In recent days, thousands of dead fish have been found along the banks of the Oder River, which crosses the Czech Republic, Poland and Germany and flows into the Baltic Sea, marking the border between Germany and Poland for most of its final stretch. (where it is called Odra). The fish were first found on the Polish shores, apparently without the country’s authorities paying much attention, and then also on the German shores. The death has been defined an “ecological catastrophe” by the authorities of both countries, but for now its causes are not clear: both Poland and Germany are investigating to try to understand whether it can be attributed to the spillage of substances into the water. toxic or for other reasons.
The first dead fish were found about two weeks ago near the Polish city of Olawa, south of Wroclaw in the west-central part of the country. Now many others have been found near Frankfurt on the Oder, some sixty kilometers east of Berlin, about 300 kilometers northwest of where they were first seen. In recent days, volunteers, fishermen and members of the Polish army have removed more than 10 tons of dead fish.
One of the hypotheses is that the fish may have died due to contamination by methylene, a toxic substance, as suggested by some surveys carried out at the end of July by the environmental protection agency of Wroclaw; however, the substance was not found in the surveys after 1 August. At the same time, some subsequent surveys carried out by the German authorities have highlighted higher than normal levels of mercury, a heavy metal that in high quantities is also highly harmful to humans. At the moment, however, there is no certain explanation.
According to Christian Wolter, researcher in the department of marine biology, fisheries and aquaculture at the Institute of Ecology and Fisheries in Leibniz, the fish living in the Oder have long been affected by the low amount of oxygen caused by the higher than average temperatures and lowering. of water, due to prolonged periods of drought caused by climate change. Wolter said the situation may have been exacerbated both by dredging activities to try to increase the depth of the river bed, and by the discharge of sewage into the river at such low water levels.
Przemyslaw Daca, director of the Polish body that deals with the management of national waters, argues that the exceptionally low levels of water may have contributed to aggravate the consequences of any contamination.
Słowa mi się skończyły .. pic.twitter.com/NMHO5yV1NW
– Mischa Von Jadczak (@michaljadczak) August 12, 2022
Various German city administrations along the Oder have urged residents to avoid swimming in the river and advised not to eat fish caught from its waters until the causes of the death are known, which according to the Polish Prime Minister Mateusz Morawiecki is likely linked to the illegal dumping of harmful substances.
In the meantime, various associations of environmentalists and residents have accused the Polish government of not having managed the emergency quickly enough despite the reports. Malgorzata Tracz, deputy of the Greens in Poland, told a Reuters that thousands of floating dead fish had been seen in the Oder a few weeks ago, but no one had warned people not to bathe in the river or approach the waters. Tracz also added that 8 tons of dead fish were recovered in the Olawa area alone and that fishing communities are now “terrified” by what he called an “ecological disaster”.
The German Environment Ministry said it was only warned by the Polish authorities on Thursday, weeks after the first dead fish were found; Minister Steffi Lemke has called for an investigation to be opened.
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