title: The distribution and stratification of persistent organic pollutants and fatty acids in bottlenose dolphin (Tursiops truncatus) blubber.
abstract: Blubber has been used for decades to monitor exposure of marine mammals to persistent organic pollutants (POPs). However, little is known about POP variability as a function of blubber depth and across the body of the animal. Remote blubber biopsy sampling (e.g, projectile biopsy) is the most common technique used to acquire samples from free-swimming animals, yet such techniques may result in variable sampling. It is important to understand whether blubber stratification or body location affects POP concentration or the concentration of other important blubber constituents such as fatty acids (FA). To investigate the influence of sampling depth and location on POP concentration, full depth blubber samples were taken from one stranded bottlenose dolphin (Tursiops truncatus) at six different body sites to assess variation in FA distribution and contaminant storage with body location. Three of the samples from different body locations were separated into histologically distinct layers to examine the effect of blubber depth and body location on POPs and FAs. In this individual, both POPs and FAs were heterogeneous with blubber depth and body location. POP concentrations were significantly greater in ventral (average ΣPBDEs 1350 ng/g lipid) and anterior (average ΣPCBs 28,700 ng/g lipid) body locations and greater in the superficial blubber layer (average ΣPCBs 35,500 ng/g lipid) when compared to the deep (8390 ng/g lipid) and middle (23,700 ng/g lipid) layers. Proportionally more dietary FAs were found in dorsal blubber and in middle and deep layers relative to other locations while the reverse was true for biosynthesized FAs. Stratification was further examined in blubber from the same body location in five additional stranded bottlenose dolphins. Although FAs were stratified with blubber depth, lipid-normalized POPs were not significantly different with depth, indicating that POP concentrations can vary in an individual with blubber depth though the direction of POP stratification is not consistent among individuals.
authors.affiliation: National Institute of Standards and Technology, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, SC 29412, United States; The College of Charleston, Graduate Program in Marine Biology, 205 Fort Johnson Road, Charleston, SC 29412, United States.
authors.forename: Debra
authors.initials: D
authors.lastname: Ellisor
authors.forename: William
authors.initials: W
authors.lastname: McLellan
authors.forename: Heather
authors.initials: H
authors.lastname: Koopman
authors.forename: Lori
authors.initials: L
authors.lastname: Schwacke
authors.forename: Wayne
authors.initials: W
authors.lastname: McFee
authors.forename: John
authors.initials: J
authors.lastname: Kucklick
mesh_terms: D000273:Adipose Tissue / Q000737:chemistry*; D000818:Animals; D050681:Bottle-Nosed Dolphin / Q000378:metabolism*; D005227:Fatty Acids / Q000032:analysis*; D008297:Male; D014018:Tissue Distribution; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D005227:Fatty Acids; D014874:Water Pollutants, Chemical
keywords: Biopsy sampling; Blubber; Bottlenose dolphin; Fatty acids; Persistent organic pollutants; Strandings