Comparison of abundance and habitat usage for common bottlenose dolphins between sites exposed to differential anthropogenic stressors within the estuaries of southern Georgia, U.S.A.
Author(s): Balmer, B.C.; L.H. Schwacke; R.S. Wells; J.D. Adams; R.C. George; S.M. Lane; W.A. McLellan; P.E. Rosel; K. Sparks; T. Speakman; E.S. Zolman; D.A. Pabst
NCCOS Center: CCEHBR (http://coastalscience.noaa.gov/about/centers/ccehbr)
Center Team: Charleston/HML
Publication Type: Journal Article
Journal Title: Marine Mammal Science
Date of Publication: 2013
Reference Information: 29(2):
Keywords: abundance; anthropogenic stressors; bottlenose dolphin density; habitat use; Tursiops truncatus
Abstract: The health of common bottlenose dolphins (Tursiops truncatus) within southern Georgia estuaries is of particular concern due to high levels of anthropogenic contaminants in their tissues. Dolphins in this reagion have the highest polychlorinated biphenyl (PCB) concentrations recorded for any marine mammal and these concentrations correlate to distance from a Superfund point-source in the Turtle/Brunswick River Estuary (TBRE). Currently, little is known about the population structure of dolpins in this region. This study identifies and compares baseline data on abundance, habitat use, site-fidelity, and ranging patterns of dolphins across two adjacent field sites; Brunswick, including the TBRE, and Sapelo, including the Sapelo Island National Estuarine Research Reserve. Sapelo is relatively undeveloped and was selected for comparison to the more contaminated TBRE. Dolphin densities increased with tributary size in both sites but dolhin density and total abundance were significantly higher in Sapelo than in Brunswick. Anthropogenic stressors within the TBRE may be an important factor contributing to the differences in abundance, density, and habitat use observed in this study.