Conservationists have called for an investigation following a mass fish die-off in a stretch of river flowing between Germany and Poland.
Huge numbers of dead fish have washed up on the banks of the Oder River, which flows from Czechia into the Baltic Sea, this week, with volunteers in Germany and Poland to organise clean-up operations.
Piotr Nieznanski, the conservation policy director at WWF Poland, said it appears that a toxic chemical was released into the water by industry, while low water levels caused by the drought gripping Europe have made conditions far more dangerous for the fish.
“A tragic event is happening along the Oder River," he said. "There is no transparent information about what is going on.”
Nieznanski urged government authorities to investigate the mass die-off in what is Poland's second-longest river.
People living along the river have been warned not to swim in the water or touch it.
Poland’s state water management body said drought and high temperatures mean that even small amounts of pollution can trigger an ecological disaster in its vital waterways, though it said the source of the pollution has not yet been identified.
The water level along Germany's Rhine River is at risk of falling so low that it could become difficult to transport goods — including critical energy items like coal and gas.
Yet, Poland and Germany are not the only European countries facing acute environmental problems caused by weather extremes.
In northern Serbia, the dry bed of the Conopljankso reservoir is now littered with dead fish that were unable to survive the drought.
This week officials in Hausen, near Zurich, rescued hundreds of fish in the almost dried-up Heischerbach, Juchbach and Muehlebach creeks.
The fish, many of them brown trout, were anaesthetized with electric shocks and quickly placed in a water tank enriched with oxygen, local media reported. Later, the fish were taken to creeks that still carry enough water.
In Italy, which is experiencing its worst drought in seven decades, the parched Po River has already caused billions of euros in losses to farmers who normally rely on Italy's longest river to irrigate their fields and rice paddies.
The drought is causing a loss of agricultural products and other foodstuffs at a time when supply shortages and Russia's war against Ukraine have caused inflation to spike.