Optical Characteristics of Natural Waters Protect Amphibians from UV-B in the U.S. Pacific Northwest
Palen WJ, Schindler DE, Adams MJ, Pearl CA, Bury RB, Diamond SA. 2002. Optical Characteristics of Natural Waters Protect Amphibians from UV-B in the U.S. Pacific Northwest. Ecology. 83(11):2951 - 2957
Increased exposure to ultraviolet-B (UV-B) radiation has been proposed as a major environmental stressor leading to global amphibian declines. Prior experimental evidence from the U.S. Pacific Northwest (PNW) indicating the acute embryonic sensitivity of at least four amphibian species to UV-B has been central to the literature about amphibian decline. However, these results have not been expanded to address population-scale effects and natural landscape variation in UV-B transparency of water at amphibian breeding sites: both necessary links to assess the importance of UV-B for amphibian declines. We quantified the UV-B transparency of 136 potential amphibian breeding sites to establish the pattern of UV-B exposure across two montane regions in the PNW. Our data suggest that 85% of sites are naturally protected by dissolved organic matter in pond water, and that only a fraction of breeding sites are expected to experience UV-B intensities exceeding levels associated with elevated egg mortality. Thus, the spectral characteristics of natural waters likely mediate the physiological effects of UV-B on amphibian eggs in all but the clearest waters. These data imply that UV-B is unlikely to cause broad amphibian declines across the landscape of the American Northwest.
- Type
- Journal Article
- Authors
- Palen, Wendy; Schindler, Daniel; Adams, Michael; Pearl, Christopher; Bury, R; Diamond, Stephen
- Units
- OLYM
- Keywords
- Amphibian (Amphibia), Animal Studies, Global Climate Change, Ultraviolet Radiation