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VERBUND’s LIFE projects

For 25 years, VERBUND has been reshaping the landscape along Austria’s major waterways. The motto is: ‘Big is beautiful.’ Modern electronics help to optimise planning and analyse the success of new fish migration aids.

Life is Life in the former quarry: where, just five years ago, heavy machinery completely transformed the rivers Krems, Kamp and the Danube oxbow lake near Altenwörth over a stretch of more than twelve kilometres, today there is an impressive natural paradise that is unrivalled in its form. It is one of the more recent EU-funded LIFE projects through which Austria’s largest electricity generator, VERBUND, is making its hydroelectric power stations passable for fish. Whilst the term ‘fish migration aid’ may officially be the correct one in Altenwörth, the life unfolding here is far more multifaceted – as colourful as one would never find on a ‘normal’ Danube bank. It is a river landscape of meanders, gravel banks and islands, set against a backdrop of willow thickets and reed beds. A refuge which, incidentally, may also be used by people.

Yet one would never guess from the idyllic scene that it is confined to a narrow strip which follows first the power station’s backwater and then the former Danube oxbow lake all the way to the power station’s outlet, overcoming a 16-metre difference in height in the process. Consequently, the waters brought together here by the Krems, Kamp and Danube flow at a brisk pace. At a bend in the river, the air is full of sand martins, flying in and out of their nesting sites in a clayey, steep riverbank face several hundred metres long. In many places along the banks, grey herons wade through the water. Reeds, willows and flowering meadows at the edge of the floodplain forest give no hint that, only very recently, 580,000 cubic metres of gravel and sediment were dredged away with the utmost precision and re-deposited according to exact GPS coordinates and a precise plan.

Ecology in the Age of Digitalisation

High-tech solutions have long been part of the equation when it comes to implementing river restoration projects not just haphazardly, but effectively. Fish and chips are making the world a better place – not in a culinary sense, but in an ecological one. Huchen, grayling, tench, trout and nase fitted with microchips allow us to understand far better than before what fish need to navigate their routes and survive in heavily used and regulated rivers.

Here’s how it works: at a narrow point in the bypass channel, a fish trap collects the fish swimming past. Every day, ecologists go out and check each individual fish by hand. Each fish has its own PIT implanted in its belly with a small prick. These microchips, known as ‘Passive Integrated Transponders’, are just about the size of a short piece of pencil lead. The procedure takes just a few seconds. From that moment on, the fish is a registered individual with data on the date of chipping, species, size and weight. From now on, the swimmer is also a passive transmitter that triggers a signal at an antenna monitoring station. Tens of thousands of fish have already become darting ‘messengers’ in the Inn and the Danube in this way. One key scientific finding is already clear: effective fish migration aids – meaning, above all, those that are sufficiently large – serve as long-term habitats for many species, and the Danube often acts as the ‘motorway’ connecting them.

You can find the full text in our INSPIRE magazine.

LIFE projects at VERBUND

WeNatureEnns

Restoration of 20 km of near-natural riverbanks along the Enns

Blue Belt Danube Inn

Habitat connectivity and fish passage at the Schärding, Passau, Jochenstein, Aschach and Ybbs-Persenbeug power stations

Riverscape Lower Inn

Development of river landscapes along the Lower Inn and fish migration aids at the Braunau and Egglfing power stations

Network Danube Plus

Fish-friendly measures between the Greifenstein and Altenwörth Danube power stations

Donau Netzwerk

Bypass channels at the Ottensheim, Abwinden-Asten and Greifenstein Danube power stations

Traisen

Recreation of the lower reaches and the mouth of the Traisen where it flows into the Danube