ECOVIEWS
THE DIAMONDBACK TERRAPIN OF AMERICA'S COASTLINES
"What's your favorite wild animal?" To sound fair and impartial, you might say you like all animals. Or in a bid for crowd popularity, name something everybody likes, such as pandas or dolphins. But for me, there is only one truthful answer: the diamondback terrapin.
Imagine a reptile with the dreamy eyes of a golden retriever and the unassuming face of a manatee. Add the docile temperament of a lamb and the beauty of a seashell. For extra credit include perseverance against natural hazards of coastal weather, a sea full of predators, and a century of human-caused adversity. This tough, attractive little turtle has a record for getting through rough times with no complaints.
Among the prettiest of turtles, diamondback terrapins are highly variable in color. Some are almost black, others milky gray, and some have splashes of yellow or green. Their faces and shells look like hand-painted sculptures. Some have brightly colored, diamond-shaped markings on the upper shell.
The terrapin is the only U.S. reptile restricted to brackish water. Sea turtles live in the ocean; freshwater turtles avoid salty water. Terrapins inhabit the narrow strip of Atlantic and Gulf coastal marshes from Cape Cod to Florida to Texas.
Diamondback terrapins were overexploited as a luxury food item during the 1800s and early 1900s. Terrapin stew was a delicacy among the East Coast elite. Millions of terrapins, especially females, which reach sizes larger than a salad plate, were removed from marshes and estuaries. Whether terrapin populations have fully recovered from the assaults is uncertain.
Since 1983, we have conducted research on terrapins in coastal areas of the Carolinas and Georgia. The majority of the work has been done in the salt marshes of Kiawah Island near Charleston, S.C., to determine if terrapins face modern threats to their survival.
Terrapins are a fun research animal because of the ways we use to catch them. We pull seines up tidal creeks. A seine is like a six-foot-high tennis net with a pole on each end. We also set trammel nets, which hang in the water like a tennis net made of thin, nylon filament, with a volleyball net hanging on either side. Anything trying to swim past is soon tangled beyond escape.
Anyone with a sense of adventure enjoys these techniques, because anything living in the Atlantic Ocean could potentially be present. Common seine and trammel net captures, aside from terrapins, are stingrays, stone and blue crabs, sea catfish, shrimp, small sharks, and jellyfish. A common hazard to researchers is an endless supply of oysters with razor-sharp shells that defy anyone to slip and fall while pulling a seine.
One finding is that terrapins are virtually unaffected by a natural phenomenon that can be devastating to humans. When Hurricane Hugo slammed into the Charleston coastline in 1989, many terrestrial habitats were destroyed. Yet hundreds of terrapins we were observing before the hurricane were found in the same tidal creeks afterward. They had weathered the storm and within two days were going about their business as though nothing had ever happened.
A serious threat to the survival of adult terrapins, aside from being killed while crossing highways, is drowning in crab traps. Thousands of terrapins die each year in coastal regions when they enter crab traps. As air breathers, trapped terrapins can drown in less than an hour. In addition, as one crab trapper told me, some smaller terrapins are killed by larger blue crabs.
But commercial crab trappers may not be responsible for most terrapin deaths. Visiting tourists abandon thousands of recreational crab traps each year in all coastal states. These "ghost traps" can do endless damage to terrapins and other marsh wildlife by continuing to kill animals that enter them. No harm is intended by those leaving the traps. A strong educational program to inform visitors of the environmental hazards of deserted traps might solve much of the problem.
Why are diamondback terrapins my favorite animal? The reasons include the way they look, the way they act, where they live, and what they represent--the same traits we use to pick our favorite people. If you come to know them, they might become your favorite animal, too.
If you have an environmental question or comment, email ecoviews@gmail.com.