Threatened crayfish move to ‘ark site’ as invaders advance

The indigenous British species is in danger from various factors, the worst of which is the much larger alien signal crayfish, which also spreads a devastating form of fatal crayfish plague.

Environment Agency workers carried out the operation yesterday at the Porter Brook, in the Fulwood area of Sheffield and took the rescued invertbrates to a secret location in the Pennines.

Ian Marshall, a bioversity officer at the agency, said the population in the Porter Brook was one of the most threatened in Yorkshire.

He added there had already been an outbreak of crayfish plague in its downstream reaches allowing the invasive signal crayfish to advance upstream.

The new site will be above a reservoir and experts hope that will act as a barrier, halting the upstream spread of the alien signal crayfish and the plague it carries, and hopefully giving the white-clawed crayfish a safe haven to help it survive.

Mr Marshall said: “The new home will be what we call an ‘ark site’ which is physically and biologically remote, giving the best protection for our native crayfish from the plague and the invasive crayfish itself.”