Distributional patterns of macro- and megafauna associated with a reef of the cold-water coral Lophelia pertusa on the Swedish west coast

Abstract

In this study the distributional pattern of the macro- and megafauna of a small (ca. 300 m2) Lophelia pertusa (L., 1758) reef was studied with a ROV (remotely operated vehicle). The reef is situated in a shallow fjord off the Swedish west coast. The number of taxa and their abundance in transects from the reef itself and from 3 zones (Zone 1 = 50 m, Zone 2 = 100 m and Zone 3 = 200 m) around the reef were compared. Both the number of taxa (from 30 to 33 transect-1) and the abundance of individuals (from 21 to 7 m -2) decreased with increasing distance from the reef. Divided into ecological guilds, predators and filter-feeders decreased with distance from the reef (predators from 7 to 0.3 ind. m-2, and filter-feeders from 13 to 6 ind. m-2 from Zone O to Zone 3), while deposit-feeders increased with increasing distance from 0.04 to 0.4 ind. m-2 from Zone 0 to Zone 3. Sessile species decreased more with increasing distance than mobile species, from 19 to 7 ind. m-2 and from 1 to 0.7 ind. m-2, respectively. Our results also show that small deep-water coral reefs enhance local biodiversity, but the advantage to individual species depends on their mode of feeding and mobility.