International Efforts Aim to Avert Disaster for Amphibians

By Daniel Gorelick

Threats to so-called charismatic fauna like elephants and polar bears capture the popular imagination and raise awareness of environmental dangers, but the most compelling signs of potentially catastrophic changes in the Earth's biosphere might lie with the humble frog.

Amphibians, including frogs, act as the proverbial canary in the coal mine. Just as miners used sensitive canaries to warn them of toxic gases, widespread amphibian death might indicate environmental conditions that are harmful to human health. The skin of frogs is highly permeable by air and water, so contaminants readily enter their bodies, making frogs exceptional indicators of environmental quality and important sentinels of potential threats to humans.

Currently, a seemingly unstoppable fungal infection is killing amphibians around the world. Of the 6,000 known amphibian species, between one-third and one-half are threatened with extinction, according to Amphibian Ark, an international organization working to ensure the global survival of amphibians. Researchers believe 165 species have become extinct since 1980. If the trend continues, biologists say the earth could be facing the single largest mass extinction since the disappearance of the dinosaurs.

"Widespread extinction of amphibians would be catastrophic," said Jeffrey P. Bonner, chairman of Amphibian Ark and president of the St. Louis Zoo in Missouri. "In addition to their intrinsic value, they offer many benefits and are a critical part of a healthy world."

Beyond their role as sentinels against environmental contaminants, frogs provide many benefits to humans and their environment. Frogs eat insects, an activity that supports agriculture and minimizes the spread of disease. Frog skin contains substances that protect frogs from microbes and viruses, offering promising medical cures for a variety of human diseases.

Amphibian Ark is a partnership of the World Association of Zoos and Aquariums (WAZA) and the International Union for Conservation of Nature (IUCN) Conservation Breeding Specialist Group and Amphibian Specialist Group. Several organizations in the United States provide funding and support including the Chicago Zoological Society and zoos in California, Colorado and Ohio. The U.S. Fish and Wildlife Service (USFWS) works with WAZA to promote amphibian conservation.

The agency is partnering with other nations to promote conservation around the world. Recently, it funded a study by the Venezuelan Institute of Scientific Research of transmission of an amphibian fungal infection in Latin America. USFWS aims to facilitate information-sharing to help halt the spread of disease among the region's amphibians.

2008, YEAR OF THE FROG

To increase public awareness and understanding of the amphibian extinction crises, Amphibian Ark is leading zoos in a globally coordinated campaign, the "Year of the Frog."

As part of the plan, select species that otherwise might become extinct will be maintained in captivity until they can be secured in the wild. Amphibian Ark will bring priority amphibian species in for safekeeping and breeding in dedicated, biosecure facilities at zoos, aquariums and other institutions around the world. These rescued amphibians will be reintroduced into the wild when the original threats have been controlled, according to a statement released by the group.

Several U.S. zoos have bred endangered frogs successfully in captivity.

In February, the Memphis Zoo in Tennessee became the first facility in the world to breed the Mississippi gopher frog (Rana sevosa), one of the most endangered amphibians in North America.

The Denver Zoo in Colorado is working to preserve the Lake Titicaca frog (Telmatobius culeus), found on the border of Bolivia and Peru. Zookeepers are working with local staff in Lima, Peru, to develop a conservation program and breeding facility and to establish frog displays in local zoos.

WIDESPREAD FROG DEATH

Amphibians are affected severely by climate change, habitat loss, pollution and pesticides. However, the most immediate cause of amphibian death in the wild is a parasitic fungus called Batrachochytrium dendrobatidis or amphibian chytrid.

This fungus is unstoppable and untreatable in the wild, even in protected areas. Many worldwide invasive pest species such as American bullfrogs and African clawed frogs are resistant to infection, which makes it even more difficult for native frog species to survive.

Although amphibians have survived past ecological challenges, many species appear unable to withstand current threats, according to a team of scientists from IUCN and the Center for Applied Biodiversity Science in Washington and NatureServe in Costa Rica.

Writing in the journal Science, the scientists speculate that current habitat and climate changes are occurring much more rapidly than in prior millennia, and that amphibians face a large number of complex threats that act synergistically. They believe that amphibians never before have been confronted with climate change, habitat loss and disease simultaneously.

"It is of utmost importance to raise awareness among national governments, world media, school educators, corporations, philanthropists, and the general public about the fragility of amphibians and the enormous responsibility that each of us has in trying to rescue the amphibians in danger," said J??örg Junhold, chairman of the "Year of the Frog" campaign and director of Zoo Leipzig in Germany.

"The outcome of the Amphibian Ark project will be that we will have saved hundreds if not thousands of species from extinction," Junhold said.

Additional information about the Year of the Frog ( http://www.fws.gov/home/feature/2008/Frog/ ) is available on the USFWS Web site.

More information about Amphibian Ark ( http://www.amphibianark.org/ ) is available on the organization's Web site.

Source: U.S. Department of State

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