In Ornans, the fishermen defend trout against the county

On the jurassian sets, the rent, paradise of the fishermen, is dying. The bottom of the River with clear waters is now covered with seaweed. Insects and small animals disappear. Trout and shadows are rare. What happened?

In Ornans (Doubs), a popular destination for fishermen at the fly of France and elsewhere, each makes the link: fish are the collateral victims of the success of the county. The favorite cheese of the French (OpinionWay survey May 14, 2025) is a regional pride. Problem: the nitrogen contained in cows droppings, transformed into manure or slurry, nourishes algae whose proliferation reduces fish populations.

However, farming cannot be solely incriminated, since the quantity of nitrogen rejected by farmers was lower in 2022 than in the 1980s. Respecting strict specifications, breeders of the PDO sector (protected designation) use very few fertilizers and chemicals.

In reality, if the rivers of Franche-Comté no longer support agricultural discharges, it is because their natural balance has changed. On the one hand, aquatic life has been undermined by pollution resulting in particular from neighboring cities, whose ancient wastewater treatment plants are failing. On the other hand, global warming accelerates the transfer of nitrogen in rivers, thwarting farmers’ efforts in terms of spreading.

To run on limestone platforms (Karst) cracked from all sides, where the waters are almost not filtered, the rivers are proved to be fragile here. Only a mobilization of everyone can save them. And trout with them.