PARENT SESSION
Contributed Oral Session 57: Polar and Alpine Ecology: Carbon and Nutrient Dynamics
Tuesday, August 9, 1:30 PM - 5:00 PM, Meeting Room 513 E, Level 5, Palais des congrès de Montréal
Contaminant biogeochemistry in freshwater Arctic Alaskan ecosystems: The role of biota.
FORD, Jesse*,1, Allen-Gil, Susan2, Muir, Derek3, Akpik, Maasak4, Nashaknik, Joshua5, Matumeak, Warren5, 1 Oregon State University, Corvallis, OR, USA2 Ithaca College, Ithaca, NY, USA3 National Water Resources Institute, Burlington, Ontario, Canada4 Translator, Barrow, AK, USA5 Expert whitefish fisherman, Barrow, AK, USA
ABSTRACT- Sockeye salmon (Oncorhyncus nerka) have been identified as significant vectors of PCBs from marine to freshwater systems of southcentral Alaska by virtue of the large biomass of spawned-out carcasses returned to receptor ecosystems. Our studies on the western Arctic Coastal Plain of Alaska were designed to reveal whether this model might also apply to Arctic Alaskan systems where atmospheric inputs might be expected to be higher (due to colder temperatures), but where salmon are scarce and the ichthyofauna is dominated by amphidromous whitefish species. Can whitefish play a significant role in transferring contaminants from summer feeding grounds in nearshore coastal waters to freshwater spawning and overwintering habitats? As expected, concentrations of persistent organic pollutants (POPs) were low in both species of whitefish studied (Coregonus sardinella and C. nasus); surprisingly, concentrations were low even relative to other areas of the circumpolar Arctic. There was little difference in POPs concentrations between migratory and freshwater resident whitefish. Mercury studies revealed a different pattern, with higher concentrations occurring in freshwater resident vs migratory C. nasus at some sites, suggesting a potential link with terrestrial sources. The relationship between biogeochemical cycling of contaminants and nutrients is discussed in light of the steadily increasing mass of contaminants now involved in global biogeochemical cycles.
Key words: biogeochemistry, contaminant, whitefish, Arctic