The occurrence of Lophelia pertusa and other conspicuous epifauna around an oil production platform in the North Sea.

Lophelia pertusa is a cold-water coral most frequently reported on the shelf edge and offshore banks of the north east Atlantic. The occurrence of this and other conspicuous large epifauna on moorings 2 km from an oil production platform in the North Sea were recorded from video surveys by remotely operated vehicle. Sea anemones and soft corals were abundant and a total of 133 colonies of L. pertusa were observed. These occurrences and those on the Brent Spar are the first documented reports of live L. pertusa in the North Sea. L. pertusa was restricted in its distribution to water >70 m, below the seasonal thermocline in the northern North Sea. It is estimated that coral sampled from a single point mooring had a linear extension rate of at least 5 mm per year, a rate comparable with existing estimates. It seems likely that these colonies will have originated from populations along the Atlantic margin with larvae transported into the northern North Sea in cooled Atlantic water, possibly via the east Shetland Atlantic Inflow current. The implications of this finding in terms of the environmental sensitivity of this species remain unclear since it is not known to what extent they have been exposed to any drilling discharges. It is possible that corals have persisted on and around oil industry installations as bottom trawling is excluded from the installation area.