<p>RESEARCH ARTICLE
Turtle soup, Prohibition, and the population
genetic structure of Diamondback Terrapins
(Malaclemys terrapin)
Paul E. Converse1*, Shawn R. Kuchta1,2, J. Susanne Hauswaldt3, Willem
M. Roosenburg1,2
1 Department of Biological Sciences, Ohio University, Athens, Ohio, United States of America, 2 Ohio Center
for Ecology and Evolutionary Studies, Ohio University, Athens, Ohio, United States of America, 3 Department
of Biological Sciences, University of South Carolina, Columbia, South Carolina, United States of America
* paulconverse@icloud.com
Abstract
Diamondback terrapins (Malaclemys terrapin) were a popular food item in early twentieth
century America, and were consumed in soup with sherry. Intense market demand for terra-
pin meat resulted in population declines, notably along the Atlantic seaboard. Efforts to sup-
ply terrapins to markets resulted in translocation events, as individuals were moved about to
stock terrapin farms. However, in 1920 the market for turtle soup buckled with the enactment
of the eighteenth amendment to the United States’ Constitution—which initiated the prohibi-
tion of alcoholic drinks—and many terrapin fisheries dumped their stocks into local waters.
We used microsatellite data to show that patterns of genetic diversity along the terrapin’s
coastal range are consistent with historical accounts of translocation and cultivation activi-
ties. We identified possible instances of human-mediated dispersal by estimating gene flow
over historical and contemporary timescales, Bayesian model testing, and bottleneck tests.
We recovered six genotypic clusters along the Gulf and Atlantic coasts with varying degrees
of admixture, including increased contemporary gene flow from Texas to South Carolina,
from North Carolina to Maryland, and from North Carolina to New York. In addition, Bayes-
ian models incorporating translocation events outperformed stepping-stone models. Finally,
we were unable to detect population bottlenecks, possibly due to translocation reintroducing
genetic di