Northwest Fisheries Science Center

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Document Type: Journal Article
Center: NWFSC
Document ID: 8553
Title: Modulation in Persistent Organic Pollutant level and profile by prey availability and reproductive status in Southern Resident killer whale scat samples
Author: Jessica I. Lundin, Gina M. Ylitalo, Rebecca K. Booth, B. F. Anulacion, Jennifer Hempelmann, K. M. Parsons, Deborah A. Giles, Elizabeth A. Seely, M. B. Hanson, Candice K. Emmons, S. K. Wasser
Publication Year: 2016
Journal: Environmental Science & Technology
Volume: 50
Pages: 6506-6516
Keywords: killer whale,Persistent Organic Pollutants,endocrine disruption,reproduction,prey abundance
Abstract:

Persistent organic pollutants (POPs), specifically PCBs, PBDEs, and DDTs, in the marine environment are well documented, however accumulation and mobilization patterns at the top of the food-web are poorly understood. This study broadens the understanding of POPs in the endangered Southern Resident killer whale population by addressing modulation by prey availability and reproductive status, along with endocrine disrupting effects. A total of 140 killer whale scat samples collected from 54 unique whales across a 4-year sampling period (2010−2013) were analyzed for concentrations of POPs. Toxicant measures were linked to pod, age, and birth order in genotyped individuals, prey abundance using open-source test fishery data, and pregnancy status based on hormone indices from the same sample. Toxicant concentrations were highest and had the greatest potential for toxicity when prey abundance was the lowest. In addition, these toxicants were likely from endogenous lipid stores. Bioaccumulation of POPs increased with age, with the exception of presumed nulliparous females. The exceptional pattern may be explained by females experiencing unobserved neonatal loss. Transfer of POPs through mobilization of endogenous lipid stores during lactation was highest for first-borns with diminished transfer to subsequent calves. Contrary to expectation, POP concentrations did not demonstrate an associated disruption of thyroid hormone, although this association may have been masked by impacts of prey abundance on thyroid hormone concentrations. The noninvasive method for measuring POP concentrations in killer whales through scat employed in this study may improve toxicant monitoring in the marine environment and promote conservation efforts.

Theme: Habitats to Support Sustainable Fisheries and Recovered Populations
Foci: Assess the impacts of toxic chemicals and other pollutants across biological scales, and identify pollution reduction strategies that improve habitat quality.