Saving Diamondback Terrapins from Crab Trap Drowning

The diamondback terrapin is a turtle that lives exclusively in tidal wetlands and estuaries along the Atlantic and Gulf coasts of North America. Throughout the species range, the primary source of adult mortality is drowning in traps that are set to catch blue crabs. Both crabs and terrapins enter the traps, but because the traps are underwater, the terrapins cannot surface to breathe and they drown. To reduce the risk of turtle mortality, some states have strict size requirements on openings on crab traps. However, many crabbers feel the small openings also restrict the capture of large crabs, so regulations are largely ignored and terrapins continue to drown. To address this problem, researchers will look at a different strategy that will let the large crabs and terrapins into the traps, but will only let terrapins exit the traps. Similar to the excluder devices used for sea turtles in offshore shrimp fisheries, researchers will design and test a release hatch in the tops of the traps that only terrapins have the ability to open. If successful, this new device may save thousands of terrapins from needless drowning each year and promote turtle conservation in estuaries of North America.