Statut de l'écrevisse à pattes blanches (Austropotamobius pallipes lereboullet, 1858) en bourgogne: Bilan de 5 années de prospection

Abstract

At a regional scale, complete information about geographical distribution of the White-clawed crayfish is very rare, even if these data are the basic ones for suitable conservation and management programs. In Burgundy, since 2000, several organisms - gathered under the Burgundy Crayfish Group have decided to conduct a large regional program of crayfish distribution. After the validation of historical information, nocturnal sampling has been systematically conducted over all the watersheds between June and October. Since the beginning of this program, 893 stations have been sampled, from 593 streams. The White-clawed Crayfish have been found in 128 small rivers, the noble Crayfish (Astacus astacus) in only 2 streams and 2 ponds. Four non-indigenous species have also been recorded: Astacus leptodactylus, Orconectes limosus, Pacifastacus leniusculus, and Procambarus clarkii. Half of the stations - where the White-clawed Crayfish was recorded during the last 30 years - is no longer colonized. To date, stations colonized by this Heritage species correspond only to small rivers from of headwater with a dense riparian vegetation and running in hardwood forest or meadows. Concerning the stations under the effects of new ponds or with coniferous forest on the edge of the river, the White-clawed Crayfish is very rare. In Burgundy, the White-clawed Crayfish populations are not very rare but very isolated and consequently, the specie status is weak. The current policies about rivers and aquatic habitats management (new ponds, drainage of wetlands, increasing in coniferous forest surfaces...) and the invasion of Pacifastacus leniusculus directly, threaten the White-clawed crayfish populations in the Burgundy watersheds.