German authorities raised alarms about a major environmental disaster after finding mercury in the transboundary Oder river, known as Odra in Polish.
Brandenburg Environment Minister Axel Vogel pointed to water soluble mercury salts as the driver of the crisis. Yet investigators have not yet determined how the contaminant reached the river.
Initial German lab results suggested alarmingly high mercury levels and were initially questioned. A second study confirmed the first findings, reinforcing concerns about the scale of pollution.
Volunteers are removing thousands of dead fish from the river while emergency services conduct ongoing relief operations along the waterway.
German Environment and Nuclear Safety Minister Steffi Lemke said Berlin awaits information from Warsaw about potential sources of the mass fish die-off in the Oder River.
There are claims that Polish authorities had previously admitted that key information about the disaster had not been disclosed domestically, with Lemke noting that such details arrived later.
Lemke expressed a wish to meet with Polish government officials to seek clear explanations for the incident and its causes.
Some German media outlets warned that the Oder crisis could strain Berlin-Warsaw relations in the near term.
Results for future years
The mayor of Schwedt, a Brandenburg town on the Polish border, described the mass fish deaths as an unprecedented disaster with ongoing implications for years. The event could impact tourism and the local fishing sector, according to Annekathrin Hoppe.
Hoppe called the incident an environmental disaster of an extraordinary scale and warned of long term consequences for the region.
Authorities in Frankfurt an der Oder advised residents to avoid contact with river water while vigilance remains high near the river’s banks.
Contaminants began to spread downriver, affecting the Barycz and Ner rivers. Polluted water carrying toxins could potentially reach the Baltic Sea ecosystem.
Beginning of the disaster
Polish fishermen reported signs of an environmental crisis in Odra on 10 August. Gazeta Wyborcza reported that the mass fish die-off was connected to the release of a toxic solvent into the reservoir.
Investigators noted that while acidification of the water was not observed, unusually high oxygen and warm water conditions suggested an unnatural origin. The presence of a substance with strong oxidizing properties might have entered the system due to reactions occurring in the water.
It was also suggested that the warming trend alone could not explain the scale of pollution. The contamination produced chlorine-like odors and widespread fish carcasses. Fishermen began bagging and disposing of the dead stock.
European fishermen noted the diversity of species affected, ranging from common bream to catfish, with thousands of fish dying in the Wroclaw region alone over the weekend.
Experts warned that stock replenishment would not quickly recover the lost biomass, and that the underlying issues required robust, long-term solutions.
Reports from several outlets indicated traces of mesitylene, a solvent used by various Polish industries, were detected in the water. Authorities later restricted water sports and fishing in several affected regions and brought in the military to assist with cleanup efforts.
Resignation of officials and search for those responsible
Prime Minister Mateusz Morawiecki said the situation is unpredictable and that responses from responsible services must speed up.
Head officials Michal Misthak and Przemysław Dats were dismissed as part of the accountability process. The prime minister pledged a strong response to identify and punish those responsible for the environmental crime, with hopes of swift action.
Morawiecki did not rule out intentional pollution of Poland’s second largest river, suggesting that a large amount of chemical waste may have been dumped with knowledge of risks and consequences.
A reward of 1 million zloty was announced for tips leading to the identification of those responsible for polluting the river. Additional rewards were offered for information aiding investigations into the perpetrators.
Questions around Sulzer Pumps Wastewater Poland, a supplier of water treatment equipment, were raised as cleanup hurdles. Authorities suggested the equipment had operated for over a decade and noted concerns about potential links to Russian capital, while a company representative noted ongoing operation of treatment plants across several cities and regions.