A recent die-off of salamanders in Utah has prompted USGS wildlife health officials to issue an October 21, 1998 wildlife health alert. The incident followed salamander die-offs earlier this summer in Maine and North Dakota. In all three cases a virus is believed to be responsible. The Utah event occurred in early September at Lake Desolation located east of Salt Lake City. U.S. Fish and Wildlife Service biologists reported finding about 200 tiger salamander carcasses littering the shoreline and lake bottom. Salamanders that were still alive appeared lethargic, swam in circles and were unable to remain upright. The sick salamanders also had red spots and swollen areas on the skin. A small number of seemingly healthy salamanders were also observed, but quickly swam into deeper water. No other species appeared to be affected.
Dr. Carol Meteyer, a USGS wildlife pathologist at the National Wildlife Health Center in Madison, Wisc., examined some of the salamanders and found bleeding beneath the skin and microscopic changes in the internal tissues that indicated a viral infection. Meteyer and Douglas Docherty, a USGS virologist, reported isolating a virus from diseased tissues. They are conducting further tests to identify and characterize the virus.
In addition to the salamander die-off at the Utah site, Docherty also found a virus in dead tiger and spotted salamanders earlier this year from Maine and North Dakota. Until these viruses are identified and characterized, Docherty will not know if they are the same virus as the iridovirus isolated from Utah event. Data from these salamander die-offs are still being collected and evaluated.
The health alert asks wildlife biologists to report any unusual observations of mortality or disease in salamanders to the USGS center. The die-offs are troubling to scientists because many amphibians (the group including frogs, toads and salamanders) have shown sharp population declines in many parts
Contact: Paul Slota
United States Geological Survey