Macrozoobenthic community structure was studied in two surveys along a transect of 13 stations following the submersed Pleistocene Elbe valley in the south-eastern North Sea during Mai to June 2000 and March 2001. Two replicates of bottom samples were taken with a van Veen grab of 0.1 m2 sampling size. In order to analyse the benthic macrofauna communities, the animals obtained were identified and counted, and MDS and cluster analysis were performed. Out of the 200 taxa identified 84 were polychaetes, 46 molluscs, 40 crustaceans, 15 echinoderms, and 15 belonged to other groups. Mean abundance was 4,860 individuals per m2, mean biomass 32.9 g ash free dry mass per m2. Mean diversity was 1.76 and mean evenness 0.54. The macrofauna of the Pleistocene Elbe valley is composed of three associations according to the cluster analysis. Each association is described by a combination of characterizing and discriminating species. An Amphiura-brachiata―Tellymya-ferruginosa-association was found in the south-eastern part of the depression, whereas a transitional association with elements of both assemblages lead over to an Amphiura-filiformes―Galathowenia-oculata―Nuculoma-tenuis-association in the north-western part of the valley. In the context of the entire southern North Sea, both associations are small-scale sub-structures, and as such are contained in the Nucula-nitidosa-community and the Amphiura-filiformis-community respectively. A north-westward shift of the community of the southern Elbe valley was found and discussed as a possibleconsequence of warm winters of the last decades.
Helmholtz Research Programs > MARCOPOLI (2004-2008) > POL4-Response of higher marine life to change