Many of the turtles, frogs and aquatic salamanders in ponds can’t survive freezing, and if the cold temperatures continue, they’re in danger of getting wiped out, biologists say.

Meanwhile, the extensive use of road salt this winter increases the likelihood that salt and other surface contaminants will wash into the ponds, threatening snails and clams, said Robert Prezant, a Montclair State University professor who studies those species.