Sarasota Dolphin Research Program

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Collaborative field effort to assess dolphin health near Brunswick, Georgia and Sapelo Island National Estuarine Research Reserve
By Lori Schwacke, PhD, National Ocean Service

Researchers examine a dolphin during the Georgia health assessment, August 2009.

During the first two weeks of August, 2009, health assessments were successfully conducted for 29 dolphins along the Georgia coast to examine health endpoints in relation to exposure to high levels of polychlorinated biphenyls, mercury and other legacy and emerging contaminants. The health assessments, conducted by researchers from the NOAA Center for Excellence for Oceans and Human Health at the Hollings Marine Laboratory, NOAA Fisheries Marine Mammal Health and Stranding Response Program, Chicago Zoological Society, Georgia Department of Natural Resources, and other partners involved a veterinary examination and medical sampling to measure chemical contaminants and examine related health effects. Dolphins were also fitted with radio transmitters to allow for follow-up monitoring and tracking of movements to better understand contaminant exposure sources.

The health study was prompted by findings of previous efforts which found high polychlorinated biphenyl (PCB) concentrations in blubber samples obtained during biopsy darting of dolphins from the Brunswick, Georgia area, as well from dolphins near the Sapelo Island Estuarine Research Reserve, a federally protected area some 50 kilometers northeast of Brunswick. The Brunswick area is home to 4 National Priority List (NPL) sites which are designated by the Environmental Protection Agency as sites with known or threatened releases of hazardous substances. PCBs are a contaminant of concern for one of the sites, Linden Chemical and Plastics (LCP), which borders the Turtle River near Brunswick. Impacts of the PCBs and other contaminants are the focus of on-going assessments being conducted by state and federal agencies in conjunction with several of the responsible parties. The data being collected as part of the dolphin health assessments will be provided to NOAA’s Assessment and Restoration Division to use with other information and data relevant for the cooperative natural resource damage assessment being conducted for the LCP site.

Study sites in Georgia.

PCBs are known to produce adverse immunological and reproductive effects, so tests were administered to the dolphins to specifically assess these endpoints. Protocols and laboratories for the health assessment were coordinated to follow those previously established by the Sarasota Dolphin Research Program so that results from the Georgia dolphins can be compared with prior Sarasota Bay dolphin health assessments. This underscores the value of the health data being collected as part of the long-term monitoring in Sarasota Bay. The Sarasota Bay study has not only established and field-tested effective capture-release sampling methods that have been adopted by other studies, but it is also helping to establish baseline measurements for dolphin health that aid in interpretation of data from other populations of concern.