This project is part of a larger research effort by NOAA to assess the health and contaminant exposure of bottlenose dolphins, an apex predator and sentinel species for ecosystem health, at a National Priority List (NPL) polluted site in Brunswick, Georgia [Turtle/Brunswick River estuary (TBRE)] and a nearby, relatively pristine, reference site [Sapelo Island National Estuarine Research Reserve (SINERR)] (Figure 1).
The TBRE encompasses the Turtle and Brunswick Rivers, Blythe Island State Park, St. Simons Sound, St. Simons Island, Jekyll Island, and the city of Brunswick. LCP Chemical located on the west side of Brunswick, is classified as an Environmental Protection Agency (EPA) Superfund Site that is currently on the NPL. Additionally, there are several other waste sites in the vicinity of the LCP site for which EPA and the State of Georgia are conducting remediation.
In contrast to the TBRE, the SINERR, about 30 km northeast of Brunswick, is the fourth largest, and one of the most pristine, barrier island areas along the Georgia coast. Smooth cord grassis the dominant vegetation type throughout this region with numerous tidal creeks bisecting the marsh and draining into Doboy Sound. The SINERR is part of the National Estuarine Research Reserve System, and is a focus for long-term ecological research projects such as water quality monitoring, primary productivity assessment, and fisheries biology.
This project will evaluate and compare seasonal abundance, site-fidelity, and habitat utilization patterns for bottlenose dolphins across these two adjacent geographic regions. An understanding of dolphin abundance and habitat utilization within these areas is essential to support effective management, and knowledge of site fidelity and movement patterns of dolphins between the two areas is critical for accurate interpretation of health data. Intensive seasonal photographic mark-recapture surveys will be used to determine dolphin abundance in both regions. Comparing sighting histories for all identified individuals will provide site-fidelity indices (i.e. amount of time dolphins are spending within each of the two areas. Environmental data (i.e. salinity, temperature, water depth, velocity, turbidity, bottom habitat type, tidal state, and chlorophyll a) in relation to dolphin, and perhaps dolphin prey, distribution, will be used to assess dolphin habitat preferences within and between the two regions. Further, this research will enhance current knowledge of coastal bottlenose dolphin population structure along the east coast of the U.S. The first mark-recapture surveys for this project will begin in February 2008.
This research would not be possible without funding from NOAA’s Fisheries Service and the Georgia Department of Natural Resources.