By Kathy Urffer
Diamondback Terrapin populations can be found along the Atlantic and Gulf Coasts of the U.S. Although their range covers thousands of miles, terrapins only inhabit the thin strip of estuaries and coastal marshes right along the coast, so their actual habitat area is quite small. Terrapins are the only species of turtle, of the approximately 270 species in the world that are exclusively adapted to live in brackish water.
Terrapins were once highly prized for their meat. In the mid-1800s, they were harvested in huge numbers to make soup which led to severe declines in many local terrapin populations. By the mid-1930s terrapins had become so rare in the region that they were considered locally extinct.
Terrapin populations have steadily recovered in many areas but are still threatened by intense coastal development. Dredging, filling, and marshland alterations have maimed the environment that is critical to terrapin survival. In our area, lawns and bulkheads now replace many of the areas that were once suitable nesting beaches leaving only the shoulders of heavily trafficked roads adjacent to salt marshes. Consequently, large numbers of females are killed by motor vehicles during their nesting season from May to mid-July.
In May 2001, Hackensack Riverkeeper began working on the Diamondback Terrapin Mortality Reduction Program, which was begun in 1998 by the Edison Wetlands Association (EWA) and the New Jersey Turnpike Authority. Our staff monitors barrier fences at four locations along the Turnpike. The fences discourage terrapins from crossing the busy roadway and instead guide them back to the creeks that flow underneath the highway. The females can then access their nesting grounds in safety.
Terrapins grow slowly, taking 3-8 years to mature and during the incubation and hatchling stages survivorship is very low. Predators, such as raccoons and foxes, destroy many nests. Root predation, another peril, occurs when the roots of beach plants invade a nest, penetrate the eggs, and absorb their nutrients. Once hatched, juveniles tend to avoid open water, and they prefer burrowing under shoreline debris, mud and tidal wracks of cordgrass.
In south Jersey efforts have been made to promote the survival of diamondbacks by the Wetlands Institute in cooperation with Richard Stockton College. The partners operate a "head-starting" facility for baby terrapins from undamaged eggs taken from road-killed females during the nesting season. The juveniles are eventually released back into the salt marshes from which their perished mothers emerged. For information on educational programs at The Wetlands Institute, call 609-368-1211.
While releasing turtles from pet stores and food markets might seem like a humane action, it is illegal and may be dangerous to local populations. Released turtles may introduce new diseases into native populations, with disastrous results. If you have a diamondback terrapin or find one that has been hurt, please call NJ Endangered and Non-game Species Program at 609-292-9400.
If you would like to learn more about terrapins or about opportunities to participate in the on-going research at Jamaica Bay Wildlife Refuge, please contact Dr. Russell Burke, Department of Biology, Hofstra University, Hempstead, NY, 11549, (516) 463-5521.
This article has been adapted from information provided by Dr. Russell Burke and The Wetlands Institute.