Following award of exclusive rights for development from the Crown Estate, East Anglia Offshore Wind Limited (EAOW) Limited commissioned Fugro EMU Limited (Fugro EMU) to conduct surveys to characterise the benthic ecology of the East Anglia THREE and FOUR cable routes. Additional sampling was also undertaken within East Anglia THREE and FOUR windfarms. These characterisation surveys were conducted during May 2013 and involved a range of industry standard sampling techniques such as grab sampling, sea bed video surveillance and scientific beam trawling to describe the distribution of sea bed habitats and associated biological communities. Samples were also collected for sediment chemistry testing. This document presents the methods, results and ecological interpretation of the sample data which will be subsequently used to inform Environmental Impact Assessment in support of the application for development consent.
2.
Data indicated a macrofaunal distribution based on sea bed sediment type. Fauna were considered to be typical of gravelly sand and sands in the southern North Sea. The most abundant species from the grab survey was Ophelia borealis. Four of the top ten most abundant species or taxa were more widely recorded and these were the polychaete worms, O. borealis, Nephtys cirrosa, Nemerteans and juvenile brittlestars, Ophiuridae, which are considered typical of the southern North Sea sand sediments.
3.
The epibenthic fauna recorded from 2m beam trawl samples were also considered typical for the southern North Sea and included invertebrate species like the common starfish Asterias rubens, the brittlestars, Ophiura albida and Ophiura ophiura and the flying crab Liocarcinus holsatus. Dominant fish species were solenette Buglossidium luteum, dab Limanda limanda, pogge Agonus cataphractus, and dragonet Callionymus lyra. In general these communities were wide ranging across the survey area.
4. 5.
One site within East Anglia THREE and one site in East Anglia FOUR were found to comprise an area of Sabellaria spinulosa reef which is an Annex I habitat.
Levels of sediment contaminants were largely below guideline limits and in all cases typical of the region.
Benthic Characterisation Report November 2013
East Anglia THREE and FOUR Offshore Cable Corridor
