Meeting Abstract
Amphibians are highly vulnerable to aquatic pollutants due to the permeability of their skin; gilled aquatic larvae may be especially susceptible. Behavioral avoidance of pollutants could mitigate the effects of exposure. Increasing application of road deicers for travel safety has led to elevated sodium chloride levels in some temperate forest wetlands. The physiological effects of road deicers on amphibians are well known, and include reduced breeding success, morphological abnormalities, and even mortality. However, less is known about the behavioral responses of adult and especially larval amphibians to increased environmental salinity. In this study, the behavioral responses of both adult and larval Wood Frogs, Lithobates sylvaticus, to increased salinity were studied via salinity choice trials. For both adults and tadpoles, time spent in salt solutions decreased with increasing salinity. The threshold for response was approximately 0.15 M (slightly hyperosmotic). Habitat selection by tadpoles has been linked to temperature, substrate, and other factors, but salinity avoidance has not been previously reported. Since increased salinity has been associated with decreased fitness, behavioral avoidance of high salinity and preference for lower saline systems could be advantageous for Wood Frogs, giving adults the potential to select breeding sites with lower solute levels and tadpoles the potential to select appropriate microhabitats within a vernal pool.
