What killed tons of fish in European river? Mystery deepens

WARSAW, Poland (AP) — Poland’s environment minister says laboratory tests following a mass fish die-off have detected high salinity levels but no mercury in the Oder River. That means the mystery is continuing as to what killed tons of fish in Central Europe. The minister said analyses of river samples taken in both Poland and Germany revealed the elevated salt levels. She says comprehensive toxicology studies are still underway in Poland. The Oder River runs from Czechia and along the border between Poland and Germany before flowing into the Baltic Sea. Poland’s prime minister vowed Saturday to do everything possible to limit the environmental devastation. A reward has been offered for information about those responsible.