A strange new fungus disease that kills frogs and toads and every other species of amphibian is spreading around the globe and -- combined with pollution and overdevelopment -- is driving more and more of the creatures to extinction, a coalition of the world's top biologists warns.

At least one-third of the world's known amphibians are threatened by the combination of attacks, and up to 122 species have become extinct within the past 25 years, the international team of specialists is reporting in today's edition of the journal Science.

"Amphibian declines and extinctions are global and rapid," 50 of the world's leading specialists on water-dwelling animals declared in a joint report. At least 427 species are "critically endangered," they said.

The effects are being felt in California's High Sierra, where Berkeley scientists found that the disease is rampant and killing yellow-legged frogs and Yosemite toads, whose populations already are being strained by development and pollution.

While the spread of the disease is a major new threat to all amphibians, the scientists reported that the greatest current danger to every threatened species is still the loss of habitat as cities and suburbs expand, streams and ponds and wetlands give way to the needs of farmers, and forest lands are destroyed.

But the fungus, a unique species called Batrachochytrium dendrobatidis, could start taking on a larger role in the increasing extinction because of global warming, which scientists suspect is lowering amphibians' resistance to the disease.

The fungus was discovered in Australia and Panama only eight years ago and since then has spread across Europe and both the Americas, causing skin infections called chytrid disease in every amphibian species it attacks. The death rate from the infections is 100 percent, biologists have found. The disease, they concluded, "causes catastrophic mortality in amphibian populations, and subsequent extinctions".

UC Berkeley Professor David Wake and his wife, Marvalee, also a UC Berkeley professor, are involved in the research. As recently as last week, they were studying amphibian populations on the shores of lakes in the Ebbetts Pass area of the Sierra.

They swabbed the bellies and legs of frogs and toads and brought the swabs back to the lab in Berkeley, where they will be analyzed for the presence of the fungus. David Wake said the fungal disease is rampant there and infecting the skin of frogs and toads. The fungus is widespread in Yosemite and the Sequoia and Kings Canyon national parks as well, he said.

What alarms the scientists most about the new disease is the pace of its assault. Less than two years ago, Karen Lipps of Southern Illinois University led a research group in Panama that found the dead bodies of 346 frogs and five salamanders, killed by the fungus disease in less than four months.



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