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BENTHIC INVERTEBRATE BIOASSAYS WITH TOXIC SEDIMENT AND PORE WATER
Citation:
Geisy, J., C. Rosiu, AND R. Graney. BENTHIC INVERTEBRATE BIOASSAYS WITH TOXIC SEDIMENT AND PORE WATER. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/J-90/118.
Description:
The relative sensitivities of bioassays to determine the toxicity of sediments were investigated and three methods of making the sample dilutions required to generate dose-response relationships were compared. he assays studied were: (a) Microtox, a 15-min assay of Photobacterium phosphoreum bioluminescence inhibition by pore water; (b) 48-h Daphnia magna lethality test in tentans performed in either whole sediment or pore water. he three methods of diluting sediments were: (a) extracting pore water from the toxic location and dilution with pore water from the control station; (b) diluting whole sediment from the toxic location with control whole sediment from a reference location, then extracting pore water; and (c) diluting toxic, whole sediment with whole sediment from a reference location, then using the whole sediment in bioassays. ased on lethality, H. limbata was the most sensitive organism to the toxicity of the Detroit River sediment. ethality of D. magna in pore water was similar to that of H. limbata. he concentration required to cause a 50% reduction in C. tentans growth (10-d EC50) was approximately that which caused 50% lethality of D. magna (48-h LC50) and was similar to the toxicity that restricts benthic invertebrate colonization of contaminated sediments. hile the three dilution techniques gave similar results with some assays, they gave very different results in other assays. he dose-response relationships determined by the three dilution techniques would be expected to vary with sediment, toxicant and bioassay type, and the dose-response relationship derived from each technique needs to be interpreted accordingly.