PARENT SESSION

WA6 Alaska North-Slope Environmental Monitoring
Room 18A/B, Level 4
8:00 AM - 12:00 PM, Wednesday, 12 November 2003
Chair: Boehm, Paul ,

(380) Persistent organochlorine contaminants and nutrients in arctic marine biota from northern Alaska.

Hoekstra, P.¹, O'Hara, T.², Muir, D.C.¹, ¹ Environment Canada, Burlington, ON, Canada² North Slope Borough, Barrow, AK, USA

ABSTRACT- Stable isotope values (¹³C, ¹⁵N), concentrations of persistent organochlorine contaminants (OCs) and various nutrients were determined in arctic biota from the southern Beaufort-Chukchi Seas near Barrow, AK, USA. Using these data we evaluated the near-shore marine trophic status of biota, the biomagnification of OCs, and species-specific abundance of nutrients. The isotopically derived trophic positions of biota from this marine food web were similar to other coastal food webs in the Arctic. Lipid normalized concentrations of OCs in marine mammals were significantly greater than in fish and corresponded with determined trophic level. OC concentrations in biota from this region were generally less than values reported in similar marine biota from other arctic regions. Overall, OCs with the greatest food web magnification factors were those either formed due to biotransformation (e.g. p,p′-DDE) or considered recalcitrant in most biota (2,4,5-Cl substituted PCBs), whereas concentrations of OCs that are considered to be readily eliminated (e.g. -HCH) did not correlate with trophic level. Differences in physical-chemical properties of OCs, feeding strategy and possible biotransformation were reflected in the variable biomagnification between fish and marine mammals. Acceptable amounts of bowhead whale tissues for human consumption were calculated based on Tolerable Daily Intake values. Nutrient analysis were compared to Canadian Recommended Dietary Allowances and demonstrated that traditional foods contain significant levels of essential vitamins (e.g. vitamin A, C), essential elements (e.g. Fe, Zn), and omega fatty acids. While OCs are present and toxicological effects remain unclear, individuals should be given well informed choices to consume these subsistence dietary items so as to maintain the high nutritional and sociocultural value of this traditional lifestyle.

Key words: human exposure, Alaska, biomagnification, subsistence