Source : Business Mirror, Philippines, 21 May '09
By : Jonathan Mayuga
  

The discovery of the chytrid fungus has prompted the Department of Environment and Natural Resources (DENR) to sound the alarm, and DENR Secretary Lito Atienza has ordered the Protected Areas and Wildlife Bureau (PAWB) to formulate a national strategy for monitoring frog populations throughout the country.

“We cannot discount the possibility that global warming is promoting the spread of this fungus because according to studies, rising temperature allows it to enter places where these amphibians reside,” Atienza said.

The infection was discovered by scientists who just concluded a two-year joint US-Philippine survey of chytrid fungus in 20 different sites in the Philippines.

Scientists said 18 of the sites are currently free of the deadly fungus, which indicates that the infection isn’t massive and could still be prevented, says Mae Diesmos, assistant professor at University of Santo Tomas and leader of the team sampling live frogs’ skin for the past two years.

Five endemic species of frogs—Luzon striped frog (Rana similes), Luzon stream frog (Rana luzonensis), Luzon fanged frong (Limnonectes woodworth and Limnonectes macrocephalus) and Puddle frog (Occidozyga laevis)—found in Mount Labo, Camarines Norte and Mount Palay-palay Cavite province were infected with the fungus scientifically known as Batrachytrium dendrobatidis, the agent causing Cyhtridiomycosis, a frog disease. It is an infectious and often lethal disease that triggered the extinctions of hundreds of species of frogs throughout the world.

Chytrid fungus causes deformities in tadpoles and interferes with the skin of adult frogs and toads. When infection levels are high, catastrophic die-offs can occur, wiping whole populations and even entire species of amphibians.

At least one of the infected frog species may be declining but scientists said further monitoring of the population of the said species is needed to come up with such conclusion in the coming years.

Scientists said a combination of habitat disturbance and forest destruction, and climate change may have triggered the rapid spread of the fungus.

While evidence or proof of such fungus infection in frogs have been found in Cavite and Camarines Norte, scientists fear it may be found in other places or could spread throughout the country.

Previously unrecorded in Asia, the chytrid fungus has recently been reported in Japan and Indonesia, Atienza said.

A third of the 5,743 known species of frogs, toads and other amphibians are classified as threatened, the Global Amphibian Assessment survey revealed, and the continuous spread of the deadly fungus is very alarming, Atienza said.

“We are looking at a possible mass extinction if we don’t do something about it,” Atienza said.

A total of 592 of the country’s 1,137 endemic species of amphibians, birds and mammals have been declared as threatened or endangered, Atienza said.

Dr. Rafe Brown, a professor of Biology in the University of Kansas, also a collaborator in the study said the fungus is a very serious threat to amphibian biodiversity in the Philippines.

A curator of amphibians and reptiles in the University of Kansas Biodiversity Institute said the Philippines is home to an incredibly diverse amphibian fauna.

He blamed forest destruction, pollution and climate change for the infection of the frogs, and warned that it may turn out to be “the final blow” that could spark major amphibian extinctions in the archipelago.

His counterpart in the Philippines, Dr. Arvin Diesmos, curator of amphibians and reptiles at the National Museum of the Philippines emphasized that one of the most disturbing findings was the fact that the pathogen is apparently present at middle to high elevations in relatively pristine forests.

Mount Labo and Mount Palay-palay Mataas na Gulod National Park are both in the southern part of Luzon, the largest and most populated island in the Philippines.

Dr. Vance Vredenburg, assistant professor at the San Francisco State University and member of the team that identified the fungus using molecular data, said of the nearly 6,500 species of amphibians in the world, more than one-third are threatened by extinction and many hundreds of Asian species are now in jeopardy.

Several studies in recent years have linked the rapid disappearance of many of the world’s frogs and toad species to global warming.

Amphibians, in particular, have suffered more species loss than any other animal group due to the deadly fungus.

According to scientists, the disease has already wiped out hundreds of frogs, toad and salamander species, and is spreading across the globe, in part because of climate change but also through international trade—much of it illegal—in wildlife.

Scientists are still scrambling to find a cure that will work in the wild even as more species disappear.