AMBIENT ULTRAVIOLET-RADIATION CAUSES MORTALITY IN SALAMANDER EGGS

Previous research has shown that amphibian species have differential s ensitivity to ultraviolet-B (UV-B) radiation. In some anuran species, ambient levels of UVB cause mortality in embryonic stages and hatching success is significantly reduced. Projected increases in UV-B may aff ect an increasing number of species. The adverse effects of UV-B may e ventually be manifested at the population level and may ultimately con tribute to population declines. Using field experiments, we investigat ed the effects of ambient UVB on salamander (Ambystoma gracile) embryo s developing at natural oviposition sites. We show that the hatching s uccess of eggs of A. gracile shielded from UV-B is significantly highe r than those not shielded from UV-B.