You are here:
ASSESSMENT OF THE RISK OF SOLAR ULTRAVIOLET RADIATION TO AMPHIBIANS. II: IN SITU CHARACTERIZATION OF SOLAR ULTRAVIOLET RADIATION IN AMPHIBIAN HABITATS
Citation:
Peterson, G., L. B. Johnson, R Axler, AND S A. Diamond. ASSESSMENT OF THE RISK OF SOLAR ULTRAVIOLET RADIATION TO AMPHIBIANS. II: IN SITU CHARACTERIZATION OF SOLAR ULTRAVIOLET RADIATION IN AMPHIBIAN HABITATS. ENVIRONMENTAL SCIENCE & TECHNOLOGY. SETAC Press, Pensacola, FL, 36(2002):2859-2865, (2002).
Description:
Ultraviolet B (UVB) radiation has been hypothesized as a potential cause of amphibian population declines and increased incidences of malformations. Realistic studies documenting UV irradiance or dose have rarely been conducted in wetlands used by amphibians. We demonstrate that 99% of UVB is attenuated in the top 5 to 20 cm of wetlands in our study region (northern Minnesota and Wisconsin). Furthermore, vegetation and other habitat at features have substantial impacts on local UVB irradiance levels and dose. UVB attenuation in the water columns of our wetlands is controlled by the specific absorption of dissolved organic carbon (DOC), and consequently, UVB attenuation is best predicted by simple laboratory absorbance measurements such as bulk water color (absorbance at 440 nm). Seasonal data indicate that the UVB absorption by early and mid-season DOC is higher than that of late summer and fall DOC, suggesting increased protection from UVB during the potentially sensitive stages of amphibian development. In addition to dissolved components, our model indicates that suspended solids played a small role in UVB attenuation in our wetlands, but apparently only at high concentrations. Models predicting UV attenuation in wetlands should be used cautiously and should consider temporal variability, given the volatility and dynamic nature of water column characteristics in wetlands. Organism behavior is a critical but poorly understood phenomenon that must be addressed for development of an accurate UV exposure risk model for amphibians.