Researchers found that placing goldfish in garden ponds may be detrimental to the health of frogs. Frogs may suffer from major viral infections, and possibly even death, scientists say.

The virus becomes more severe as people release exotic and non-native species in ponds together with the frogs.

Researchers from the University of Exeter reviewed long-term data pertaining to the deaths of common frogs in Britain. The researchers particularly looked at the features linked to mortalities due to ranavirosis. Pond owners from the UK told Froglife, the charity that produces the data, that mass frog deaths have been noted since 1992.

"Our results show that we can all help limit the impact of this devastating disease," says Alexandra North, lead author of the study. "It is important to reduce the use of garden chemicals like slug pellets and weed killers, which weaken the immune systems of frogs, and to stop stocking ponds with non-native species like goldfish."

Ranavirosis is caused by ranavirus, which may result in grave skin ulcers and generalized bleeding in amphibians. These primary effects may subsequently lead to limbs deficit and ultimately, death. The virus is believed to have penetrated through the pet trade and has since become a major factor in the deaths of amphibians worldwide. The presence of ranaviruses is a global concern and is linked to amphibian mortalities in Europe, America and Asia.

"We are currently undergoing a mass extinction of species, and amphibians are particularly under threat. The unprecedented loss of amphibians indicates widespread environmental degradation," Dr. Amber Griffiths of the Environment and Sustainability Institute announced at the University of Exeter's Penryn Campus in Cornwall. "The interactions between disease and climate change are deadly. The deeper problem is climate change, but our study shows that people can make an immediate difference by changing their habits in their own gardens."

North is asking all people to stop placing goldfish and other animals who are non-natural inhabitants of ponds. She also discourages the public from using garden substances such as weed killers and slug pellets, as these compromise the immune systems of frogs. To that end, pond owners can help to reduce the incidence of frog mortality across Britain due to ranavirus, in their own simple ways. Experts also strongly suggest not moving animals, weeds, ornaments and other pond products from one pond to another, as this contributes to the increased transmission of the disease.

Photo: brownpau | Flickr