The disaster on the Odra will repeat itself. “None of the factors that led to it were liquidated”

For the reconstruction of the Key Odra ecosystem, it is to limit the drop of salty mine waters – pointed out prof. Krzysztof Lejcuś from the University of Life Sciences in Wrocław. Scientists studying the state of the second longest river in Poland also point to agricultural and municipal pollution.

Scientists from the University of Life Sciences in Wrocław (university leading in this project) and specialists from the University of Silesia, the University of Opole, the University of Zielona Góra and the University of Szczecin studied the quality of water in the Oder for a year. Expertise was commissioned in connection with the ecological disaster that happened in July 2022. Fish dreams were then recorded for about 1.5 months along the entire river running. About 250 tons of dream fish were collected during this period. Among the causes of the disaster, experts indicated the development of the Golden Algae river, which may be associated with with the degree of salinity of water.

A team of scientists studied physicochemical and biological water quality indicators at 21 river measuring points. “The goal was to determine the state of the Oder in Poland in the period from April 2023 to March 2024,” said the coordinator of this research project, prof. Krzysztof Lejcuś from the Institute of Environmental Engineering at the University of Life Sciences in Wrocław, quoted in the Tuesday's communication of the university.

The scientist emphasized that For most of the measuring period on most of the analyzed sections, the quality of the water in the Oder was bad. “High concentrations of biogenic compounds, high salinity and high temperature in the summer promotes the development of phytoplankton, including the prime minister of Parvum – the so -called golden algae forming blooms, which are dangerous for aquatic organisms,” he said.

He added that the golden algae occurred in the spring in a significant part of the analyzed length of the Oder. “Fortunately, these were not a major threat to fish and mussels. Which does not mean that there is no problem. The conditions in the Oder are conducive to the development of this species,” the professor emphasized.

The expert pointed out that so far none of the factors that – as he said – led to the ecological disaster in 2022 was liquidated. This means, according to him, that the risk of her replay is high.

The scientist emphasized the need to take action to rebuild the Odra ecosystem along the entire length. “In the first place, water and sewage management should be sorted out in the Odra catchment area and its tributaries. Without a significant reduction in the supply of industrial, agricultural and municipal pollutants, effective reconstruction of the Odra River ecosystem will not be possible,” he pointed out.

He added that the key to the reconstruction of the Odra ecosystem is to limit the drop of salty mine waters, which – as the professor said – are introduced to the rivers in the Śląskie and Lower Silesian Voivodships.

He also pointed to the need to increase the frequency and scope of water quality monitoring. “The existing system should be expanded and systematized. The newly created surface water monitoring to measure basic physicochemical parameters with high frequency, at several dozen measuring points, should be supplemented with monitoring covering biological indicators,” said the scientist.

Prof. Lejcuś also drew attention to actions to revitalize the river, emphasizing that they should be preceded by tests – for example on the outflows of the Oder. “The simplest and probably raising the least controversy can be the reproduction of oxbow lakes or rebuilding the hydraulic connection of the oxbow lake with the troughor reduction of boundary fortifications in places with a small impact of boundary erosion, “he assessed.

He added that it is also worth considering determining the boundary belts (so -called buffer zones), aimed at limiting the supply of area pollutants. “When planning and implementing revitalization activities, you should remember to protect the flood of the population living in the catchment area. Let's not forget that Odra is partly a cross -border river. You should also take into account the role of measles as a waterway, to the extent resulting from environmental, social and economic conditions” – added the scientist. (PAP)

PDO/ AGT/