Although once abundant, populations of diamondback terrapin have decreased along stretches of the species’ range, including the coast of the Gulf of Mexico. Historically, terrapins were exported from the Gulf coast to the Northeast for consumption and also represented a readily available food source to local residents. Populations in Alabama have declined to such a degree as to warrant a designation of “species of special concern” by the state despite sparse knowledge of the terrapin’s regional ecology. The study's objective was to determine the current status of terrapin populations in Alabama to aid in the development of an optimal management strategy. Several types of surveys were completed in numerous salt marshes from 2004-2008 to identify strong aggregations (head surveys and modified crab traps in salt marshes), locate and monitor nesting beaches (depredated nest surveys and drift fences with pitfall traps), and characterize threats (examined efficacy of bycatch excluder devices on crab traps and identified nest predators with wildlife cameras).
Results/Conclusions
The aggregation inhabiting Cedar Point Marsh represents the strongest in the area based on head and depredated nest surveys. Twenty terrapins were captured in modified crab traps in Cedar Point Marsh and nine were captured on the nesting beach surrounding the marsh in 2006. In 2007, number of captured terrapins decreased to zero in modified crab traps and seven on the nesting beach. The ability of the 5x15cm by-catch reduction device to prevent terrapin mortality was not able to be determined, but it did not significantly alter the capture of blue crabs that were of legal harvestable size. Wildlife cameras positioned by important nesting areas on the beach by Cedar Point Marsh photographed raccoons in the vicinity. These cameras will be used in 2008 to help identify the locations of terrapin nests on Cedar Point nesting beach, which from the surveys offers the greatest chance of finding and removing nests before predators can reach them. The eggs will be incubated at the Dauphin Island Estuarium and a head-starting program will be initiated. Hatchlings will be released back into Cedar Point Marsh, and local schools may be utilized in the recovery program to increase public awareness. Terrapins in Alabama face an uncertain future, however, surveys performed in this study have provided crucial background ecological information that will be applied in the management and recovery program to contribute to the conservation of this unique animal.
