Tests find high salinity level in river after fish die-off

WARSAW — Laboratory tests following a mass dying off of fish detected high levels of salinity but no mercury in waters of Central Europe’s Oder River, Poland’s environment minister said Saturday. Anna Moskwa, the minister of climate and environment, said analyses of river samples taken in both Poland and Germany revealed the elevated salt levels. Comprehensive toxicology studies are still under way in Poland, she said.

Writing on Twitter, Moskwa said test results transmitted from Germany had so far not shown a high presence of mercury.

The Oder River runs from the Czech Republic, also known as Czechia, and along the border between Poland and Germany before flowing into the Baltic Sea. Some German media had reported that the river could be poisoned with mercury.

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

On Saturday, Morawiecki vowed to do everything possible to limit the environmental devastation. Poland’s interior minister said a reward of 1 million zlotys ($200,000) would 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 river’s contaminated water was expected to reach the estuary area Saturday evening.

“The extent of the fish die-off is shocking. This is a blow to the Oder as a waterway of great ecological value, from which it will presumably not recover for a long time,” said Alex Vogel, the environment minister for Germany’s Brandenburg state.

The head of Poland’s national water management authority said Thursday that 10 tons of dead fish had been removed from the river. Hundreds of volunteers were working to help collect dead fish along the German side.

Morawiecki acknowledged that some public officials were “sluggish” in reacting after huge numbers of dead fish were first seen. Two Polish officials were dismissed for what Morawiecki described as tardiness in their response. “If I come to the conclusion that there was a serious breach of duties, further consequences will be drawn,” the prime minister said.