Cairns, Australia--A fungus is to blame for recent mass frog deaths in Australia, according to research presented at a meeting here last month. Researchers reviewed growing evidence that the chytrid Batrachochytrium, a fungus implicated in frog declines elsewhere in the world (Science, 30 April 1999, p. 728 ), is also the major killer of Australian amphibians.
Prior to the conference, organized by the Cooperative Research Centre for Tropical Rainforest Ecology and Management, "there was considerable doubt in the community that the chytrid was a serious threat" to the country's frogs, says Ken Aplin of the Western Australian Museum in Perth. But findings presented at the 26 to 30 August meeting suggest otherwise, Aplin says.
Aplin's work, for instance, shows that the fungus is a relatively recent invader. Aplin found no trace of the killer on 600 museum specimens collected between 1950 and 1985, but the telltale spores showed up on frogs collected more recently. Other researchers found that frogs living in some of Australia's cool upland regions, where the fungus thrives, were harder hit than populations in adjacent but warmer lowlands.
Government officials in Australia's Northern Territory are convinced of the fungus threat; they have just enacted a ban on the import of amphibians into the state, which has been free of chytrids so far. And researchers are recommending that the government mount a national campaign to prevent the killer's spread, starting by formally designating the fungus as a problem. That move may come too late for the remote and rugged Kimberley region in the north of Western Australia; its first infected frog has just been found. The outbreak is "a great concern," Aplin says, because of the region's great frog biodiversity.