Direct effects of beamtrawling on macrofauna in a sandy sediment in the southern North Sea

Abstract

The presence of certain species of benthic infauna in catches from a beamtrawl indicated that tickler chains and the ground chain can scrape off successive layers of sediment and reach at least 6 cm into the sediment. Direct effects of beamtrawling on benthic species in the North Sea were determined by comparing faunal abundance before and after commercial beamtrawling on a hard-sandy sediment. In autumn 1989 three-fold trawling of the experimental area resulted in a decrease in density (10–65%) of a number of species of echinoderms, polychaetes and molluscs.