Wormsloe Pristine coastal land provides a place for UGA students and faculty to do research by Kelly Simmons photos by Andrew Davis Tucker
t is cold on the Moon River near Savannah on this March morning, a blustery 40 degrees. Alyssa Gehman lowers herself from the bow of the boat into the 56-degree water and trudges through the thick muck to reach the oyster reef that lines the marsh. At the reef she breaks off chunks of the oyster shells. Once her two buckets are filled, she wades back to the boat. Later she’ll rinse off the pieces of shell and use an oyster knife to look for tiny mud crabs, some of which are infected with parasites nicknamed body snatchers
for their practice of castrating their hosts and reproducing. If the host is male, the parasite converts it into a female to reproduce. From this batch of shells she finds 15 crabs, only two infected with the parasite. “It’s usually 40 percent,” she says of the number caught that are infected. “That kind of goes along with my salinity hypothesis.” Since these came from farther up river from the ocean, the water is less salty. Gehman’s hypothesis is that the parasites would be less prevalent in areas with less salinity.
The saltiness of the water is among the factors Gehman is researching in order to determine in what environment the parasites thrive. Another is how well parasites handle changes in water temperature. “There’s a whole body of literature that says parasites will do well as temperature increases,” she says. Which means that if the Earth continues to warm, the number of parasites will increase, an issue not just for the mud crabs but for all living organisms. Gehman, a doctoral student in the Odum School of Ecology, is spending spring break at Wormsloe Plantation in Isle of Hope. One of six Wormsloe Fellows, Gehman is allowed to use the site and facilities for her research, even living in a renovated former slave cabin that provides housing for faculty and students. Funded by the Wormsloe Foundation, founded in 1954 as a charitable organization, the fellows study the human and natural history of Wormsloe and the surrounding coastal community. The first six were selected in 2008; so far there have been 14 fellows. JUNE 2014 • GEORGIA MAGAZINE