CHANGES IN MEGAFAUNAL BENTHIC COMMUNITIES IN DIFFERENT HABITATS AFTERTRAWLING DISTURBANCE

As part of a long-term study to examine the ecological effects of beam -trawling, we investigated the immediate impact of fishing on the mega faunal component of a benthic community and the extent to which it had recovered 6 months later. A quantitative dredge was used to collect m egafaunal samples following a replicated, paired control and treatment design to maximize the chances of detecting any effects due to trawli ng. There were two different habitats with distinct communities in the experimental area, one with stable sediments and a rich fauna, the ot her with mobile sediment and a relatively impoverished fauna. Immediat ely after fishing the composition of the community in the stable sedim ents was significantly altered. While the abundance of some species de creased (e.g. sea mice Aphrodita aculeata), others apparently increase d (e.g. hermit crabs Pagurus bernhardus). Variation between samples fr om the fished areas was higher than those From the control areas. This suggests that the effects of trawling were not uniform, even though t he treatment area was entirely swept at least once. The effects of fis hing were not delectable in the mobile sediments. Six months later, se asonal changes had occurred in both communities and the effects of the trawling disturbance were no longer evident. :(C) British Crown copyr ight 1998.