Ark sites

The most effective approach for WCC conservation is the creation of ‘ark sites’. An ark site is a pond, lake, river or stream where WCC can be safely rehomed away from the threat of the American signal crayfish, and/or poor water quality and habitat degradation.

Over the last few years, projects have attempted to establish ark sites using existing wild waterbodies with mixed success. Existing ponds or streams are often not a feasible long-term solution due to the presence of predatory species or poor water quality.

Saving Devon’s Native Crayfish project is trialling a new approach by constructing a bespoke ark site at Wildwood Devon designed specifically for WCC where we can be certain no predatory or invasive species are present.

The finished pond will have a gravel bottom with rock piles and other underwater habitat where crayfish can hide away and breed. Newly planted trees and shrubs around the edge will provide shade to keep the water cool, and marginal and aquatic plants will help keep the water oxygenated. A solar powered aeration system will also ensure good water quality. Part of the pond will be over 2 metres deep so that the water temperature stays cool and stable during the warmer months of the year.

WCC will be introduced to the ark site from the Wildwood Trust Devon hatchery. The crayfish will then mature and breed in the pond and a percentage will be translocated to other ark sites or river reintroductions in the following years under license from Natural England and Devon Environment Foundation.