Natterjack toad threatened by UK drought – intensive conservation efforts needed to protect amphibians

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.