title: Vertical distribution of lipids, fatty acids and organochlorine contaminants in the blubber of southern hemisphere humpback whales (Megaptera novaeangliae).
abstract: Persistent organic pollutants (POPs), such as toxic lipophilic organochlorine (OC) compounds, accumulate in the blubber tissue of marine mammals. Toxicological sampling methods most frequently target only the superficial blubber layer. Vertical distribution of these contaminants through the blubber mantle may, however, not be homogenous and could reflect any dissemination of lipids and fatty acids (FAs). It is therefore critical to assess stratification patterns in a species of interest as a quality control measure for interpretation of toxicological data. Here, we analysed and compared the distribution of lipids, FAs, and OCs in the outermost and innermost blubber layer of southern hemisphere humpback whales. FA stratification was evident for short-chain (≤18) monounsaturated fatty acids (SC-MUFA), which were concentrated in the outer layer, consistent with the thermoregulatory role of this blubber layer. This stratification was, however, not reflected in OC distribution, which was similar in the inner and outer blubber layers of male humpback whales. By comparison, a noticeable gradient in total blubber lipid from the outer to the inner layer was observed in two lactating females, which coincided with higher lipid normalised contaminant levels in the inner layer. This study contains the most comprehensive assessment of humpback whale blubber stratification to date, however, further investigation of biological and ecological influencing factors is required.
authors: The University of Queensland, The National Research Centre for Environmental Toxicology, Brisbane, QLD 4108, Australia. Electronic address: c.waugh@uq.edu.au.
authors: Courtney A
authors: CA
authors: Waugh
authors: CSIRO Marine and Atmospheric Research, Wealth from Oceans Flagship, GPO Box 1538, Hobart, Tasmania 7000, Australia.
authors: Peter D
authors: PD
authors: Nichols
authors: The Norwegian Institute for Air Research (NILU), Kjeller, Norway.
authors: Martin
authors: M
authors: Schlabach
authors: The University of Queensland, Cetacean Ecology and Acoustics Lab (CEAL), School of Veterinary Science, Gatton, QLD 4343, Australia.
authors: Michael
authors: M
authors: Noad
authors: Griffith University, Southern Ocean Persistent Organic Pollutants Program, School of Environment, Nathan, QLD 4111, Australia.
authors: Susan
authors: S
authors: Bengtson Nash
mesh_terms: D000273:Adipose Tissue / Q000737:chemistry*; D000818:Animals; D004784:Environmental Monitoring; D005227:Fatty Acids / Q000032:analysis*; D005260:Female; D050640:Humpback Whale; D006843:Hydrocarbons, Chlorinated / Q000032:analysis*; D008055:Lipids / Q000032:analysis*; D008297:Male; D014018:Tissue Distribution; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D005227:Fatty Acids; D006843:Hydrocarbons, Chlorinated; D008055:Lipids; D014874:Water Pollutants, Chemical
keywords: Antarctica; Blubber stratification; Fatty acids; Lipids; Persistent organic pollutants; Southern hemisphere humpback whales