Prepared by Terry M. Norton, DVM, Diplomate ACZM

In 2003, there was a perceived increased incidence of emaciated and barnacle-laden loggerhead sea turtles (Caretta caretta) found stranded along the southeastern US Atlantic coast.  To investigate this problem further, the Wildlife Conservation Society’s St. Catherines Island (SCI) Wildlife Survival Center and the Georgia Department of Natural Resources organized a workshop on SCI in November of 2003.  Fifteen people attended the workshop ranging from turtle biologists representing Florida, Georgia, South Carolina, and North Carolina, veterinarians, toxicologists, immunologists, and experts from the National Oceanic and Atmospheric Administration (NOAA).

It was determined at this meeting that there was an increasing trend of debilitated sea turtles stranding with the highest incidence in 2003 (NC 3%, SC 22%, GA 10%, and FL 21-25% of the total turtle strandings). The species composition of debilitated sea turtle strandings was primarily loggerheads, with the exception of Florida, where green (Chelonia mydas), Kemp’s ridley (Lepidochelys kempii) and possibly hawksbill (Eretmochelys imbricata) turtles were affected.

A debilitated turtle is defined as an emaciated turtle with small barnacles on the skin. Heavy epibiota can be a normal finding on the carapace and plastron of loggerhead sea turtles, but should not be on the skin.  Health assessment and necropsy data from cases presented at the meeting by the veterinarians indicated the turtles were being affected by a wide range of secondary bacterial and parasitic infections with the primary cause still to be determined.  Some of the debilitated turtles showed high levels of polychlorinated biphenyls (PCBs), chlordane, and mercury.

In order to provide consistent standardized results, protocols were developed for visual assessment, physical examination and morphometrics, clinical pathology, contaminant analysis, immune function tests, gross necropsy and histopathology on debilitated turtles.  These protocols were used to evaluate debilitated loggerhead turtles that stranded in the southeastern US in 2004 and 2005.

This work has continued through the efforts of Dr. Terry Norton at the Georgia Sea Turtle Center and our continuing collaborations with other investigators.

Click here for preliminary results.