Examining the crayfish, Astacus pallipes, in foodweb transfers of nonpolar contaminants from Dreissena polymorpha

Crayfish, Astacus pallipes, were exposed to dissolved non-polar PAH and PCB congeners in short term water-only exposures. Uptake and elimination rate constants were determined for total body mass and internal organ tissues. The uptake clearance was slow (ranging 14--44 ml g{sup {minus}1}h{sup {minus}1}) and negatively related to total body mass but positively correlated with log K{sub ow}. Individual tissues, ovary, hepatopancreas and muscle in the thorax, all showed decreased uptake rate coefficients, (k{sub u}) with increased tissue mass and increased with log K{sub ow}. The elimination rates were also slow (ranging 0.002--0.019 h{sup {minus}1}) and decreased with increasing log K{sub ow}. The ovaries eliminated the contaminants most rapidly while the thorax muscle was slowest. In addition to water-only exposures, the predation of crayfish on the zebra mussel Dreissena polymorpha and estimated uptake rates associated with ingestion of zebra mussel tissue when the mussels are preexposed to radiolabeled contaminants will be described.