A quantitative analysis of fishing impacts on shelf-sea benthos

1, The effects of towed bottom-fishing gear on benthic communities is the s ubject of heated debate, but the generality of trawl effects with respect t o gear and habitat types is poorly understood. To address this deficiency w e undertook a meta-analysis of 39 published fishing impact studies. 2, Our analysis shows that inter-tidal dredging and scallop dredging have t he greatest initial effects on benthic biota, while trawling has less effec t. Fauna in stable gravel, mud and biogenic habitats are more adversely aff ected than those in less consolidated coarse sediments. 3. Recovery rate appears most rapid in these less physically stable habitat s, which are generally inhabited by more opportunistic species, However, de fined areas that are fished in excess of three times per year (as occurs in parts of the North Sea and Georges Bank) are likely to be maintained in a permanently altered state. 4. We conclude that intuition about how fishing ought to affect benthic com munities is generally supported, but that there are substantial gaps in the available data, which urgently need to be filled. In particular, data on i mpacts and recovery of epifaunal structure-forming benthic communities are badly needed.