Environmental Statement - Maersk Oil

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Balloch Field Development Environmental Statement
Section 3 Baseline Environment
(IUCN) has assessed the conservation status of a limited number of fish groups and recommended
that two North Sea inhabitants, the basking shark (Cetorhinus maximus) and the common skate
(Leucoraja batis), be added to the IUCN 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 thus are not vulnerable to human activity in the area of Quadrant 15.
Of the species listed, only the European sturgeon (which is relatively rare), the basking shark (UK
Biodiversity Action Plan and 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
(Rogers and Stocks, 2001). Although present within the North Sea, they are uncommon and widely
dispersed; hence they 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).
Of the four species listed above, only the harbour porpoise is a regularly occurring species in the
region of the proposed development.
The bottlenose dolphin and harbour porpoise are also classified as European Protected Species (EPS),
along with all cetacean species 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
potential offences to EPS species (Section 5.4.4).
3.5. THE SEABED
Through the processes of erosion, transport and deposition, seabed sediments are often in a state of
dynamic equilibrium. Understanding the nature of the seabed sediments in the area of the Balloch
development will help assess the potential for scouring in the area, as well as any impacts it may have
on the proposed development.
3.5.1. SEABED SEDIMENTS
Seabed sediments comprising of mineral and organic particles occur commonly across the United
Kingdom Continental Shelf (UKCS) in the form of mud, sand or gravel and are dispersed by processes
driven by wind, tides and contrasts in water density. The nature of local seabed sediments is an
important factor in providing information to help assess the potential for scouring of sediments
around installed facilities. The seabed sediment distribution in the North Sea is illustrated in Figure
3‐8.