Blackwater fish kill has 'an unjust and negative impact' on stocks, committee to hear

EPA director Tom Ryan is expected to say that when 'detrimental incidents' like the Blackwater kill occur, and where the wrongdoer can be identified, 'then they should be held to account'

The events on the Blackwater in early August, which saw 30,000 salmon and brown trout killed, comprised an event that is 'not to be tolerated', the EPA director will say. Picture: Dan Linehan

Ireland’s worst-ever fish kill in the River Blackwater has had an “unjust and negative impact” on the locality’s communities, according to the State’s environmental regulator.

The director of the Environmental Protection Agency (EPA), Tom Ryan, is set to tell an Oireachtas committee that the events on the Blackwater in early August, which saw 30,000 salmon and brown trout killed, comprised an event that is “not to be tolerated”.

The kill is expected to materially set back the fish stocks in the region, which could take up to 10 years to be fully replenished.

The fish kill has caused consternation among locals and anglers alike, as an inter-agency probe of the event published last week concluded that the cause could not be established.

It said that there was no evidence of a chronic problem with water quality before or after the fish kill, or any evidence of a systemic disease in the dead fish, concluding that a waterborne agent had likely entered the water three days before the kill before dissipating quickly.

“The extensive fish mortalities that occurred on the Blackwater in Cork during August 2025 are serious harm to the local fish stocks, and have had an unjust and negative impact on the local communities,” Mr Ryan is due to tell the Oireachtas environment committee on Tuesday.

Mr Ryan is expected to say that when “detrimental incidents” like the Blackwater kill occur, and where the wrongdoer can be identified, “then they should be held to account”.

He is to say that when the EPA first heard of the kill on August 12, it had “immediately mobilised” in deploying three teams of inspectors to EPA-regulated sites in the Mallow and Kanturk areas.

No cause established

The subsequent investigation saw 41 separate investigations of 31 facilities within the Blackwater catchment, including industrial sites, wastewater treatment facilities, and drinking water plants.

Despite those intensive investigations, no cause of the kill could be established.

Mr Ryan is expected to reaffirm that, despite the “history of failure” of North Cork Creameries to achieve compliance with its licence for discharging water into the river, breaches which have led to enforcement action and prosecutions by the EPA, no “causal link” between its discharges and the kill could be established.

Separately, Barry Fox — the deputy CEO of waterways regulator Inland Fisheries Ireland (IFI), one of the co-sponsors of the Blackwater investigation — will tell the same committee that the “harrowing sight” of thousands of dead and decomposing fish had been “both unacceptable and deeply alarming”.

Describing the kill as a “catastrophic environmental incident”, he will say that the event prompted “one of the most extensive investigations in IFI history, but one which was unable to determine the reason for the deaths".

Despite the lack of a definitive conclusion of the investigation, Mr Fox will assert that the penalties available to the lower courts in handling events such as a mass fish kill “significantly undermine the effectiveness of enforcement efforts”.

“We strongly contend that these penalties are not proportionate to the severity of environmental crimes, which cause significant harm to fisheries, their habitats, and the economic communities that depend on our rivers and water quality for both amenity value and livelihoods,” he will say.