Abstract:
Diamondback terrapins (Malaclemys terrapin) are currently sold for human
consumption in many large cities in the United States. Some Asian cultural groups utilize
large numbers of terrapins, both regionally and world-wide, as a protein source. Terrapin
populations face many prevalent problems including predation by both native and non-native
predators, and anthropogenic disturbances (such as habitat destruction, roadkill, and bycatch in blue crab traps). The additional anthropogenic dilemma of terrapins sold in fish markets is particularly troubling when added to the long list of widespread disturbances. Terrapin harvesting is restricted in each state throughout the Atlantic and Gulf coastal range of the
species; however, enforcement of these restrictions is weak. The objective of our study was to determine the origin of terrapins sold in New York City’s Fulton Fish Market. In 2004, we collected blood samples from 63 individual terrapins confiscated from illegal sellers in
the Market. Some of these terrapins were released off the coast of Maryland, based on the
belief that the terrapins were originally harvested in the Chesapeake Bay. In this study, we
used microsatellite DNA variation to test the hypothesis that M. terrapin collected in the
Market are from the Coastal Mid-Atlantic terrapin metapopulation. We extracted DNA from
blood samples, performed PCR, and screened each turtle at 12 polymorphic microsatellite
DNA loci developed for bog turtles (Glyptemys muhlenbergii). Statistical analyses relied on
assignment tests to determine the most likely region of origin for each terrapin to the
metapopulation and subpopulation level. Many of the terrapins were assigned to the
Chesapeake Bay metapopulation (or subpopulations in Maryland); however, some terrapins
were assigned to the Coastal Mid-Atlantic or the Coastal Carolina region. Rules and
regulations (and the enforcement of these rules) need to be improved to adequately protect
terrapins from direct harvest.
