Sea Turtle Population Study in Florida Bay

Funded in part by the National Fish and Wildlife Foundation

The Importance of Florida Bay

Florida Bay is an important sea turtle habitat located between the southern tip of the Florida peninsula and the Florida Keys.

Every summer, a team of researchers capture loggerheads and gather data. These studies establish long-term trends that are essential to monitor and investigate overall health and any changes in the habitat.

Researchers are attempting to answer the following questions:

1. What are the growth rates of loggerhead and green turtles in Florida Bay?
2. Do loggerheads exhibit long-term fidelity to foraging sites?
3. What are the long-term prevalence rates of fibropapilloma disease?
4. Is the population of marine turtles that inhabit Florida Bay increasing or decreasing?

About 75-100 live loggerheads are captured from Rabbit Key Basin, Twin Key Basin and Arsnicker Basin over a 10-day sampling period in early summer each year.

Researchers go out on two flat-bottomed vessels, traveling at a slow speed in a random search pattern until a turtle is spotted. Snorkelers then dive near the turtles and capture them by hand.

Coordinates of the capture site are taken using a Global Positioning System (GPS) unit. Environmental data is noted, including water and air temperature, salinity, water depth and a description of the sea bottom. The turtle is brought on board and measured, weighed, examined externally and photographed. Any signs of injuries or fibropapilloma tumors are documented.

The turtle is then tagged with Inconel metal tags along the rear edge of both front flippers. Passive integrated transponder (PIT) tags are also placed into the right front flipper using a sterile hypodermic needle. The PIT tag is a tiny microprocessor capable of transmitting a unique identification code when excited by a detector.

Before releasing the turtle, a number is painted on the carapace to make sure the same one is not recaptured during the sampling period. The paint is not permanent - it fades after a few weeks.