Comprehensive toxicology studies are still underway since 10 tons of dead fish have been removed from the river.
Hundreds of volunteers were working to help collect dead fish along the German side while fishermen expressed their concerns.
The Oder River runs from Czech Republic to the border between Poland and Germany before flowing into the Baltic Sea.
Laboratory tests following a mass die-off of fish in the Oder River detected high levels of salinity but no mercury poisoning its waters, Poland’s environment minister said Saturday as the mystery continued as to what killed tons of fish in Central Europe.
Germany’s environment minister said the mass die-off of fish in the Oder River is an ecological catastrophe and it isn’t clear yet how long it will take for the river to recover.
Steffi Lemke spoke Sunday at a news conference alongside her Polish counterpart, Anna Moskwa, after a meeting in Szczecin, a Polish city on the Oder River.