Over 20,000 fish killed after river pollution incident in Ireland
By BBC, June 4, 2026More than 20,000 fish have been killed after a river in the Republic of Ireland was polluted.
Inland Fisheries Ireland (IFI) said the “harmful ecological event” at the River Glyde near Tallanstown in County Louth was discovered on Tuesday.
Species of fish discovered dead include adult and juvenile Atlantic salmon, eel, brown trout, pike, and coarse fish.
In a statement IFI said a definite line of enquiry is being pursued, and local authorities have been notified.
The agency’s eastern river basin district director Ronan Matson told Irish broadcaster RTÉ the cause is believed to be an “agricultural discharge upstream of Tallanstown”.
“Right now, you can see a few dead fish around Tallanstown,” he said.
“Where I am it’s kind of washed down a bit but there are other locations where there’s thousands. So the current estimate is in excess of about 20,000 fish.”
He said the majority of dead fish are made up of minnow and stickleback, which are both tiny, common, freshwater fish.
A water sample has been sent on for testing to confirm the cause, Matson said, and river recovery will begin immediately.
“Pollution will wash out relatively quickly, but it can take a few years for the fish to come back,” he said.
Matson added that the pollution appears to have occured away from where “most of the spawning seems to be occurring.”
“So, there should be good regeneration once the source of pollution is stopped, which we’re confident it is,” he said.
2025 Pollution incident
Members of the Six Mile Water Trust (SMWT) voluntary group said they had seen dead fish being washed downstream and “numerous” others in distress.
They described the numbers as “significant”.
The Department of Agriculture, Environment and Rural Affairs (Daera) has confirmed that the incident is being investigated.
‘Environmental impact assessed’
The Six Mile Water is one of the main rivers flowing into Lough Neagh.
Jim Gregg from the SMWT said the river was fast-moving due to heavy rain during Storm Amy, and that would help disperse any pollution.
He said “well over 100 very large trout” have been found dead, as well as younger fish.
“This time of year is when the salmon and trout come to find spawning grounds and we’re seeing some small dead fish, so it could have quite an effect on the populations,” he added.
“To have this happen is just absolutely devastating, and it’s not the first time that it’s happened.
“There is difficulty trying to do sort of autopsies on fish to see what may have been the cause.
“It could be years before we actually find out what happened.”