The fish kill in the Oder is an ecological catastrophe. A rare species of fish apparently did not survive.
Reitwein – Fish died en masse in the Oder in the summer. The extent of the consequences of the man-made environmental catastrophe is initially unclear. The entire ecosystem on the Oder – mussels, molluscs (mollusks), algae and bacteria – are affected. A rare species of fish – the so-called Baltic goldfish apparently did not survive. A research group from the Leibniz Institute for Freshwater Ecology and Inland Fisheries (IGB) is investigating whether the Oder is recovering. The search for the Baltic Goldsteinbeißer (Sabanejewia baltica) was initially unsuccessful, reports the dpa news agency.
Fish deaths in the Oder: Rare species of fish apparently eradicated
The Baltic Goldwolf is about 12 centimeters long. The fish species actually lives in Eastern Europe and Asia. In the Oder, a population of around 500 animals was last observed in 2021. It was considered the westernmost occurrence. So far, however, the researchers have not found a single specimen. It differs from the common loach by its shiny golden scales on its flanks. But in the German-Polish border river, the fish species probably did not survive the summer of 2022.
Oder fish die-off: environmental disaster in summer 2022 “man-made”
The salinity in the Oder rose sharply in August. It is still unclear where the high concentration of common salt came from. “It’s a man-made problem,” states the IGB in its most recent report on the Oder disaster. The salt is blamed for a massive and unusual growth of toxic algae. An algae toxin was detected in the water samples from the Oder. It is the poison of a species of algae ( Prymnesium parvum) that only occurs in brackish water and in water with an increased salt content. Under natural conditions in the Oder, a so-called algal bloom would not have been possible.
The consequences are fatal: the algae toxin (Prymnesium toxins) attacks and decomposes the mucous membranes and fine blood vessels of those who breathe gills, such as fish, molluscs, mussels and amphibians.
In the summer of 2022, a massive fish kill will begin in the Oder. In Brandenburg, the State Office for the Environment (LfU) said it received the first indications of environmental pollution on August 9, 2022. A skipper had reported on the fish kill and therefore contacted the Berlin-Brandenburg State Laboratory (LLBB). Tons of dead fish are recovered from the Oder over the next few days.
Will the Oder recover? So far there has been no all-clear for the ecosystem: the salinity is almost as high as in August. This is reported by Deutschlandfunk, citing a research group from the Leibniz Institute for Freshwater Ecology and Inland Fisheries on Tuesday (October 25, 2022).
In September, 19 healthy fish species were detected during sampling in a section of the Oder in Brieskow-Finkenheerd near Frankfurt (Oder). That’s what the scientist at the Institute for Inland Fisheries in Potsdam-Sacrow (IfB) said, as reported by the dpa news agency. The more than 1,800 fish caught included everything from juvenile fish to perennial fish. With such samples, however, only a fraction of the fish that are actually in the Oder would be recorded. The institute in Potsdam conducts research, among other things, on fish ecology in inland waters.
During the first sampling on August 19, according to the state fishing association, 14 species were discovered among 550 healthy fish, including perch, small zander, pike and wolffish. (ml with dpa material)