During the cleaning by the Voies Navigables de France (VNF) of the reach of the Canal du Midi, at the level of Les Minimes, on Wednesday January 25, nearly a ton of fish was degraded by the teams of the Fishing Federation 31. Its director , Gaël Durbe, talks about this rescue operation. Interview.

How did the teams from the Fishing Federation 31 transfer fish from the reach of the Canal du Midi?

It is an operation that we generally do in November, but there has been a change in the VNF schedule. These fish were saved following targeted flushing around the lock areas. The fish tend to descend when the valves are opened, so we do not have all the fish trapped. As soon as there is work on structures on watercourses and there are risks of trapping, legally, the client must compel himself to request electric fishing to avoid fish mortality. .

How are they fished?

It is an electric fishing which makes it possible to paralyze the fish. They are paralyzed for a short time and are transported in special tanks, with oxygen to keep them alive, and are returned to the reaches upstream and downstream of the sector. In this case, it was the reach of Béarnais.

How many fish have been saved?

For two days, we caught about a ton of fish. They were divided between Port Saint-Sauveur and the Ponts-Jumeaux.

It was several species of fish, including catfish?

There are catfish which, oddly, are restricted to the downstream part of the Canal du Midi. Naturally, they do not develop on the upper Garonne part of the Canal du Midi, rather on the side channel. There was a large quantity of white fish, cyprinids: bream, roach, bleak mostly. But also big carp, catfish, pike and less widespread species such as ruffe, some eels and black bass, a species that came from America delivered a hundred years ago.

Have you noticed an evolution of species in the Canal du Midi?

So far, it’s not moving. The thermal acceptance ranges for these fish are between 5°C and 30°C. Fish will not necessarily pass through the locks during navigation, some are more present than others.

Is the catfish a predator for other species?

Apparently not that much. On the bodies of water, which have functional breeding areas, there is no particular dominance of catfish. This is what we observe in large dams, the catfish tends to cohabit with other species.