Test the hypothesis that PCBs are transferred along the food chain from contaminated algae to zebra mussels to gammarids and ultimately to many edible fish species.

The introduction of the zebra mussel into Lake Erie may result in a radical shift of contaminant distribution in environmental sinks and foodchains. If algae are contaminated with PCBs, zebra mussels may accumulate PCBs or the compounds could be eliminated in concentrated form in feces or pseudofeces. If the latter occurs, organisms such as gammarids which ingest contaminated feces could convey the toxins to fish which prey upon gammarids. Thus, gammarids could be a pivotal point in the foodchain which spread zebra mussels-directed contaminants to many edible fish species.

Partitioning of HCBP into algae will be conducted under static conditions using 1 day old Chlamydomonas cells. A coulter counter will be used to determine cell density and size. Adult zebra mussels (20-25 mm) will be allowed to filter contaminated algae at a density of 140,0090 cells/ml. Exposed mussels will then be put in clean water and fecal material will be collected over 48 hours. The latter will then be offered to adult gammarids. Total HCBP will be assessed at each step in every compartment. Mass balance and assimilation efficiencies will be calculated.

A methodology for exposing zebra mussels to contaminated algae was developed. Assimilation efficiency and contaminant body burden can be quantified using toxicokinetic methodology. The method also permits assessment of uptake from contaminated sediment.