Fish deaths in Ostallgäu: Heat stress endangers our waters!

Fish deaths in Ostallgäu: Heat stress endangers our waters!

The temperatures are rising and the effects are noticeable: In Ostallgäu and Kaufbeuren, the consequences of climate change are knocking mercilessly on the door. Dry springs and hot summers have already pulled the plug on many bodies of water. In many places, the once bubbling streams and rivers are now only shadowy rivulets. This was recently vividly documented when images showed dead fish on the surface of the water, a worrying sign for fish stocks in the region. The Swabian Fisheries Association sounds the alarm and makes it clear: “The combination of temperature stress and lack of water” could have catastrophic consequences that pose an acute threat to the existence of many species.[Allgäuer Zeitung]

"Snow? What is that?" one could almost ask when thinking about last spring. The snow melt in the mountains largely failed to materialize this year, which had a dramatic impact on the rivers and streams: the water level is low and puts many sensitive fish species such as trout, huchen and grayling in a precarious situation. These species need cool, oxygen-rich water, and that is exactly what is now increasingly missing. Even the Mühlkoppe, a protected species, is in jeopardy as its habitat continues to dwindle.[Allgäuer Zeitung]

Diversity on the brink

But this is not the only threat to the fish fauna. In addition to climatic events, pollution from sewage systems and the deforestation of bank areas also contribute negatively to the situation. Zott, a spokesman for the fishing association, emphasizes: “A lack of shade-providing trees and tall shrubs leads to the water warming up more quickly.” And as a result, the diversity of the region's fish diet is at serious risk. There is a danger that only a few species such as catfish and carp will survive.[Allgäuer Zeitung]

As if that weren't enough, artificial retention basins come into play for flood protection. These are often not conducive to the preservation of species, as the bank areas have to be leveled after flood events in order to accelerate water drainage. For Zott it is clear: “We need renaturation of the banks, intact floodplain landscapes and deeper, cooler water areas.” This is the only way to secure the future habitat of the fish.[Allgäuer Zeitung]

Nature conservation initiatives

A promising initiative that could help in this difficult situation is the “Bach Whisperer” campaign by the Swabian Fisheries Association. This is intended not only to promote the sustainable maintenance of small streams, but also to strengthen cooperation with municipalities and residents in order to improve water structures and shading.[Allgäuer Zeitung]

It would be desirable that such initiatives also find their way into Germany. For example, the LANAT-3 project of the Wyss Academy for Nature in Switzerland shows how important it is to protect biodiversity in our waters. Even if the legal basis is in place, there are often difficulties in implementation. A lack of data, insufficient resources and conflicting goals make it difficult to overcome the challenges effectively.[Eawag]

The threat to our waters and the species that live in them continues to increase due to climate change, and it is in our hands to stop the threat. Only by acting together can we protect and preserve the diversity of nature from which we all benefit.