In a recent article published in “Dziennik Zachodni” on Friday, September 1st, Irena Pluta, Ph.D., Professor Emeritus of the Main Mining Institute, and a member of the Chemical Sciences Committee of the Polish Academy of Sciences, evaluated Greenpeace’s accusations against mines and argued that activists’ claims that “mines are poisoning the Oder River” are not supported by research.
Pluta emphasized that supporters of Greenpeace should consider supplementing their knowledge about the Oder River based on the extensive work conducted by Polish scientists in this field. She also pointed out that Greenpeace’s allegations, as outlined in the organization’s 2022 report, disregard the results of numerous previous studies on the Oder River and the findings of the final report from the Institute of Environmental Protection.
Saline waters from the Upper Silesian Coal Basin mines have been under investigation for over 70 years. Long-term scientific efforts to protect the river ecosystems have been effective, demonstrated, among other things, by the results of an international Polish-Czech project confirming the efficiency of the Olza retention-dosing system, which has been used by the mines to protect the Oder River.
Pluta noted that while saltwater and brine were discharged into the Oder for decades, especially since the 1960s with the opening of ROW (abbrev. for Rybnik Mining Area – ed.) mines, the salinity levels in the river were much higher than they are now. Despite this, there were no mass fish die-offs.
“In the Oder River, despite the discharge of saline mine waters, the environment was favourable for the life of a large number of fish species such as bream, roach, pike-perch, perch, catfish, eel, and pike,” explained Prof. Irena Pluta, adding that there were no invasive, toxic algae, which were detected in the Oder last year.
The expert pointed out the paradox that Greenpeace’s conductivity measurements of the Vistula River water showed more than five times higher salinity compared to the Oder:
“Why then did waters with significantly higher salinity, also discharged for many years, not destroy the Vistula River ecosystem? Greenpeace’s claim that an ecological catastrophe scenario on the Vistula due to salinity could repeat itself is unfounded,” noted Prof. Irena Pluta.
Scientists believe there was a direct correlation between fish mortality in the Oder and the activity of Prymnesium Parvum (P.P.) algae. Studies confirmed the presence of golden algae in the river even before the discharge points of mine waters, at the Polish-Czech border. It turns out that algal blooms were not directly proportional to the increase in the salinity of the Oder’s waters. The causes of toxic blooms were, in sequence, sunlight, temperature, water level, and only then sewage discharges related to salinity and biogens.
“Regarding salinity, it should be noted that in the case of the Oder River, it has existed for decades and has not caused blooms,” emphasized Prof. Irena Pluta, adding that it would be impossible to reduce salinity in the river to a level where algae would perish, not due to the mines but, for instance, because of road salt usage in winter.
According to the researcher, the toxic development of golden algae is attributed not to chlorides, sodium, and sulfates from bottom waters, but to biogenic pollution containing nitrogen and phosphorus compounds.
“These pollutants are found in sewage from agricultural activities, untreated urban sewage, and biologically treated sewage, the quantities of which discharged into the Oder far exceed the amount of mine waters,” concluded the scientist.