Environmental statement - Flyndre and Cawdor - Maersk Oil

Flyndre and Cawdor Environmental Statement
Section 3 Environmental Baseline
Pockmarks have been observed as habitats for unusual and prolific fauna which may be related to the
carbon associated with the MDAC and an increase in sulphide compounds being available to enter the
food chain or the physical presence of the MDAC as a hard substrate. In addition, as a result of the
depression, currents are likely to be reduced within the pockmark and finer sediments with higher
organic content are likely to accumulate. The lower bottom currents can lead to high levels of larval
settlement, thus a higher abundance of deposit feeding organisms is often observed in comparison to
the surrounding area. Bivalve species such as Thyasir sarsi and Lucinoma borealis are dependent on
high sulphide concentrations and are only found within pockmarks, not the rest of the open North
Sea. There is also a tendency for higher levels of suspended solids to be associated with the water
within pockmarks which may lead to increased abundance of shrimps and euphausids. Fish also may
take advantage of the sheltered conditions within the pockmark for example cod (Gadus morhua),
torsk (Brosme brosme) and ling (Molva molva) (Dando, 2001).
3.2.2. SPECIES
The designation of fish species requiring special protection in UK waters is receiving increasing
attention with particular attention being paid to large slow growing species such as sharks and rays.
At a national level ‘The Wildlife and Countryside Act 1982, which implements the Convention on the
Conservation of European Wildlife and Natural Habitats, lists seven protected species of marine and
estuarine fish (European sturgeon, Allis and Twaite shad, basking shark, the whitefish Coregonus
lavaretus, the giant goby and the couchs goby). Under the EC Habitats Directive there are six fish
species (European sturgeon, Allis and Twaite Shad, River and Sea lamprey, basking sharks and the
whitefish Coregonus lavaretus) that are afforded protection. In addition the International Union for
the Conservation of Nature and Natural Resources (IUCN) has assessed the conservation status of a
limited number of fish groups, and have recommended that two North Sea inhabitants; the basking
shark (Cetorhinus maximus) and the common skate (Leucoraja batis), be added to the red list of
endangered species.
Few of the fish species listed above have distributions that extend into the offshore waters of the
North Sea, and are thus not vulnerable to human activity in the areas of Quadrant 30.
Of the species listed, only the European sturgeon (very rare offshore species), the basking shark (UK
Biodiversity Action Plan & IUCN Red List – Endangered), tope (IUCN Red List – Vulnerable) and
porbeagle (IUCN Red List – Vulnerable) are likely to occur in the CNS. Generally, these species occur
in small numbers throughout the North Sea at times of peak zooplankton distribution and abundance
(CEFAS, 2001). Although present within the North Sea they are uncommon and widely dispersed and
are unlikely to be found in particular concentrations within this block.
Four species from Annex II of the Habitats Directive occur in relatively large numbers in UK offshore
waters;
Grey seal (Halichorerus grypus)
Common seal (Phoca vitulina)
Bottlenose dolphin (Tursiops truncatus)
Harbour porpoise (Phocoena phocoena).
The bottlenose dolphin and harbour porpoise like all the cetacean species found in UK waters are also
categorised as European Protected Species status, along with several other marine mammals found in
UK waters. As such developers must consider the requirement to apply for the necessary licences
should they consider there to be a risk of causing any of the potential offences to EPS species, this is
discussed further in the section on marine mammals (Section 3.5.5.). Of the four species that are
being considered for SAC, only the harbour porpoise inhabits the offshore area in the region of the
proposed development.
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