Armageddon for amphibians? Frog-killing disease jumps Panama Canal
Rhett A. Butler, mongabay.com
October 12, 2008
Chytridiomycosis is caused by Batrachochytrium dendrobatidis, a fungal pathogen that has been implicated in the extinction of more than 100 species of frogs and toads since the early 1980s. While scientists don't yet know the origin of the fungus, they suspect it might be the African clawed frog, a species that has been shipped around the world for research purposes. The fungus is highly transmissible and has spread to at least four continents, in some cases probably introduced unintentionally by humans in the treads of their shoes. As it spreads, the disease lays waste to more than 80 percent of amphibians across a wide range of habitats, including those that are undisturbed by humans. Some researchers have suggested that climate change could be creating conditions that exacerbate the impact of the pathogen — which predominantly affects highland species — although the theory is still controversial.
Panama golden frogs mating in captivity. Photo by Rhett A. Butler
Panama's golden frog (Atelopus zetecki), a species that may now be extinct in the wild due to Chytridiomycosis. In many parts of Panama this frog — actually a species of harlequin toad — is considered a good luck charm and was once collected from the wild by people to put in their homes.
The Red-eyed tree frog, a species that is often found in lowland areas in Central America, is not particularly at risk from Chytridiomycosis.
The scientists say that physical barriers to the spread of Chytrid — including salt water, deforested lowlands where high temperatures kill the fungus, and the Panama Canal — are being "easily overcome" in Panama by "human movement of the pathogen". In other words, human activities like tourism, scientific research, and construction are facilitating the epidemic. The authors suggest that measures to reduce transportation of Chytrid such as "bleaching boots and cleaning field gear between sites, and providing information at eco-lodges" could help contain the disease.
Adding to the gloom for amphibians
Two variations of Oophaga pumilio, the strawberry poison dark frog, in Panama. Photos by Rhett A. Butler
In an effort to save the most at-risk species, last year saw the launch of the Amphibian Ark, an initiative by zoos, aquariums, and botanical gardens to establish captive populations for 500 species at about $100,000 per species. Overall the coalition is looking to raise $400 million over 5 years for long-term research, protecting critical habitats, reducing trade in amphibians for food and pets, and establishing captive breeding programs. Amphibian Ark hopes to return rescued species to the wild once Chytrid and other threats have been controlled.
Douglas C. Woodhams at al. (2008) "Chytridiomycosis and Amphibian Population Declines Continue to Spread Eastward in Panama." EcoHealth DOI: 10.1007/s10393-008-0190-0