What killed tons of fish in the European river? Mystery deepened

Warsaw, Poland — Laboratory tests following a mass die-off of fish in the River Oder have discovered high salinity, but no mercury poisoning the water, Poland’s environment minister said on Saturday, as the mystery persisted over what tons of fish were in Central Africa. Europe killed.

Anna Moskwa, the climate and environment minister, said analyzes of river samples taken in both Poland and Germany revealed elevated salt levels. Extensive toxicology studies are still underway in Poland, she said.

She said the Polish veterinary authority has tested seven species of dead fish and ruled out mercury as the cause of the die-off, but is still waiting for results from other substances. She said test results from Germany had also not shown high levels of mercury.

The Oder River runs from the Czech Republic to the border between Poland and Germany and empties into the Baltic Sea. Some German media had suggested that the river may have been poisoned with mercury.

Polish Prime Minister Mateusz Morawiecki said on Friday that “huge amounts of chemical waste” were likely deliberately dumped into his country’s second-longest river, causing environmental damage so severe that it would take years to restore the waterway.

On Saturday, Morawiecki pledged to do everything possible to limit environmental destruction. Poland’s interior minister said a reward of 1 million zloty ($220,000) will be paid to anyone who helps track down those responsible for polluting the river.

Authorities in the northeastern German state of Mecklenburg-Western Pomerania warned people not to fish or use water from the Szczecin lagoon, as the contaminated water from the river was expected to reach the estuary area on Saturday evening.

“The magnitude of the fish kill is shocking. This is a blow to the Oder as a waterway of great ecological value, from which it is unlikely to recover for long,” said Alex Vogel, the environment minister of the German state of Brandenburg, along which the river runs.

The head of Polish Waters, Poland’s national water management authority, said on Thursday that 10 tons of dead fish had been removed from the river. Hundreds of volunteers were on the German side collecting dead fish.

German labs said they discovered “atypical” levels of “salts” that could be associated with the dieback, but which they would not fully explain on their own.

Morawiecki acknowledged that some Polish officials reacted “slowly” after huge numbers of dead fish were seen floating and washing up, and said two of them had been fired.

“For me, however, the most important thing is to tackle this ecological disaster as quickly as possible, because nature is our common heritage,” Morawiecki said.

His comments were echoed by Schwedt mayor Annekathrin Hoppe, whose German town is adjacent to the Lower Oder Valley National Park. She called the pollution of the river “an environmental disaster of unprecedented magnitude” for the region.

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