A Comparison of the Ecological Risks from Fisheries and Pollution to the North Sea Biota

Abstract

A prototype of the ecological risk analysis framework REFEREE is used to demonstrate a comparative evaluation of the effects of three main perturbing factors on the functioning of the North Sea ecosystem. Fisheries obviously have a large impact on fish species: some are reduced, others are increased in density. Fisheries also contribute substantially to the decline of mammals, although pollution is the main causative factor in their demise and that of birds. Oddly, some fish species appear to benefit from contamination. Eutrophication causes an increase in crustaceans, polychaetes, coelenterates and meiofauna, and a decrease in echinoderms and molluscs. Sole is one of the few fish species that appears to benefit from eutrophication, the others are suppressed.

Overview of Hypoxia around the World

“…However, hypoxia is not the only stress factor. Other factors implicated in declining stocks or populations are eutrophication (Caddy, 1993), bycatch (Andrew and Pepperell, 1992; Chesney et al, 2001), trawl disturbance (Currie and Parry, 1996), fishing pressure (Turkstra et al, 1991), habitat loss (Chesney et al, 2001), and harmful algal blooms (Rosenberg et al, 1988). Given the complexity and potential synergism of stressors, the effects of hypoxia are more clearly expressed in other coastal systems around the world than the northern Gulf of Mexico.…”