As Switzerland comes to grips with the hottest summer since 1864, fish are struggling to survive. Water temperatures above 20 degrees Celsius already represent “a stress factor for most fish species.” In some rivers and lakes the water temperature has surpassed 23 Celsius, in extreme cases it is above 25.
For grayling, trout and whitefish in Lake Constance and the Rhine river, the current temperatures pose an existential threat.
“In most of the cantons in the Central Swiss Plateau it has already been necessary to rescue fish,” by relocating them to cooler waters, reads a statement by the Swiss Fisheries Federation.
The unusually hot and dry summer is haunting Switzerland's environmental authorities as the specter of 2003, when water temperatures in the Rhine river reached 27 degrees Celsius and thousands of fish died, haunts the country once again.
“We are extremely worried,” says Philipp Sicher, head of the Swiss Fishing Federation (FSP), in a recent statement by the organization. “Indicators show that tragedy is near,” added Sicher.
With not nearly enough rainfall in sight in the near future, the FSP calls on residents living near water courses to play their part to safeguard several species of fish. The following guidelines have been issued: