COMMUNITY-LEVEL FIELD METHOD FOR TESTING THE TOXICITY OF CONTAMINATEDSEDIMENTS IN ESTUARIES

The objective of this study was to demonstrate a method for testing th e toxicity of contaminated sediments under field conditions. An artifi cial sediment that matches field sediment in grain-size distribution a nd organic matter content was mixed from 11 components and used as the test substrate. Clean sediments and sediments spiked with zinc (appro ximately 8,000 mg/kg) were exposed in the field on a holding rack anch ored on the bottom of Mobile Bay, Alabama. The abundance and diversity (species richness) of benthic invertebrate recruits were used as indi cators of sediment quality. The number of recruits was significantly r educed by the presence of zinc in one-week exposures.