Absorption of Hydrophobic Contaminants from Ingested Chlamydomonas rheinhardtii and Chlorella vulgaris by Zebra Mussels, Dreissena polymorpha

Abstract

The zebra mussel, Dreissena polymorpha, has the potential to influence contaminant cycling in freshwater systems because of its large population density, high lipid content, and high filtering rate. Ingestion of contaminated particles such as algae dominates exposure routes for the zebra mussel for strongly particle-associated contaminants. However, the data on absorption efficiency are limited and models to predict contaminant accumulation for the lower food web have identified the absence of such data as limiting and necessary to improve predictions. Accumulation of 2,2′,4,4′-tetrachlorobiphenyl (TCBP), 3,3′,4,4′,5-pentachlorobiphenyl (PCBP), 2,2′,4,4′,5,5′-hexachlorobiphenyl (HCBP) and 1,1- dichloro-2,2-bis[4-chlorophenyl] ethylene(DDE) was determined at two algal concentrations from exposures to contaminated Chlamydomonas rheinhardtii and Chlorella vulgaris. The contaminant absorption efficiencies were determined based on a chemical-mass-balance model. Mussel absorption efficiencies for the four chemicals at the two different algal concentrations for the two algal species ranged from 68.3% to 95.4% and were independent of algal concentrations and algal species for the same chemical.