Fifty of the leading amphibian researchers in the world have called for a new Amphibian Survival Alliance, a $400-million initiative to help reduce and prevent amphibian declines and extinctions — an ecological crisis of growing proportion that continues to worsen.

In a policy statement published today in the journal Science, the scientists say that 32 percent of all amphibian species are threatened and at least nine — perhaps as many as 122 — have become extinct since 1980. It’s time, they say, for a more organized and effective approach to address the various diseases, habitat loss, invading species and other causes of this problem.

“This is part of an overall biodiversity crisis, and amphibians seem to have been hit the hardest of all vertebrate species,” said Andrew Blaustein, a professor of zoology at Oregon State University, a co-author of the statement who documented amphibian declines almost 20 years ago.

“Amphibians play a major role in many ecosystems; in some places the amphibian biomass is greater than that of all the other vertebrates.” he said. “The long-term ecological repercussions of their decline could be profound, and we have to do something about it.”

Programs of research, training, monitoring, salvage operations, disease management, captive breeding and other efforts are envisioned under the new initiative, which may include a global network of centers for amphibian recovery and protection. Support from individuals, government agencies, foundations, and the conservation community will be sought, the researchers said in their report.

Amphibians have been around for more than 300 million years, thriving before the dinosaurs and living long after they and many other species had disappeared. Their dramatic decline and extinctions now has alarmed many researchers since it first became apparent in the past two decades.

“Amphibians have sensitive skin, they live in both land and water, have no protective hair or feathers, and their eggs have no hard outer shell,” Blaustein said. “So it’s clear why they may be vulnerable on some levels. However, they persisted for hundreds of millions of years and just now are disappearing in many areas.”

Some of the causes have been identified. Rising levels of ultraviolet radiation, increases in pollutants, pesticides, extensive habitat loss due to agriculture or urbanization, invasive species, and various fungal diseases have all been implicated.

Some biologists have called amphibians the “canary in the coal mine” — the first clear and sweeping biological example of environmental change, pollution and toxicity that may ultimately affect many other animal species, including humans.

The demise of amphibians also has ecological ripple effects; they provide a major control of insect pests, and in turn serve as part of the food supply for birds, fish and other animals. The demise of entire species also eliminates their possible use in biomedicine and biotechnology.

Scientists at OSU and the University of California-Berkeley were among the first to note amphibian decline, publishing some professional papers in the early 1990s. One publication by this group has been listed as the 10th most-cited paper in the journal Conservation Biology.

Amphibian declines have been documented in North and South America, Europe, Asia and Africa. Several species in the Pacific Northwest are listed as candidates for the endangered species list. More than a dozen species have disappeared from Australia in recent years.

Traditional programs and current laws and policies alone are insufficient to address global threats that cross boundaries of reserves and nations, the scientists said in their report.