Cooperative Fish and Wildlife Research Units Program: Texas
Education, Research and Technical Assistance for Managing Our Natural Resources

Several lines of evidence indicate that amphibian populations are declining globally. However, factors for these declines can be varied and the contribution of environmental contaminants, in particular, is not fully understood. This research will be conducted in and around Big Bend National Park in Texas, an apex site for ongoing Amphibian Research and Monitoring Initiative (ARMI). Waterborne contaminants have been implicated in reproductive disruption of birds and fish inhabiting the lower Rio Grande valley and Big Bend regions of Texas, but to our knowledge the impact of aquatic contaminants on reproductive and developmental biomarkers in amphibians has not been examined. Elemental contaminants will be determined in selected sites of the study the area and reproductive and health biomarkers will be measured in Rio Grande leopard frogs. In addition, a new biomarker of thyroid disruption recently reported for teleost fishes will be tested for it use in amphibians.