The macrozoobenthos of an important wintering area of the common scoter (Melanitta nigra)

Abstract

In October 1994, 39 macrobenthic samples, divided between two areas, were taken on the western Belgian Coastal Banks. The two areas could not be clearly divided, concerning their macrobenthic communities. Multivariate techniques revealed five coherent communities, linked with typical sedimentological factors: (1) the Barnea candida community in a very compact muddy sediment (median 14 μm); (2) a second community characterized by the presence of spat of Mytilus edulis, with a medium sandy sediment (median 456 μm); (3) the Lanice conchilega community inhabiting a fine sandy sediment (median 211 μm); (4) the Nephtys cirrosa–Echinocardium cordatum community in a coarser fine sandy sediment (median 242 μm); and (5), closely related to the latter, the N. cirrosa community also occurring in a fine sandy sediment (median 224 μm). Only the L. conchilega community belongs to the diverse transition zone. The other four communities seem to be part of the heterogeneous, species-poor coastal zone associations. No open sea communities have been detected in the area.

On the western Coastal Banks only the L. conchilega community, because of the high numbers of Abra alba, Tellina fabula, and Spisula subtruncata, can be interesting as feeding grounds for the common scoter (Melanitta nigra (Aves: Mergini)). Comparison of the spatial distribution of the wintering common scoters and the L. conchilega community revealed no direct similarity. The factors possibly causing this dissimilarity have been discussed.