The controversial chemical Virkon was used to clear Mallorcan midwife toad ponds of the Chytrid fungus.
How do you clean out your reptile enclosure? Generally, you first remove your reptile, throw away the substrate if it is disposable, and then with a bleach and water combination, you scrub your enclosure as best you can, making sure to remove all traces of bleach with a good hose down.
Well, a similar cleaning regimen may have paid off for some Mallorca toads that have been living in ponds infected with Batrachochytrium dendrobatidis, also known as the chytrid fungus.
As reported in the journal Biology Letters, researchers on the island of Mallorca spent seven years trying to figure out how to eliminate Bd from the ponds. They took a novel approach in an effort to eliminate chytrid fungus in five area ponds on the island, ponds that are home to the Mallorca midwife toad (Alytes muletensis).
In order to achieve this, the scientists collected all tadpoles in the ponds and treated them with anti-fungal drugs in an effort to stop the disease. That procedure failed, so they took it a step further and drained the ponds to let them dry in the sun and then returned the treated tadpoles back into the ponds. That failed also. So the scientists basically went nuclear on the ponds, removing the tadpoles and draining the ponds and then cleansing the empty ponds with a laboratory disinfectant called Virkon S. All rocks, gravel, crevices, and vegetated areas were given the Virkon treatment. They then returned the toads back to the ponds and after two years, the ponds and the toads have tested negative for the fungus.
While the initial mitigation of the fungus was successful, the scientists stress that reintroduction of the disease via amphibians that were not captured during the testing phase is possible. The scientists also noted their awareness of the controversy surrounding the Virkon chemical but believe that their use of the chemical was prudent given the rapid decline of the midwife toad on Mallorca.
The scientists who conducted the years long study include Jaime Bosch, Eva Sanchez-Tomé, Andrés Fernández-Loras, Joan A. Oliver, Matthew C. Fisher, and Trenton W. J. Garner. They are from the Museo Nacional de Ciencias Naturales in Spain and the Conselleria de Medi Ambient i Mobilitat in Spain, the Institute of Zoology, Regent's Park in London, and Department of Infectious Disease Epidemiology, Imperial College London, St Mary's Hospital, Norfolk Place in London.
The complete paper, “Successful elimination of a lethal wildlife infectious disease in nature” can be read on the Biology Letters website.
John Virata keeps a western hognose snake, a ball python, two corn snakes, a king snake, and two leopard geckos. His first snake, a California kingsnake, was purchased for $5. His first pet reptile was a green anole that arrived in a small box via mail order. Follow him on Twitter @johnvirata