Pollution-induced tolerance to copper of nematode communities in the severely contaminated restronguet creek and adjacent estuaries, Cornwall, UnitedKingdom

Pollution-induced community tolerance (PICT) has been proposed as an indica tor of the deleterious effects of pollutants on communities in the field. N ematode assemblages were sampled at 10 estuarine sites that ranged from unc ontaminated to grossly contaminated with metals. Relative tolerance of thes e assemblages to Cu was quantified using acute toxicity tests. There were t arge differences between sites in tolerance to Cu, and copper tolerance was strongly correlated with severity of contamination. Enhanced Cu tolerance occurred at two sites where Cu concentration in sediment was around 180 mu g/g but not at a third site, where Cu concentration was 214 mu g/g. This im plies a threshold of effects on these nematode communities at similar to 20 0 mu g/g Cu. Comparison with studies of nematode community composition in t hese same estuaries indicates that PICT is at least as sensitive as the bes t available ecological monitoring methods. It is, however, faster to carry out and requires much less taxonomic expertise. The PICT appears to he a se nsitive indicator of ecological effects of pollution and has considerable p romise as a monitoring tool.