Submitted to: Bulletin of Environmental Contamination and Toxicology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 14, 2009
Publication Date: July 1, 2009
Citation: Knight, S.S., Lizotte Jr, R.E., Shields Jr, F.D. 2009. Hyalella azteca Responses to Coldwater River Backwater Sediments in Mississippi, USA. Bulletin of Environmental Contamination and Toxicology. 83(4): 493-496. DOI 10.1007/s00128-009-9804-7 [online]. Interpretive Summary: Sediment quality in three flood plain water bodies along the Coldwater River, Mississippi was examined using an aquatic animal (invertebrate), Hyalella azteca. Flooding from the Coldwater River into the three flood plain water bodies varied widely among the three locations. Sediments were contaminated with seven metals and seven pesticides. Sediment quality was poorest in the most frequently flooded water body in association with greatest contamination. These results are of interest to regulatory and other agencies and the pesticide industry by providing additional information to improve and sustain river and flood plain sediment quality and overall environmental quality.
Technical Abstract: Sediment from three Coldwater River, Mississippi backwaters was examined using 28 d Hyalella azteca bioassays and chemical analyses for 33 pesticides, 7 metals and 7 PCBs. Hydrologic connectivity between the main river channel and backwater varied widely among the three sites. Mortality occurred in the most highly connected backwater while growth impairment occurred in the other two. Precopulatory guarding behavior was not as sensitive as growth. Fourteen contaminants (7 metals, 7 pesticides) were detected in sediments. Survival was associated with heptachlor while growth and behavior were associated with organochlorine pesticides (aldrin, alpha-BHC, gamma-BHC, heptachlor).