Climate change, fungal disease threaten frogs
Reuters News Service, Oct. 25, 2006
LONDON (Reuters) - A deadly fungal disease linked to climate change is wiping out huge numbers of amphibians in Spain and could push some species to the brink of extinction, researchers said on Wednesday.
The infectious illness that has already killed entire populations of frogs in Central and South America has now been spotted in Europe.
"We have found an association between increasing temperatures and amphibian disease in a mountain region in Spain," said Dr Matthew Fisher of Imperial College in London.
"This is a global emerging amphibian pathogen which is one of the worst vertebrate infectious diseases found so far. It is causing a huge amount of extinction and disease within amphibian populations," he added in an interview.
More than 100 species of amphibians are known to be affected by the disease known as BD. Some are very susceptible and die quickly while others which are more resistant are carriers of the pathogen.
Fisher and scientists in Spain uncovered an association between the emergence of the disease and global warming while studying changes in the number of midwife toads in the Penalara Natural Park in the mountains of Spain between 1976 and 2002.
BD, Batrachochytrium dendrobatidis, infects the skin of amphibians such as frogs, toads, salamanders and newts and interferes with their ability to absorb water.
Fisher, who reported the findings in the journal Proceedings of the Royal Society B, said climate change could be worsening the impact of the disease in one of two ways.
Global warming, which is blamed on burning fossil fuels, could be decreasing the amphibians' ability to mount a successful immune response to the fungus. Amphibians are cold-blooded so their ability to respond to a pathogen could change along with the external temperature.
"Or, on the other hand, global warming could be increasing the fungus' ability to grow faster on the amphibian and cause more disease," Fisher added.
Climate change and disease are main factors for the extinction of the Golden Toad of Costa Rica, Ecuador's Jambato Toad and an Ecuadorean toad known as Atelopus Longirostis, according to the 2004 Red List of endangered species.
The Global Amphibian Assessment survey published earlier this year warned that a third of the world's amphibian species are in danger of extinction, many because of BD.
"This is a wake-up call that we are losing biodiversity fast," Fisher said. "Climate change appears to be changing patterns of disease and previously resistant species are becoming highly infected -- even, in a number of cases, becoming extinct."
(c) Reuters 2006