| Popis: |
Using formulated sediment as the test substrate and field exposures, we examined the effects of zinc contamination on the benthic invertebrate community in Mobile Bay. Formulated sediment was mixed to match field sediment in grain size and organic matter content. Clean sediments and sediments dosed with zinc to target concentrations from 250–5000 μg g−1 were exposed in field holding racks anchored on the bottom. The abundance and diversity of benthic invertebrate recruits were used as indicators of sediment quality. We found significant differences in both indicators between clean and zinc contaminated sediments. All taxa did not respond similarly to changing zinc concentrations. Several families of polychaetes, harpacticoid copepods and ostracods appeared to be most sensitive to zinc. Under certain conditions, some taxa, particularly gastropods, were attracted to zinc-contaminated sediments. Taken together, the results suggest that zinc contamination can profoundly affect the nature of the benthic community recruiting into such sediments. |
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