The Rivers Trust, the leading advocate for the protection and improvement of Northern Ireland, Ireland, and Britain’s freshwater environments, has expressed concern and anger over the recent pollution incident in a tributary of Lough Neagh, which has killed hundreds of trout and salmon and threatens critical spawning areas.

The Rivers Trust All-Ireland Director Mark Horton said: “This slurry pollution incident has caused long-term damage to the Callan River and will negatively impact the wider ecosystem. Hundreds of fish have been killed, and their future in the river has been destroyed because their spawning beds have also been damaged.

Dead river fish — Just some of the hundreds of fish that have been killed in the River Callan after the pollution incident. Photo credit: Ulster Angling Federation.

“In addition to the immediate destruction of aquatic life, the impact of the slurry pollution extends beyond the river. Thanks to the years of hard work by local conservation volunteers, the area around the Callan River was home to otters and rare pine martens. However, both are highly sensitive to water pollution. This slurry spill has wrecked their habitat and food source and may have destroyed an important nature corridor cherished by the local community.

“Our local River Blackwater Catchment Trust, supported by The Rivers Trust, has been working for many years in that area to change land management practices and reduce pollution by installing nature-based solutions such as tree planting, creating buffer zones along rivers and empowering the public to monitor the quality of their local rivers and loughs through training and citizen science programmes. An incident like this set their work back by decades.”

The 26-mile historic Callan River runs from Darkely, Co Armagh, into the Blackwater, then into Lough Neagh, which has recently been the focus of public concern due to the extreme contamination by blue-green algae.

A River Blackwater Catchment Trust spokesperson said: “The Callan River saw substantial improvements with a 3km restoration project undertaken by CatchmentCARE last year. The positive changes along the river were a testament to the commitment and hard work invested by all those involved.

“The presence of multiple community groups actively engaged in monitoring and sampling activities along the Callan River attests to the collective dedication to the cause of safeguarding this invaluable natural resource. Despite this devastating setback, we remain committed to restoring and preserving this beautiful river.”

The recent pollution incident could not have come at a worse time, just weeks away from spawning season. At this time of year, salmon and brown trout are coming into the river system to breed.

Eyewitness reports suggest the remains of Salmon Parr, Trout, and Dollaghan – both adult and young – lie strewn on the water’s edge and riverbed. Invertebrates, insects, worms, and larvae that they feed on have also been affected.

“This incident is not just terrible for the Callan River and its wider community, but it also impacts the broader ecosystem, Mark continued.

“Our freshwater systems are deeply interconnected, with six major rivers flowing directly into Lough Neagh. One of the primary drivers of blue-green algae in Lough Neagh is the nutrient load in the water. Nutrients, such as phosphate and nitrate, cause algal blooms to thrive. Ultimately, this slurry spill will pollute the Callan River and contribute to the ongoing, long-term problems in Lough Neagh.”

The Rivers Trust emphasise the importance of collaborative efforts to prevent pollution spills like this to avoid long-term damage it can inflict on vital ecosystems.

"It will take decades for the ecosystem of the Callan River to recover from this devastating incident, which took just moments of carelessness to occur," Mark said.

“The Rivers Trust continues to work tirelessly in its mission to protect and restore our rivers, and we have learned that prevention is much better, easier, and cheaper than clean up.

“That is why we are committed to supporting the farming community to implement Nature-based Solutions, such as tree planting and clean water initiatives on farms, to reduce runoff and prevent such catastrophic pollution events.

“However, these catchment-scale interventions require funding, policy and collaborative efforts from government bodies, landowners, local communities and water management experts like The Rivers Trust."

To avoid further river pollution slurry incidents, The Rivers Trust is directly appealing to all farmers to urgently review their slurry management plan, taking into account recent severe weather events and checking that all above-ground slurry tank valves are properly maintained and secure.