Tietge J E, Diamond S A, Ankley G T, DeFoe D L, Holcombe G W, Jensen K M, Degitz S J, Elonen G E, Hammer E
Mid-Continent Ecology Division, U.S. Environmental Protection Agency, 6201 Congdon Blvd., Duluth, MN 55804, USA.
Photochem Photobiol. 2001 Aug;74(2):261-8. doi: 10.1562/0031-8655(2001)074<0261:asurcm>2.0.co;2.
Recent reports concerning the lethal effects of solar ultraviolet-B (UV-B) (290-320 nm) radiation on amphibians suggest that this stressor has the potential to impact some amphibian populations. In this study embryos and larvae of three anuran species, Rana pipiens, Rana clamitans and Rana septentrionalis, were exposed to full-spectrum solar radiation and solar radiation filtered to attenuate UV-B radiation or UV-B and ultraviolet-A (UV-A) (290-380 nm) radiation to determine the effects of each wavelength range on embryo and larval survival. Ambient levels of solar radiation were found to be lethal to all three species under exposure conditions that eliminated shade and refuge. Lethality was ameliorated by filtration of UV-B radiation alone, demonstrating that ambient UV-B radiation is sufficient to cause mortality. Although several studies have qualitatively demonstrated the lethality of UV-B to early life stage amphibians this study demonstrates that the larval life stages of the three species tested are more sensitive than the embryonic stages. This suggests that previous reports that have not included the larval life stage may underestimate the risk posed to some anuran populations by increasing UV-B exposure. Furthermore, this study reports quantitative UV-B dosimetry data, collected in conjunction with the exposures, which can be used to begin the assessment of the impact of environmental changes which increase UV-B exposure of these anurans.
近期有关太阳紫外线B(UV-B,290 - 320纳米)辐射对两栖动物致死效应的报告表明,这种应激源有可能影响一些两栖动物种群。在本研究中,对三种无尾目物种——豹蛙、绿蛙和北美林蛙的胚胎及幼体,进行了全光谱太阳辐射、过滤掉UV-B辐射的太阳辐射或过滤掉UV-B和紫外线A(UV-A,290 - 380纳米)辐射的处理,以确定每个波长范围对胚胎和幼体存活的影响。发现在消除遮蔽和避难所的暴露条件下,环境水平的太阳辐射对所有这三个物种都是致命的。仅通过过滤UV-B辐射就能减轻致死率,这表明环境中的UV-B辐射足以导致死亡。尽管已有多项研究定性地证明了UV-B对两栖动物早期生命阶段具有致死性,但本研究表明,所测试的这三个物种的幼体生命阶段比胚胎阶段更敏感。这表明之前未包括幼体生命阶段的报告可能低估了因UV-B暴露增加而对一些无尾目种群构成的风险。此外,本研究报告了与暴露同时收集到的UV-B剂量测定定量数据,这些数据可用于开始评估环境变化对这些无尾目动物UV-B暴露增加所产生的影响。