# Regional fish die-offs and water pollution

> Live situation record from CLSTR: https://clstr.news/situations/regional-fish-die-offs-and-water-pollution
> Updated: 2026-10-04T09:10:36.000Z. Sources: 5. Developments: 2.

Reports of significant fish die-offs have emerged across several water bodies in the Balkan region, linked to varying environmental stressors.

In Serbia and Croatia, massive losses were recorded in Belgrade’s Veliko blato protected habitat, where approximately 35,000 carp died, reportedly due to insufficient water levels maintained by municipal services. Near Ilok on the Danube, fishermen reported hundreds of dead carp, pike, and catfish. While investigators noted that drought, high temperatures, and low oxygen levels contributed to the event, they are also monitoring for potential contamination near a wastewater treatment plant discharge point.

In North Macedonia, scientific analysis from the Veterinary Faculty at Ss. Cyril and Methodius University confirmed that the Treska River near Kichevo is highly polluted. Water samples showed extreme organic and fecal loading, including high ammonia and E. coli levels. Pathohistological examinations of dead Macedonian trout revealed necrotic liver changes and hemorrhagic nephritis, leading researchers to link the die-off to heavy pollution. In response, political groups have called for criminal investigations and audits of local wastewater treatment facilities.

## Timeline

### 2026-10-04: Treska River pollution linked to fish die-off near Kichevo

Reports confirm the Treska River near Kichevo is highly polluted (Category V), linking a massive fish die-off to extreme organic and fecal contamination. Levica is demanding a criminal investigation.

2 sources. https://clstr.news/cluster/treska-river-pollution-linked-to-fish-die-off-near-kichevo

### 2026-09-25: Massive fish die-offs reported in Belgrade and near the Danube

Massive fish die-offs have been reported in Belgrade's Veliko blato habitat and along the Danube near Ilok, linked to low water levels, heat, and potential pollution.

3 sources. https://clstr.news/cluster/massive-fish-die-offs-reported-in-belgrade-and-near-the-danube

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Cite as: Regional fish die-offs and water pollution. CLSTR, https://clstr.news/situations/regional-fish-die-offs-and-water-pollution
