Oder river: Speculation over 'environmental disaster' in Germany and Poland

euronews.com:

Speculation is growing over the cause of an "environmental disaster" in Germany and Poland, following a mass fish die-off in the river Oder.

Thousands of lifeless fish began washing up on the banks of the river Oder, running along the borders of Germany and Poland, at the end of July. 

Since then, officials have tried to determine the cause of the mass die-off, which they say will take years to recover from as the river is damaged so badly. 

Laboratory tests into the source of the disaster have not detected mercury, Poland’s environment minister said Saturday.

Authorities believe the fish were likely poisoned. 

Polish Prime Minister Mateusz Morawiecki said Friday that “huge amounts of chemical waste” were probably dumped into his country's second-longest river. 

He vowed to do everything possible to limit the environmental devastation, with Poland's interior minister later offering a reward of 1 million zlotys ($200,000) to anyone with information on who was responsible for polluting the river. 

Anna Moskwa, the minister of climate and environment, said analyses of river samples taken in both Poland and Germany revealed elevated salt levels. 

Comprehensive toxicology studies are still underway 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 death of the fish is "atypical," said Axel Vogel, Minister of the Environment for the German state of Brandenburg, estimating that "tons" of fish have probably already perished.

“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,” he said.  

Fish die-offs are often caused by the