The Danube is a special river – for biodiversity, humans and for both of us. It connects our home countries Germany and Slovakia plus eight other countries, more than any other river in the world. It´s the biggest river in Europe outside of Russia and 80 million live in its basin spread out in over 20 countries. It crosses several climatic zones and is the most important wildlife corridor in Europe. It is home to over 2,000 plant and 5,000 animal species including some species that depend on it like six species of sturgeon.
However, it has been also deeply altered in the last decades. Over 700 barriers like dams and weirs exist in the river basin and in most places, the Danube is pressed into a course determined by men. The former floodplains are nowadays mostly cut off from the river through dikes and used for intensive agriculture. Sidearms were cut off and drained to create even more space for agriculture.
After riding parallel to the Danube for several hundred kilometers, we got a first glimpse of its diversity of landscapes and wildlife ourselves. We arrived at the Danube a few hours upstream of Vienna in Stockerau. Before we see it for the first time, we have to cross the nature reserve “Stockerauer Au” protecting a riparian forest. As we get closer to Vienna, we embankments become more fortified, but we also come across more and more people cycling or strolling along the river.
While we spend a few days in Vienna, we join the crowds flocking to the Danube banks to relax on a hot summer day. While we can´t really spot much wildlife here, there are definitely plenty of interesting people to observe. A few days later, we are excited to leave Vienna and head towards our next goal, Donau-Auen National Park. The park starts just outside Vienna and protects the floodplains and riparian forests between Vienna and Slovak border close to Bratislava.
The Danube as our ancestors knew it
As we ride out of Vienna, we start feeling that we follow a special stretch of the Danube. Even though the cycling trail runs on top a man-made dike, we are surrounded by tall and dense riparian forests that look like they are bursting of life. We stop several times to observe wildlife or admire the beautiful wetlands and sidearms. For both us, this is a special experience. For Jonas, because he is deeply impressed by this beautiful riverine landscape that barely exists along the Main and Rhine, the two rivers that are most familiar to him. For Hanna, because she knows this area very well. She grew up only 60km downstream and she has worked at Donau-Auen National Park a few years ago.
So, when we arrive at the headquarters of the park, the staff welcomes us enthusiastically and the catch-up talk starts immediately. Hanna´s former colleagues tell her about what has happened in the national park and its projects since she left.
There are still wild islands on the Danube
For example, about DANUBEPARKS, a network of Protected Areas that brings together 19 nature conservation institutions from nine countries along the Danube. Its goal is to secure and enhance the ecological connectivity along the Danube. Since its establishment in 2014, it has successfully done this by facilitating cooperation and securing large-scale projects for its members. The most recent one is the LIFE project WILDislands, that has started in 2021 and is coordinated by Donau-Auen. There are over 900 islands along the 3000 km long Danube, almost 150 of them completely wild. Within WILDislands, DANUBEPARKS members will do a series of measures to improve the ecological conditions on these islands and thus enhance connectivity along the Danube.
The Danube is an ecological corridor of outstanding relevance for Europe, connecting more bio-geographic regions than any other European river, and hosting extremely rich biodiversity. The Danube islands represent unique sites in the river ecosystems, stand for intact river dynamics and sediment regime, and demonstrate the original beauty and natural rivers, valuable habitats with characteristic fauna and flora.DANUBEPARKS Network
Restore, not destroy
Another cooperation project of Donau-Auen National Park is “Dynamic LIFE Lines Danube”. One of the activities in it is the ecological restoration of the “Spittelauer Au”, a Danube sidearm that was cut off by several mounds. The national park, in cooperation with the waterway authority, has removed four mounds that cut off the sidearm at low water. Sophia, an intern at the park, shows us the progress of the restoration. After walking through a large riparian forest, the view opens up to a beautiful mosaic of last flowing currents, shallow waters, flooding areas, gravel banks, escarpments and thick undergrowth. Removing artificial barriers has restored the natural river dynamics here, which means that water flows at different speeds in different areas and at different times. This creates a changing environment, where soil is washed away at some places and deposited at others. Each part is an important habitat for different species, which makes it very biodiverse.
Always in motion
Standing on the shore and watching this landscape, we dive into the dynamic that make rivers so special. Everything here is always in motion. Depending on rainfall, snow melt and water use in its 800,000 km² large basin, the flow in the Danube is never the same. Neither are the habitats in and along it. Riparian forests, wet meadows and gravel banks are characterized by recurring flooding and depending on the water level and season, the present wildlife varies. Many birds breed on gravel banks that disappear just weeks later. Beavers and the dams they build might flood areas while others fall dry. And high waters might flush away a river bank and create an escarpment, where the common kingfisher finds a place to nest.
Donau-Auen National Park is working to restore these special places as much as possible on its territory and advocates for similar changes all along the Danube through its close cooperation with other protected areas. And from its start, it was clear that the local population is behind its mission. In 1984, a big hydropower plant was supposed to be build here. It would have destroyed a wetland that already protected at this time. NGOs organized a large protest and public boycott of the plans, which the politicians eventually gave in to. And only last year, active citizens won another battle for the national park. The Viennese government planned to build a large highway tunnel under the park´s territory, which led to protests and boycotts by NGOs and environmental activists once again. Eventually, the federal government announced that the project is cancelled.
So, as we follow the park downstream after our visit, we are optimistic that this special part of the Danube will only become more special. Thanks to the people supporting it and the great staff of Donau-Auen. And we are excited to see more of the Danube, as we follow it until Budapest and will meet it again at its delta.