The contamination wave had not yet reached Szczecin or the Szczecin Lagoon, according to Zbigniew Bogucki, West Pomeranian Voivode, who spoke on Monday. He noted that by Friday, 45 tons of dead fish from the Odra had already been recovered within the voivodeship.
What did the German authorities learn? They reported that mercury values fell within ecological tolerance ranges.
The contagion wave remained ahead of Szczecin, for now
When asked about the cause of the fish deaths, Bogucki explained that neither side in Poland nor Germany had a definitive answer yet. He reminded listeners that German authorities also conduct water level tests and noted there were no fish toxicology tests conducted the previous day. Poland had already sent fish samples to Puławy and was conducting parallel tests in Szczecin, which showed no heavy metals in tissue samples.
— described Bogucki, voivode of the Western Pomeranian Voivodeship, during his remarks in Krajnik Dolny on Monday.
He emphasized that the reason for the fish die-off remained unknown despite strong cooperation between Poland and Germany.
Regarding bathing safety in the Baltic Sea, he pointed out that Sanepid surveillance and ongoing investigations apply. He noted that bathing areas in three Odra basin municipalities—Świnoujście, Dziwnów, and Międzyzdroje—were tested with elevated monitoring, and the water was deemed safe.
— Bogucki added.
He also mentioned staying in touch with regional fishermen’s associations, who reported that no fish fatalities were observed in Zalew Szczeciński on Sunday.
The contagion wave had not yet reached Szczecin and not yet reached the Szczecin Lagoon, he concluded, though the polluted water or any pathogen could eventually flow toward that area. He asserted that Szczecin would still offer the freshest fish available in Gryfino.
— the voivode stated. He underscored that there is no Odra poviat in the West Pomeranian Voivodeship without samples being collected; in every poviat, at least one Odra sampling point is operated by the Provincial Inspectorate for Environmental Protection.
— Bogucki noted. He added that Gryfino faced a particularly challenging situation with four sampling points, and experts indicated that the varying parameters did not align with those typically associated with large-scale fish mortality.
The first water samples in the West Pomeranian Voivodeship were collected on August 5, roughly a week before the first single dead fish appeared in the region.
He reported informing the German side about service activities and requesting reciprocal updates, including any ban on river use. He said he was still awaiting a response.
Ten dams had been constructed in the voivodeship, including more than 800 meters of flexible dams and a permanent dam to catch dead fish. By Friday, 45 tons of dead fish had been recovered.
Signs of dead fish in the Środa Wielkopolska lake and the Wełna River in Rogoźno
Any signal of dead fish in Greater Poland waters is taken seriously and verified by the appropriate services, the Greater Poland voivode stressed. Information about fish deaths at the lake near Środa Wielkopolska and the Wełna River in Rogoźno was promptly investigated.
— Michał Zieliński, voivode of Wielkopolska, announced via social media on Monday evening.
He added that officials from VIEP, PSSE, KP PSP, Druhów OSP, and KP Police were immediately dispatched to both sites. The area was secured and water samples were taken for testing.
The municipal bathing beach in Środa Wlkp was closed until results from the water tests were available. Measures were put in place to clean the reservoirs and monitor the analyzed area.
— Zieliński noted. He reminded that any similar situation should be reported promptly to the police or state fire brigade.
On Saturday, the Wielkopolska Voivode convened a Provincial Crisis Management Team meeting to discuss the river Ner incidents, which flow through Łódź and Greater Poland as a tributary of the Warta.
“I am coordinating the services and ensuring no panic,” Zieliński stated. “The situation is under constant control.”
Recommendations were issued not to bathe or water livestock in the Ner, nor to fish or engage in recreational activities in the area. The measures were preventive, aimed at safeguarding regional residents.
The Wielkopolska Voivodeship Office in Poznań announced that, due to heightened water-level monitoring, water samples from the Ner River were collected near Dąbie in the Koło district. Preliminary findings suggested no visible changes in the river and normal basic parameters. A detailed investigation is underway, with ongoing reports from the relevant services. The State Fisheries Guard and the State Fire Service are involved in the response.
The fire service has installed a dam on the Ner River near Rzuchów, and daily checks of all river inlets are conducted by sanitation services. The Provincial Crisis Management Center in Poznań is coordinating with counterparts in Łódź and Koło districts.
Agency dpa: Mercury not confirmed as the cause of fish deaths
The drivers behind the death of up to 100 tons of fish in the Oder are still unknown. The German Environment Ministry has called it a serious environmental disaster with cross-border implications. The suspicion that mercury caused the fish kill has not been confirmed, according to the dpa agency.
From a German perspective, the Odra events are a major, transboundary incident. The ministry’s spokesperson noted the challenge of pinpointing the damage’s cause given the timing of information flows to Poland. Official statements indicate the river’s harm spans roughly 500 kilometers and may involve multiple factors, including low oxygen, increased salinity, and drought-related stress. Water testing covers hundreds of substances, with results still pending, and researchers are examining fish behavior prior to death.
Early findings suggested possible contamination with mesitylene in July samples, but subsequent tests did not confirm this substance. Environmental authorities are pursuing multiple potential causes, including drought, low water levels, and ecosystem disruption as plausible contributors to the fish kills.
Polish authorities have hinted at possible pollution from chemical waste as a factor, and investigators have offered a substantial reward for information leading to the perpetrators. Local authorities and companies have denied links to mesitylene or mercury in their processes, though investigations continue. Meantime, Mecklenburg-Vorpommern authorities remain on standby, monitoring the Szczecin Lagoon, which receives Odra water and connects to the Baltic Sea. Special dams are in place to curb potential fish spread. Analyses of lagoon samples are ongoing.
[Cita: wPolityce] These developments are being tracked by multiple regional and national agencies, with ongoing coordination between Polish and German authorities.