Potentiation of chloride toxicity to central Maryland amphibians by climate change and resource quality

Abstract

Amphibians in central Maryland can experience the effects of multiple, simultaneous stressors in breeding and developmental habitats. Some of these stressors include salinization of freshwater habitats and elevated temperature associated with climate change. Further complicating these issues is the potential disparity standard toxicity test protocols and environmental relevance. Specifically, resource quality can vary between different standard test protocols as well as that of amphibian breeding and development habitats. I sampled seven known amphibian breeding habitats to measure chloride concentration and temperature. Then, I conducted acute and chronic toxicity tests on two common central Maryland anurans (Lithobates clamitans and L. sylvaticus), including chloride concentration, temperature elevation, and/or resource quality as experimental factors. I found significant effects of chloride on the survival of developing larvae of both species, and potentiation of these effects when temperature is elevated. Resource quality exerted significant effects on the mass and body condition of surviving larvae.