Summary

Description

A unique laboratory exposure system was used in applying environmentally relevant conditions river traffic simulations and environmentally relevant sediment concentrations total suspended solids 300 mgL to determine the bioaccumulation and biological response of sediment associated contaminants in fish. We used sediments collected from areas of the upper Mississippi River reported high in metal concentrations and assessed the bioaccumulation of sediment associated arsenic, cadmium, copper, lead, and zinc to green sunfish following 28 days of intermittent pulses of contaminated suspended sediments and sediments not in suspension bedded. Blood enzyme activity deltaaminolevulinic acid dehydratase, ALAD was assessed in the fish as an indicator or biomarker of exposure to lead present in the contaminated suspended and bedded sediments. Results of the metal analysis of filtered and unfiltered water from all treatments indicated that the majority of the metals were associated with particulate matter in suspension. The bioconcentration of copper, lead, and zinc were greater in fish exposed to suspended sediments than bedded sediments as evidence of greater body burden. Arsenic and cadmium concentrations in whole fish were not significantly different in suspended or bedded tests due to low ambient concentrations. The suspended test resulted in greater blood lead 0.02 0.2 ugmL and blood zinc 8.80 14.5 ugmL concentrations than were observed in the bedded tests. And although neither; blood lead nor zinc significantly correlated with ALAD activity, the enzyme was significantly reduced in fish subjected to suspended contaminated sediments compared to fish exposed to bedded contaminated sediments.