Effects of fishing on the structure and functioning of estuarine and nearshore ecosystems

Estuaries and associated coastal waters support many essential fisheries, a fact which contributes to their disproportionately high economic value. Th ey are, however, also among the most extensively modified and threatened of aquatic environments. Almost all have been strongly affected by human bein gs, and fisheries are an integral part of human activities on the coast. We have taken a global perspective in synthesizing the effects of fishing on estuaries and coastal waters. Rather than attempt to cover an regions of th e world in detail, we review eight process-orientated categories affected b y fishing, with case studies for each of them: target organisms, non-target organisms, nursery functions, trophic effects, habitat change, reduced wat er quality, human environment, and potential for local extinctions. Fishing in the estuarine and nearshore environment has clear impacts on the struct ure and functioning of these ecosystems, although other, non-fishing issues also effect these ecosystems. This creates multiple interactions and reinf orces the need for an integrated approach to coastal zone management. Nonet heless, some form of fish-based action plan could be created. especially wi thin estuaries, which would provide management objectives for a particular system. (C) 2000 International Council for the Exploration of the Sea.