Climate change: mountain rivers are getting warmer – vorarlberg.ORF.at

Previously, it was assumed that the warming of mountain rivers was quenched by snow or ice. However, air temperatures in mountain regions are rising faster than the global average, so warming effects can also be expected on cold river ecosystems.

The Tyrolean mountain rivers Inn and Großache were examined in the study. Both have gotten much warmer in recent decades, especially in the winter months. With Großache it was about half a degree every ten years. It may not seem like much, but it’s a lot for the ecosystem.

The water temperature determines the age of the river

Since water temperature is one of the critical factors for life in the water, this evolution has far-reaching consequences for the river’s habitat. Brown trout in particular are experiencing difficulty as temperatures rise, says ecologist Georg Niedrist, who conducted the study. They can no longer reproduce well, and parasites that are dangerous to them can spread more easily thanks to the warmth.

Warming is accelerating faster in Vorarlberg

Since the water in Vorarlberg is somewhat lower, warming is likely to be faster here, says Nederst.