A license is required to hunt terrapins, but there is no limit on the number taken. These laws do help, but there are still problems which threaten diamondback terrapins. The only terrapins that are larger than six inches are the females. If females are taken during hunting season, fewer and fewer eggs are laid. Also, many adults are injured or killed by boat propeller blades.
Terrapins drown in crab pots where they are lured by the bait meant for blue crabs.
Although figures are not available on the diamondback population in Maryland, it is probably safe to say that they will never be as plentiful as they were in the eighteenth century.