Efforts to conserve and endangered species which lives in Sheffield rivers have been dealt a ‘major set-back’, the Environment Agency has revealed.
A plague has affected crayfish in Porter Brook, EA ecologists confirmed, after the discovery of dead and dying crayfish in the river which runs into the city near Ecclesall Road.
The environment body is now planning to undertake a comprehensive survey of the watercourse to find out how much of an impact the plague has had on the population. It is hoped the plague will have run its course by next year.
Porter Brook had previously been noted as a nationally-significant habitat for the native species because the native population was so strong. Last year, crayfish from Porter Brook were used to colonise other watercourses, as part of ongoing efforts to conserve the endangered species.
The native species is under threat from the invasive American signal crayfish, and from crayfish plague. Native white-clawed crayfish have no natural defence against the plague: once the fungal disease has become established, an entire population can be wiped out in just a week.
Ian Marshall, Biodiversity Officer at the Environment Agency, said: “This is terrible news, and a real set-back to the work we are doing to save this endangered species.
“At this stage we don’t know how the plague infected Porter Brook. It could be that signal crayfish were moved here from another watercourse, or the disease could have been spread from another watercourse by people’s clothing or equipment.
“This incident demonstrates the importance of crayfish conservation work and how speed is of the essence in ensuring the survival of this species. We are currently working with partners to create new crayfish ark sites and improve the habitat of already established populations.
“It is fortunate that we did get the chance to take donor stock from Porter Brook last year. Without intervention the species could be extinct in this country within 20-30 years - time really is of the essence.
“This incident also serves as a reminder to all watercourse users that it is essential that they follow our biosecurity advice: always check, clean and dry your clothing and equipment when moving between watercourses.”
Those using rivers have been encouraged to find out more at www.nonnativespecies.org/checkcleandry