Nick Upton / Emma Settle of GWT disinfecting her boots before helping to release White-clawed crayfish (Austropotamobius pallipes) at an ARK site, safe from Signal crayfish (Pacifastacus leniusculus) and Crayfish...

Nick Upton / Large White-clawed crayfish (Austropotamobius pallipes) caught in a well stocked stream ahead of translocation to an ARK site, safe from Signal crayfish (Pacifastacus leniusculus) and Crayfish plague,...

Nick Upton / Large male White-clawed crayfish (Austropotamobius pallipes) with claspers visible under the tail, caught in a well stocked stream ahead of translocation to an ARK site, safe from Signal crayfish (Pac...

Nick Upton / John Field releasing a very large male White-clawed crayfish (Austropotamobius pallipes) back to a well-stocked stream where it was caught in case it proved too aggressive for safe translocation to an...

Nick Upton / GWT team processing White-clawed crayfish (Austropotamobius pallipes) in a well-stocked stream to check their size, sex and health ahead of translocation to an ARK site, safe from Signal crayfish (Pac...

Nick Upton / White-clawed crayfish (Austropotamobius pallipes) collected from a well-stocked stream in a bucket ready for release at an ARK site, safe from Signal crayfish (Pacifastacus leniusculus) and Crayfish p...

Nick Upton / White-clawed crayfish (Austropotamobius pallipes) found in shallow stream by GWT team for translocation to an ARK site, safe from Signal crayfish (Pacifastacus leniusculus) and Crayfish plague, Englan...

Nick Upton / Very small White-clawed crayfish (Austropotamobius pallipes) beside a much larger one caught in a well stocked stream, with the smaller one not large enough for translocation to an ARK site, safe from...

Ashley Cooper / Rare native White clawed crayfish (Austropotamobius pallipes) killed by an illegal chemical spill on the river Mint near Kendal Cumbria UK. June 2004

Ashley Cooper / Rare native White clawed crayfish (Austropotamobius pallipes) killed by an illegal chemical spill on the river Mint near Kendal Cumbria UK. June 2004

Ashley Cooper / Rare native White clawed crayfish (Austropotamobius pallipes) killed by an illegal chemical spill on the river Mint near Kendal Cumbria UK. June 2004

Will Watson / White clawed crayfish (Austropotamobius pallipes) on gravel bed of stream, north Herefordshire, England, UK, October.