Spatial Variation in Mercury Accumulation in Bottlenose Dolphins (<i>Tursiops</i> spp.) in Southeastern U.S.A.
Mackenzie L. Griffin,
Colleen E. Bryan,
Tara M. Cox,
Brian C. Balmer,
Russell D. Day,
Laura Garcia Barcia,
Antoinette M. Gorgone,
Jeremy J. Kiszka,
Jenny A. Litz,
Robin M. Perrtree,
Teri K. Rowles,
Lori H. Schwacke,
Randall S. Wells,
Eric Zolman
Affiliations
Mackenzie L. Griffin
Department of Marine and Environmental Sciences, Savannah State University, Savannah, GA 31404, USA
Colleen E. Bryan
Chemical Sciences Division, National Institute of Standards and Technology, Charleston, SC 29412, USA
Tara M. Cox
Department of Marine and Environmental Sciences, Savannah State University, Savannah, GA 31404, USA
Brian C. Balmer
Conservation Medicine, National Marine Mammal Foundation, Charleston, SC 29405, USA
Russell D. Day
Chemical Sciences Division, National Institute of Standards and Technology, Charleston, SC 29412, USA
Laura Garcia Barcia
Institute of Environment, Department of Biological Sciences, Florida International University, Biscayne Bay Campus, Miami, FL 33199, USA
Antoinette M. Gorgone
Marine Mammal and Turtle Division, Southeast Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Miami, FL 33149, USA
Jeremy J. Kiszka
Institute of Environment, Department of Biological Sciences, Florida International University, Biscayne Bay Campus, Miami, FL 33199, USA
Jenny A. Litz
Marine Mammal and Turtle Division, Southeast Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Miami, FL 33149, USA
Robin M. Perrtree
Department of Marine and Environmental Sciences, Savannah State University, Savannah, GA 31404, USA
Teri K. Rowles
Marine Mammal Health and Stranding Response Program, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Silver Spring, MD 20910, USA
Lori H. Schwacke
Conservation Medicine, National Marine Mammal Foundation, Charleston, SC 29405, USA
Randall S. Wells
Sarasota Dolphin Research Program, Brookfield Zoo Chicago, c/o Mote Marine Laboratory, Sarasota, FL 34236, USA
Eric Zolman
Conservation Medicine, National Marine Mammal Foundation, Charleston, SC 29405, USA
Bottlenose dolphins (Tursiops spp.) inhabit bays, sounds, and estuaries (BSEs) throughout the southeast region of the U.S.A. and are sentinel species for human and ecosystem-level health. Dolphins are vulnerable to the bioaccumulation of contaminants through the coastal food chain because they are high-level predators. Currently, there is limited information on the spatial dynamics of mercury accumulation in these dolphins. Total mercury (THg) was measured in dolphin skin from multiple populations across the U.S. Southeast Atlantic and Gulf of Mexico coasts, and the influence of geographic origin, sex, and age class was investigated. Mercury varied significantly among sampling sites and was greatest in dolphins in St. Joseph Bay, Florida Everglades, and Choctawhatchee Bay (14,193 ng/g ± 2196 ng/g, 10,916 ng/g ± 1532 ng/g, and 7333 ng/g ± 1405 ng/g wet mass (wm), respectively) and lowest in dolphins in Charleston and Skidaway River Estuary (509 ng/g ± 32.1 ng/g and 530 ng/g ± 58.4 ng/g wm, respectively). Spatial mercury patterns were consistent regardless of sex or age class. Bottlenose dolphin mercury exposure can effectively represent regional trends and reflect large-scale atmospheric mercury input and local biogeochemical processes. As a sentinel species, the bottlenose dolphin data presented here can direct future studies to evaluate mercury exposure to human residents in St. Joseph Bay, Choctawhatchee Bay, and Florida Coastal Everglades, as well as additional sites with similar geographical, oceanographic, or anthropogenic parameters. These data may also inform state and federal authorities that establish fish consumption advisories to determine if residents in these locales are at heightened risk for mercury toxicity.
