Interactions between eutrophication and contaminants - partitioning, bioaccumulation and effects on sediment-dwelling organisms

摘要

This report describes an experiment on the interactions between eutrophication and contaminants in marine sediments. The experiment was performed in 24 continuously flushed glass aquaria within which three sediment- dwelling species were kept in a marine sediment. A filter-feeder, blue mussel, was kept in downstream aquaria. The experiment combined three environmental factors: oxygen availability, the presence or absence of contaminants, the addition of organic matter. The objectives were: (1) to quantify differences in the partitioning of contaminants between sediment, pore water and biota as a result of the treatment, (2) to quantify effects of treatments and interactions between treatments on sediment-dwelling organisms, (3) to identify differences, if any, in the release of contaminants from the sediment as the result of treatments. All three contaminants bio accumulated to higher levels in sediments with increased levels of organic material. Feeding directly or indirectly appeared to be the major route for bioaccumulation of benzo(a)pyrene and mercury. Cadmium was also controlled by the concentration in pore water. Sediment in enriched aquaria released more contaminants than sediment with low organic content. Organic enrichment strongly affected growth in the three sediment-dwelling organisms. Growth was less affected by decreased oxygen availability. The presence of contaminants had little effect on the three sediment-dwelling species at the concentrations used in the experiment. 103 refs., 14 figs., 12 tabs.