Summary

Description

Savannah Harbor, located near the mouth of the Savannah River, Georgia and South Carolina, is impacted by industrial and municipal effluents. Contaminants released to the river are ultimately stored in the sediments but redistributed through dredging and shipping operations. For proper management of the system and protection of wildlife resources, contaminated areas need to be located. During 1991, sediment samples were collected at 26 sites within the harbor area for toxicity testing with luminescent bacteria Photobacterium phosphoreum and the amphipod Hyalella azteca. The bacteria were tested with pore water and solidphase sediment according to standard Microtox R assay procedures, and H. azteca were exposed to pore water and solidphase sediment in 10day staticrenewal tests. The Microtox assays on pore water were inconsistent and less predictivethan H. azteca; pore water collected on site was toxic EC50s 60 at eight stations, whereas pore water collected in the laboratory was toxic at all stations. Porewater toxicity to H. azteca was more pronounced than that shown in the solidphase sediment. Toxicity and reduced leaf consumption demonstrated reduce sediment quality at specific sites within Savannah Harbor and Back River. The primary factors contributing to decreased sediment quality were ammonia and metal cadmium, chromium, lead, molybdenum, and nickel concentrations. Elevated concentrations of metals and toxicities in Back River sediments indicate impacts from adjacent dredgespoil areas.