uk/NorthernIreland/Rathlin%20Island%202007%20report.pdf 

Picton, B.E. & Morrow, C.C. 2007 Astropecten irregularis. [In] Encyclopedia of Marine Life of Britain and 

Ireland: http://www.habitas.org.uk/marinelife/species.asp?item=ZB410 

Picton, B.E. 1993 A Field Guide to the Shallow-water Echinoderms of the British Isles. London: Immel 

Publishing 



Cambridge 

135


Anseropoda placenta (Pennant, 1777) - Goosefoot Starfish 

Description 

A very thin, leaflike, flat starfish with short webbed arms. The dorsal surface has a granular texture 

of small plates. The colour is white with five radiating red lines, one down the centre of each arm. 

The centre of the disc is red and there are red margins to the arms. The red coloration may be more 

developed in some individuals and may cover most of the dorsal surface. Up to 20cm across. 


Can be distinguished from other starfish by its thin form. 

Habitat 

Characteristically found on muddy sand or muddy gravel. Often covers itself with sand or gravel. 

Apparently feeds on small crustaceans, but it is not known how these are caught. Lives in the sea at 

depths of 10-200m or more in sea loughs and on open coasts 


Rapid decline. Rare - confined to a small population of one or two sites in Northern Ireland with 

Northern Ireland being a stronghold consisting of over half the Irish population. 


It has undergone rapid decline and is scarce in Northern Ireland and the UK. This species lives in 

areas subject to bottom fishing for scallops and flatfish. It is vulnerable to damage by fishing gear. 

Distribution 

A southern species, distributed from the British Isles south to the Mediterranean, Canary Islands 

and Azores (Southwood & Campbell 2006). Found sporadically all round the British Isles, 

especially in water of 20 - 40m: present Irish Sea, English Channel. Rare on western coasts as far 

north as Shetland (although reasonably common in Scottish Sea Loughs (MNCR)); very rare on NE 

coast (Southwood & Campbell 2006). 


In Northern Ireland this species has been found at a few sites on the Antrim coast (mainly the 

Maidens, Ballygalley Head and north ends of Islandmagee; also one record from Rathlin) and at the 

Copeland Islands. 


Recorded from east of Ballygalley Head. Areas where the majority of populations occur fell 

136


outside target areas for SSNI. Vulnerable to discharge of hyper-saline water/future development 

near Larne. Survey of area around Islandmagee recommended. 

References 

Goodwin, C.E. 2007 Isle of Muck and Maidens Survey, a Seasearch survey summary report. Seasearch 


http://www.seasearch.co.uk/NorthernIreland/Muck%20and%20Maidens%202005-2006%20Seasearch% 

20NI.pdf 

Picton, B.E. 2007 Anseropoda placenta – Goosefoot Starfish. Northern Ireland Priority Species Reports 



Picton, B.E. & Morrow, C.C. 2007. Anseropoda placenta. [In] Encyclopedia of Marine Life of Britain and 




Cambridge 

137


Solaster endeca (Linnaeus, 1771) – the Northern sunstar 

Description 

A starfish with nine or ten arms. The dorsal surface is rough, with a close-set armament of clusters 

of fine spinelets. Colour varies from a dirty cream colour to a beautiful pink-purple. The tips of the 

arms are often turned up and pale coloured. Up to 40cm diameter, commonly 20cm. The only 

British starfish with as many arms is Crossaster papposus; however, this species usually has light 

concentric rings on its body, longer spine brushes “paxillae” which give the surface a bumpy 

appearance, and arms which taper more regularly. The colour and texture is similar to some 

specimens of Henricia oculata, but that species has only five (occasionally six) arms. 

Habitat 

Normally found on muddy gravel with boulders, or on silty rock surfaces in sheltered or semiexposed 

conditions. 


Decline, with Northern Ireland being a stronghold consisting of over 50 per cent of the Irish 

population. 


This species lives mostly in areas not subject to bottom fishing and feeds on other starfish so there 

are no obvious pressures on the populations from human activities. It is possible that it will be a 

sensitive indicator of global warming as Northern Ireland is at the southern limit of its shallowwater 

distribution. It probably has low fecundity and high genetic diversity due to its mode of 

reproduction. 

Distribution 

Recorded from the south coast of Ireland north around the British Isles to the North Sea. 

Apparently absent from the south coast of England, and much commoner in Scotland. Distributed 

as far north as the Arctic. 


In Northern Ireland this species has been found most often close to the Narrows in Strangford 

Lough but there are records from all round the Northern Ireland coast. There are recent Seasearch 

records from Rathlin Island and Red Bay (Goodwin 2006), Strangford Lough and the Outer Ards 

Peninsula (Goodwin 2008). 

138



One record from NW of McLaughlin Rock in Strangford (070724/01). This is a large conspicuous 

species and can readily be recognised in the field. It is surprising the SSNI made so few 

observations of this species, and it may have decreased significantly since the 1980s. Its 

distribution should be monitored in the future as it may be a good indicator for climate change. 

References 

Goodwin, C.E. 2006. Rathlin Survey 4-9th June 2005, a Seasearch survey summary report. Seasearch 


http://www.seasearch.co.uk/NorthernIreland/Rathlin%202005%20Seasearch%20NI.pdf 

Goodwin, C.E. 2008. Strangford Lough Survey 2007, a Seasearch survey summary report. Seasearch 


http://www.seasearch.co.uk/NorthernIreland/Strangford%202007%20Report.pdf 

Picton, B.E. 2007. Solaster endeca - the Northern Sunstar. Northern Ireland Priority Species Reports 



Picton, B.E. & Morrow, C.C., 2007. Solaster endeca. [In] Encyclopedia of Marine Life of Britain and 




Cambridge 

139


Leptasterias muelleri (M Sars, 1846) - Northern starfish 

Description 

A small spiny starfish, usually mauve or green in colour. In smaller specimens the spines may form 

regular lines along the arms, in larger ones they are scattered. Between each group of spines there 

are single papillae. The green colour form lives on the shore and in shallow water; the colour is due 

to single-celled algae in the tissues of the starfish. Typically up to 6cm across. Could easily be 

confused with small individuals of the common starfish, Asterias rubens or the spiny starfish 

Marthasterias glacialis. 

This starfish has direct development, brooding eggs beneath the body which hatch into small 

starfish. This is unusual; most starfish release gametes into the water column and have an extended 

swimming larval stage which gives them high fecundity and considerable dispersal powers. A 

number of northern species share this direct development, including the small cushion star Asterina 

phylactica and the purple sunstar, Solaster endeca. 

Clark and Downey (1992) separate the species into two sub-species: L. muelleri muelleri has 

stouter arms and longer spines and occurs from Norway to the Shetlands and L. muelleri celtica 

which has slightly tapering arms and shorter spines which is present in Scotland and Northern 

Ireland. 


Decline, with Northern Ireland being a stronghold consisting of over 50 per cent of the Irish 

population. Scarce - confined to a small population of one or two sites in Northern Ireland with 

Northern Ireland being a stronghold consisting of over 50 per cent of the Irish population. 


It is possible that this species will be a sensitive indicator of global warming as Northern Ireland is 

at the southern limit of its shallow-water distribution. It probably has low fecundity and high 

genetic diversity due to its mode of reproduction. 

Distribution 

Occurs under boulders and in pools on the shore, also sublittorally in moderately or very exposed 

shallow rocky sites (Picton 1993). A northern species, distributed from Norway and the Arctic, 

Britain represents the southernmost extent of its range. Occasional records on the west coast as far 

south as southwest Ireland (Picton & Costello 1998) and the Scilly Isles (MNCR), and in the North 

Sea down to Dogger Bank (Southwood & Campbell 2006). However, the majority of records from 

the British Isles are from Northern Ireland (NISS), the west coast of Scotland and the Shetland 

140


Islands (MNCR). 

Distribution in Northern Ireland 

Despite it’s priority status this species is present and fairly common on all Northern Irish coasts 

(NISS). 

Findings and Recommendations from SSNI 

Still numerous over much of the Northern Ireland coast. Would benefit from continued monitoring, 

as it may be a useful climate change indicator. 

References 

Clark, A.M. & Downey, M.E. 1992 Starfishes of the Atlantic. Chapman and Hall, London, 794 pp. 


Publishing 

Picton, B.E. 2007 Leptasterias muelleri - Northern starfish. Northern Ireland Priority Species Reports 





Picton, B.E. & Morrow, C.C., 2007 Leptasterias muelleri. [In] Encyclopedia of Marine Life of Britain and 




Cambridge 

141


Paracucumaria hyndmani (Thompson, 1840) 

– a sea cucumber 

Description 

A gherkin-shaped body with glistening white skin and five broad double rows of tube-feet are 

characteristic of this species. The tentacles are pale brown or pale pink in colour and sparselybranched. 

The body is usually covered with particles of shell and is buried in mud. The spicules are 

flat and irregular with numerous holes. Length up to 10cm by 2cm diameter. Pawsonia saxicola 

has a similar skin but lives in rocky habitats. 


Rapid decline. Rare with Northern Ireland being both a UK and Irish stronghold. 


In rapid decline possibly due to physical impact of bottom fishing gear in its habitat, although 

initial observations on areas which had been dredged recently (Brown & Picton, 1987) suggested 

that sea cucumbers were less affected than other species due to their burial in the bottom. The 

target for the fishery is the queen scallop, Aequipecten opercularis, which lives in more open 

muddy patches between the horse mussel clumps, but requires stable biogenic reefs for successful 

recruitment. 

Distribution 

Lives buried in muddy sediments usually with a high content of dead shells. 

Recorded from the south, west and north-east coasts of the British Isles, in water of 20-1150m 

depth (MNCR, Seasearch, UKOOA); particularly associated with sea lochs on the west coast of 

Scotland. More widely distributed from the Mediterranean to Norway (Southward & Campbell 

2006). 


Associated with horse mussel beds in Strangford Lough. Two previous records from Long Sheelah 

in Strangford Lough; also found once during the SLECI survey. 


This species should be included in the species monitored in relation to the Modiolus modiolus 

restoration project in Strangford Lough. 

References 

Picton, B.E. 2007 Paracucumaria hyndmani - Hyndman’s Sea cucumber. Northern Ireland Priority Species 

142




Picton, B.E. & Morrow, C.C. 2007 Paracucumaria hyndmani. [In] Encyclopedia of Marine Life of Britain 

and Ireland: http://www.habitas.org.uk/marinelife/species.asp?item=ZB4690 



Cambridge 

143


Ocnus planci (Brandt, 1835) - a sea cucumber 

Description 

A brown epifaunal sea cucumber with a smooth skin and 10 small tentacles. In larger specimens, 

the tube-feet are in five double rows, but a small, apparently neotenous form (called Ocnus 

brunneus) is known which looks exactly like Ocnus lactea, but is brown. The two species often 

occur together. The spicules are knobbly but have more than 4 holes. Normal form up to 8cm long , 

neotenous form 1cm. 


There is some confusion about the taxonomy of three closely related species; O. planci, O. 

brunneus (Forbes ms. in Thompson, 1840) and O. lacteus (Forbes & Goodsir, 1839). O. lacteus has 

a brilliant white body, but the other two species are brown. O. brunneus is a very small species (up 

to 25mm in length), originally described from Strangford Lough. O. planci is a Mediterranean 

species which can reach up to 150mm in length and is known to occur in Carlingford Lough. O. 

lacteus and O. brunneus were synonomised by Mortensen (1927) as he could find no difference 

between them apart from colour. O. brunneus has been regarded as a juvenile form of O. planci 

(Cherbonnier 1951; Panning 1971). For a full discussion, see McKenzie (1984). All three are 

currently regarded as separate species (McKenzie 1984; Southwood & Campbell 2006). 



Ireland being a stronghold consisting of >50% Irish population and >20% UK population/range. 

Declining (1% year). 


Populations in Carlingford Lough are considered vulnerable due to eutrophication and excessive 

siltation of Carlingford Lough caused by port development and aquaculture activities. 

Distribution 

Habitat is not well-defined, but apparently epifaunal on algae, shells, worm-tubes and other sessile 

invertebrates in sheltered sites. 

Western coasts of the British Isles, Irish Sea and Dogger Bank. Further distribution includes the 

Mediterranean. Apparently the small neotenous form, Ocnus brunneus, which is believed to only 

reproduce by transverse division, has a more northerly distribution than the normal, sexually 

reproducing form. The Carlingford population is unusual in that it is a northern population which 

contains large sexually mature individuals. Confusion between Ocnus lactea and Ocnus brunneus 

144


has resulted in distribution information about these species being unreliable. 


Certainly known to occur in Carlingford Lough, but elsewhere distribution is not known due to 

confusion with other species, particularly Aslia lefevrei (Southwood & Campbell 2006). 

Ocnus planci specimens were collected during previous surveys in Carlingford Lough, and were 

unusual in being much larger than the specimens reported from elsewhere in the British Isles, 

which are probably Ocnus brunneus if that is truly a separate species. 


Ocnus planci populations were found in Carlingford Lough and appeared to be abundant and in 

good health. It is recommended that molecular work is undertaken to compare these animals with 

specimens from the Mediterranean Sea and with Ocnus brunneus. A population study of Ocnus 

brunneus is also recommended, to investigate the genetic diversity within the species with a view 

to determining the level of asexual reproduction taking place. Samples were collected from 

Carlingford Lough for comparison with other populations. Ocnus brunneus was not found during 

the survey. 

References 

Cherbonnier, G. 1951 Inventaire de la faune marine de Roscoff. Bryozoaires-Echinodermes. Travaux de la 

station Biologique de Roscoff 15 (Supp. 4): 1-15 

McKenzie, D. 1984 Description of a neotype for the holothurian Ocnus brunneus (Forbes MS in Thompson, 

1840) from Strangford Lough, Northern Ireland (Holothurioidea; Dendrochirotida). Bulletin of the British 

Museum of Natural History (Zoology) 47:265-272 

Mortensen, T.H. 1927 Handbook of the Echinoderms of the British Isles. Clarendon Press, Oxford. Reprinted 

1977, Backhuys, Rotterdam 

Panning, A. 1971 Bermerkungen über die Holothurien – Familie Cucumariidae (Ordung Dendrochirota). 6. 

Mitteilungen aus dem Hamburgischen Zoologischen Museum und Institut 67: 29-51 

Picton, B.E. & Morrow, C.C. 2007 Ocnus planci. [In] Encyclopedia of Marine Life of Britain and Ireland: 

http://www.habitas.org.uk/marinelife/species.asp?item=ZB4850 


Publishing 



Cambridge 

145


Thyonidium drummondii Thompson, 1840 

- Red sea cucumber 

Description 

This sea cucumber extends its large red tentacles from muddy sediments. The tentacles are finely 

branched and may be dark red or lighter pink in colour, becoming white at the tips. The body is 

white and thick-skinned, covered all over with tube-feet. There are two rings of tentacles; an outer 

ring of five pairs of large ones and an inner ring of five pairs of small ones. Spicules are absent 

except in the introvert and tentacles. The ones in the introvert are tables with a perforated disc and 

delicate spire. Up to 25 cm in length. 


Thyonidium hyalinum (Fleming, 1828) is similar, but smaller with a more transparent skin and 

spicules with a shorter spire. 


It is scarce and has undergone rapid decline with Northern Ireland being the stronghold for the Irish 

population. This is a species primarily confined to horse mussel beds in Northern Ireland where it 

used to be present in densities of several per 10m 2 . 


This sea cucumber was a characteristic and moderately long-lived component of horse mussel beds 

in Strangford Lough until 20 years ago, but appears to have declined rapidly in recent years. This 

species is scarce and has undergone rapid decline with Northern Ireland being the stronghold for 

the Irish population 

Threatened primarily by bottom fishing with trawls or dredges which disrupt the biogenic reef 

habitat. As this species is more common farther north, it may disappear if the water becomes 

warmer. Investigations in 2003 confirmed that the horse mussel beds have declined considerably in 

the past 30 years, and this species in particular seems to have become rare. It was not seen during 

the 2003 SLECI (Strangford Lough Ecological Change Investigation) fieldwork, but there was one 

sighting in 2005 during a Seasearch dive. Sea cucumbers are known to disappear beneath the 

surface for extended periods and it is possible that more specimens are present than have been 

observed. 

146


Habitat 

Lives buried in mud, usually in sheltered sites and deeper than 20m. Associated with horse mussel 

beds in Strangford Lough. Strangford Lough is the type locality for this species. 

Distribution 

Recorded from all around the British Isles. Frequent in sea lochs and sheltered sites in west 

Scotland. As far north as Iceland, Greenland and Northern Norway; British populations represent 

the southern extent of its range. 


Only known from Strangford Lough. 


Some individuals were found associated with areas of horse mussel beds, but the densest 

populations occurred in areas of muddy sand adjacent to the beds (070606/06, SE Black Rock). 

This type of habitat would merit further survey work. May hibernate for parts of the year, so timing 

of surveys should be considered. 

References 

Picton, B.E. 2007 Thyonidium drummondii - Drummond’s Sea cucumber. Northern Ireland Priority Species 



Picton, B.E. & Morrow, C.C. 2007 Thyonidium drummondii. [In] Encyclopedia of Marine Life of Britain and 




Cambridge 

147


Leptosynapta bergensis Őstergren, 1905 – a sea cucumber 

Description 

A worm-like holothurian with twelve pinnate tentacles and no tube-feet. Each tentacle has 8-11 

pairs of digits, increasing in length towards the end of the tentacle. Colour is pink with a 

transparent skin and obvious longitudinal muscle-bands. Spicules are anchors associated with pearshaped 

anchor-plates. Typically 10-30cm in length. 


May be confused with other burrowing sea cucumbers. Identity can be confirmed by examination 

of the spicules. 

Habitat 

Burrows in muddy sand or gravel in the sublittoral. 

Distribution 

Found on all coasts of the British Isles but fairly scarce, most records are from the west coast of 

Scotland and offshore north east Scotland (MNCR, UKOOA). Two records from the west coast of 

Ireland (BioMar). Wider distribution north to Faeroes and Norway and as far south as northern 

France (Southwood & Campbell 2006). 


Only previous record from SE of Dunnyneill Island, Strangford Lough. 


Not found during SSNI. This species may be hard to find due to its infaunal mode of life. Targeted 

searching for this species in the area where it was previously recorded would be needed to establish 

the status of its populations. 

References 


Publishing 

Picton, B.E. & Morrow, C.C. 2007 Leptosynapta bergensis. [In] Encyclopedia of Marine Life of Britain and 




Cambridge 

148


Labidoplax media (Ostergren, 1905) - a sea cucumber 

Description 

A tiny transparent worm-like holothurian which lives at the surface of soft mud. There are twelve 

tentacles each with four digits. The body wall is transparent and five longitudinal muscle-bands are 

visible internally by transparency. The spicules consist of anchors and racket-shaped anchor-plates 

with handles. 2-3cm in length. 


Labidoplax buski (McIntosh, 1866) is very similar, but has 11 tentacles with a long terminal digit 

and a single pair of lateral digits. 


Declining (1% year) with Northern Ireland being a stronghold consisting of >50% Irish population 

and >20% UK population/range. Scarce in Northern Ireland. 


Ecological deterioration of Strangford Lough due to excessive fishing pressure and eutrophication. 

Distribution 

Lives at the surface or just buried in flocculent mud. It was originally described from two damaged 

specimens dredged in Norway in 1905. It was not reported again until dredged from Strangford 

Lough in 1960. Further specimens were obtained from the same area in 1971 and 1972 (Gotto & 

Gotto 1972). There are also records for Strangford Lough from the Northern Ireland Sublittoral 

Survey (Erwin et al. 1986). More recently, other UK records have been made from sheltered sea 

lochs on the west coast of Scotland; it has been recorded from Loch Sunart, Loch nan Ceall, Loch 

Maddy, Loch Skip and Loch Uiskevagh (MNCR). The related species, Labidoplax digitata, occurs 

in coarser, fine sand substrates, and is more widespread. 


Locally abundant in areas of fine, glutinous, black mud in Strangford Lough (Gotto & Gotto 1972). 

Originally recorded at 10m depth off Salt Island and Green Island in the Quoile Estuary (Gotto & 

Gotto 1972). During the Northern Ireland Sublittoral Survey, further records were obtained from 

east of Town Rock, Quoile Estuary, and Bird Island Passage (Erwin et al. 1986). These were also 

all from fine mud habitats; the Bird Island passage record was somewhat deeper water (up to 20m). 

149



This tiny sea cucumber is hard to see in the field. One observation (September 2005, B.E. Picton) 

of numerous specimens attached to collected shells in Bird Island Passage suggests that substantial 

numbers are probably still present in Strangford Lough. 

References 



Gotto, D.M. & Gotto, R.V. 1972 Labidoplax media Oestergren: a sea cucumber new to British and Irish 

waters, with observational notes. Irish Naturalists’ Journal 17(8): 250-252 

Picton, B.E. & Morrow, C.C. 2007 Labidoplax media. [In] Encyclopedia of Marine Life of Britain and 


150


Pyura microcosmus (Savigny, 1816) - a sea squirt 

Description 

A dirty brown, wrinkled solitary ascidian. The test is very thick and leathery and is wrinkled even 

when the animal is fully expanded. It is covered with detritus, algae and other epibionts. The 

siphons are fairly long when fully expanded, but sensitive to light or disturbance so that they 

quickly contract on close inspection. They are longitudinally marked with red and white lines, most 

obvious on the inner surfaces. The openings become square and fluted in partial contraction. 


Similar species are Polycarpa pomaria, Microcosmus claudicans and Pyura squamulosa. 


Rapid decline in Northern Ireland (2% per year over the last 25 years). Scarce. 


Strangford Lough was the Northern Ireland stronghold for this species. In Strangford Lough it was 

associated with the horse mussel bed communities. It has been impacted by any damage to these. 

Distribution 

Found on western and southern coasts of the British Isles, common, particularly on the west coast 

of Scotland. Extends southwards to the Mediterranean. 


The majority of Northern Ireland records are from Strangford Lough, where it is characteristic of 

the horse mussel bed (Modiolus modiolus) communities. There are also scattered, fairly scarce, 

records from the north and north-east coast from the Skerries to Carnlough and one record from the 

Copelands. 


Despite resurveying the Strangford Lough horse mussel beds, this species was not found. We 

recommend that it is searched for on future surveys of this area (for example those carried out by 

the Modiolus restoration group). Ascidians are a very poorly known group and lack of knowledge 

of their taxonomy may result in under recording by marine surveyors. We recommend that a 

training course on ascidian taxonomy be organised; this would increase the profile of the group and 

hopefully result in more records of ascidian species in the future. 

151


References 

Erwin, D.G., Picton, B.E., Connor, D.W., Howson, C.M. Gilleece, P. & M.J. Bogues 1990 Inshore Marine 


Millar, R.H. 1970 British Ascidians. Synopses of the British Fauna, no 1. The Linnean Society of London. 

Academic Press: London and New York 



152

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