A chronicle of an environmental disaster on the River Oder: Images of huge quantities of dead fish – covering all species and sizes – shocked the German, Polish and international public in August 2022. IGB researchers set about tracking down the causes. IGB was the first institution to determine that the disaster was definitely man-made.
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.
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.
“Those calling for more dams in response to drought and dry riverbeds have nothing understood – they promote habitats with potential for catastrophy,” wrote Christian Wolter in Terra X – Die Wissens-Kolumne.
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?
Naturalne przyczyny tej zaistniałej katastrofy są mało prawdopodobne. Ostatnie badania wzmocniły podejrzenie, że w Odrze masowo rozwinęły się toksyczne glony słonawowodne.
Neueste Untersuchungen erhärten den Verdacht, dass die Massenentwicklung einer giftigen Brackwasser-Alge in der Oder stattgefunden hat. Von einem natürlichen Phänomen gehen die Forschenden nach wie vor nicht aus, denn die Algenart Prymnesium parvum kommt auf den betroffenen Oder-Abschnitten unter natürlichen Bedingungen nicht massenhaft vor.
Katastrofa ekologiczna na Odrze wywołuje również wielkie poruszenie wśród naukowców z Instytutu Ekologii Słodkowodnej i Rybactwa Śródlądowego Leibniza (IGB) w Berlinie. IGB od dziesięcioleci prowadzi badania Odry, skupiając się nad ekologią rzeki i zbiorowisk rybnych. Ponadto instytut koordynuje program reintrodukcji jesiotra bałtyckiego w Odrze. Dlatego też IGB rozpoczęło własne dochodzenie; naukowcy podążają tropem silnej toksyny, która może być wytwarzana przez gatunek glonów Prymnesium parvum. Badacze wykryli duże ilości tych glonów w próbkach wody z Odry.
