Toads, salamanders and toads around the world are now under attack from an increasing range of interactive pathogens that threaten to devastate global amphibian populations.
This is the blatant warning from the top zoological experts who will gather this week in London in an attempt to establish an emergency plan to save these endangered creatures. "The world's amphibians are facing a new crisis, caused by attacks from multiple pathogens," said Professor Trent Garner of the Zoological Society of London, who is organizing the conference. "We desperately need to devise strategies that can protect them."
Thirty years ago, experts realized that amphibian populations were dipping into different areas of the world as an emerging fungal disease, known as chytridomycosis, or simply chytridium, began to take its toll on frogs and toads. At least 100 species have been swept away from the face of the planet. These include the golden toad in Costa Rica (Incilius periglenes); the dripping toad in southern Australia (Rheobatrachus silus); and Arthur's stubfoot toad (Atelopus arthuri) in Ecuador. Hundreds of other amphibian species also suffered severe declines – as a result of chytrid infections.
But scientists also know that chytrid is not the only cause of the amphibian deaths now occurring around the world. Another pathogen known as ranavirus, which exists in at least four varieties, has been observed killing amphibians. In addition, they found that there are at least two species of chytrid, and within them, many different genetic types.
"The bottom line is that these different pathogens are no longer acting alone," added Garner. "They are interacting and combining are killing more and more amphibians. These interactions are often much worse than the effects of individual pathogens. "
In addition to the direct loss of species, the reduction in the number of amphibians is harmful to the environment because frogs, frogs and toads play an important role in maintaining healthy ecosystems. For example, frogs eat mosquitoes that spread disease. They also provide food for birds and other animals. In addition, tadpoles chew algae and thus help prevent algal blooms. "So far Britain has been very lucky," Garner said. "There was no mass mortality recorded as in other countries – at least as far as chytrid infections are concerned."
However, ranaviruses are a different problem, he added. They have caused declines in the common toad (Temporary frog) in the United Kingdom, but also infect the common toad (Bufo bufo), often with fatal results. As a result, zoologists urged the public to report sick or dead sightings of amphibians through sites such as Garden Wildlife Health and also urged people not to move eggs, tadpoles or pond toad frogs.
"That way, you prevent the spread of infections," Garner said. "Anything you can do to reduce the pressure on these creatures is important."
In addition, this week's conference – Mitigation of a single pathogen and co-infections that threaten amphibian biodiversity – will try to outline ideas to try to save amphibians from the multipathogenic threats they now face. "We will be hosting a one-day workshop where we will bring together the best people in the field – conservationists, zoologists, and co-infection experts together and get them working out the best strategy to deal with it. Unless we have one, it's going to get much worse. "