The Distribution and Stratification of Persistent Organic Pollutants and Fatty Acids in Bottlenose Dolphin (Tursiops truncatus) Blubber
Debra Ellisor, William McLellan, Heather Koopman, Wayne E. McFee, Lori Schwacke, John Kucklick
Blubber has been used for decades to monitor the exposure of marine mammals to persistent organic pollutants (POPs). However, little is known regarding POP variability as a function of blubber depth and across the body of the animal. However, such sampling techniques may not fully penetrate the blubber layer, penetrate at an angle, or may strike different body locations. Therefore 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 sampling location on POP concentrations, full depth blubber samples were taken from one stranded bottlenose dolphin (Tursiops truncatus) at one dorsal and one ventral site cranial to the dorsal fin, even with the caudal insertion of the dorsal fin and even with the anus (6 sites total) to assess variation in FA distribution and contaminant storage with body location. Three of the blubber samples from different body locations were also separated into histologically distinct layers to examine the effect of blubber depth and body location. In this one individual, both POPs and FAs were heterogeneous with blubber depth and body location. Proportionally more dietary FAs were found in the dorsal blubber and in middle and inner layers relative to other locations while a greater proportion of biosynthesized FAs were found in the ventral blubber and outer layers. Blubber stratification was further examined in blubber from the same location collected from six stranded individual bottlenose dolphins. Although FAs were stratified with blubber depth, lipid-normalized POPs were not significantly different among blubber depths. These results indicate that POP concentrations can vary in an individual with blubber depth however the direction of POP stratification is not consistent among individuals.
, McLellan, W.
, Koopman, H.
, McFee, W.
, Schwacke, L.
and Kucklick, J.
The Distribution and Stratification of Persistent Organic Pollutants and Fatty Acids in Bottlenose Dolphin (Tursiops truncatus) Blubber, Environmental Toxicology and Chemistry, [online], https://doi.org/10.1016/j.scitotenv.2013.06.017
(Accessed December 8, 2023)