Biological Assessment of Upper Mississippi River Sediments.
ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MS ENVIRONMENTAL LAB
Pagination or Media Count:
The objective of this study was to determine the potential for polychlorinated biphenyls PCB and metals to bioaccumulate in the tissues of fish and invertebrates as a result of exposure to sediment from various dredging sites in the upper Mississippi River area. The acute toxicity of these sediments was of secondary interest. Water fleas Daphnia, catfish, and bluegills were exposed to suspensions of fine-grained sediment from three test sites and one reference site for 4 to 6 days, approximately the duration of a typical dredging and disposal operation on the upper Mississippi River. Survival and tissue concentrations of contaminants in fish were determined after exposure. Fawnfoot and three-ridge clams, mayfly larvae, and amphipods were exposed to deposited sediments for up to 14 days, after which survival and contaminant concentrations in tissues of clams were determined. All three test sediments were of low toxicity to all species except the amphipods, in that no sediment produced statistically greater mortality than occurred in the controls and reference sediment. Although statistical comparisons were not made, amphipod mortality in some Upper Mississippi River sediments apparently exceeded that in the controls but probably not that in the reference sediment. Bioaccumulation was the exception, rather than the rule, with 72 species-sediment-contaminant combinations being studied and bioaccumulation potential being indicated in 8 11 percent of the cases. Even in these cases, resulting concentrations were below those considered likely to cause adverse impacts.
- Biological Oceanography
- Physical and Dynamic Oceanography