Spring rainfall starts migration and breeding for amphibians, but high salinity can make life difficult
By Chloe Bennett
Walk an Adirondack forest trail in the spring and you will encounter shallow, fleeting pools of rainwater. Although some appear insignificant in size, vernal pools are teeming with life. One creature that relies on the water is the spotted salamander, which makes its trek to vernal pools on rainy nights in March and early April to breed.
Motor vehicles, driven at night, pose a threat to the migrating amphibians, prompting the Department of Environmental Conservation to send volunteer crossing guards to protect their annual migration. But one human-made hazard, which has garnered attention from Adirondack scientists for more than a decade, can’t be fixed by caring neighbors: Road salt runoff.
Because of their reliance on shallow, unmoving waters, spotted salamanders are particularly vulnerable to chemicals found in road salt and other treatments. According to a study with the SUNY College of Environmental Science and Forestry researchers, wood frogs are also affected due to their breeding habits in vernal pools.
“All life stages are considered to be a lot more susceptible to chemicals and other pollutants and things because every life stage is pretty much exposed to a lot of exchange with the environment,” Stacy McNulty, associate director of research at SUNY ESF, said about amphibians. “So if the environment’s not clean, then obviously they’re going to pick that stuff up.”
Although road salt application ends with the snow season, the salt that lands in vernal pools can have lifelong effects on amphibians. Some eggs may not hatch because of high saline levels and hatchlings could have spine deformities, making them less likely to survive.
Turtle eggs, which are generally laid in mid-May, have tougher shells that may withstand saline waters. Their habitats in drier, sandy areas also make them less vulnerable to runoff.
Researchers found that vernal pools more than 160 yards away from roads can have salt in them. “That’s basically a football field and a half, that’s a pretty far distance,” McNulty said.
The harmful effects of road salt on Adirondack waters have been raised by scientists and advocates for years. A state task force report that will outline road salt usage and recommend legislation to reduce applications has been expected for several months.
Although researchers have attempted to map vernal pools, the natural features are not protected by the state because they are too small to be categorized officially as wetlands. McNulty said the lack of policy adds to the difficult task of protecting the waters.
But there are some ways for people to help. McNulty said homeowners concerned about road salt impacts should start by getting their water sources tested.
“If there’s impact on frogs and salamanders, the impact on humans, particularly young humans, is probably significant, too,” she said.
Those who want to protect their amphibian neighbors should also get to know their environment and seek out the often overlooked vernal pools, McNulty added. The little wetlands are not mosquito habitats, she said, but important facets of Adirondack biodiversity.
“Salamanders don’t make any noise really, so you kind of have to go in the spring and find them because that’s the only time you’re going to see them, when they’re coming into the wetlands to breed,” she said.
“But they don’t tell you that they’re there,” she said.