News

Together with Dr Jörn Gessner from IGB and the Director of the Lower Oder Valley National Park, Dirk Treichel, Federal Environment Minister Steffi Lemke today released 600 sturgeons into the Oder River near Criewen. The new home of the young fish is a special habitat, as the Oder is the last major river in Germany where sturgeon and other animals can migrate unhindered over long distances. Since 2006, it has been a priority area for the reintroduction of the Baltic sturgeon.

In July and August 2022, a man-made environmental disaster occurred in the in the Oder River: a mass die-off of fish, mussels and snails that started in the Polish section of the Oder and then continued downstream until it reached the border Oder. The immediate cause of their death was a toxin-producing (planktonic) brackish water alga, scientifically known as Prymnesium parvum, which was able to grow en masse due to high salinity, high solar radiation, and low water flow. An IGB Fact Sheet summarises the current state of scientific knowledge.

Today, Federal Environment Minister Steffi Lemke visited the Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB) in Berlin to learn about the first interim results of the special investigation programme on the environmental disaster in the Oder River (“ODER~SO”), which has been funded by the Federal Ministry for the Environment, Nature Conservation, Nuclear Safety and Consumer Protection (BMUV) since February 2023. Fish stocks in the Oder River have declined by 53 to 67 per cent as a result of last summer’s environmental disaster, especially midstream.

Routine fishing on 29 November this year was the first large inventory conducted in the middle of the Oder since the man-made environmental disaster that occurred in summer. The result: much fewer fish were caught in total, and species such as the blue bream and the asp, which are important to this ecosystem, were lacking completely. Moreover, water analysis conducted by the researchers shows that the salt concentration is still far too high. There could be a repeat of the disaster when temperatures increase, endangering remaining stocks.

IGB researchers have carried out sample fishing in the River Oder to get a better overview of the remaining fish population after the man-made environmental disaster. The results are very sobering.

The man-made environmental disaster, resulting in masses of dead fish, mussels and snails, has caused severe damage to the Oder ecosystem. What can now be done to help the river – and how can the risk of such major ecological and economic damage be reduced in the future? IGB has published its recommendations in an IGB Policy Brief. 

In the Oder River, a massive algal bloom can be detected with satellite data. In close coordination with the IGB, satellite data from the European Copernicus satellite Sentinel 2 were processed.

The Oder is the last major river in Germany where fish and other animals can still migrate freely over long stretches. Since 2006, it has been the focus area for the reintroduction of the Baltic sturgeon. What is the fate of the sturgeon now?