PH19 Biomonitoring
Exhibit Hall
8:00 AM - Thursday
(PH225) Spatial and Seasonal Dynamics of PCB Transport and Bioaccumulation using Freshwater Mussels.
Craig, G1, Middelraad, I2, Salazar, M3, Salazar, S3, Portt, C4, 1 G.R. Craig & Associates Inc, Schomberg, Ontario, Canada2 I. Middelraad & Associates, Guelph, Ontario, Canada3 Applied Biomonitoring, Kirkland, Washington, United States4 C. Portt & Associates, Guelph, Ontario, Canada
ABSTRACT- Caged freshwater mussels, Lasmigona costata and Elliptio complanata, were transplanted to a shallow, slow flowing watercourse draining an historic transformer manufacturing site containing PCBs. Cages were also placed in the receiving river upstream and downstream of the drainage outfall. Transplant studies were conducted over three years from spring to fall. Consecutive 28 day and longer overlapping deployments of mussels in the system indicated that PCB concentrations in mussels decreased along the route of transport and declined from spring to late summer. Total PCBs accumulation by mussels were influenced by seasonal changes in flow rates in the drainage system and depuration of PCBs during periods of uncontaminated flow. The data suggest that depuration of up to 50% of accumulated PCBs may occur within 9 days of exposure to uncontaminated conditions. Transport of total PCBs was related to the < 14 micron suspended particle size fraction. The data show that even persistent chemicals can take on a seasonal and spatial dynamic depending on local transport conditions and the characteristics of biological receptors.
Key words: mussels, PCBs, clearance, accumulation