Polish firefighters have recovered 100 tonnes of dead fish from the Oder river running through Germany and Poland, deepening concerns of an environmental disaster for which no cause has yet been identified.
“We’d never had an operation of this scope on a river before,” said Monika Nowakowska-Drynda from the national firefighter press office on Tuesday.
She confirmed that around 100 tonnes (220,500lb) of dead fish had been recovered since Friday. More than 500 firefighters have been recovering the dead fish in Poland with the help of dams, boats, quad bikes and even a drone.
German municipalities banned bathing and fishing in the Oder after thousands of dead fish were found floating in the 520 mile (840km) river, which runs from the Czech Republic to the Baltic Sea along the border between Germany and Poland.
Conservationists expressed fears that the mass die-off could wreak havoc on the entire ecosystem of the Oder. “We have to see how the bird population develops and what will happen to the racoons and otters,” Karina Dörk, a district administrator of Germany’s Uckermark region, told the Tagesspiegel newspaper. “It is a catastrophe that will stay with us for years.”
The cause of death remains uncertain, and Poland has offered a reward of 1m złoty or €210,000 (£180,000) for anyone who can “help find those responsible for this environmental disaster”. “Probably enormous quantities of chemical waste was dumped into the river in full knowledge of the risk and consequences,” Polish prime minister Mateusz Morawiecki said last week.
But climate and environment minister Anna Moskwa said on Tuesday that “none of the samples tested so far has shown the presence of toxic substances”. Polish scientists said laboratory tests found only elevated salt levels.
She said the government was also looking into possible natural causes and in particular higher concentrations of pollutants and salinity as a result of lower water levels and high temperatures.
A third hypothesis being examined is that industrial waste water with a high chlorine content was poured into the river, she said.
Water samples have been sent to laboratories in the Czech Republic, the Netherlands and Britain in the hopes of finding the cause.
The first reports of mass fish deaths were made by Polish locals and anglers as early as 28 July. In Poland, the government has also come under heavy criticism for failing to take swift action. On Friday, Morawiecki fired the CEO of Polish Waters, the state-owned company in charge of water management, and the head of the environmental protection inspectorate in response to their handling of the Oder pollution.
German officials have accused Polish authorities of failing to inform them about the deaths, and were taken by surprise when the wave of lifeless fish came floating into view.
The Oder has in recent years been known as a relatively clean river, and 40 domestic species of fish are found in the waterway.
But now, dead fish – some reaching up to 40 centimetres (16in) – can be seen across the river.
With Agence France-Presse