On the shore of the Malý Dunaj (Little Danube) in Bratislava, fishermen and locals have recently seen a disturbing sight: hundreds, even thousands of dead fish floating downstream. Ecologists are sounding the alarm, as this is not an isolated case but a regularly recurring problem.
What is the cause of the disaster?
The main suspicion again falls on the Bratislavská vodárenská spoločnosť (Bratislava Water Company, BVS). Its treatment facilities in Vrakuňa likely cannot handle the large flow of wastewater during summer storms. Because of this, tons of untreated sewage with feces enter the river, causing the death of fish and other river inhabitants.
The BVS company itself denies these accusations. According to their official statement, the central treatment plant in Vrakuňa operated normally, without accidents or leaks. The company insists that only the permitted amount of already treated water was discharged into the Malý Dunaj (Little Danube). BVS also reminds that in March 2026, the station repaired the aboveground biogas pipeline, which could have caused a temporary smell, but emissions were supposedly minimal. Additionally, since August 5, 2026, the company has been conducting smoke tests of the sewer system in Vrakuňa to check rainwater connections. Because of this, white smoke may appear, which, according to BVS, is harmless.
Response of environmental protection authorities
The situation is already being handled by the environmental inspection. Inspectors took water samples for analysis, and results are expected soon.
Threat to the Danube: not only pollution
This problem arose against another issue — an abnormally low water level in the Danube due to a prolonged drought in the summer of 2026. A similar situation already caused mass deaths of crayfish and fish in the Čunovo area in 2021. Low water also harms navigation and tourism: cruises have to be canceled and ship traffic restricted. In July 2026, the monitoring station Bratislava/Devin recorded the lowest water level for this month since 1876.
Ecologists explain that due to the low water level, the Danube's side arms overheat and become shallow. This creates a direct threat to fish, amphibians, and other wildlife.
The situation on the Malý Dunaj (Little Danube) once again shows how vulnerable river ecosystems are and why water quality control must be stricter.
