The diamondback terrapin is Maryland’s state reptile. Inhabiting the brackish waters in the bays and creeks of the Atlantic and Gulf coasts, it is the only turtle in North America restricted to estuaries. Relatively little is known about this species; terrapin have been threatened historically and its numbers continue to decline in some parts of its range.
Numerous conservation organizations, research scientists, and private individuals are researching terrapins and working to help protect this beautiful natural resource. Terrapin are considered a keystone species because they provide high quality food for many species higher in the food web, and they control numbers of periwinkle snails and invasive pests. The loss of an integral species like terrapin could have drastic ripple effects on ecosystems.
If you see a terrapin, please consider registering it to assist with a new Mid-Atlantic initiative to determine where our turtles populations are thriving.
Annual Diamondback Terrapin Surveys
The Maryland Coastal Bays Program has been collecting a variety of data relating to diamondback terrapin populations in the Coastal Bays. Organized terrapin headcount surveys began in 2012 in collaboration with Maryland DNR and other members of the diamondback terrapin work group.
The current population status of this terrapin in the Coastal Bays is poorly understood. To better understand its status, MCBP had continued to coordinate these counts annually, engaging the community on protecting Maryland’s state reptile.
The surveys traditionally took place in the Coastal Bays, including brackish-water creeks, throughout a designated week. The week is typically the end of May, which is their their courtship season.
The program is now evolving into a collective Northeast Region program to get a better understanding of the greater terrapin population on the East Coast.
According to research from the Virginia Institute of Marine Science, diamondback terrapin face numerous threats, many of which are human related. Habitat loss, climate change, boat strikes, and nest predation by household animals and generalist species, like raccoons and gulls, have all contributed to the stress put on the terrapin population.
A serious problem that you can do something about is crab pot entrapment. Terrapin enter crab pots the same way crabs do, attracted by the same bait, and are then consequently trapped. Turtles have lungs not gills, so if someone is not checking a crab pot regularly, the terrapin can drown. Recreational pots are the most dangerous because they are typically set in shallow water where smaller terrapin, capable of getting caught, spend more time. Installation of a bycatch reduction device will stop most terrapin from entering a crab pot, but still allow the biggest crabs through.
Waterfront property owners are legally allowed to crab with a maximum of two recreational crab pots. Maryland regulation requires each entrance be equipped with a by-catch reduction device (BRD). If you are in need of BRD devices, please reach out to please contact Sandi Smith at sandis@mdcoastalbays.org
There were no surveys conducted for 2024 or 2025. There are limited land surveys being conducted for this year and we will be launching a more progressive program with our Mid-Atlantic partners to include water surveys for 2027.
2023 Annual Terrapin Survey Report