Baltic Sea

What Killed Tons of Fish in the European River? The mystery deepens

WARSAW, Poland (AP) – Laboratory tests following mass fish die-off high salt levels in the Oder but no mercury found poisoning its waters, Poland’s environment minister said on Saturday as the mystery continued, killing tons of fish in central Europe.

Climate and Environment Minister Anna Moskwa said analyzes of river samples taken in both Poland and Germany had revealed elevated levels of salinity. Comprehensive toxicological studies are still ongoing in Poland, she said.

She said Poland’s state veterinary service tested seven species of the dead fish and ruled out mercury as the cause of the death, but is still awaiting results from other substances. She said test results from Germany also did not show high levels of mercury.

The Oder flows from the Czech Republic to the border between Poland and Germany before emptying into the Baltic Sea. Some German media had suggested the river had been poisoned with mercury.

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

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

Authorities in the north-east German state of Mecklenburg-Western Pomerania warned people not to fish or use water from the Szczecin Lagoon as the river’s contaminated water was expected to reach the estuary on Saturday evening.

“The scale of the fish kill is appalling. This is a blow to the Oder as a waterway with high ecological value, from which it is unlikely to recover for a long time,” said Alex Vogel, Environment Minister of the state of Brandenburg, through which the river flows.

The Head of Polish Waters, Poland’s national water management agency, said Thursday that 10 tons of dead fish had been removed from the river. Hundreds of volunteers worked to help collect dead fish on the German side.

German labs said they had discovered “atypical” levels of “salts” that could be linked to the die-off but would not fully explain them on their own.

Morawiecki acknowledged that some Polish officials reacted “sluggishly” after large numbers of dead fish floated and washed ashore, and said two of them had been fired.

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

His comments were echoed by Schwedt’s Mayor Annekathrin Hoppe, whose German town lies next to the Lower Oder Valley National Park. She called the river’s contamination “an environmental disaster of unprecedented proportions” for the region.


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