Amphibian defenses against ultraviolet-B radiation.
As part of an overall decline in biodiversity, amphibian populations throughout the world are disappearing. There are a number of potential causes for these declines, including those related to environmental changes such as increasing ultraviolet-B (UV-B) radiation due to stratospheric ozone depletion. UV-B radiation can kill amphibian embryos or can cause sublethal effects that can harm amphibians in later life stages. However, amphibians have defenses against UV-B damage that can limit damage or repair it after exposure to UV-B radiation. These include behavioral, physiological, and molecular defenses. These defenses differ interspecifically, with some species more able to cope with exposure to UV-B than others. Unfortunately, the defense mechanisms of many species may not be effective against increasing persistent levels of UV-B radiation that have only been present for the past several decades due to human-induced environmental damage. Moreover, we predict that persistent UV-B-induced mortality and sublethal damage in species without adequate defenses could lead to changes in community structure. In this article we review the effects of UV-B radiation on amphibians and the defenses they use to avoid solar radiation and make some predictions regarding community structure in light of interspecific differences in UV-B tolerance.
Blaustein
Andrew R
AR
University of Washington, Seattle, WA 98195, USA. blaustea@bcc.orst.edu
Belden
Lisa K
LK
D000663:Amphibians; D000818:Animals; D004249:DNA Damage; D004260:DNA Repair; D004255:Deoxyribodipyrimidine Photo-Lyase / Q000378:metabolism; D004625:Embryo, Nonmammalian / Q000528:radiation effects*; D006360:Heat-Shock Proteins / Q000378:metabolism; D010063:Ovum / Q000528:radiation effects*; D018462:Photobiology; D013045:Species Specificity; D014466:Ultraviolet Rays
D006360:Heat-Shock Proteins; D004255:Deoxyribodipyrimidine Photo-Lyase