Human construction and rising sea levels have taken a bite out of the Chesapeake Bay’s turtle populations and their habitats, but Naval Air Station (NAS) Patuxent River has taken them under its wing. A base volunteer program, the Northern Diamondback Terrapin Survey, finds and protects turtle nests while gathering actionable data about turtle health.

Northern diamondback terrapins swim ashore to lay eggs on the Patuxent beaches every May through July. Program volunteers walk the beaches twice a day—one volunteer in the morning and one in the afternoon—during “turtle nesting season” to find nests and place protective crates over them to keep predators away.

“Naturally, not that many babies would have made it. Now we have so many more terrapins that we’re releasing into the area,” said Rebecca Stump, NAS Patuxent River resources specialist and program director. “In the long run, we’re trying to reset the balance.”

The volunteers also gather data on egg size, color, weight, and anything abnormal. This, they share with researchers at the Chesapeake Biological Laboratory, a University of Maryland Center for Environmental Science facility studying the impacts of pollution, climate change, and other challenges on turtle populations.

NAS Patuxent River started its survey program in 2013. The base’s Environmental Division oversees it, and the Maryland Department of Natural Resources receives its findings. The volunteers are primarily service members and civilians from the base, and many return season after season.

“Each year, we’ve gotten better volunteers. People more dedicated with more knowledge. They come back year after year, and we’re finding more nests and learning how to find the nests better,” Stump said.

Stump said that volunteer shifts continue until October 1—eggs take up to 50 days to hatch, so some babies are not born until the fall.

The base shuts down an aircraft landing zone near the beach during nesting season. This lets the turtles nest undisturbed.

“We really appreciate that, because a lot of our nests are on that landing zone right now,” said Danielle Deville, program intern who oversees the volunteers.

Deville said that the program is now tracking around 65 nests total. Finding them is no small feat: Mother turtles hide their eggs well, so volunteers must look carefully for subtle signs of digging.

“These females are very crafty,” she said. “You want to look for an area that is disturbed in some sense. If you’re in an area with a lot of pebbles, you want to find an area that doesn’t have a lot of pebbles.”

Volunteers also look for turtle footprints: “You can kind of see their claws in the sand once it’s more dry,” Deville said.

Baby turtles have many enemies: Raccoons, raccoons, foxes, squirrels, muskrats, and birds all eat turtle eggs. In addition, moles destroy eggs by tunneling through nests, and some invasive grasses’ roots grow right through eggshells, impaling embryos.

But Chris Rowe, Chesapeake Biological Laboratory biologist, warns that turtles face an even bigger peril from climate change. Temperatures change turtle embryos’ gender: A rise of just two degrees Celsius results in primarily female babies. Rowe said that warming temperatures could result in too few males, and with that, fewer babies being made.

“It’s getting warmer, so we want to know how the nest temperatures are changing. And we are trying to project ahead. In another 50 years, it’s going to be two or three degrees warmer. What does that mean for the sex ratio and the population?” Rowe said.

Coupled with this, rising sea levels exacerbate erosion of beach habitats. Shorelines in much of the region have been whittled away, and where there were gently sloping sandbanks, there are now steep cliffs rising eight feet or higher.

When turtles cannot climb the cliffs, they lay their eggs low on the cliff faces. There, eggs are often drowned by high tides or washed away by rainstorms. Rowe said that when volunteers find nests in these cliffs, they move them to sands further inland where the tide cannot reach them.

Rowe said that erosion in the Bay region has worsened in recent decades due to sea-level rise. And turtles have already lost habitat due to human construction, he noted.

Rowe said that researchers will need more data over time to determine how the turtle populations are doing. He credited the survey program with being a valuable data source.

“We’re not doing the same thing, but we work together,” Rowe said. “We and Rebecca’s group have a common goal, and that’s taking care of these animals.”