No. 13–Diamondback Terrapin, Part II

It is counterintuitive to think of an air-breathing animal being able to sniff out food under water. That the diamondback terrapin is able to do so was a surprising conclusion I came to years ago through observing the first one in residence at the old North Street Aquarium. After initial observations that led me to think that might indeed be the case, I conducted a simple experiment that confirmed my assumption.

The experiment consisted of removing the terrapin from its tank prior to its being fed and hiding a piece of shrimp under the oyster shell substrate. Upon being returned to the tank the terrapin treaded water against the glass while focusing its attention on me. Typical “OK, where’s my breakfast?” behavior. I walked away.From across the room I observed the terrapin began a slow swim about at the surface while dipping its head under water a couple of times. Suddenly it submerged and its swim strokes quickened as it crisscrossed the bottom. Within less than a minute of submerging it had zeroed in on the spot where the shrimp was secreted and began tearing away at the shells covering the treat.

It is the ability to pick up and follow a scent trail under water that gets terrapins into trouble in the wild. There are no statistics kept on the number of terrapins that are attracted to the bait in crab traps (they will scavenge a meal) and drown but it is not an uncommon occurrence.

This spring the Estuarium will be partnering with a number of other organizations and agencies to address the problem as a project under the Port Royal Sound Conservancy. A simple By-catch Reduction Device (BRD) has been developed and used successfully on Kiawa Island where the terrapin population has been in steady decline. BRDs will be available throughout Beaufort County and being installed on recreational crab traps free of charge before the next crabbing season begins. Information on the program will be widely distributed in a timely fashion.

As of deadline, I am still awaiting information from a couple of authoritative sources I queried regarding our local subspecies of terrapin and its apparent fondness for fresh water as per last month’s column. There have been communication problems. Maybe next month.