APPLICATION OF TOXICITY IDENTIFICATION PROCEDURES TO THE ECHINODERM FERTILIZATION ASSAY TO IDENTIFY TOXICITY IN A MUNICIPAL EFFLUENT

Toxicity was detected in a municipal effluent with the echinoderm fert ilization assay. Dendraster excentricus appeared more sensitive to the effluent than did Strongylocentrotus purpuratus. A Phase 1 toxicity i dentification evaluation (TIE) was conducted using procedures adapted to the echinoderm fertilization bioassay. The Phase 1 TIE implicated c ationic metals as the cause of toxicity, and follow-up investigations suggested that copper was the primary cation responsible. As part of t he TIE, bioassays were conducted on ammonia and several cations. No-ob servable-effect concentrations for D. excentricus were >13.4 mu g/L (A g), >9.4 mu g/L (Cd), 3.8 to 13.1 mu g/L (Cu), >0.7 mu g/L (Hg), and 1 0 mg/L (N, as total ammonia). The data also suggested that interspecif ic differences in sensitivity to copper and ammonia exist between Dend raster excentricus and Strongylocentrotus purpuratus.