Application of the Chironomus tentans Survival and Growth Bioassay in Evaluating Sediment Quality from Four Great Lakes Harbors

Sediment samples from four Great Lakes harbors were evaluated for possible effects of toxic chemicals using a 10-day bioassay with larval stages of the insect, Chironomus tentans. The bioassay of each sediment was conducted according to a protocol in which overlying water was renewed to provide approximately four volume exchanges daily and the larvae were fed the equivalent of 4.0 mg of dry solids daily. The bioassay was replicated five times for each sediment sample tested. Sediment samples from sites within each harbor were compared to one or more reference site sediments from the respective harbors using the endpoints of larval survival and growth