Because of their thin, moist skin and dependence on moisture, amphibians are considered important "indicator" organisms for environmental problems. For this reason, recent reports of amphibian disease and decline are of global conservation concern. The goal of the proposed study is to determine the direct and/or indirect effects of environmental stressors, especially chemical pollutants and predators, on the transmission and spread of parasitic disease in amphibians. We are particularly interested in parasitic flatworms (trematodes), since these have been linked to debilitating deformities in frogs. Trematodes are also responsible for major diseases in humans, including schistosomiasis and echinostomiasis, diseases that afflict over 200 million people in tropical regions. We will focus on particular species of trematodes known to infect amphibians, including Ribeiroia ondatrae and Echinostoma trivolvis. These are transmitted from snails to amphibians and cause limb deformities and kidney damage respectively. This grant proposal is a collaborative effort with ecologist Jason Rohr et al. at Pennsylvania State University. Our main contribution will be to use immunological assays to investigate the effects of environmental stressors on the immune system in amphibians. An important component of the proposal is the opportunity for interaction among undergraduates, graduate students, and faculty at the two institutions.
