Relationship between persistent organic pollutants (POPs) and ranging patterns in common bottlenose dolphins ( Tursiops truncatus) from coastal Georgia, USA

• Published in: The Science of the total environment Vol. 409; no. 11; pp. 2094 - 2101
• Main Authors: Balmer, Brian C., Schwacke, Lori H., Wells, Randall S., George, R. Clay, Hoguet, Jennifer, Kucklick, John R., Lane, Suzanne M., Martinez, Anthony, McLellan, William A., Rosel, Patricia E., Rowles, Teri K., Sparks, Kate, Speakman, Todd, Zolman, Eric S., Pabst, D. Ann
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 01.05.2011; Elsevier
• Subjects: Adipose Tissue - metabolism; Animal, plant and microbial ecology; Animals; Applied ecology; Biological and medical sciences; Bottle-Nosed Dolphin - metabolism; Bottlenose dolphin; Brackish; Cetacea; Coastal; Contamination; Dolphins; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on vertebrates; Environmental Monitoring; Female; Fundamental and applied biological sciences. Psychology; Georgia; Male; Males; Mammalia; Marine; Marine mammals; Organic Chemicals - metabolism; Persistent organic pollutants; Photo-identification; Point sources; Polychlorinated biphenyls; Polychlorinated Biphenyls - metabolism; Remediation; Tursiops truncatus; Water Pollutants, Chemical - metabolism; Water Pollution, Chemical - statistics & numerical data; Georgia; United States; North America; America; USA, Georgia, Brunswick R; ASW, USA, Georgia, Sapelo I; Polychlorinated biphenyls; Bottlenose dolphin; Photo-identification; Persistent organic pollutants; Tursiops truncatus; Brackish water environment; Estuaries; Polychlorobiphenyls; Concentration; Persistent organic pollutant; Vertebrata; Mammalia; Spatial distribution; Cetacea; Animal population
• DOI: 10.1016/j.scitotenv.2011.01.052
• ISSN: 0048-9697

Bottlenose dolphins ( Tursiops truncatus) are apex predators in coastal southeastern U.S. waters; as such they are indicators of persistent organic pollutants (POPs) in coastal ecosystems. POP concentrations measured in a dolphin's blubber are influenced by a number of factors, including the animal's sex and ranging pattern in relation to POP point sources. This study examined POP concentrations measured in bottlenose dolphin blubber samples (n = 102) from the Georgia, USA coast in relation to individual ranging patterns and specifically, distance of sightings from a polychlorinated biphenyl (PCB) point source near Brunswick, Georgia. Dolphin ranging patterns were determined based upon 5 years of photo-identification data from two field sites approximately 40 km apart: (1) the Brunswick field site, which included the Turtle/Brunswick River Estuary (TBRE), and (2) the Sapelo field site, which included the Sapelo Island National Estuarine Research Reserve (SINERR). Dolphins were categorized into one of three ranging patterns from photo-identification data. Individuals with sighting histories exclusively within one of the defined field sites were considered to have either Brunswick or Sapelo ranging patterns. Individuals sighted in both field sites were classified as having a Mixed ranging pattern. Brunswick males had the highest concentrations of PCBs reported for any marine mammal. The pattern of PCB congeners was consistent with Aroclor 1268, a highly chlorinated PCB mixture associated with a Superfund site in Brunswick. PCB levels in Sapelo males were lower than in Brunswick males, but comparable to the highest levels measured in other dolphin populations along the southeastern U.S. Female dolphins had higher Aroclor 1268 proportions than males, suggesting that the highly chlorinated congeners associated with Aroclor 1268 may not be offloaded through parturition and lactation, as easily as less halogenated POPs. Individuals sighted farther from the Superfund point source had lower Aroclor 1268 proportions. ► We compared total PCBs to dolphin ranges between a contaminated and reference site. ► We compared PCBs to mean sighting distance of dolphins from point-source location. ► Total PCBs and point-source PCBs were higher closer to contaminated site. ► Male dolphins in contaminated site had highest PCBs of any marine mammal. ► Female dolphins did not offload point-source PCBs as easily as other contaminants.