Comparison of the relative sensitivity of three benthic invertebrates to copper-contaminated sediments from the Keweenaw Waterway

The relative sensitivity of the amphipod Hyalella azteca, the chironomid Chironomus tentans, and the oligochaete Lumbriculus variegatus to Keweenaw waterway sediments from 11 sites in a former major copper-mining area was determined by 10-d tests. The results of water-only acute exposure to copper indicated that the survival sensitivity of H. azteca and L. variegatus was equal to and greater than that of C. tentans but exposure to sediments significantly reduced survival at 8 sites for H. azteca and at 7 sites for C. tentans. No sediment samples had a significant impact on the survival of L. variegatus, but reproduction was reduced significantly by sediments from 6 sites. Comparison of reduced survival for H. azteca and C. tentans and impaired reproduction of L. variegatus as endpoints produced some agreement in the designation of toxic sites but differences in test species lifestyles or sensitivity to physico-chemical sediment characteristics could influence sediment toxicity test results. There are 33 references.