title: Habitat-based PCB environmental quality criteria for the protection of endangered killer whales (Orcinus orca).
abstract: The development of an area-based polychlorinated biphenyl (PCB) food-web bioaccumulation model enabled a critical evaluation of the efficacy of sediment quality criteria and prey tissue residue guidelines in protecting fish-eating resident killer whales of British Columbia and adjacent waters. Model-predicted and observed PCB concentrations in resident killer whales and Chinook salmon were in good agreement, supporting the model's application for risk assessment and criteria development. Model application shows that PCB concentrations in the sediments from the resident killer whale's Critical Habitats and entire foraging range leads to PCB concentrations in most killer whales that exceed PCB toxicity threshold concentrations reported for marine mammals. Results further indicate that current PCB sediment quality and prey tissue residue criteria for fish-eating wildlife are not protective of killer whales and are not appropriate for assessing risks of PCB-contaminated sediments to high trophic level biota. We present a novel methodology for deriving sediment quality criteria and tissue residue guidelines that protect biota of high trophic levels under various PCB management scenarios. PCB concentrations in sediments and in prey that are deemed protective of resident killer whale health are much lower than current criteria values, underscoring the extreme vulnerability of high trophic level marine mammals to persistent and bioaccumulative contaminants.
authors.affiliation: School of Resource and Environmental Management, Faculty of Environment, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada.
authors.forename: Juan José
authors.initials: JJ
authors.lastname: Alava
authors.forename: Peter S
authors.initials: PS
authors.lastname: Ross
authors.forename: Cara
authors.initials: C
authors.lastname: Lachmuth
authors.forename: John K B
authors.initials: JK
authors.lastname: Ford
authors.forename: Brendan E
authors.initials: BE
authors.lastname: Hickie
authors.forename: Frank A P C
authors.initials: FA
authors.lastname: Gobas
mesh_terms: D000818:Animals; D059001:Aquatic Organisms / Q000187:drug effects / Q000378:metabolism; D001955:British Columbia; D004305:Dose-Response Relationship, Drug; D056727:Endangered Species; D004781:Environmental Exposure; D004784:Environmental Monitoring / Q000379:methods*; D020387:Food Chain; D019015:Geologic Sediments / Q000032:analysis; D007448:Invertebrates / Q000187:drug effects / Q000378:metabolism; D008954:Models, Biological; D009792:Oceans and Seas; D010839:Phytoplankton / Q000187:drug effects / Q000378:metabolism; D011078:Polychlorinated Biphenyls / Q000378:metabolism / Q000633:toxicity*; D018570:Risk Assessment; D012474:Salmon / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000378:metabolism / Q000633:toxicity*; D050685:Whale, Killer / Q000378:metabolism*; D015048:Zooplankton / Q000187:drug effects / Q000378:metabolism
chemical_list: D014874:Water Pollutants, Chemical; D011078:Polychlorinated Biphenyls