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Presented at the NABS Annual meeting, Pittsburgh, Pennsylvania, 2002
in Restoration Ecology
EFFECTS OF ACID MINE CONTAMINATED SEDIMENT ON MACROINVERTEBRATES IN LABORATORY BIOASSAYS AND FIELD EXPERIMENTS.
J. Dsa1, J. Last1, and K.S. Johnson2. 1Environmental Studies, Ohio University, Athens OH 45701, 2Department of Biological Sciences, Athens OH 45701
Although the effects of metals in the water column on macroinvertebrates have been reasonably well investigated, the effects of metal contaminants in the sediment are less well-understood. Understanding the conditions under which sediments may or may not retain toxicity to biological communities is important for predicting the success of specific remediation efforts. After identifying sites with visible metal precipitates and elevated water column Fe, Al, or Mn, Ctenodaphnia magna and mayfly nymphs (Ephemeroptera) were used to bioassay sediment toxicity in static containers. Sediment from all 4 of the AMD impacted sites was highly toxic to C. magna, and mayfly growth rates were reduced at 2, but toxicity was not correlated with specific metal content. We also monitored colonization of contaminated substrate after transplantation into the bed of a healthy stream. After 5 weeks in a clean stream, the same Al and Fe contaminated substrate was no longer toxic to daphnia and was readily colonized by even sensitive benthic macroinvertebrates (mayflies, stoneflies, caddisflies). These results suggest that sediment at these sites will not retain toxicity after remediation of the AMD input.
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