Method development for accessing the impacts of road salts on P. acuta behavior and egg viability

By Sophia Weldi

Faculty Mentor: Professor Tyler Frankel

In the US, nearly 24.5 million tons of road salt was distributed across public roadways in 2014. Of the various substances used in these formulations, NaCl accounted for 90% of these treatments. After application, up to 55% of these salts have been shown to enter local waterways via runoff and have been shown to cause many negative effects on the environment including inhibition of algal growth, reductions in activated sludge respiration rates, and mortality in all life stages of some amphibians. However, the effects of NaCl on aquatic invertebrates has been poorly explored. Thus, the goals of this study were to determine 1) the effects of NaCl on Physa acuta egg cluster viability, 2) methods to assess the baseline locomotion behavior of Physa acuta (average mobile speed, average speed, total distance traveled, acceleration, number of frozen events and time spent frozen), and 3) assess the effect of NaCl on these endpoints. Sixteen newly laid egg clusters were collected and exposed to 0, 100, 500, or 1000 mg/L NaCl and viability determined after 15 days of exposure. The locomotor behavior of seven unexposed adult snails were recorded and analyzed using ToxTrac (v. 2.83) to determine the basal movement patterns of this species. To assess the impacts of NaCl exposure on adult mobility, adult Physa acuta (n=3) were exposed to the above treatments for 7 days and locomotor behaviors quantified on days 3 and 7. While this study is still ongoing, it is expected that increased NaCl concentrations will cause a decrease in egg cluster viability and dose dependent impacts on mobility. These findings will help to elucidate the impacts of a commonly used deicing substance on a common invertebrate species.