ROUNDTABLE SESSION 4A: MANAGEMENT: REINTRODUCTIONS AND RESTOCKING.

Abstract

The present paper summarizes the outcome of a roundtable discussion on reintroductions or restocking as a management strategy for native European crayfish, which took place during the European Crayfish conference in Poitiers, France in September 2001. Aspects related to the suitability of the target habitat, the stocking material and the stocking procedure itself are important to consider during any reintroduction measure: Apart from general water quality and structural parameters, a suitable habitat is ideally geographically isolated from other surface waters and human activities such as intensive fishing pressure. However, it is of striking importance to make sure that the target habitat is free of crayfish plague, e.g. by experimental in situ exposure of native specimens. Overexploitation should be avoided if the stocking material originates from other surface waters and genetic aspects should be considered in stocking material originating from both natural surface waters and crayfish farms. Information for the stocking procedure itself are summarized from experiences gathered in various European countries. As an overall result of the discussion, the following three key questions related to reintroductions of native crayfish arised: 1. Why are the native crayfish not present (anymore) in the target habitat? 2. Do native crayfish survive in situ exposure as a test for crayfish plague? 3. Is the reintroduction or restocking measure successful in establishing a self-sustaining stock of native crayfish?