Experts warn of another ecological catastrophe

Konjic, September 11, 2026 — Around 60 representatives of public institutions, academia, environmental organisations, and citizens gathered today in Konjic for an expert symposium titled “Neretva - One Year Since the Fish Kill: What Were the Causes and How to Prevent a New Disaster?” The event was organised by the Sports Fishing Association “Konjic” with the support of the international organisation Riverwatch.

Exactly one year ago, the upper Neretva suffered a massive fish kill. For several kilometres downstream of the Ulog hydropower plant, the river was littered with dead fish - including the rare softmouth trout - as well as crayfish and other aquatic life.

Following public outcry, the authorities said they found no evidence linking the fish kill to the Ulog hydropower plant.

The message from today’s symposium, held on the occasion of the first anniversary of the mass mortality event, was unequivocal: the illegal operation of the Ulog hydropower plant caused the ecological catastrophe - and there is a real risk that it could happen again.

An independent team of experts has established a direct link between the operation of HPP Ulog near Kalinovik and the fish kill. Scientific monitoring and satellite imagery show that the plant operated in a prohibited peak-load regime, known as hydropeaking, in violation of its environmental permit conditions. The permit explicitly requires the plant to operate in a run-of-river regime.

Hydropeaking can cause water-level fluctuations through the sudden release of large volumes of oxygen-depleted water from a reservoir's deeper layers. According to the expert analysis, this is exactly what happened at Ulog and caused the mass mortality of fish and other aquatic organisms downstream.

Prof. Dr Gabriel Singer of the University of Innsbruck conducted the analysis with Academician Prof. Dr Muriz Spahić and researcher Mirza Čelebičić.

Presenting the findings today in Konjic, Prof. Singer said:

“We could clearly prove that the Ulog power plant released massive amounts of oxygen-poor water over a period of several hours. The oxygen level was way below what trout, crayfish and aquatic insects need to survive. They simply suffocated.”

Hrabren Kapić, an expert associate of the Sports Fishing Association “Konjic” and host of the symposium, called on the relevant institutions to make protecting the Neretva a priority.

“Protecting our fish populations is important for nature, but also for the local economy. We must prevent such a catastrophe from happening again. Relevant institutions must do their job, and HPP Ulog must stop its illegal operation in peak-load regime.”

The issue is also on the agenda of the Government of the Federation of Bosnia and Herzegovina. In June 2026, the Government adopted information and conclusions prepared by the Federal Ministry of Environment and Tourism and the Federal Ministry of Agriculture, Water Management and Forestry. The stated objective was to protect the interests of the Federation of BiH regarding the operation of HPP Ulog and the potential impacts of hydropower projects on the Neretva River basin.

The two ministries and the Federal Attorney’s Office were given three months to report on the progress of measures taken - a deadline that expires on September 15, 2026.

The coming days will show whether the authorities are prepared to take concrete action. One year after the destruction of aquatic life in the upper Neretva, independent experts have identified the cause. Now the authorities must act to establish accountability and, above all, ensure the same catastrophe does not happen again.

To save the Neretva River network and to prevent another disaster, scientists and the Konjic Sports Fishing Association call for immediate action:

• Abandon all Dam projects on Neretva and its tributaries
• Grant legal protection to all remaining free-flowing rivers and streams in the Neretva basin from their sources to Konjic.
• Ensure that the Ulog hydropower plant operates strictly in accordance with its permit (run-off the river)
• Establish a publicly accessible, real-time monitoring system for water levels, oxygen concentration and temperature in the reservoir (close to the dam), in the residual flow section between the dam and the powerhouse and below the powerhouse, where hydropeaking hits the hardest.
• Establish an inter-entity response plan to be prepared for another ecological emergency.
• Adopting the new Law on Freshwater Fisheries of the Federation of Bosnia and Herzegovina, already approved by the Government of the Federation of Bosnia and Herzegovina in draft form in 2022, would significantly improve and expedite the response of the competent institutions in the event of incidents affecting our rivers and lakes. The existing law dates back to 2004 and is not harmonised with European Union legislation, while the draft new law is fully aligned with EU legislation.