INTRODUCTION Since April 1972 an ecological trawl-survey programme has been undertaken by the Netherlands Institute for Sea Research (NIOZ), Texel, in the southern North Sea with the R. V. "Aurelia". The main object is to obtain information on distribution, density, biomass and fluctuations of crawling or swimming demersal (epibenthic) fauna such as small fishes, shrimps, prawns, crabs, asteroids, ophiuroids and some gastropods, for the evaluation of the role of these carnivores in the benthic ecosystem of the southern North Sea. Sedimentological aspects of the area are described by Creutzberg & Postma (1979). Within the context of the present paper the most important feature is the mesh of 5 x 5 mm2 of the cod end of the 51/2 m beam-trawl used and the... |