2022 Oder environmental disaster
During the summer of 2022, a mass mortality event involving fish, beavers, clams, crayfish and other wildlife occurred in the Oder river.
Dead fish in the Oder river on the border between Germany and Poland | |
Large-scale fish die-offs were reported in the river around Oława at the end of July | |
| Date | July–August 2022 |
|---|---|
| Location | Oder |
| Type | Environmental disaster |
| Cause | Harmful algal bloom of Prymnesium parvum |
Over 100 tonnes of dead fish were removed from the Polish section of the river, and a further 35 tonnes from German sections, causing concern that the water was poisoned.
At first the cause was not clear, theories included the effects of the summer heat and lower water levels due to the European drought, reduced oxygen levels due to the heat and nutrient loading, a spike in oxygen levels due to the introduction of an oxidizing agent, and pollution by chemicals including mercury, mesitylene, salts or other sewage, as well as the possibility of an algal bloom. It was later determined to be an algal bloom.
The Polish authorities were slow to react, causing a scandal and resulting in the dismissal of officials responsible for water management and environmental protection. A reward of 1 million zlotys (about €222,000, as of September 2023) was offered for information about possible culprits.