Not a lot is known about sea turtle nutrition. Currently that makes things a bit tricky when trying to ensure that sea turtles undergoing rehabilitation get enough of the vitamins and minerals they need. In an effort to make the rehab process more uniform the GSTC is working to identify the nutritional needs of loggerheads and then, with the help of the zoo and exotic animal food supplier Mazuri, create a sea turtle specific multivitamin. Simultaneously, the Center has had it’s “fish milkshakes” nutritionally analyzed and is working with Mazuri to create a standardized powered tube feed formula. The goal is that both of these products can be supplied to rehabilitation centers, zoos, and, aquariums around the world. Furthermore, the information from this study will provide important baseline data that can be used to evaluate the nutritional health of loggerhead sea turtles in the wild and captivity. Organochlorine contaminants inhibit vitamin A synthesis. The vitamin A data set from this study will also be used in another collaborative study focused on contaminant analysis and biomarkers for various contaminants. Funds to conduct this study were obtained through a grant provided by the Riverbanks Zoological Park in Columbia, South Carolina. 

This research will be completed by evaluating fifteen nesting female loggerheads on Jekyll Island, 15 sub-adult loggerheads and as many males up to 15 and females up to 15 that are captured on the Georgia Bulldog shrimp trawl research vessel by the SC DNR, the GSTC staff, and other colleagues. Fifteen loggerheads will be evaluated every 2 weeks through the rehabilitation process with identical protocols utilized for the healthy free-ranging and nesting turtles.

A complete physical examination will performed along with morphometric measurements and body weight on each sea turtle. Body condition will be evaluated by the relationship between carapace length and body weight and physical exam findings.  Sex will determined using tail length (e.g., long tail in adult males) and by testosterone level for foraging and rehabilitated sub-adult turtles.Standard blood tests will be used to further assess the health of each turtle including a complete blood count and a plasma biochemical profile. Plasma vitamin D (25-hydroxycholecalciferol) will be measured by radioimmunoassay. Plasma vitamin A (retinol) and vitamin E (tocopherol) concentrations will be determined by high performance liquid chromatography (HPLC) at the Nutrition Laboratory at Mystic Aquarium, Department of Nutrition. Trace mineral panels will be conducted by the University of Pennsylvania College of Veterinary Medicine Toxicology Laboratory.

Fifteen fresh dead stranded loggerheads will receive a complete gross necropsy (autopsy) and histopathology (microscopic examination of the tissue). Turtles will be selected that die from acute traumatic injuries (e.g. boat strikes) or acute drowning in shrimp trawl nets. Necropsy results will be used to determine if the turtle was healthy other than the immediate cause of death. Liver and kidney samples will be collected and frozen at -70ºC until processed. Trace minerals, vitamin A, E, and carotenoids will be measured on these tissues utilizing similar techniques as described for the plasma.

Freshly caught prey items commonly consumed by the loggerhead sea turtle will be nutritionally analyzed. These will include blue crabs, horseshoe crabs, whelks and possibly others. Necropsy records from the Georgia DNR will be reviewed to assess the common prey items consumed by loggerheads in coastal Georgia.

The information generated from this project will be presented at the annual sea turtle rehabilitation workshop and the annual meeting for the AAZV and ARAV in 2009 or 2010, depending on when results are available.  The results and dietary formulations will be made available to sea turtle rehabilitators and aquariums. Ultimately the information from this study will be published in a peer reviewed journal.