“We’ve never done an operation of this scale on a river before,” Monika Nowakowska-Drida of the fire brigade’s national press office said on Tuesday. He confirmed that about 100 tons (220,500 pounds) of dead fish had been recovered since Friday. More than 500 firefighters have retrieved the dead fish in Poland using dams, boats, quad bikes and even a drone. German municipalities banned swimming and fishing in the Oder after thousands of dead fish were found floating in the 840km river, which stretches from the Czech Republic to the Baltic Sea along the border between Germany and Poland. Conservationists have expressed fears that the mass die-off could wreak havoc on the entire Oder ecosystem. “We have to see how the bird population develops and what will happen to raccoons and otters,” Karina Dörk, regional administrator of Germany’s Uckermark district, told the Tagesspiegel newspaper. “It’s a disaster that will stay with us for years.” The cause of the mass death remains a mystery, although pollution is a leading theory. Photo: Lisi Niesner/Reuters The cause of death remains uncertain and Poland has offered a reward of 1m zlotys or €210,000 (£180,000) for anyone who can “help find those responsible for this environmental disaster”. “Probably huge amounts of chemical waste were dumped into the river with full awareness of the danger and consequences,” Polish Prime Minister Mateusz Morawiecki said last week. However, Climate and Environment Minister Anna Moscow said on Tuesday that “none of the samples tested so far have shown the presence of toxic substances”. Polish scientists said laboratory tests found only elevated salt levels. He said the government was also looking at possible natural causes, particularly higher concentrations of pollutants and salinity as a result of lower water levels and higher temperatures. A third hypothesis being considered is that industrial wastewater with a high chlorine content was dumped into the river, he said. Water samples have been sent to laboratories in the Czech Republic, the Netherlands and Britain in the hope of finding the cause. The first reports of mass fish kills were made by Polish locals and fishermen as early as July 28. In Poland, the government has also been heavily criticized for failing to act quickly. On Friday, Morawiecki fired the CEO of Polish Waters, the state-owned company responsible for water management, and the head of the environmental protection inspectorate in response to the handling of the Oder pollution. German officials accused Polish authorities of failing to inform them of the deaths and were surprised when the wave of lifeless fish appeared. The Oder has been known in recent years as a relatively clean river, and 40 native fish species are found in the waterway. But now, the dead fish – some as long as 40cm (16in) – can be seen across the river. With Agence France-Presse
