TA7 Bioaccumulation and Kinetics of POPs
201 Oregon Ballroom
8:00 AM - 12:00 PM, Tuesday
() A comparison of the mechanisms controlling POP bioaccumulation in lakes of different latitudes: A modelling approach.
Gewurtz, S1, Gandhi, N1, Christensen, G2, Evenset, A2, Gregor, D3, Stern, G4, Franzin, W4, Ryan, M4, Diamond, M1, 1 University of Toronto, Toronto, Ontario, Canada2 Akvaplan-niva, Tromso, Norway3 MDA Consulting Limited, Campbellville, Ontario, Canada4 Department of Fisheries and Oceans, Winnipeg, Manitoba, Canada
ABSTRACT- The bioaccumulation of POPs have been shown to be complex, dependent on many interrelating factors, and even for the relatively well studied PCBs, is not well understood. The objective of this study was to quantify and tease apart the influence of contaminant loadings, temperature, and lake productivity, in controlling POP dynamics in several aquatic food webs located in different climatic regions. POP concentrations were measured in the sediment, water, invertebrates, and fish of Lake Ellasjøen and Lake 
yangen, located in the Norwegian high arctic, Lake Laberge, a sub-arctic lake, located in YT, Canada, and the north and south basins of Lake Winnipeg, a temperate lake, located in MB, Canada. Additional data from Lake Erie as well as Trout Lake, located in ON, Canada, were obtained from the literature. A food web model that assumed non-equilibrium conditions in plankton and considered the influence of temperature on organism physiology was applied to these lakes. The results showed that when lake specific loadings were taken into account, top predators from the higher latitude lakes were able to biomagnify contaminants from their prey to a much greater extent than warmer regions due to their slower gut elimination. High nutrient inputs were shown to result in decreased POP bioaccumulation, which resulted primarily from processes, such as growth dilution, occurring at the base of the food web.
Key words: POP, food web model, bioaccumulation