Eradication to fight extinction: the case of the red swamp crayfish
The red swamp crayfish (Procambarus clarkii) has been established in Belgium since 1996 and is now slowly spreading throughout the country. It has recently been detected in several sites in the LIFE RIPARIAS project areas. This emerging crayfish species is on the list of invasive alien species of Union concern. Indeed, its impact is particularly deleterious on aquatic plants, amphibians and fish as well as on aquatic environments (weakening of banks, etc.).
Thousands of red swamp crayfish were detected in 2019 in an isolated pond in the town of Grez-Doiceau. Funding from the LIFE programme made it possible to initiate a local eradication operation for this population, under the supervision of the Service Public et des Contrats de Rivière de Wallonie.
The eradication action consisted in emptying the colonized pond (after rescuing the fish) and keeping it dry for a period of two years, in agreement with the pond owner. In order to avoid the dispersal of the crayfish, a semi-buried barrier was installed all around the pond and a grid was placed on the evacuation monk. Post-management monitoring will be carried out using traps after re-filling the pond to ensure the success of the eradication project.