Life history as a source of variation for persistent organic pollutant (POP) patterns in a community of common bottlenose dolphins ( Tursiops truncatus) resident to Sarasota Bay, FL

• Published in: The Science of the total environment Vol. 408; no. 9; pp. 2163 - 2172
• Main Authors: Yordy, Jennifer E., Wells, Randall S., Balmer, Brian C., Schwacke, Lori H., Rowles, Teri K., Kucklick, John R.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 01.04.2010; [Amsterdam; New York]: Elsevier Science; Elsevier
• Subjects: Age; Age Factors; Animal and plant ecology; Animal, plant and microbial ecology; Animals; Applied ecology; Biological and medical sciences; Bottle-Nosed Dolphin - physiology; Bottlenose dolphin; Cetacea; Communities; Contaminant mixtures; Contaminants; Dolphins; Ecosystem; Ecotoxicology, biological effects of pollution; Environmental Monitoring; Female; Fundamental and applied biological sciences. Psychology; General aspects; Hydrocarbons, Chlorinated - analysis; Hydrocarbons, Chlorinated - metabolism; Life Cycle Stages - drug effects; Life Cycle Stages - physiology; Life history; Male; Males; Marine; Milk; Persistent organic pollutants; Pesticide Residues - analysis; Pesticide Residues - metabolism; Polybrominated Biphenyls - analysis; Polybrominated Biphenyls - metabolism; Polychlorinated biphenyls; POPs; Populations; Sea water ecosystems; Synecology; Tursiops truncatus; Water Pollutants, Chemical - analysis; Water Pollutants, Chemical - metabolism; ASW, USA, Florida, Sarasota Bay; Life history; Bottlenose dolphin; Persistent organic pollutants; POPs; Contaminant mixtures; Tursiops truncatus; Marine environment; Persistent organic pollutant; Aquatic environment; Vertebrata; Pollution; Mammalia; Delphinus delphis; Cetacea; Bay; Sedentary; Community; Contaminant; Organic compounds
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2010.01.032

As apex predators within coastal ecosystems, bottlenose dolphins ( Tursiops truncatus) are prone to accumulate complex mixtures of persistent organic pollutants (POPs). While substantial variations in POP patterns have been previously observed in dolphin populations separated across regional- and fine-scale geographic ranges, less is known regarding the factors influencing contaminant patterns within localized populations. To assess the variation of POP mixtures that occurs among individuals of a population, polychlorinated biphenyl (PCB), organochlorine pesticide (OCP) and polybrominated diphenyl ether (PBDE) concentrations were measured in blubber and milk of bottlenose dolphins resident to Sarasota Bay, FL, and principal components analysis (PCA) was used to explain mixture variations in relation to age, sex and reproductive maturity. PCA demonstrated significant variations in contaminant mixtures within the resident dolphin community. POP patterns in juvenile dolphins resembled patterns in milk, the primary diet source, and were dominated by lower-halogenated PCBs and PBDEs. A significant correlation between principal component 2 (PC2) and age in male dolphins indicated that juvenile contaminant patterns gradually shifted away from the milk-like pattern over time. Metabolically-refractory PCBs significantly increased with age in male dolphins, whereas PCBs subject to cytochrome p450 1A1 metabolism did not, suggesting that changes in male POP patterns likely resulted from the selective accumulation of persistent POP congeners. Changes to POP patterns were gradual for juvenile females, but changed dramatically at reproductive maturity and gradually shifted back towards pre-parturient profiles thereafter. Congener-specific blubber/milk partition coefficients indicated that lower-halogenated POPs were selectively offloaded into milk and changes in adult female contaminant profiles likely resulted from the offloading of these compounds during the first reproductive event and their gradual re-accumulation thereafter. Overall, these results indicate that significant variations in contaminant mixtures can exist within localized populations of bottlenose dolphins, with life history factors such as age and sex driving individual differences.