The death of around 360 tonnes of fish in the Oder River last summer was caused by a major toxic algal bloom identified as Prymnesium parvum, according to a report by the European Commission’s Joint Research Centre and the European Environment Agency analysing the likely causes of this major ecological disaster, published on Friday 17 February.
Given the presence and continued spread of this invasive algal species, management strategies to prevent future occurrences of this nature should now be prioritised in the Oder, but also in other sensitive European river basin districts, the report says.
It recommends, among other things, improving knowledge and monitoring, response, risk and environmental management, and the establishment of an up-to-date public inventory of emissions. In a statement, the European Commissioner for the Environment, Virginijus Sinkevičius, “invite[s] competent national authorities to rigorously implement its recommendations”.
According to the report, a key factor in the algal bloom is most likely the high salinity of the Oder at that time, resulting from discharges of industrial wastewater with a high salt content, for example from industrial activities such as mining. Drought and the resulting low water levels also contributed to this situation, as did high phosphorus and nitrogen concentrations.
See the report: https://aeur.eu/f/5e8 (Original version in French by Aminata Niang)