Researchers complete first major survey of amphibian fungus in Asia

LAWRENCE — An international team of researchers has completed the first major survey in Asia of a deadly fungus that has wiped out more than 200 species of amphibians worldwide. The massive survey could help scientists zero in on why the fungus has been unusually devastating in many parts of the globe-and why Asian amphibians have so far been spared the same dramatic declines.

From 2001 to 2009 to the present, an international team focused on Asia has surveyed more than 3,000 amphibians — mostly frogs — from 15 Asian countries, sampling skin from the undersides of frogs to attempt to detect the lethal fungal pathogen Batrachochytrium dendrobatidis (or “Bd”).

Rafe Brown of the University of Kansas Biodiversity Institute led the Philippine component of the study. Together with colleagues from the Philippine government and the National Museum of the Philippines, the team sampled skin from more than 1,000 specimens of the country’s 105 species of frogs. Some of the findings for this small island country were alarming.

It is possible that Asia, like the Americas of 20-30 years ago, may be on the verge of a chytridiomycosis epidemic, which could cause a cascade of species extinctions throughout the region. The group thinks that such an endemic, if about to occur, could be initially triggered in the Philippines.

“The prevalence and intensity of Bd infection is much higher (in the Philippines) than anywhere else in Asia,” said Vance Vredenburg of San Francisco State University. “Bd in the Philippines today looks similar to Bd in early outbreaks in California and South and Central America.”

The team found that the prevalence of Bd across Asia was very low, appearing in only 2.4 percent of the frogs. The Philippines, Kyrgyzstan, Laos, Indonesia, Malaysia and South Korea were the only countries with any Bd infection. But, as Arvin Diesmos of the National Museum of the Philippines emphasized, infection intensity was very high in some Philippine populations -- approaching the level that has caused die-offs in American amphibians populations.

“This study is extremely interesting but has amphibian biologists in the Philippines very concerned,” said Brown.

“There are so many unanswered questions,” said Mae Diesmos of the University of Santo Tomas (Manila) and a collaborator on the publication. “What is badly needed now is a massive study focused on the Philippines to determine the extent and distribution of the chytrid fungus, and to determine which amphibian populations may be at risk of extinction.”