Scientists have discovered that more than twice the number of amphibian species are at risk from chytrid fungus than was previously estimated.


In 2007 approximately 200 species were predicted to be under threat from the fungal disease with 501 shown to be at risk today, 6.5 per cent of described amphibian species.

“There is no longer any question that the world has entered a global mass extinction event, beginning with the vanishing of frogs,” says Dr Jonathan Kolby one of the papers authors. "The unabated spread of chytrid is now causing the most severe disease-driven loss of biodiversity in human history."

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Chytridiomycosis is caused by two species of fungus, Batrachochytrium dendrobatidis and B. salamandrivorans, and it is believed that both originated in Asia and have been spread around the world by humans.

Both species of fungus attack the skin of amphibians and creates issues with respiration and water uptake.

The disease is now found in more than 60 countries, and the study shows that the worst affected areas are Australia and South and Central America.

Chytridiomycosis was first reported in the UK in 2005 in southeast of England.

The disease is believed to be the cause of 90 species' extinctions and the ongoing decline of many more.

However, some surviving species' populations are showing signs of recovery.

Kolby adds, “To make matters worse, this only takes into account B.dendrobatidis, while North America is also on the verge of invasion by salamander chytrid fungus B. salamandrivorans.

The authors call for better biosecurity and wildlife trade restrictions in order to prevent any more extinctions.


Read the paper in Science.