MP3 Chronic and Sublethal Sediment Toxicity
254 Portland Ballroom
1:20 PM - 4:40 PM, Monday
() A field assessment of chronic laboratory sediment toxicity tests with the amphipod Hyalella azteca and the midge Chironomus dilutus.
Ingersoll, C1, Wang, N1, Jones, S1, Jones, J2, Hayward, J2, Ireland, D3, Mount, D4, 1 USGS, Columbia, MO, USA2 University of Missouri, Columbia, MO, USA3 USEPA, Chicago, IL, USA4 USEPA, Duluth, MN, USA
ABSTRACT- The objective of this study was to compare the response of organisms exposed in the laboratory and in the field to contaminated sediments. Endpoints evaluated included standardized 10- to 60-d laboratory toxicity tests with Hyalella azteca and Chironomus dilutus (formerly C. tentans) and controlled 3-month invertebrate colonization exposures conducted in ponds. Exposures were conducted with sediment spiked with DDD or with dilutions of a sediment collected from the Grand Calumet River located in northwestern Indiana (contaminated primarily with PAHs, PCBs, and metals). Survival, growth, or reproduction measured in laboratory sediment toxicity tests with amphipods or midge were needed to predict toxic effects observed on benthic communities exposed to similar sediments in the field. Effects on the benthic organisms colonizing the trays occurred at lower chemical concentrations compared to concentrations that were toxic in 10-d laboratory tests. Bioaccumulation of DDD by oligochaetes collected from the colonization trays was similar to results of previously conducted laboratory sediment exposures with the oligochaete Lumbriculus variegatus confirming that laboratory sediment exposures with L. variegatus can be used to predict bioaccumulation of oligochaetes exposed in the field to contaminants in sediment. Results of this study indicate that use of chronic laboratory tests and manipulative field experiments that control for potential confounding factors may be needed to estimate impacts observed on benthic communities exposed to contaminated sediments in addition to estimating impacts using synoptic surveys of benthic communities. Finally, recommendations will be provided for conducting future colonization studies with contaminated sediments.
Key words: sediment quality triad, sediment, field validation, chronic toxicity