Originally published in Seven Mile Times' Memorial Day 2016 Issue
104
It was June, and the world smelled of roses. The sunshine was like powdered gold over the grassy hillside. ~ Maud Hart Lovelace
Don’t Let the Tough Ex terior Fool You...
DIAMONDBACK TERRAPINS
Need Your Help! By Dr. Lenore Tedesco of The Wetlands Institute
iamondback terrapins are a keystone species of the marsh – their fate impacts many aspects of the marsh ecosystem. They are gray-skinned turtles with highly variable patterns and markings that live in our local salt marsh. Diamondback terrapins are special because they are the only species of turtle that is adapted to life in the salt marsh. Terrapins are meat-eaters, and one of their primary food sources is the marsh periwinkle snail. These snails feed on marsh grasses, and without healthy populations of terrapins to control snail populations, large sections of the marsh would be stripped of vegetation and potentially lost. These diamonds of the marsh are most often seen when the females, who are much larger than males, climb onto roadways, over sand dunes, and even into backyards to nest each summer from May until July. You also might have seen the quickly retreating head of a terrapin as you kayak through local creeks. If you are lucky, perhaps you have seen the quarter-sized hatchlings, which emerge from their nests in the fall and spring. Some days, it can seem like terrapins are everywhere. Yet, terrapins are in trouble throughout their range. They can be found in coastal wetlands from Texas to Cape Cod. Development and heavy use of the terrapin’s salt-marsh and barrier-island habitat has led to stark declines in terrapin numbers. Climate change is adding more stress as well. Although Memorial Day 2016
males rarely leave the water, nesting females often must cross roads in search of higher ground to nest, and hundreds are killed each summer as a result. Untold numbers become unintended catch in crab traps and drown each year. Nest and hatchling predators such as raccoons and skunks are now more abundant in our communities, thriving on the feast our garbage provides. This overabundance of predators reduces the number of hatchlings that survive to maturity. All of these threats combine to make the future of the diamondback terrapin uncertain. The Wetlands Institute has worked diligently for more than 25 years to make sure terrapins remain a vital part of our local coastal ecosystem for years to come. The program promotes the conservation of diamondback terrapins through applied research, conservation programs, citizen science projects and educational programs. Started by Dr. Roger Wood in conjunction with Stockton University, The Wetlands Institute’s terrapin research and conservation program works to increase our understanding of terrapins and develop ways to protect them from the various threats they face. One important tool that we pioneered and have helped spread is the use of terrapin barrier fencing along the causeways to keep terrapins from entering high traffic areas. The black tubing along the side of the roadways provides space for nesting while keeping the females out of harm’s way. In 1991, we began patrols of local roadways to document the impact of vehicles on terrapin populations. Each year from May through July, we patrol 38
miles of coastal roads from Stone Harbor to Sea Isle City. You have probably seen the cars out twice a day rescuing injured turtles or helping them cross. Data collected during patrols have revealed the scale of the threat roads pose to terrapins. Through 25 years of patrols, nearly 500 female terrapins on average are killed each year on patrolled roadways. While this is a sobering statistic, our patrols allow us to do much to reduce the impact from roads. Many terrapins killed on roads still hold viable eggs. We retrieve these eggs and incubate them in our lab. Incubation temperature determines sex for terrapins; therefore, we adjust incubator temperatures to produce female hatchlings and help offset the loss of their deceased mothers. With the help of Stockton University and trained schoolteachers, we raise these hatchlings for one year, keeping them active and fed year-round. This process, called headstarting, allows terrapins to reach a size up to three times that of wild turtles the same age, and leaves them less vulnerable to predators. Over the years, our program has released 2,250 headstarted terrapins to local marshes. In addition, each year we treat injuries and save hundreds of terrapins during patrols. We also work with partners to install fencing, advise road modifications, and create alternative nesting habitat to limit the number of terrapins crossing roads. Since 1997, we have been conducting a long-term population study of terrapins in our local marshes. Each year, we capture terrapins on our property and in tidal creeks. We mark them with uniquely
coded microchips that let us identify individuals. The microchips are just like the ones a vet would use to identify your pet. By marking, releasing and recapturing turtles, we can track things like population size, survival rates, growth, movements and individual nesting habitat preferences. To date, we have marked nearly 5,000 terrapins, and are currently analyzing data to help us better understand and protect the population. For the past several winters, The Wetlands Institute staff and volunteers have searched back-bay creeks for lost or abandoned crab traps. These ghost traps are a hazard because they continue to fish, with captured animals becoming the bait in an endless cycle. Diamondback terrapins are especially susceptible to being trapped because they are attracted by the bait fish used in blue-crab traps. Terrapins have lungs and are air breathers just like people. So, once inside the traps, terrapins struggle to escape and usually drown. In addition to working to retrieve lost traps, the institute also developed and distributes Bycatch Reduction Devices (BRDs). BRDs fit in the entrance to crab traps and help prevent terrapins from entering the traps, while still allowing crabs to enter freely. BRDs are required in all crab traps that are being used in the back bays and creeks where terrapins live. The Wetlands Institute is distributing BRDs free of charge in an effort to increase their usage. It’s an easy action and it makes a difference. If you love blue crabs and diamondback terrapins as much as we do, please make sure that your crab traps, and those of WWW.SEVENMILETIMES.COM