Diamondback Terrapin Biological Status Assessment

FWRI is collaborating with partners to conduct a biological status assessment of the diamondback terrapin (Malaclemys terrapin) in Florida. The Florida coastline represents approximately 20% of the species range and is home to five of seven subspecies, three of which occur only in Florida. However, little is known about the status and distribution of diamondback terrapins in Florida, and stakeholders are concerned about a perceived decline. The goal of this project is to provide information needed by the agency to assess the status and long-term viability of terrapin populations in Florida, and thereby establish meaningful management goals and appropriate regulatory recommendations.

We are in the process of conducting population assessments at three locations with known terrapin populations to estimate population sizes, sex ratios, and age distributions, which will help assess population trajectories. The mark-recapture fieldwork needed for these assessments has been completed and data analysis is underway. We are also working with partners running similar projects at multiple other sites within the range of all five subspecies. Other efforts have included gathering and consolidating existing data from partners statewide to map the known distribution of terrapins in Florida to develop a spatial model to quantify habitat availability. Also, in collaboration with research partners, we have collected >1,000 samples for genetic analysis to assess the validity of the currently recognized subspecies taxonomy.  Finally, to assess the probability and magnitude of past or future population reductions, we conducted a literature review of sources documenting historic habitat losses and projecting habitat changes into the future.

Stay tuned for future updates and publications from this project!