To counter the predation of great cormorants, the fishing federation submerges reefs which serve as shelter for the fish.
These are boxes made of wooden planks and weighted with concrete blocks, which are submerged 2 or 3 meters deep in the bodies of water of Haute-Vienne. Their objective: to allow the fish to hide when the great cormorants attack them.
Twelve reefs of this type were laid in October in the Peyrat-le-Château pond. A similar initiative had previously been carried out in bodies of water in Saint-Paul, Saint-Yrieix-la-Perche, Ambazac (Jonas pond) and Limoges (Uzurat).
A predator
“As we have no longer been able to carry out regulation shots on great cormorants for two years in open waters, we looked for local solutions,” comments Bastien Gadaud, project manager at the Haute-Vienne fishing federation.
Already faced with pollution, the artificialization of waterways, the destruction of wetlands or global warming, the fish population would also be threatened by great cormorants, believe fishermen.
“This bird has expanded its territory and we are observing a significant increase in its numbers in New Aquitaine, which is seriously impacting various fish populations. On average, each cormorant consumes 425 grams of fish per day, with peaks reaching 661 grams,” underlines the regional association of fishing and aquatic environment protection federations of Nouvelle-Aquitaine, which campaigns for the regulation of the species. .
For laying
In Haute-Vienne, the reefs have been filled with broom, which is a spawning support for fish. “Bodies of water are often poor in habitats for fish, with few submerged trees or refuge areas,” notes Bastien Gadaud.
In any case, the initiative seems promising. At the Uzurat water body, since the submergence of four reefs, fishermen have noticed that the great cormorants often leave with an empty beak.
Guillaume Bellavoine
