I remember hearing years ago that the world’s frogs were in peril

From the Editors of E/The Environmental Magazine

I remember hearing years ago that the world’s frogs were in peril. How are they doing today?

—Omar Khan, Columbus, IN

According to Harvard biology professor Jim Hanken, “Overall, the situation has definitely gotten worse. The problem is more serious than we originally thought.” Scientists are particularly concerned because frogs are considered a “sentinel species”—they serve as an indication of environmental quality.

According to the Declining Amphibian Populations Task Force (DAPTF), formed by the World Conservation Union, many species of amphibians (frogs, toads, salamanders, and newts) throughout the world have experienced population declines or extinction over the last 50 years. Causes for such changes may include deforestation, draining of wetlands, ozone depletion, and pollution. In a few cases, as with the Costa Rican golden toad, entire species have disappeared almost overnight.

Beginning in 1988, herpetologists around the world started to report declines in amphibian populations in protected and pristine habitats, leading experts to believe that there may be one or more global factors, such as increased ultraviolet-B (UV-B) radiation due to stratospheric ozone depletion, acid rain and pollution-caused diseases, according to DAPTF.

In addition to population declines is the phenomenon of amphibian deformities. In the United States alone amphibian malformations have been reported in 44 states since 1996, according to the U.S. Geological Survey Center for Biological Informatics. Deformities include extra legs and eyes, and misshapen or incompletely formed limbs. High rates of deformities, in some cases up to 60 percent of a species, exceed what scientists generally consider natural. Research on malformations is investigating several potential causes, including parasites, contaminants, and UV-B radiation.

CONTACTS: Declining Amphibian Populations Task Force, Department of Biological Sciences, The Open University, Walton Hall, Milton Keynes, MK7 6AA, United Kingdom, (+00 44 19) 086-52-274, www.open.ac.uk/daptf/index.htm; U.S. Geological Survey Center for Biological Informatics, 302 National Center Reston, VA 20192, (703) 648-6244, www.frogweb.gov; Amphibian Conservation Alliance, c/o Ashoka Foundation, 1700 North Moore Street, 20th Floor, Arlington, VA 22209, (703) 807-5588, www.frogs.org