In Chesapeake Bay, diamondback terrapins - the only species of turtle living in the bay - drown incidentally as by-catch in commercial traps used for harvesting blue crabs. The proposed research will determine the impact of commercial crab traps on the size and age structure of terrapin populations. First, side-scan sonar will be used to locate and retrieve commercial crab traps lost during tropical storm Ernesto in August 2006. Dead terrapins in these abandoned traps will be sexed and aged, and shell dimensions will be measured. The age-size relationship of drowned terrapins will be compared with live terrapin populations being surveyed in adjacent terrapin habitats with and without commercial crabbing pressures.
The proposed research will assist policy and management decision-making by providing timely data determining the impact of commercial crabbing on diamondback terrapins in Virginia waters of Chesapeake Bay. In addition to student training opportunities and publication in scientific journals, presentations at non-technical outlets will help to make the science accessible and promote better understanding of the relevant fishery and conservation issues. The research will provide data to assist the structure of an ecosystem-based management plan for the blue crab fishery - one that includes diamondback terrapins - before the fishery collapses.
