Peconic Bay Sea Turtle Project

A 1947 film of an "arribada" (mass nesting) of Kemp’s ridley turtles estimated 40,000 turtles at Rancho Nuevo, Tamaulipas, Mexico. Apart from a few isolated cases, this was and is the only known nesting site for the species. The next available data was collected in 1965 when the biggest arribada numbered 5,000 turtles. Despite protective measures, the population declined drastically during the following years. Today, with only some 400-500 breeding females left, the Kemp's ridley is the most seriously endangered of all eight sea turtle species.

Although as adults they primarily inhabit the Gulf of Mexico, many juveniles, at about the size of a dinner plate and weighing only 8-12 pounds, drift out into the Atlantic to spend their first few years, and then migrate up the warm current of the Gulf Stream to feed in Peconic Bay, off Long Island’s eastern end. They are joined there by other juvenile sea turtles, including loggerhead, a few green, and more rarely, leatherback turtles.

The waters of the Peconic Bay suffer general environmental deterioration through groundwater contamination, recreational boating, noise pollution, and spills and accidents from commercial development. How does this environment affect the population and health status of these endangered and threatened species, their habitat, and food sources?  As a “sentinel” species, what can their health tell us about the health of the ecosystem and its waters, which could affect our own health?

These are the questions under study in the New York Bioscape Initiative’s Peconic Bay Sea Turtle Ecology and Health Assessment, currently in its second year. The New York Bioscape Initiative was launched by Wildlife Trust in April 2002 under the direction of Dr. Fred Koontz, Executive Vice President, as a long-term collaborative effort to determine the effects of human-induced changes such as environmental degradation and pollution on human, wildlife, and ecosystem health within a 100-mile radius of midtown Manhattan. The Sea Turtle Project is a collaboration between Wildlife Trust, The Riverhead Foundation for Marine Research and Preservation, Cornell University, Cornell Cooperative Extension, and the National Marine Fisheries Service.

Combining traditional ecological methods and techniques with the new field of Conservation Medicine, which examines the links between human, wildlife, and ecosystem health, the Sea Turtle Project will provide ecological and health evaluations of threatened sea turtles visiting Peconic Bay.

Dr. Michele Sims, a recent Tufts University Veterinary School graduate, joined the project as a Conservation Medicine Intern for this field season, which began July 21. Michele is working on site at The Riverhead Foundation for Marine Research and Preservation, in Riverhead, New York. The team includes Wildlife Trust’s Director for Conservation Medicine, Dr .Alonso Aguirre, Dr. Steve Morreale from Cornell University, Chris Smith with Cornell Cooperative Extension of Suffolk County, and Riverhead’s Rob DiGiovanni and Kim Durham.

A total of nine local fishermen have agreed to contact the team when they accidentally retrieve sea turtles from their pound nets. The team meets them dockside to collect morphological data, and small blood and tissue samples as part of the health assessment, before the turtles are released.

Dr. Aguirre is particularly interested in evidence of Fibropapillomatosis, also known as FP- fibrous tumors which, although usually benign, can nevertheless prove fatal to sea turtles. The tumors can grow under turtles’ flippers and near their mouths to a large size that impedes the turtles’ ability to swim and eat normally. FP can also produce nodules on internal organs including the lungs, liver, and heart.

Over the last ten years, Dr. Aguirre and other veterinarian epidemiologists have observed a dramatic increase of FP tumors in sea turtle populations worldwide. One theory is that turtles may become infected during the period of their lives when they move to coastal environments. It seems likely that multiple causes are involved, including an infectious agent and/or a combination of toxins that suppress immune response and make the turtles more vulnerable to disease. A herpes virus is sometimes found in turtles with FP, and will be screened for in Peconic Bay turtles as well. If it is found that FP is occurring in the Peconic Bay population, it will be important to determine the degree of its presence, to confirm any correlation with specific environmental stressors, and to propose policies that can improve turtle and ecosystem health.

Much of our knowledge about local juvenile migratory turtles is derived from a similar capture-and-release study conducted by Dr. Morreale some 10 years ago. An informal assessment of the turtles’ overall health at that time was reported on the whole as very good.

Turtles in the 2002 study group fit within the parameters of previous years for length, width, and weight and all appeared to be in good to fair body condition, with no gross abnormalities on physical exam or blood analysis. Due to a delay in acquiring permits, however, the 2002 sample size was too small to make a broad generalization of current species status and health.

Although only nine turtles have been (as of September 10) captured, sampled, and released so far this year, the team plans to analyze specimens collected from both 2002 and 2003 for evidence of environmental pollutants such as DDT, PCBs and heavy metals, and infectious disease agents. Eventually, the hope is to have enough specimens to compare differences between turtles arriving early in the season (July/August) and turtles departing on their way south to warmer waters (October/November.)

For further information about New York Bioscape Initiative projects, please contact:
Dr. Fred W. Koontz
Executive Vice President
koontz@wildlifetrust.org

For information regarding Conservation Medicine and sea turtle health, please contact:
Dr. Alonso Aguirre
Director for Conservation Medicine
aguirre@wildlifetrust.org