Partners With USGS Scientists to Study Diamondback Terrapins in the Everglades

The National Save The Sea Turtle Foundation Partners With USGS Scientists to Study Diamondback Terrapins in the Everglades

Michael Cherkiss, Wildlife Biologist,
U.S. Geological Survey

Mathew Denton, David Roche, and Michael Cherkiss from the U.S. Geological Survey joined Devon Nemire-Pepe, Brian Smith, and Thomas Selby from Cherokee Nation Technologies to complete a five-day research trip on board the National Save The Sea Turtle Foundation’s research vessel Hawksbill February 17 - 22, 2018 in the Big Sable Creek (BSC) complex of Everglades National Park (ENP). The objective was to capture mangrove Diamondback terrapins (Malaclemys terrapin) as a part of long term population ecology study led by USGS scientist Dr. Kristen Hart (Davie, FL office of the USGS Wetland and Aquatic Research Center). The team also evaluated impacts to the study site from Hurricane Irma.

The Diamondback Terrapin (Malaclemys terrapin) Photo: Holly Lynn Claude.

Captain Nick Reeves (left) with the USGS “terrapin team” aboard the National Save The Sea Turtle Foundation’s Research Vessel Hawksbill. Photo: Holly Lynn Claude.

Photo: Holly Lynn Claude.

Diamondback terrapins are long-lived estuarine turtles, with high site fidelity. As part of a long-term mark-recapture and resource use study we have been sampling terrapins in the BSC complex within ENP for the past 18 years. During a research trip we capture terrapins and their prey by hand in several creeks within the complex of mangrove-lined creeks on the remote west coast of ENP. We also collect blood and scute samples from each terrapin before releasing them at their capture location. By sampling multiple tissues with both short (blood) and long- (scutes) turnover times, we can investigate spatiotemporal changes in resource use. From a subset of captured terrapins on each trip, we collect fecal samples to identify the percent contribution of recently consumed dietary items which will be incorporated into our stable isotope models. During the same time period as our terrapin sampling we also collect resource items (vegetation and prey such as fiddler crabs (Uca sp.)). to establish isotopic baselines for the environment at that sampling time period. In the lab we then process all biological tissue samples and send them to be analyzed using a mass spectrometer to determine their Carbon and Nitrogen stable isotopic signatures.

In the fall of 2017, Hurricane Irma impacted coastal lagoons, marshes, and forested wetlands in south Florida that provide habitat for a variety of protected species. This widespread disturbance events had impacts on wildlife and wetland resources. Thus, this trip was a part of our investigation of factors contributing to the vulnerability of wetland fauna, including terrapins, after this severe storm. Analyses are underway to determine the effects of the storm on terrapin survival and population estimates, as well as shifts in resource use.