Are embryonic and larval Green Frogs (Rana clamitans) insensitive to road deicing salt?

Deicing agents have been used to control ice build-up on roads in winter for at least five decades in North Americaand Europe. This legacy of contamination of streams and wetlands threatens the availability of fresh water in these regions.The issue is of interest because amphibian skin and membranes of amphibian eggs are highly permeable, renderingamphibians particularly sensitive to chemical contaminants. In addition, saline solutions can travel nearly 200 m from roadsand into wetlands, thereby contaminating amphibian habitats. The objective of this study was examine the effects of roadsalt on an amphibian that breeds in permanent wetlands, the Green Frog (Rana clamitans), for comparison with priorresearch on vernal pool-breeding species. Survival in all five ecologically-relevant treatment levels was > 93% in embryosand > 87% in larvae. However, when accounting for malformations, survival at the highest treatment level (3000 μSconductivity) dropped to 80% and 82%, respectively. Larval growth was unaffected by road salt, but 15% of larvae weremalformed at the highest conductivity level. Rana clamitans appears to be relatively tolerant to road salt at low andmoderate concentrations and less sensitive than other North American amphibians. At conductivity levels observed in thefield, it is unlikely that road salt currently impacts populations of R. clamitans.