At least 30 tons of fish have died in French waterways since this summer's heatwave, according to recent reports. Volunteers have been conducting rescue operations, recovering fish such as carp and sandroper in areas like the Rochefort marsh in Charente-Maritime. Jean-Luc Fougeroux, a member of the association La Loutre Rochefortaise, described the number of fish deaths this year as "completely exceptional," noting that the group has conducted five rescue operations, a record for the association. A national study by research organizations including Inrae, the CNRS, and the University of Montpellier has recorded about 150 mortality events, representing more than 22,000 dead fish observed. Arnaud Sentis, a researcher at Inrae, stated that this figure is likely the "tip of the iceberg," as the system does not capture all mortalities. Pike and carp in lakes, as well as trout and grayling in rivers, are the most affected species. The study also noted a 152% increase in fish mortality during heatwaves compared to non-heatwave periods. Hamid Oumoussa, general director of the National Fishing Federation (FNPF), described the current drought as "the most intense and longest drought episode in terms of natural environments" in the federation's collective memory. He noted that volunteers are struggling with the scale of the crisis, as there are many dried-up streams and interrupted flows. The FNPF has criticized the agricultural emergency law for undermining the protection of wetlands and local water management. In contrast, some areas in the North, such as the Selle river near the Aisne border, have seen improved fish conditions due to better water quality and a constant flow. Christian Logez, president of the approved association La Truite Suplicienne et Béninoise, attributed this to the absence of rain, which avoids leaching of nutrients from agricultural soils into the waterways. The association has obtained a temporary ban on fishing in part of the Selle until the end of 2027 for a scientific study on water quality and pollution impact. Arnaud Sentis proposed solutions including maintaining water levels and flows by restoring wetlands, which act as "sponges" storing water during wet periods and releasing it during dry periods. He also recommended limiting water withdrawals from industry, hydroelectricity, and agriculture during periods of environmental stress and maintaining riparian vegetation to limit water warming. He emphasized the need for fish to have access to thermal refuges, noting there are more than 4,000 obstacles to flow in France. A parliamentary report estimated that 500 million euros per year would be needed for the ecological restoration of waterways.