Large numbers of dead fish were found in the Ner river, in the central Łódzkie province, following a similar incident in the River Odra, which flows through Poland and Germany.
The Ner runs through Łódzkie and Wielkopolskie provinces. It is one of the right tributaries of the Warta River, the third largest river in Poland which flows into the Odra, against the German border.
“A significant number of dead fish was spotted (in the Ner – ed.) on the border of the Poddębicki and Łęczyca counties,” Dagmara Zalewska, spokeswoman for the Łódzkie province said on Saturday afternoon.
“Research is ongoing. We are monitoring the situation,” Zalewska added.
Mateusz Daszkiewicz, the spokesman for the Wielkopolskie province, told PAP on Saturday that, for now, “no visible forms of pollution have been found that could affect the situation on our river in some way.”
He added that “the water samples that have been tested so far also showed no alarming changes.”
Local authorities have called an emergency meeting to investigate the reports of dead fish in the Ner river.
More than ten tonnes of dead fish have been found since late July in Odra, Poland’s second largest river, which also runs through Germany.
The exact cause of the mass fish die-off, which was labelled an “ecological disaster” remains unclear.