The brown trout Salmo trutta is highly heat-sensitive. Credit: Ulrich Wasem
Researchers from the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL) have proposed a warning tool that predicts, up to three weeks in advance, when river fish in Switzerland will be at risk from heat. As heat waves become more frequent with climate change, this early warning system gives people time to act and protect fish populations from future heat waves.
Preparing for weather extremes
When do rivers become too hot for river fish in Switzerland? To predict when river fish are at risk from heat waves, ecologists and climatologists at the Swiss Federal Institute for Forest, Snow and Landscape Research WSL joined forces with experts from across Switzerland to develop a forecasting tool. The forecasts are updated twice a week and are publicly available on drought.ch. The study is published in the journal Ecological Modelling.
With heat waves becoming more frequent and severe due to climate change, fish are particularly at risk, as their body temperature depends entirely on their environment. Unable to cool themselves, fish are ectothermic, more commonly referred to as "cold-blooded" animals. "When the water temperature rises, chemical reactions in the fish's cells change—and that's what we call heat stress," said Camille Albouy, senior researcher at the joint WSL and ETH research group Ecosystems and Landscape Evolution.
