A recently published review paper in Nature draws attention to the dangers of globalisation and international trade which facilitate spreading of fungal diseases. The authors collected data from all over the world and showed that fungal infections had increased, caused extinction of several species and even contributed to climate change in the last few decades. They claim that immediate action is needed to prevent devastating impacts of the spreading of fungal diseases mainly by more research and better implementation of science into policy and practice.

The scientists looked at the problem holistically and pointed out some unusual links. They state for example that fungal diseases can contribute to climate change through killing or damaging trees that otherwise would have absorbed significant amount of CO2. They also highlight that biodiversity loss is accelerated by fungal pathogens. Due to small population effects and decreased ecosystem diversity, a fungal disease can wipe out entire species as it is seen in the case of amphibians. In case of animal species, fungal infections already account for 72% of infection-related extinctions which is more than viral and bacterial caused extinctions altogether.

Fungal pathogens can even facilitate invaders’ success. In the well known case of the North American signal crayfish in the UK a fungus-like disease (Crayfish Plague) helps the invader. The signal crayfish is tolerant to the infection which is lethal to the indigenous white-clawed crayfish. By spreading the disease around and wiping out the native crayfish the invader can occupy more and more habitats.

Food security is also in danger. Fungal infections of our five main food crops (rice, wheat, maize, potatoes and soybeans) are already causing serious problems and destroy a significant amount of the yield each year. Newly emerging fungal diseases can affect agriculture directly while new pathogens affecting animals can also have an indirect effect on crop production. Estimations suggest that White Nose Syndrome which decreases bat populations in North America can cause huge extra costs ($3.7 billion) to agriculture through the lack of bat control on insect pests.

The authors point out that human behaviour (international travel and trade) is the major cause of the recently recognised expansion of fungal diseases. Therefore, they call for stronger international biosecurity by strengthening international trade regulations, quarantining more rigorously and tackling illegal trade more effectively through trade control organisations. They also emphasise that integrated research on identifying, monitoring and mitigating the impacts of these diseases is much needed to get ahead of fungal epidemics.

For more on the subject, listen to the latest Planet Earth Online podcast.

The original paper: MC Fisher et al. Emerging fungal threats to animal, plant and ecosystem health. Nature, 12 April 2012. DOI 10.1038/nature10947

The persistent dry weather which has led to the current hosepipe ban in South East England is also threatening the future of one of Britain’s rarest amphibians, the natterjack toad.

With fewer than 50 breeding populations remaining in mainland Britain, the natterjack is highly vulnerable to the drying-out of the shallow coastal dune slacks it relies on as breeding habitat. Low rainfall for the past two years means that these wet hollows have begun disappearing before natterjack tadpoles have metamorphosed into toads, causing a significant drop in breeding success.

In response, Natural England has introduced a programme of water saving techniques and pond management across a number of its National Nature Reserves (NNRs), which support a large proportion of the remaining natterjack population. For example, at Saltfleetby Theddlethorpe Dunes NNR in Lincolnshire, staff have created captive pools in which water levels are controlled to allow tadpoles to mature before being they are allowed to escape into the surrounding dunes. Dr Pete Brotherton, Natural England’s Head of Biodiversity is optimistic about the success of the scheme saying ‘we are confident that the toad can bounce back if conditions prove wetter next year’.

Further afield, targeted conservation interventions to protect amphibians are also taking place in Central America. In this region, in addition to the threat of a changing climate, species of frog are being severely impacted by the spread of ‘chytrid’ – a virulent fungal disease. In some regions, the fungus is spreading at a rate of around 20 miles a year and can reduce frog populations by up to 90%. In response, scientists have started a programme of collecting healthy frogs from their forest habitats and transporting them to specially designed ‘arks’ to be held until ongoing research provides a solution to eradicate the fungus. Such a seemingly drastic response is partly due to the considerable potential value of amphibian diversity for human health. For example, a species of tree frog from Australia has been found to produce compounds that destroy HIV cells, whilst the phantasmal poison frog produces a painkiller 200 times more powerful than morphine. Already, the gastric-brooding frog – thought to offer a possible cure for peptic ulcers – has gone extinct.

In order to prevent the loss of further amphibian species with significant human, ecological and intrinsic value, such conservation efforts may need to be become more widely applied in the future.

For more on the natterjack toad, see Natural England’s press release on the subject. Further detail on amphibian conservation and the chytrid fungus can be found on the BBC news website.

Welsh Environment Minister John Griffiths yesterday launched the Welsh Government’s Strategic Framework for Bovine TB Eradication, which outlined a programme of badger vaccination to be introduced in the Intensive Action Area.

The Minister said the decision to pursue vaccination as opposed to culling of badgers was made based on ‘the evidence provided…including scientific and legal advice’ and that, at present, he is ‘not satisfied that a cull of badgers would be necessary to bring about a substantial reduction in cases of TB in cattle’.

A five year programme of vaccination is to be designed by the Chief Veterinary Officer and the Strategic Framework outlines a comprehensive longterm plan including measures for improved management of persistent cases of TB, piloting of an audit technique to assess TB testing, a voluntary scheme to facilitate the sharing of bovine TB data between neighbouring farms, and an advisory service for farmers whose herds are affected by the disease.

In his launch speech, Minister Griffiths emphasised that TB eradication will require longterm commitment and the use of new technological and scientific advances as they become available. A working group of experts, led by the Chief Veterinary Officer, will be created to develop the vaccination strategy.

The full Strategic Framework can be found on the Welsh Government website.

The fifth in a series of ESRC-funded seminars on biosecurity is taking place at Birkbeck College, University of London, on 22-23 September 2011. ‘The Future of Biosecurity and Biosecuring the Future’ will bring together speakers, discussion panels, exhibition and film to consider:

- what is the future for biosecurity, and what will future biosecurity practices and approaches entail?

– Will climate change demand a new paradigm of ecological management through the growing disparity between ‘native’ species and suitable national ecological conditions?

– Will we learn to live with and value ecological change?

– Or will climate change be used to justify greater biosecurity control, as pest species and diseases ever expand their ecological ranges?

The transport and accomodation costs of participants will be covered in full. Initial expressions of interest in attending are now welcome to Dr Sarah Taylor, Keele University.

Lord Krebs FRS, Chair of the House of Lords Science and Technology Committee, criticised the UK Government on the Radio Four ‘Today’ programme this morning, accusing ministers of ‘ignoring’ scientific evidence by sanctioning a badger cull. Secretary of State Caroline Spelman MP announced the cull on Tuesday in a statement to the House of Commons. Lord Krebs questioned why the National Farmers Union, also speaking on the programme, were in favour of a cull, when the evidence shows that farmers located nearby to the cull sites, but not themselves participating, would experience a higher incidence of the disease as a result of the intervention.

In delivering her statement to the Commons, Caroline Spelman stated that ‘doing nothing is not an option’, given the devastating impact of bovine TB on the livlihoods of farmers and of rural communities. Outlining why vaccination of badgers and cattle is not yet an option to control the disease, the Secretary of State commented that ‘a useable and approved cattle vaccine and oral badger vaccine are much farther away than we thought and we cannot say with any certainty if and when they will be ready‘. Instead, the proposal is for a controlled cull in England, with Natutal England issuing licenses to groups of farmers and landowners who then commit to paying, at their own expense, trained experts to shoot free running badgers across an area of 150 km2 for a minimum period of four years. There will be two pilots in year one, to assess the efficacy of shooting and whether badgers have been killed humanely.

The potential effectiveness of the cull is a hotly debated issue within science, as Professor Krebs’ appearance this morning illustrates. Professor Krebs oversaw an initial review of the evidence for the transmission of TB between cattle and badgers in 1997. As a result of his recommendations, the Independent Scientific Group (ISG) was established to oversee the 10-year Randomised Badger Culling Trial (RBCT), which published its final report in 2007. The ISG showed that reactive culling increased the incidence of TB in cattle, making this unacceptable as a future policy option. Proactive culling, carried out over an area of 100 km2, reduced the incidence of bovine TB but this beneficial effect was offset by an increase in disease in un-culled areas. The group concluded that this was due to ‘perturbation’; the disruption of the badgers’ territorial social groups, causing the animals to roam and so spread the disease into uninfected areas.

The ISG concluded that badger culling could not meaningfully contribute to the future control of cattle TB in Britain. And yet, Caroline Spelman was adamant in the House on Tuesday that Defra’s policy is science-led and evidence-based. The scientific community does seem to be split on this issue. Several members of the ISG wrote a letter to the Times on 13th July, calling for the ‘untested and risky’ approach of badger control by shooting to be carefully monitored, whilst nine other members of the ISG were cited by Caroline Spelman this week as supporting a badger cull.

A group of independent scientific experts assembled by the Defra Chief Scientific Advisor, and including Lord Krebs, met on 4th April this year to consider the evidence and make recommendations to Defra. This group concluded that the science base (the RBCT and subsequent follow-up studies) indicates that a proactive badger cull resulted in a beneficial effect compared to areas where no cull took place. Perturbation was transient and that 12-18 months after the cull, this effect subsided. However they concluded too that the more a badger policy deviates from the conditions of the RBCT, the more likely it is that the outcome will differ; this presumably includes shooting of free-running badgers, which was untested by the RBCT, which instead trapped badgers in cages before shooting them.

The experts conclude that culling must be coordinated and sustained, over a minimum area of 150km2 and for a minimum period of four years, to avoid making matters worse. They suggest that the incidence of disease could be reduced by 20-34% after nine and a half year period, but given the perturbation effect in the area surrounding the cull locations, the net benefit would be likely to be smaller (between 3% and 24%).

Professor Krebs argued this morning that the cost of a badger cull would far outweigh the benefits; given that the total disease incidence would be eight of herds experiencing TB breakdowns in hot-spots, compared to nine out of ten herds. Questions to Caroline Spelman in the Commons earlier this week revealed that Defra will need to pay £200,000 annually to cover extra cost of policing which will be needed to deal with protests against the cull, whilst Caroline Spelman herself commented that it would ‘cost a modest amount more’ to include culling within the measures needed to deal with bovine TB in Britain. The Secretary of State suggested that reducing the social impacts of herd breakdowns, to farmers and rural livlihoods, would outweigh these monetised costs.

The Welsh Government announced earlier this week that plans for a controversial cull of badgers in north Pembrokeshire would be put on hold whilst Ministers await the outcome of a science review. Professor John Harries, Chief Scientific Advisor to the Welsh Government, will appoint scientists to an independent panel to consider the scientific evidence for a badger cull. The report of the panel is expected in the autumn.

More on this story from the BBC website ‘No cull of badgers in Wales during scientific review‘ (21st June).

The announcement of a badger TB vaccination trial on the National Trust’s Killerton Estate has been welcomed by both farmers and local environmental groups. The four year programme which will commence this May aims to show that vaccination is a viable alternative to culling programmes, particularly in places where Defra’s culling criteria cannot currently be met.

Bovine tuberculosis is a major burden for both farmers and taxpayers in the UK. Last year the cost of the disease to the taxpayer was almost £63 million, mainly paid out in compensation to farmers who had cattle destroyed as a result of the disease. However farmers say that this sum does not cover the cost of replacing lost animals, and more needs to be done to prevent the spread of the disease.

Badger culling, the current recommended strategy for control of bovine TB, has been shown to be effective within culling sites but can have detrimental knock on effects for surrounding areas, which often see an increased incidence of the disease. As a consequence of the Randomised Badger Culling Trial (RBCT) which showed these effects Defra introduced stringent criteria to set the conditions under which badger culling can take place, which require farmers to demonstrate that they can minimize any potential edge effects, and cull within a minimum area size of 150km2. There are very few instances when these criteria can be met. When these criteria cannot be fulfilled it seems that vaccination may be the only viable option but so far there is little evidence to show how effective it might be.

The new programme funded by the National Trust aims to demonstrate to the government and farmers that vaccination is a viable alternative to culling. It also aims to stimulate research into an oral vaccine, such as the type which has been used with great success to treat rabies, which would be a cheap and easy to administer option for carrying vaccination out on a larger scale. Mark Harold from the national trust said that he hopes that this project can “pave the way for more widespread use of vaccination as an effective alternative to culling”, and also noted that “the National Trust is in a unique position as a major landowner in rural areas” allowing them to pioneer the scheme.

The vaccination programme will involve 18 tenant farmers on 20 km2 farmland in the Killerton estate, a prime example of a site that cannot meet current DEFRA criteria for badger culls. It is expected to cost around £80,000 per year and run until 2015. Badgers will be trapped, vaccinated and marked by licensed experts.

Eight months ago plans to implement a badger cull in west Wales were put on hold following a winning appeal from the Badger Trust. The case has since been revived, and will tomorrow call upon Welsh Assembly Members (AMs) to vote on a legislative order. If votes are found to be in favor, the new legislation will allow authorities to proceed with a badger cull in north Pembrokeshire, and parts of Ceredigion and Carmarthenshire, Wales.

The controversial plans to cull badgers are part of a government attempt to help eradicate bovine TB, which is spread to cattle from badgers who are known carriers of the disease. There has been extensive research and much debate into the matter, with arguments over whether or not a cull offers an effective solution to controlling the disease making national headlines.

Welsh Rural Affairs Minister Elin Jones said “we must continue to pursue a comprehensive approach towards the eradication of bovine TB from Wales” and that she had decided to go ahead with the order subject to “substantial scientific evidence”. Opposition groups such as the Badger Trust and Pembrokeshire Against the Cull (PAC) argue that cases of infected cattle are falling, and that vaccination offers a more effective and humane method of control. The practical problems and costs associated with doing so however often limit vaccination success. Additionally, they argue that implementing a badger cull may actually increase the incidence of bovine TB, as culling badgers encourages their dispersal, and as a result spreads the disease further.

If AMs do not object at tomorrows vote, the legislative will come into force as of 31st March 2011, however if the voting indicates opposition to the cull, it could lead to further debate and a vote in the Senedd.

The Badger Trust has been told that it can appeal against a Judicial Review’s decision to back the Welsh Assembly Government’s planned badger cull in Pembrokeshire.

The cull aims to cut the rate of tuberculosis in cattle, but opponents say that it is not justified by science. The trust argued that the assembly government had not demonstrated that a cull would “eliminate or substantially reduce” the rate of TB infection, as the law meant it had to.

In response, Mr Justice Elias agreed that these two points were “arguable”, and granted the trust leave to appeal.

However, a spokesman for the assembly indicated that the cull will proceed, although the a date has not been set for fear of disruption from campaigners.

Source article: “Wales’s Badger cull faces new legal challenge” by Richard Black

A new report, commsissioned by Defra and produced by Imperial College and the Zoological Society of London, casts doubt on the effectiveness of badger culling in reducing the incidence of bovine TB in the UK. The report examines the aftermath of the Krebbs random badger culling trials which took place between 1998 – 2005.

Speaking to the BBC, Professor Christl Donnelly, lead author of the report from Imperial College London, said that “although badger culling reduced cattle bovine TB during the trial and immediately thereafter, our new study shows that the beneficial effects are not sustained, disappearing four-years post-cull.” The report also suggests that savings to the Government and to farmers, through reduced bovine TB incidence in cattle, are two to three times lower than the cost of culling badgers.

Wales is preparing to instigate a badger cull later this year. Dr Christianne Glossop, Chief Veterinary Advisor in Wales, commenting on the findings of the report, said that the Welsh approach would not be the same as that used in the Krebbs trials and would instead see a limited cull couple with strict cattle control measures, over a limited area and for a sustained period. Dr Glossop said that she anticipated that the badger cull in Wales would be successful.

Professor Rosie Woodroffee, Senior Research Fellow at the ZSL, appeared on the BBC’s Today Programme this morning at 7am, commenting on the report. The programme is available to listen to again online.

More information on badgers and bovine TB is available from the BES website.