U. S. Geological Survey (USGS) scientists are making headway in unraveling clues to the causes of massive die-offs of frogs and other amphibians. The agency announced today that a little-understood, emerging iridovirus disease associated with large die-offs of frogs and salamanders in the Midwest and the East has caused another recent die-off, in North Dakota.
USGS wildlife pathologist D. Earl Green said an iridovirus infection is the culprit in most of the deaths of U.S. western tiger salamanders at the U.S. Fish and Wildlife Service's Cottonwood Lake Study Area near Jamestown, North Dakota.
Wildlife health scientists at the USGS National Wildlife Health Center in Madison, Wisconsin, also are investigating numerous other amphibian die-offs that recently occurred or are continuing to occur in several locations across the United States. The die-offs, which involve multiple species of frogs, toads, salamanders and one species of newt, are occurring on private, state, and federal lands including several national parks.
"The U.S. Geological Survey is leading the government's efforts to help determine why amphibians are disappearing," said Interior Secretary Bruce Babbitt. "This is a crisis that has attracted worldwide concern. It requires timely, aggressive research. It is no exaggeration to say that USGS research on these die-offs has global implications."
Whether some of the ongoing die-offs are related to recent local or regional amphibian declines across the United States, or are sustained, long-term events only recently discovered, is still unknown. The wide geographic distribution of these mortality events and the number of species involved may represent an entirely new phenomenon or may be partly the result of increased surveillance of amphibian populations. Amphibian researchers and land managers worldwide, however, are concerned about the often severe and mostly unexplained declines of amphibian populations on many continents, includi
Contact: Paul Slota
United States Geological Survey