https://www.dw.com/en/mysterious-mass-fish-kill-in-oder-river-climate-change-or-poison/a-62784099 * * Visit the new DW website Take a look at the beta version of dw.com. We're not done yet! Your opinion can help us make it better. Go to the new dw.com We use cookies to improve our service for you. You can find more information in our data protection declaration. More info OK 1. Inhalt 2. Navigation 3. Weitere Inhalte 4. Metanavigation 5. Suche 6. Choose from 30 Languages * Albanian Shqip * Amharic 'amaarenyaa * Arabic l`rby@ * Bengali baaNlaa * Bosnian B/H/S * Bulgarian B'lgarski * Chinese (Simplified) Jian * Chinese (Traditional) Fan * Croatian Hrvatski * Dari dry * English English * French Francais * German Deutsch * Greek Ellenika * Hausa Hausa * Hindi hindii * Indonesian Indonesia * Kiswahili Kiswahili * Macedonian Makedonski * Pashto pStw * Persian frsy * Polish Polski * Portuguese Portugues para Africa * Portuguese Portugues do Brasil * Romanian Romana * Russian Russkii * Serbian Srpski/Srpski * Spanish Espanol * Turkish Turkce * Ukrainian Ukrayins'ka * Urdu rdw Wrong language? Change it here DW.COM has chosen English as your language setting. DW.COM in 30 languages DW AKADEMIE ABOUT DW DW.COM Deutsche Welle Deutsche Welle [ ] * TOP STORIES + Coronavirus + World o Africa # The 77 Percent # Crime Fighters # Africa on the Move o Asia o Europe o Americas o Middle East + Germany o Berlin Wall + Business o Founders Valley + Science + Environment o Global Ideas o Living Planet + Culture o Film o Books o Music o Arts o Digital Culture o Lifestyle o Travel o BTHVN2020 + Sports SPECIAL + 100 Must-Reads + 50 kitchens, one city + Baking Bread + DW Freedom + Expedition Humboldt + Meet the Germans + Planet Berlin * Media Center + Live TV + All media content + Latest Programs + Podcasts * TV + Schedule and Reception + TV Programs TV programs + Afrimaxx + Arts.21 + Art.See.Asia + Business + Check-in + Close up + Conflict Zone + Covid-19 Special + DocFilm + DW News + Eco Africa + Eco India + Euromaxx + Faith Matters + Focus on Europe + Global 3000 + Her + In Good Shape + Kick off! + Made in Germany + Reporter + REV + Shift + Sports Life + The Day + The 77 Percent + Tomorrow Today + To the Point + World Stories * RADIO * LEARN GERMAN German Courses + German Courses + Quick start + Harry + Deutsch Interaktiv + Radio D + Mission Europe + Deutsch - warum nicht? + Audiotrainer + Deutschtrainer + Die Bienenretter German XXL + German XXL + Deutsch Aktuell + Deutsch im Fokus + Telenovela + Bandtagebuch + Landeskunde Community D + Community D + Das Portrat + Podcasts & Newsletter + Service Teaching German + Teaching German + DW im Unterricht + Unterrichtsreihen + Deutschlehrer-Info * Coronavirus * World * Germany * Business * Science * Environment * Culture * Sports TOP STORIES / Environment Advertisement Environment Mysterious mass fish kill in Oder River: Climate change or poison? After Polish anglers removed tons of dead fish from the Oder River bordering Germany, the die-off has been labeled an "ecological disaster." But what's to blame? Chemical pollution suspected in Oder River fish deaths Thousands more dead fish have been discovered in the Oder River that borders Germany and Poland, this time in the vicinity of the eastern city of Frankfurt (Oder). Local authorities have warned residents, along with their pets and livestock, not to touch the river water. The exact cause of the mass fish kill, also reported upstream around two weeks ago, remains unclear. At the end of July, Polish anglers reported removing tons of dead fish from the Oder near the town of Olawa, about 300 kilometers (186 miles) upstream from the current fish die-off. At the time, the Lower Silesia Water Authority based in the nearby Polish city of Wroclaw detected a toxic substance in two locations on the Oder that is likely the solvent mesitylene, which is known to have a toxic effect on fish. However, subsequent tests have shown no trace of the substance. Meanwhile, water samples taken by authorities on the German side of the river in the state of Brandenburg have indicated significant levels of mercury pollution, reported public broadcaster RBB on Friday. As yet, no official explanation for the higher mercury levels has been given. Christian Wolter, researcher at the department of fish biology, fisheries and aquaculture at the Leibniz Institute of Freshwater Ecology and Inland Fisheries, said that ongoing dredging to deepen the river channel might have released embedded mercury. "The only source of mercury in the Oder River is the bottom sediment which is known to be enriched in mercury from past pollution," he told DW. But he also believes the problems on the Oder run deeper. a map showing the course of the Oder river The River Oder runs though the Czech Republic, Poland and Germany Heat and drought could be factors Fish in the river are struggling, Wolter said, due to lower oxygen levels caused by historically low water levels (a trend since 2018) and high water temperatures of around 25 degrees Celsius (77 Fahrenheit). "When fish are stressed, respiration goes up," he said, meaning aquatic life needs more oxygen. This situation has been exacerbated by ongoing discharges of wastewater into the Oder. "This is legal and usually wouldn't matter," Wolter explained. "But with low water levels you get a higher concentration of [oxygen consuming] salt and organic material." Added to the mix is work on the Polish side of the Oder building groins -- a rigid structure created with rock, soil and gravel to prevent erosion. This has increased sediment, which also reduces oxygen levels in already shallow water, Wolter said. This contradicts reports from water authorities that higher oxygen levels have been detected in the river, which could be linked to the concentration of mesitylene. Yet there are no measurable high toxic levels to back this claim, according to Wolter, adding that water oxygen levels always vary throughout the day. The fisheries researcher believes it is less likely that mesitylene contamination killed the fish found this week downstream from Olawa since it already would have dissipated. "If it was released by an accident at the end of July, it should have passed Frankfurt much earlier," he said of the toxic solvent. Meanwhile, local anglers told Wolter that fish die-offs were observed further upstream from Olawa as early as March. This suggests a deeper and more widespread problem than a single contamination event in late July. Wolter also noted that floodplains in the area have been overly drained in recent decades, causing much drier and stressed river systems. Polish Greens decry lack of action Lawmaker Malgorzata Tracz from the Polish Green Party told DW that despite alerting authorities about the ecological catastrophe on the Oder, Polish government institutions did not even warn residents that they should not touch the river water. She said that around 8 tons of fish were found near Olawa alone. "The problem is huge," she said. "It is not something that can be ignored or that will be overcome on its own." The local fishing community "are terrified by the situation," she noted, saying that anglers have been most vocal on the issue in Poland due to the lack of support from public institutions. Tracz has written emails to local and federal water and environmental agencies and ministries asking them to investigate the source of the contamination, and to "punish the people that did it." So far, she has received no response, despite what she described as "an environmental disaster." Tracz said that "there are many theories" about the cause of the fish kill and is urging an in-depth investigation. dead fish lie in shallow water Polish anglers who rely on the Oder 'are terrified by the situation' German campaigners demand water protection German environment groups are blaming insufficient water conservation measures for the die-off, as well as a lack of cross-border cooperation on the frontier river that crosses the Czech Republic, Poland and Germany. "This ecological catastrophe would not have been of such magnitude if the German and Polish authorities had worked together more intensively," said Antje von Broock, managing director of the German Association for the Environment and Nature Conservation (BUND), adding that targeted warnings should have been put in place. "Dead fish have been floating on the Oder since the end of July, now over a distance of several hundred kilometers," she said in a statement. A "diverse and healthy ecosystem" could better resist toxic substances in the river, if they were responsible for the die-off, von Broock added. "The fish kill is therefore also a symptom of decades of poor planning in water management and chronic underfunding of water protection." Both BUND and Malgorzata Tracz said the International Commission for the Protection of the Oder, a joint agreement between Poland, the Czech Republic and Germany to protect one of Europe's more pristine waterways, needed to be upheld. * A droplet disturbs the surface of water How climate change is impacting the world's rivers Life-giving water The vast majority of the Earth's water is found in the ocean. But only a fragment of the planet's water - roughly 0.01% - flows through its rivers. And without these rivers, many other sources of surface water, like lakes and wetlands, would run dry. This is becoming a problem with climate change, and it's posing a threat to humans and animals alike in varied and, sometimes, unexpected ways. * Satellite images of Lake Chad from 1963, 1973, 1987 and 1997 How climate change is impacting the world's rivers Climate change felt for decades The dramatic effects of climate change aren't a recent phenomenon. Lake Chad, shown here in 1963, 1973, 1987 and 1997, has shrunk from roughly 25,000 km2 to under 2,000 km2 over the past 60 years. Long blamed on dams and irrigation, researchers have found that its water loss also comes from fluctuating temperatures which have negatively impacted its second most important river, the Komadugu Yobe. * A pile of salmon stare into the camera How climate change is impacting the world's rivers Biodiversity and food loss Lake Chad is a stark example of how climate change is forcing people to search for new sources of water and food. The region has seen a rise in tensions as farmers and cattle herders move towards richer land. But other continents just now feeling the pressure of climate change are starting to see their fish stocks unsuited to warmer waters - and their waters evaporating in the heat. * German heat wave in 2018 exposed sandbanks, rocks and vegetation in the Rhine How climate change is impacting the world's rivers Europe feeling the heat Europe is one of these places. In the summer of 2018, the mighty Rhine River went from a powerful current to a gentle stream when temperatures soared past 30C (86F) and drought left the otherwise lush, rainy habitat too low to accommodate more than one lane of shipping. * Sheep search for grass to nibble on now dry land below India's Himalayan Mountains. How climate change is impacting the world's rivers Glaciers melting away Other regions of the world are also coming to terms with what they once considered reliable water sources, like glaciers. Known as the world's water towers for their ability to reliably store large amounts of snow and ice, glaciers supply nearly 2 billion people with water. Experts fear the Himalayas, seen here, will lose a third of their volume by the end of the century. * Cultivated land in India's Indus River valley How climate change is impacting the world's rivers South Asia depends on Himalayas Farmers in the Indus River Basin, pictured above, are dependent on glacier melt from the Himalayas for crops like rice and cotton. They're part of a larger river basin in South Asia, which includes the Ganges and Brahmaptura Rivers. In total, these three waterways sustain roughly 129 million farmers and a total of 900 million residents with water. * A satellite image shows a mushroom shaped chunk of land on fire in Australia How climate change is impacting the world's rivers Bush fires also bad for rivers Unprecedented wildfires across the globe, as seen here in Australia, have been yet another side effect of climate change. The aftermath of the fires could prove toxic for Australia's most important watershed, the Murray-Darling water basin. Ash washed into the rivers that feed into the basin threaten to turn the water toxic for the 2.6 million Australians, not to mention many native species. * A satellite image of the coast of New York where algal bloom has turned the water bright green How climate change is impacting the world's rivers Algal bloom and the dead zone It's not just ash and sediment from wildfires that can choke up the water. Heavier rainfall associated with extreme weather in the US, has been sweeping more runoff pollution from farms, for example, into the rivers, which then carry it to the open sea. Algal blooms like this one off of the coast of New York is one result. Another result is a dead zone, or an area deprived of oxygen by pollution. * Satellite picture of Hurricane Laura 2020 How climate change is impacting the world's rivers More rain isn't always good news In fact, nitrogen pollution has also become a big problem for the Mississippi River, which runs through many US states. Besides a higher volume of nitrogen being washed into the water through flooding, increasingly powerful hurricanes connected to climate change are hurting the river's wetlands, which protect it from storm surges. Author: Kathleen Schuster Edited by: Jennifer Collins DW recommends Once Upon a River - Cambodia's Mekong Crisis New hydropower dams on the Mekong River are leaving fishing and farming communities high and dry. The dams provide clean electricity, but they also cause massive damage to Cambodia's plant and animal worlds. Once Upon a River - Bangladesh's polluted delta Bangladesh is struggling just to stay afloat. Literally: By 2050, it's estimated that climate issues will displace one in seven of the country's inhabitants. Just how dangerous is mercury, anyway? With talks underway in Geneva on plans to ban the use of the poisonous substance mercury, you might be surprised to read that it's technically safe to drink - although you shouldn't try it at home. Audios and videos on the topic Chemical pollution suspected in Oder River fish deaths Undoing damage a dam caused to fish * Date 12.08.2022 * Author Stuart Braun * Homepage DW News - * Related Subjects Fish * Keywords fish, Oder river, fish die-off, Frankfurt (Oder), water levels, waterways * Feedback: Send us your feedback. * Print Print this page * Permalink https://p.dw.com/p/4FR0l Related content An investigation is now underway to determine the cause of the ecological disaster. Masses of fish die in river at German-Polish border 12.08.2022 Thousands of dead fish have washed up along the banks of the Oder river bordering Germany and Poland in recent weeks. High levels of mercury have been detected in water samples taken from the river. An investigation is now underway to determine the cause of the ecological disaster. 10.08.2022, Blick vom ausgetrockneten Rheinufer auf Mainz. Durch geringen Niederschlag und anhaltend hohe Temperaturen ist der Wasserstand im Rhein stark gesunken. Germany: Rhine water levels expected to drop even further 11.08.2022 Already critically low water levels in Germany's most important waterway could drop even lower next week. Shipping costs have climbed as much as five times as barges are forced to carry fewer goods. Sandbanke an der Niedrigwasser fuhrenden Donau. +++ dpa-Bildfunk +++ Rivers across Europe are too dry, too low and too warm 10.08.2022 Extended heat and low rainfall across Europe are causing major rivers to dry up. This is having serious consequences for wildlife, the economy and the people living near the Rhine, Po, Thames and other affected rivers. * Date 12.08.2022 * Author Stuart Braun * Homepage DW News - * All videos DW News * All videos in Media Center * Related Subjects Fish * Keywords fish, Oder river, fish die-off, Frankfurt (Oder), water levels, waterways * Send us your feedback. * Print Print this page * Permalink https://p.dw.com/p/4FR0l * TOP STORIES * Coronavirus * World * Germany * Business * Science * Environment * Culture * Sports * * A - Z Index * MEDIA CENTER * Live TV * All media content * Latest Programs * Podcasts * TV * Schedule and Reception * TV Programs * * RADIO * LEARN GERMAN * German Courses * German XXL * Community D * Teaching German * ABOUT DW * Who we are * Press * GMF * Business & Sales * Advertising * Travel * SERVICE * Reception * Apps & Co. * Newsletters & Co. * FAQ * Contact * * DW AKADEMIE * About us * Media Development * Master's Degree * Traineeship * Training (c) 2022 Deutsche Welle | Privacy Policy | Accessibility Statement | Legal notice | Contact | Mobile version