The Houston Zoo, in partnership with a number of other institutions, has launched a pilot project to determine the status of diamondback terrapins (Malaclemys terrapin) in the Galveston Bay area. Surveys will determine the range of the species along the Texas coast, estimate population sizes, identify key habitats, and broaden our understanding of this animal’s natural history.
The diamondback terrapin is a small- to medium-sized turtle uniquely found in salt marshes, estuaries, and tidal creeks. The species ranges along the eastern shores of North America from Cape Cod to the Texas Gulf Coast. There are seven recognized subspecies; M. t. littoralis is the one native to Texas. For many years, diamondback terrapins were considered a culinary delicacy and over-harvesting decimated populations near metropolitan areas. In the recently approved Texas Wildlife Action Plan, the diamondback terrapin is classified as a medium priority species.
While there have been a number of studies of this species along the northeastern Atlantic Coast, very little is known about Texas populations, except that they are believed to be in decline due to habitat alteration, nest site disturbances, mortality from abandoned crab traps , and estuarine pollution. Up to one-third of all terrapins caught in crab traps drown.
A better knowledge of diamondback terrapin population status and trends may speak volumes about the environmental quality of Galveston Bay. Terrapins are at the top of the food chain, feeding on shellfish and mollusks that accumulate contaminants such as copper, mercury, and dioxin. Hence, the status of the terrapin population is conceivably an indicator of environmental contamination.
Houston Zoo staff from various zoo departments will participate in this project over the next few years with partner organizations including:
View photos of Houston Staff participating in a diamondback terrapin survey.
