Odra

The final report of the Team for the Situation Arising on the Oder River has been published. The publication of the document is a summary of the Team's activities.

Minister Krzysztof Gołębiewski, the Chief Inspector of Environmental Protection, has announced that an Alert Procedure for detecting mass blooms and the threat of contamination by 'golden algae' toxins is in force.

An international workshop on Prymnesium parvum or golden alga has taken place. The 13 April 2023 online event is the result of an arrangement between the Environment Ministers of Poland and Germany.

Polish environmental services conduct continuous and precise monitoring of the Oder River. Water samples are taken twice a week. Biological and chemical monitoring is correlated with testing for the presence of 'golden algae'. The adopted testing scheme allows for constant monitoring the river's condition before the growing season. Intervention monitoring results from the recommendations of the Team for the Situation Arising on the Oder River set up by the Minister of Climate and Environment in 2022.

'If we create the right conditions, aquatic ecosystems quickly recover. Even so, it must be assumed that this process takes years,' says Prof. Piotr Parasiewicz from the Stanisław Sakowicz Inland Fisheries Institute in Olsztyn. The Institute is involved in ichthyological research. A control catch was carried out in autumn 2022 as part of the nationwide monitoring. Nearly 5,500 fish were caught in the Oder River. Almost 30 species were identified. Dominant among them were perch and roach as well as gudgeon and bleak. The researchers also recorded the presence of the protected bitterlings and spined loaches. 'Ichthyological monitoring is only one of the activities,' Professor Parasiewicz emphasises at the beginning of the interview. 'Our Institute continues to study the Oder River ichthyofauna status and is also developing an ecosystem remediation plan. Only through thorough research analysis can rational solutions be created,' the expert adds.

As part of state environmental monitoring, the Stanisław Sakowicz Inland Fisheries Institute in Olsztyn conducted a study of the fish populations in rivers in Poland. Specialised control fisheries conducted in autumn 2022 also covered the Oder River. A summary of the monitoring is included in the report: Assessment of surface water bodies surface water bodies for ichthyofauna for the year 2022.

According to a report by the Team for the Situation Arising on the Oder River, the cause of the massive fish die-off in the river was a toxin produced by 'golden algae'. These rare occurring microscopic algae may have found their way into the waters carried by, for example, birds. 'Golden algae' are not only found in marine waters but also inland reservoirs and rivers, generally in industrialised areas with higher salinity of the waters, fish ponds, and others. So far, they have appeared on all continents except for Antarctica.

"We present today the conclusions and recommendations of scientists on the Oder River, developed during the last weeks of the Team's work," said Deputy Minister of Climate and Environment Małgorzata Golińska, during a conference summarizing the work of the Team for the situation arising on the Oder River, which took place on September 29, 2022 in Warsaw.

Scientists have proven that a fast-acting toxin produced by 'golden algae' led to fish deaths. Heavy metals, pesticides or petroleum-based substances did not cause the die-offs. On the other hand, the massive bloom of microalgae was generated by overlapping factors: changes in water parameters, including increased salinity caused by hydrological drought, hot weather raising the water temperature to 27oC and high sunlight, higher than in previous years, which accelerates the growth of algae. These conclusions were drawn on the basis of more than 36,000 surveys carried out.

Researchers from the University of Gdańsk have isolated the DNA and RNA of prymnesins, namely the toxins produced by 'golden algae.' The researchers are currently developing a standard that will precisely determine these little-known ichthyotoxins. There are no research standards in this area in the European Union.