7 years of hard work by ZSL scientists has finally found a method to eradicate the deadly Chytrid Fungus which has already decimated many species of Frog Scientists discover method to eliminate killer fungus in amphibians | Zoological Society of London (ZSL)
Without wishing to dampen the spirits here.........has anyone actually read the paper? The 'environmental treatment' effectively requires that a disinfectant (Virkon S) is applied to the environment to kill the fungus. While I'm sure this is effective, it no doubt also wipes out entire communities of natural bacteria and fungae, most of which are of course, not only non-pathogenic but probably beneficial to the functioning of the ecosystem. This is the material safety sheet for Virkon S...... http://www.nrm.co.nz/uploads/pdf/Virkon-S-MSDS-1407.pdf Have a look at the ingredients..... It is acutely toxic (invertebrates, algae, fish) at 6.5-around 20 mg/L and causes chronic toxicity (in the studies listed here, this means it inhibits reproductive performance (and therefore populations) at concentrations of around 0.2 mg/L. The MSDS says 'The product should not be allowed to enter drains, water courses or the soil.' because of these effects on representative organisms. The paper says 'Environmental disinfection was done using Virkon S (DuPont Inc.) at 1% final concentration and a single application applied ad libitum to the environment. The disinfectant was liberally applied to all rock, gravel, crevice and vegetated areas that surrounded the immediate environs of each breeding site.' 1% equates to approx. 10 mg/L. OK - so one application and not applied directly to the water but it must have wiped out much of the micro-fauna in the immediate areas of application and much will enter the watercourse and have an effect there before being diluted to below effect concentrations. In terms of this study, the overall impact was probably negligible, but do we really want to be 'disinfecting the environment' to kill one disease..........however damaging it may be. The inference is that this would need to be applied over a wide area where ever the disease occurs, and who knows what the ecological implications of this would be....... To be fair to the authors, they do state 'We acknowledge that Virkon S is a controversial chemical to use environmentally and our use of it was driven by the urgency of midwife decline on Mallorca [21]. ' and 'Research on the application of these chemicals for control of wildlife diseases must also include investigation of the potential impacts of chemical application to other biodiversity, the environment and associated ecosystem services.' Spot on! So I would too very much welcome this news (we know we can kill the fungus), but we must be sure we don't make things worse by focussing on a single problem rather than the big picture......there are of course, numerous examples of us getting this wrong in the past (DDT anyone?).
