Evaluating Ultraviolet Radiation Exposure with Satellite Data at Sites of Amphibian Declines in Central and South America

By E. Middleton, Jay R. Herman, E. Celarier, J. Wilkinson, C. Carey, R. J. Rusin. 2001

93 citations recorded by the source corpus.

Abstract: Many amphibian species have experienced substantial population declines or have disappeared altogether during the last several decades at a number of amphibian survey sites in Central and South America. Our study addresses the use of trends in solar UV‐B radiation exposure (280–320 nm) at these sites over the last two decades, derived from the Total Ozone Mapping Spectrometer satellite data. It is intended to demonstrate a role for satellite observations in determining whether UV‐B radiation is a contributing factor in amphibian declines. We used these data to calculate the daily erythemal (sunburning) UV‐B, or UV‐Bery , exposure at the latitude, longitude, and elevation of each of 20 survey sites. The annually averaged UV‐Bery dose, as well as the maximum values, have been increasing in both Central and South America, with higher levels reached at the Central American sites. The annually averaged UV‐Bery exposure increased significantly from 1979–1998 at all 11 Central American sites we examined (r 2 = 0.60–0.79; p≤ 0.015), with smaller but significant increases at five of the nine South American sites (r 2 = 0.24–0.42; p≤ 0.05). The number of days having the highest UV‐B exposure (≥6.75 kJ/m2/day) increased in both regions from <40 days per year to approximately 58 days per year in 1998 (r2 = 0.24–0.42; p≤ 0.001). In Central America, the contribution of these very high UV‐Bery exposure levels to the annual UV‐Bery total increased from approximately 5 to approximately 15% over the 19‐year period, but actual daily exposures for each species are unknown. A UV‐B ratio, the highest monthly UV‐B exposure relative to the annual average for the highest UV‐B category (≥6.75 kJ/m2), increased in both regions over this time period (r 2 = 0.73; p≤ 0.001). This UV index was consistently higher for Central America, where species declines have been the most severe. These results should justify further research into whether UV‐Bery radiation plays a role in amphibian population declines and extinctions. We discuss synergy among UV‐B radiation and other factors, especially those associated with alterations of water chemistry (e.g., acidification) in aqueous habitats.

Subfields: Ecological Modeling, Global and Planetary Change, Social Psychology

View Paper: https://www.semanticscholar.org/paper/f6e3215a574137ac72312fb1302782c1e63f4264

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Citations in the corpus

Ultraviolet radiation, toxic chemicals and amphibian population declines (2003, background): “Data from several sources indicate that levels of UV-B radiation recently have risen significantly (especially since 1979) in the tropics and in temperate regions (Kerr & McElroy, 1993; Herman et al., 1996; Middleton et al., 2001).”
Complexity in conservation: lessons from the global decline of amphibian populations (2002, background): “Below we discuss some of the context dependency that has been observed among several potential factors that have been proposed to explain amphibian population declines.”
Effects of Widespread Fish Introductions on Paedomorphic Newts in Europe (2005, background): “Global warming (Gibbs & Breisch 2001) and increasing levels of ultraviolet (UV) radiation (Middleton et al. 2001) have also been proposed.”
Direct and Indirect Effects of Climate Change on Amphibian Populations (2010, background): “Levels of UV-B radiation have risen significantly in modern time (especially since 1979) both in the tropics and in temperate regions [23-25].”
Ecological Traits Predicting Amphibian Population Declines in Central America (2003, background): “We cannot rule out indirect effects of UV-B through interactions with other aspects of the biology of amphibians (e.g., diet, larval ecology, pathogens) or their environment (Middleton et al. 2001).”
Declining amphibian populations: a global phenomenon in conservation biology (2001, background): “However, recent remote sensing analysis (MIDDLETON et al., 2001) has identified increases in both annual and daily levels of UV–B exposure (average and maximum) between 1978–1998 at Central and South American sites where amphibian population declines have been recorded (e.”
Climate change and amphibians (2005, methodology): “Middleton et al. (2001) used satellite–based observations to estimate surface UV–”
COMBINED EFFECTS OF UV‐B RADIATION AND NITRATE FERTILIZER ON LARVAL AMPHIBIANS (2003, background): “The intensity of UV-B radiation reaching aquatic ecosystems at the Earth’s surface is increasing due to anthropogenic influences including ozone depletion, acidification, and climate change (Herman et al. 1996, Yan et al. 1996, Pienitz and Vincent 2000, Middleton et al. 2001).”
The amphibian decline crisis: A watershed for conservation biology? (2005, background): “Furthermore, satellite-based measures of UV radiation levels at 20 sites in Central and South America recorded increases between 1979 and 1998 that were greatest in areas where amphibian declines have been most severe (Middleton et al., 2001).”
Amphibian Population Declines: Evolutionary Considerations (2007, background): “…from remote sensing indicate that levels of UVB radiation have recently risen significantly (especially since 1979) in both tropical and temperate regions (Kerr and McElroy 1993, Herman et al. 1996, Middleton et al. 2001), and amphibian populations are declining in these areas (Stuart et al. 2004).”
The complexity of deformed amphibians (2003, background): “Because levels of UV-B radiation are increasing at the earth's surface (Kerr and McElroy 1993; Middleton et al. 2001), and previous research has shown that UV-B radiation can induce a variety of physical abnormalities in amphibians, it is logical to examine its role.”
Population Decline of the Jambato Toad Atelopus ignescens (Anura: Bufonidae) in the Andes of Ecuador (2003, background): “According to Middleton et al. (2001), of 20 sites in Central and South America where annual UV-B levels were measured between 1979 and 1998, the site with the highest values was the one with the highest altitude (Cordillera de Mérida at 4000 m in Venezuela).”