The combined forces of researchers from ZSL's Institute of Zoology, UCL and Queen Mary University of London have discovered that climate change has already increased the spread and severity of a fatal disease caused by Ranavirus that infects common frogs (Rana temporaria) in the UK and the study was published in Global Change Biology.
The researchers found a match in the historical trends in mass-mortality events attributed to the disease in the pattern of increased temperatures recorded over recent decades with disease outbreaks predicted to become more severe, more widespread and occurring over a higher proportion of the year within the next few decades, if carbon emission continue at their current rate.
The international conservative charity ZSL (Zoological Society of London), UCL, Queen Mary University of London and University of Plymouth conducted the research and used a three-pronged approach involving cell cultures, live models and historical data from the Met Office and Froglife's Mortality Project. The study demonstrated that warm weather where temperatures reach 16oC dramatically increases the risk of Ranavirus causing a disease outbreak in common frogs.
The discovery aid the explanation to the seasonality of the disease, with incidence peaking during the hottest months of the summer, showing that climate change could see outbreaks becoming more frequent from April to October.
In the spring, the disease outbreaks could result in the deaths of large numbers of tadpoles which could have repercussions for population survival. Till present, Ranavirus disease has mainly been restricted to England, but as average monthly temperatures increase to exceed 16oC in more areas over more extended periods, as predicted by the IPCC's high carbon-emission model, the disease is likely to spread across most of the UK in the next 50 years.
In his explanation, the lead author of the study from ZSL's Institute of Zoology and UCL, Dr. Stephen Price said that climate change is not something that is happening in faraway places - it is something real and present that is already had hard-to-predict impacts on wildlife in the back gardens in the UK.
He pointed further that a number of scientists have already alluded to the fact that climate change could increase the spread of disease, but this is one of the first studies that provide strong evidence of the impact of climate change on wildlife disease and helps to explain how it may facilitate the spread of Ranavirus across the UK.
Scientists at ZSL suggest that frogs may be better able to cope with infection if they have areas in which they can cool down, adding log piles, vegetation or nearby shady patches as well as keeping ponds deep will help reduce the level of sun exposure frogs receive and thus reduce the growth rate of the virus.
