STONE HARBOR - “I Brake for Turtles” bumper stickers take on extra meaning this month, because Northern diamondback terrapin nesting season begins in late May and runs through mid-July, corresponding with the year’s busiest time,when tourists and locals use county roads in higher numbers.
Conservation efforts to protect terrapins by The Wetlands Institute (TWI), of Stone Harbor, and the Borough of Avalon seem to have been somewhat successful, according to officials, but road mortality and habitat destruction are persistent issues impacting local terrapin populations.
Terrapins are turtles that spend time both on land and in brackish, swampy water. The word “terrapin" comes from an Algonquian Indian word, meaning “a little turtle."
Of the seven subspecies of diamondback terrapin in the U.S., only the Northern diamondback terrapin resides in New Jersey. TWI’s work to enhance nesting habitats in the area specifically aims to conserve Northern diamondback terrapin populations.
According to Brian Williamson, a research scientist at TWI, “While we cannot definitively state whether or not local terrapin populations are declining, the threats that face diamondback terrapin populations, including road mortality and habitat destruction, are persistent issues, and each year continue to impact local terrapin populations.”
Every year, hundreds of vulnerable diamondback terrapin turtles emerge from the salt marsh and seek higher ground to dig their nests, Williamson said.
During nesting season, the turtles are more active, crossing roadways searching for optimal locations to lay their eggs. They are regularly hit by cars, drown in fishing gear, and have their habitats destroyed.
“In addition to countless terrapins lost as bycatch in crab traps and taken for the illegal pet trade, road mortality alone removes 500 adult female terrapins from local populations on average each year,” Williamson said.
“Terrapins take up to eight years to reach adulthood, and they have a naturally low survival rate during their early years,” he continued. “Therefore, the survival of adults, who have very few natural predators, is important because it may take many years for them to successfully reproduce.
"The loss of large numbers of adult terrapins each year on roadways upsets this balance by preventing females from surviving long enough to successfully reproduce and puts the health of terrapin populations at risk.”
Additionally, terrapins depend on salt marsh and coastal upland nesting habitats for their survival.
“Unfortunately, both of these habitats are threatened by sea-level rise, and nesting habitats are at risk to development,” the scientist said. “These are persistent problems that will continue to threaten terrapins in the future and may be adding to, or driving, declines of local terrapin populations.”
Williamson said if someone encounters a terrapin on the roadway, “and it is safe to do so, please help her in the direction she is headed, but only if you will not put yourself at risk.”
If someone finds an injured terrapin or other wildlife in need of help this summer, Williamson asks that a state-certified wildlife rehabilitator be contacted, a list of which can be found at: https://bit.ly/3btw7Uj.
“The Wetlands Institute works diligently to prevent injury of terrapins on roads and monitoring the population, but we are not a licensed wildlife rehabilitation facility, and we cannot accept or treat injured wildlife,” he stressed.
“Additionally, we ask that you please leave all terrapins in the wild. They are protected as a non-game species in New Jersey and removing them from the wild is illegal. They do not make good pets and will likely not survive for long due to specialized care needs,” Williamson said.
TWI created or enhanced terrapin nesting habitats at several locations throughout Cape May County, according to Williamson, and all have attracted terrapins to nest within a year of construction.
“We are beginning work this year to understand nest success rate at artificial nest sites to determine how it compares with natural sites, and whether or not this is an effective long-term strategy for terrapin conservation,” he noted.
The construction of one nesting habitat, in Avalon, was completed in 2019, and TWI continues to advise on this and other habitat enhancement projects in the area, as needed.
According to Scott Wahl, Avalon's business administrator, there has been an existing terrapin nesting area south of the boat ramp in the Bay Park Marina, along the bayfront.
With TWI, they established a turtle fence, made with the circular plastic tube often found on some causeways, including Avalon Boulevard.
“That’s a county road, but we feel so empowered by terrapin conservation, the borough takes responsibility for the fence, as we know it helps with keeping the turtles alive,” Wahl said.
The borough has a comprehensive plan to rehabilitate its Bay Park Marina along the bayfront, according to Wahl. Part of the plan is to create a handicapped-accessible kayak launch area, put in a new bulkhead for resiliency, and a new boat ramp.
Wahl said the project could go out to bid in the fall and is supported by a $1.2 million grant from the Cape May County Open Space program.
“The turtle nesting habitat will be advanced under this project,” he explained. “I received confirmation from the NJDEP (New Jersey Department of Environmental Protection) that they wish to talk to us about one integral component of the program - a living shoreline for resiliency - as living shorelines have proven to be very effective with keeping tidal waters out.
"A date for that meeting has not been secured, but confirmation that the state wants to talk to us, at our request, was made May 5. At that point, we will talk about the living shoreline for resiliency, further discuss alternatives to a barrier that will help keep the nesting turtles in their natural habitats, and have that area provide not only the shoreline for resiliency, but also create suitable nesting areas for the turtles, as well.”
Wahl said the neighbors who live across from the area have been “big” stakeholders in trying to keep the turtles safe.
“The barrier has certainly helped, but this project is a great launch to do better,” he noted.
Williamson said terrapins successfully nested in the new habitat within three months of construction.
“We did see a small decrease in the number of terrapins killed near Avalon Bay Park Marina, in 2019, following installation, but there are many factors that influence road mortality, and more time is needed to observe this trend and see if it continues,” he said.
Tests, in 2019, showed both the currently used corrugated tubing and Animex fence were effective at preventing terrapin passage, but Williamson said there was “no clear answer as to which was the better choice. Animex fencing may be better suited for areas where low vegetation can reduce the effectiveness of the currently used tubing, and it may be more durable. We are planning more extensive tests of Animex fencing in the future."
“We still have much to learn about the status of our local terrapin populations, and this is a complex question we are still working to answer,” Williamson admitted.
However, in the meantime, he urged, “Do not disturb nesting terrapins. Feel free to watch from a safe distance but be respectful of our local wildlife and let her complete her nest.”
To contact Karen Knight, email firstname.lastname@example.org.