Food Web Bioaccumulation Model for Resident Killer Whales from the Northeastern Pacific Ocean as a Tool for the Derivation of PBDE-Sediment Quality Guidelines.
Resident killer whale populations in the NE Pacific Ocean are at risk due to the accumulation of pollutants, including polybrominated diphenyl ethers (PBDEs). To assess the impact of PBDEs in water and sediments in killer whale critical habitat, we developed a food web bioaccumulation model. The model was designed to estimate PBDE concentrations in killer whales based on PBDE concentrations in sediments and the water column throughout a lifetime of exposure. Calculated and observed PBDE concentrations exceeded the only toxicity reference value available for PBDEs in marine mammals (1500 μg/kg lipid) in southern resident killer whales but not in northern resident killer whales. Temporal trends (1993-2006) for PBDEs observed in southern resident killer whales showed a doubling time of ≈5 years. If current sediment quality guidelines available in Canada for polychlorinated biphenyls are applied to PBDEs, it can be expected that PBDE concentrations in killer whales will exceed available toxicity reference values by a large margin. Model calculations suggest that a PBDE concentration in sediments of approximately 1.0 μg/kg dw produces PBDE concentrations in resident killer whales that are below the current toxicity reference value for 95 % of the population, with this value serving as a precautionary benchmark for a management-based approach to reducing PBDE health risks to killer whales. The food web bioaccumulation model may be a useful risk management tool in support of regulatory protection for killer whales.
School of Resource and Environmental Management, Faculty of Environment, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada. jalavasa@sfu.ca.|Ocean Pollution Research Program, Vancouver Aquarium Marine Science Centre, PO Box 3232, Vancouver, BC, V6B 3X8, Canada. jalavasa@sfu.ca.
Juan José
JJ
Alava
Ocean Pollution Research Program, Vancouver Aquarium Marine Science Centre, PO Box 3232, Vancouver, BC, V6B 3X8, Canada.
Peter S
PS
Ross
School of Resource and Environmental Management, Faculty of Environment, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada.
Frank A P C
FA
Gobas
D000818:Animals; D002170:Canada; D004784:Environmental Monitoring; D058735:Environmental Policy; D020387:Food Chain; D017408:Guidelines as Topic; D055768:Halogenated Diphenyl Ethers / Q000032:analysis / Q000378:metabolism* / Q000592:standards; D008962:Models, Theoretical; D010140:Pacific Ocean; D014874:Water Pollutants, Chemical / Q000378:metabolism* / Q000592:standards; D050685:Whale, Killer / Q000378:metabolism*
D055768:Halogenated Diphenyl Ethers; D014874:Water Pollutants, Chemical