title: Changes in blubber contaminant concentrations in California sea lions (Zalophus californianus) associated with weight loss and gain during rehabilitation.
abstract: California sea lions have high levels of persistent organic pollutants (POPs) in their blubber. Animals affected by domoic acid fast and refeed during their rehabilitation. We studied the effect of decreases in total body mass (16 +/- 7% of initial body mass) on blubber POP contaminant concentrations and estimated POP burdens during fasting (12 +/- 5 days) in 19 California sea lions. The effect of refeeding (92 +/- 8% of initial body mass) was also investigated. Significant increases in the concentration of all POPs were found over the mass loss period and decreases during mass gain. A basic mass balance model indicated that the changes did not conform to a simple concentrating and diluting pattern and a proportion of the contaminants were lost from the lipid pool. During mass loss, the lower chlorinated polychlorinated biphenyl congeners, chlordanes, and hexachlorocyclohexanes were lost at a higher rate than the other contaminant classes (particularly polybrominated diphenyl ethers). During mass gain the behavior of all contaminant classes was more consistent with the dilution model. These results indicate the importance of considering the energetic contextwhen sampling blubberfor long-term contaminant monitoring and suggest an initial approach to adjust for such differences.
authors.affiliation: Sea Mammal Research Unit, Gatty Marine Laboratory, University of St Andrews, St Andrews, Fife, KY16 8LB, UK. ajh7@st-andrews.ac.uk
authors.forename: A J
authors.initials: AJ
authors.lastname: Hall
authors.forename: F M D
authors.initials: FM
authors.lastname: Gulland
authors.forename: G M
authors.initials: GM
authors.lastname: Ylitalo
authors.forename: D J
authors.initials: DJ
authors.lastname: Greig
authors.forename: L
authors.initials: L
authors.lastname: Lowenstine
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism*; D000818:Animals; D004784:Environmental Monitoring; D005260:Female; D006843:Hydrocarbons, Chlorinated / Q000378:metabolism; D050356:Lipid Metabolism; D010647:Phenyl Ethers / Q000378:metabolism; D011075:Polybrominated Biphenyls / Q000378:metabolism; D046070:Sea Lions / Q000502:physiology*; D014874:Water Pollutants, Chemical / Q000378:metabolism*; D015430:Weight Gain / Q000502:physiology*; D015431:Weight Loss / Q000502:physiology*
chemical_list: D006843:Hydrocarbons, Chlorinated; D010647:Phenyl Ethers; D011075:Polybrominated Biphenyls; D014874:Water Pollutants, Chemical