The end of Cop15 this Monday, December 19, devoted to the end of the erosion of biodiversity, is an opportunity to look into one of its greatest threats: invasive alien species. In Aveyron, the red-spotted crayfish has been threatening an entire ecosystem for 3 years.
The Cop15 ends this Monday, December 19. It must allow the adoption of a new global strategic framework to put an end to the erosion of biodiversity. Among all the threats to the latter, invasive alien species (IAS) figure prominently. By their proliferation, they are a real threat to the ecosystems they colonize, such as the red-spotted crayfish which is emerging in Aveyron.
For 3 years, this small American crustacean has felt at home in the rivers of Aveyron.
Voracious, aggressive, each time it is introduced into a new environment, the latter completely destroys its ecosystem. “It is one of the most invasive crayfish in the world”warns Marion Sudres, director of the Aveyron Amont watershed joint union. “Its energy requirement is higher than other crayfish, its population is dense and it has a strong impact on the population of other crayfish, on aquatic fauna and flora.” In addition, this crayfish is a healthy carrier of crayfish plague.
Despite an investigation carried out by the OFB, the French Office for Biodiversity, it is impossible today to determine the conditions under which this crayfish ended up in a watercourse in the Aveyron (voluntary or accidental). .
The Faxonius Rusticus appeared for the first time in 2019 and quickly, Aveyron became the first European home for this invasive alien species. The crustacean mainly develops on a body of water and in a watercourse downstream from it.
As soon as it was discovered, eradication campaigns were carried out in the department in order to safeguard its biodiversity. These are still ongoing. “We are implementing advanced methods to capture and destroy them”explains Marion Sudres. “These are operations by hand or via traps to destroy only this invasive species.” 6,269 individuals have been captured and destroyed since the start of the operation.
It is still too early to analyze the success or otherwise of these operations. “We consider that there is still hope to eradicate it and prevent its spread to other waterways”reacts Stéphane Charretier, of the French Office for Biodiversity.
These eradication campaigns are carried out with the Aveyron Fishing Federation, the Adour Garonne water agency and the DREAL. They fall under the “punchy” actions to fight against invasive alien species of the Ministry of Ecological Transition.