Scientists launch ambitious amphibian programme

[Al-khiyal]

Scientists from across the world gathered in Atlanta recently to launch an ‘‘Amphibian Ark’’ for thousands of species of frogs, toads and salamanders threatened by a deadly fungus.

The ark project was envisaged as scientists came to realise that the amphibians could not be saved in the wild, said Kevin Zippel, Amphibian Programme Officer for Amphibian Ark. The group is appealing to zoos, aquariums and botanical gardens across the world to construct special, bio-secure facilities for 500 each of nearly 2,000 endangered amphibian species - most of which are frogs.

After the frogs are collected, they would be cleaned to make sure they did not bring the fungus into the captive environment. That stopgap portion of the project is estimated to cost about $40 million.

The scientists estimate their fuller goal of researching how to save the species will cost ten times that amount. They are establishing a global fundraising campaign and plan to designate 2008 ‘‘Year of the Frog.’’

The crisis now facing amphibians from the fungus and other causes is one that scientists liken to the extinction of dinosaurs: about 170 of the nearly 6,000 species of amphibians have become extinct in the last decade and 2,000 more are threatened.

‘‘This is a mass extinction never before seen in human history,’’ said Joseph Mendelson, curator of herpetology at Zoo Atlanta and executive director of the International Union for the Conservation of Nature and Natural Resources’ amphibian specialist group. ‘‘From a purely cold-hearted scientific perspective, it’s a fascinating thing to document when we’re still guessing what happened to dinosaurs.’’

Among the extinct species is the Costa Rican golden toad. The Panama golden frog and the Dominican mountain chicken frog are close to extinct. In California, about 85 per cent of the 650 frog populations at the Yosemite National Park are infected with the fungus.

Since their skin is so permeable, amphibians are particularly sensitive to new diseases and changes in the environment, such as climate change, pollution and deforestation.

The rapidly-spreading deadly fungus - the chytrid fungus - was discovered and named as a new genus in 1998. It is a microscopic parasite that invades the surface layers of the frog’s skin, making it difficult for them to use their pores and regulate water intake.

There is no evidence that the fungus could shift from amphibians to other organisms such as mammals or plants, but the scientists who traveled to Zoo Atlanta from countries as diverse as Colombia, Australia, Germany and India argue that the plight of amphibians presents a warning for humans, as well as a critical opportunity to learn.

One of the most abundant vertebrate groups, amphibians play a critical role in the ecosystem, functioning as a middle system in food chains.

Without amphibian tadpoles in streams in the cloud forests of Panama, a hyper-prolific algae is spreading, affecting stream ecology and water chemistry. Meanwhile, entire groups of predators that rely on amphibians, such as snakes, have slowly starved to death.

Amphibians also have significant biomedical value for humans: the skin of the Ecuadorian tricolor frog produces a pain reliever that is more powerful than morphine, without any addictive side effects; secretions from the Peruvian giant monkey frog are used to treat seizures and depression; antimicrobial peptides secreted from the Australian red-eyed tree frog’s skin disables HIV infection.

‘‘As they disappear, our medicine chest goes with them,’’ Mendelson said.

Scientists are not sure of the fungus’s origin. The Centers for Disease Control and Prevention recently published a study suggesting that it began in Africa. Researchers across the world are studying the African clawed frog, which carries the fungus on its skin, but is immune to its fatal effects.

‘‘Bringing (frogs) into an amphibian ark is really the last option,’’ said Kevin Buley, director of herpetology at Chester Zoo, England, and chair of the European Zoos and Aquariums’ amphibian ark. ‘‘Everyone is aware of endangered pandas and tigers, but no one is making noise about these tiny creatures that have lived for 200 million years.

‘‘Think of them as the canaries in the coalmine,” he said.

Scientists launch ambitious amphibian programme

[Al-khiyal]

Amphibian Ark

[Al-khiyal]

May 24, 2007 -- Scientists have found a bacterium that appears to repel the deadly fungus blamed for the rapid decline in populations of amphibians around the world.

Experiments show that Pedobacter cryoconitis - found on the skin of red-backed salamanders - wards off the chytridiomycosis fungus threatening amphibians. "There's a crying need for some way of treating or mitigating the infection," said Matthew Fisher, an epidemiologist at Imperial College London. He said further research was needed.

Reid Harris, of the James Madison University, Virginia, worked on the bacterium with colleagues at Duke University. He presented his research yesterday at the American Society for Microbiology's annual meeting in Toronto.

Fungus fighter found