THE NEED FOR WATER-QUALITY CRITERIA FOR FROGS

Amphibians are considered reliable indicators of environmental quality . In the western United States, a general decline of frog populations parallels an apparent worldwide decline. The factors thought to be con tributing to declines in frog populations include habitat loss, introd uction of exotic species, overexploitation, disease, climate change, a nd decreasing water quality. With respect to water quality, agroecosys tems use 80-90% of the water resources in the western United States, f requently resulting in highly eutrophic conditions. Recent investigati ons suggest that these eutrophic conditions (elevated pH, water temper ature, and un-ionized ammonia) may be associated with frog embryo mort ality or malformations. However, water quality criteria for frogs and other amphibians do not currently exist. Here, we briefly review data that support the need to develop water quality parameters for frogs in agroecosystems and other habitats.