Lessons learned and research-based recommendations to avoid future ecological damage in EU rivers, a joint analysis from DG ENV, JRC and the EEA
During summer 2022 massive fish kills totalling approximately 360 tonnes of fish impacted the Oder River. It is almost certain that a substantial toxic algal bloom caused their deaths. The causal species: Prymnesium parvum, is adapted to brackish salinities. A key factor enabling the proliferation of this species was the high salinity of the river during this time, probably in part resulting from discharges of saline industrial wastewater e.g. from mining. Other contributing factors were the drought and resulting low water levels reducing dilution and flow and also hydromorphological modifications to the river. High nutrient concentrations, especially phosphorus and nitrogen, are also key in promoting such blooms.
To prevent such events occurring in future it is recommended to improve online monitoring, have mandatory communication of pollution events across international river basin districts, review and implement dynamic control of licenced discharges and review the role of hydromorphological modifications in slowing the flow allowing time for blooms to develop. A complete investigation of discharges in the catchment should be done to explain the increase in salt load that played a key role in bloom development. A continued presence and spread of this invasive algal species is likely. Management strategies to prevent a future occurrence must now be prioritised in this and other susceptible European catchments. A preliminary risk assessment of rivers in Europe is presented.
FREE Gary;
VAN DE BUND Wouter;
GAWLIK Bernd;
VAN WIJK Lorenzo;
WOOD Maureen;
GUAGNINI Enrico;
KOUTELOS Konstantinos;
ANNUNZIATO Alessandro;
GRIZZETTI Bruna;
VIGIAK Olga;
GNECCHI Marusca;
POIKANE Sandra;
CHRISTIANSEN Trine;
WHALLEY Caroline;
ANTOGNAZZA Federico;
ZERGER Benoît;
HOEVE Rolf-Jan;
STIELSTRA Hans;
2023-02-17
Publications Office of the European Union
JRC132271
978-92-76-99314-8 (online)(ENG),
978-92-68-03255-8 (online)(GER),
978-92-68-03256-5 (online)(POL),
1831-9424 (online),
EUR 31418 EN,
OP KJ-NA-31-418-EN-N (online)(ENG),
OP KJ-NA-31-418-DE-N (online)(GER),
OP KJ-NA-31-418-PL-N (online)(POL),
https://publications.jrc.ec.europa.eu/repository/handle/JRC132271,
10.2760/067386 (online)(ENG),
10.2760/583066 (online)(GER),
10.2760/536489 (online)(POL),
