assess it and monitor it? by Prof. J.G HARMELIN - Regional Activity ...

LE CORALLIGENE, UN PATRIMOINE EXCEPTIONNEL :
COMMENT L’EVALUER ET LE SURVEILLER ?
J.G. Harmelin, Tabarka, 01 2009

THE CORALLIGENOUS COMMUNITY,
AN EXCEPTIONAL HERITAGE:
HOW TO EVALUATE AND TO MONITOR IT?
J.G. Harmelin, Tabarka, 01 2009

Why y this heritage g is so remarkable?
- Biodiversity hot-spot: local species richness > 600 esp.,
about 1700 species recorded (Ballesteros (Ballesteros, 2006). 2006)
- Construction of huge bioherms.
- Structural importance of long-lived species with weak
population dynamics (slow growth, sporadic recruitment).
- Occurrence of rare, vulnerable species.
- Occurrence of species with very high commercial value value.
- Exceptional aesthetic value of the coralligenous
scenery scenery, shaped by sessile and mobile species species.

But the coralligenous heritage is impacted
But the coralligenous heritage is impacted
by many sources of alteration

Pollution Facies of Lithophyllum incrustans at 400 m
from the Marseille’s sewer outlet
- Increase of turbidity & silting +
chemical pollutants
• Exclusion of sensible species species,
proliferation and monopolization
of habitat by opportunistic species
Gulf of Fos, 21 m: industrial area
+ harbour + Rhône river
at 3000 m from the
same sewer outlet

Fishing gears
Physical damages in
hi highly hl ffrequented t d sites it
Divers
This
Paramuricea was
probably
50 yrs old!
Anchors

Invasive algae
Port-Cros, Galère,
34m, 06/2003
Port-Cros,
Gabinière Gabinière,
33m, 08/2004
Port-Cros, Gabinière 30m, 09/2007
Filamentous
algae g
Exotic Caulerpa racemosa cylindracea

Paramuricea clavata
Positive thermal anomalies
1999, 2003: mortality of many invertebrate
species
Spongia officinalis
Pentapora fascialis

Excessive fishing

The coralligenous habitat is particularly vulnerable
and thus needs a particular attention
Two main objectives:
- evaluation of its condition, at various spatial scales;
- characterization of changes occurring in sites.
Great need for :
(1) reliable and easily perceptible criteria of good health
of the coralligenous assemblages,
(2) methods of assessment and monitoring easy to
(2) methods of assessment and monitoring easy to
operate

Same objectives as for the other Mediterranean icon:
the Posidonia oceanica beds
• 1 single founding species, species
photosynthetic & infralittoral
• limited vertical distribution,
• criteria of quality simple
and quantifiable

Coralligenous
assemblages form a
much more complex,
multiform system!
• formed o ed by multiple u t p e
engineer species, often
patchtly p y distributed, ,

Coralligenous assemblages form a much more complex, multiform system!
Coralligenous bioherm: the true
coralligenous habitat fide Laubier
(1966), Ballesteros (2006), and al.,
… or a particular p facies among g the
coralligenous assemblages
• Contrast between bioherms
bbuilt ilt by b Corallinacae
and rocky walls dominated by
llarge suspension-feeder i f d
invertebrates

Coralligenous assemblages form
a much more complex, multiform
system!
• integrates intimately
many communities, from
algae assemblages to
cave communities

Coralligenous assemblages form a much more complex, multiform system!
North-Western Mediterranean
(F (France, Port-Cros, P t C 44 44m)
)
• presents a wide geographic variability
Eastern Mediterranean (Turkey, Kas, 45m)

Coralligenous assemblages form a much more complex, multiform system!
• distributed over a vast vertical range
in the Circalittoral zone.
15 m 65 m
> 100 m
limited accessibility
+ high survey costs

Biodiversity is the
fundamental quality
of the coralligenous
habitat
How to qualify and to
quantify this diversity at
different geographic
scales?
How to monitor temporal
changes in diversity ?
Through inventories covering
all groups? A considerable work which
• Laubier (1966): 544 invertebrates, needs destructive sampling and
• Hong (1980): 682 species an armada of taxonomists,
• Ros et al.: 497 species and information obtained is local

Necessity to focus
on particular large
species, or limited
assemblages
3 approaches
1 - Visual censuses and
direct measurements
Particular species or small assemblages
Some targets:
large perennial algae
scleractinians
gorgonians
large erect bryozoans
large crustaceans
large echinoderms
fish
2 - Photographic &
video id recordings di
Larger assemblages
3 - In situ experiments
ee.g., g colonisation by cryptic
bryozoans;
diversity and activity of bioeroders

Necessity to focus on particular large species, or limited assemblages
1 - Visual censuses and
direct measurements
Particular species or small assemblages
Examples of targets:
1.1 - gorgonians
1.2 - large erect bryozoans
1.3 - fish

1.1 - Assessment of the condition of
gorgonian populations
• Size measurements
( ( demographic
structure, biomass)
• Density of population
+
• Rate of necrosis
• Fouling stage

1998 1999
Pérèz et al., unpublished
Monitoring of Paramuricea clavata populations
affected by mortality events
A
B
Permanent plot before (A) and after (B) the mass
mortality at la Gabinière, Port-Cros in 1999
Linares et al. (2008)
18 quadrats (2 m²)
1992
La Galère, 22-30m
P. clavata
Biomass
2004
Harmelin & Garrabou, 2005
Density (N colonies/m²): changes
between 1999 and 2007

1.2 - Large erect bryozoans as indicators of
healthy coralligenous habitat
Adeonella calveti Smittina cervicornis Pentapora fascialis Turbicellepora avicularis
Myriapora truncata Reteporella grimaldii
Distribution of 6 large erect bryozoans in
g y
coralligenous bottoms subjected to
pollution gradients

1.2 - Large erect bryozoans as indicators of
healthy coralligenous habitat
Adeonella calveti Smittina cervicornis Pentapora fascialis Turbicellepora avicularis
Myriapora truncata Reteporella grimaldii
Average N of species and colonies in
0.25 m² quadrats

Fish as indicators of global change and protection in coralligenous bottoms:
1.3 - Censuses of the dusky grouper population in the National Park of Port-Cros
120 N
100
80
60
40
20
0
Coralligenous sites
10-155
20-255
30-355
Port-Cros, October 2008
Demographic structure
40-455
50-555
60-655
70-755
80-855
Total length (cm)
90-955
100-1055
110-1155
120-1255
450
N
400 Sh Shallow ll sites it
350
300
250
200
150
100
50
0
Coralligenous sites
1993 1996 1999 2002 2005 2008

Necessity to focus on particular large species, or limited assemblages
2 - Photographic &
video recordings
Examples:
2.1 - red coral
22- 2.2 - plurispecific assemblages
associated to Paramuricea
2.3 - invasion of coralligenous
assemblages by Caulerpa racemosa

2.1 - Assessment of the status of the local red coral populations:
Size of colonies
Not protected: Marseille
PProtected: t t d SScandola d l
Old method: direct measurements
New method: photogrammetry.
Measurements obtained by y image g
analyses
O. Bianchimani, 2005
R. Graille, 2007

Approach 2: Photographic recordings
Medchange
Objectif 3
Aspects écologiques
2.2 - Long-term analyses of the community
dynamics: photographic series by J. Garrabou
Medes (Catalonia)
series: since 1993
Riou (Marseille)
series: since 2000
Joachim Garrabou Núria TEIXIDÓ
Joachim Garrabou, Núria TEIXIDÓ,
Eva MÁRQUEZ I CANALS

Medchange
Objectif 3
Aspects écologiques
2.2 - Characterization of macrospecies biodiversity
in two gorgonian communities

Objectif 3
Caractérisation de la biodiversité des communautés de
Paramuricea clavata
3 localities
Photo-quadrats (25 x 25
cm) within permanent
plots in the P. clavata
community
Identification of species within the photo-quadrats,
+ if needed, d d verification ifi ti with ith mini-samples.
i i l

Objectif 3
Caractérisation de la biodiversité des communautés de Paramuricea clavata
Premiers résultats
22 bryozoaires
Nombre de taxons:
7 algues
7 tuniciers
10 cnidaires 3 polychètes
39 éponges
1f 1 foraminifère i ifè

Objectif 3
Caractérisation de la biodiversité des communautés de 2
gorgonaires Quadrats de P. clavata
Scandola Marseille Mèdes
Sit Sites SPA SPL SGL PGP PCO MME MPT MRB
Nombre
d’espèces pour
une même
surface
65 54 63 67 57 59 50 60
Cnidaires (sur
10) 8 6 5 8 5 6 7 6
Bryozoaires (sur
21) 16 12 14 15 14 12 11 10
E Eponges (sur ( 42)
23 19 26 28 25 26 22 28
Total des espèces
suivies 97

Objectif 3
Caractérisation de la biodiversité des communautés de Paramuricea clavata
Premiers résultats
% Occurrence of taxa on 1m2 quadrats: geographic variability of the
community composition
• Clear differences between
regions: Corsica # Marseille
#M # Medes d
• Differences within regions
and within sites are also
sometimes well marked:
1. Site de Pallazinu très
différent des autres
2. Grande différence entre les
deux quadrats du site de la
Grotte Pérès

Marseille, Riou Is., 35 m
Remark on inter-sites
differences
The occurrence of a particular
species may be informative,
not its lack, except if proved that
it was formerly yp
present
Port-Cros national Park,
Gabiniere Is., 35 m
Red coral: common at Marseille
is naturally absent at Port-Cros
= 0

2.3 - Monitoring of the colonization of the coralligenous bottoms by
Caulerpa racemosa cylindracea at Port-Cros (GIS Posidonie, 2008)
Impact p on the assemblages g of deep-water p Cystoseira y spp. pp and Corallinacae
Study by photo-quadrats
and image g analyses, y , and
in situ measurements of
the Cystoseira population
parameters

Necessity to focus on particular large species, or limited assemblages
3 - In situ experiments
Examples:
3.1 - colonisation by cryptic bryozoans
32- 3.2 - diversity and activity of bioeroders

Assessment of the coralligenous species richness through the
study of colonisation by cryptic bryozoans
Why?
• Cavities of the coralligenous
bioherm are occupied by rich
assemblages dominated by
bryozoans
• This part of the coralligenous
biodiversity is poorly accessible
and standardization of sampling
is not easy
• Dispersal of larvae produced
by cryptic bryozoans is very
limited
recruitment mirrors the
recruitment mirrors the
local assemblage

3.1 - In situ experiments : colonisation by cryptic bryozoans
altered
sites i
« normal »
sites
Cyclostomes
are good d
indicators
from Harmelin & Capo (2002)

3.2 - In situ experiments : diversity and activity of bioeroders
Wh Why? ?
• Bioerosion increases in altered coralligenous sites
(Hong (Hong, 1980)
• This part of the coralligenous assemblage is poorly
accessible and standardization of sampling is not
easy
Experimental colonization
of standardized blocks of
coralligenous concretion
may provide information
about the environmental
status of sites (cf. poster by S.
Sartoretto Sa to etto et a al.) )

Concluding remarks
• The complexity and multiplicity of aspects of the coralligenous
bottoms imply multiple monitoring targets and the use of various
methods.
• Changes in the status of some flagship species of the
coralligenous assemblages bring obvious indications.
• HHowever, a systemic t i approach h would ld bbe ddesired i d ffor evaluating l ti
the coralligenous sites.
A methodology using a panel of bioindicators and physical
parameters p should be conceived for the coralligenous g
assemblages, such as CARLIT methodology for littoral and
upper-sublittoral upper sublittoral communities (Ballesteros et al., 2007).

1966
1996
Last remark from an old diver
(and photographer)
We need to store carefully
the memory y of the ppresent
UW landscapes!
Unfortunately, y we have already y lost a
considerable amount of information on
the evolution of the physiognomy of
sites during the last fifty years, a
crucial period!

Somewhere in Provence,
40m, during the sixties,
but where exactly?
And now, how is this
landscape?
after repeated impacts of
anchors, nets, thousands of
We need to store carefully
the memory of the present
UW landscapes!
It is time now to use the
proper tools to map precisely
series of reference sites in
every y region, g , and to ppicture
them precisely at different
landscape? spatial scales scales.
divers divers, temperature
anomalies, and invasive
algae?

THANK YOU FOR YOUR ATTENTION