An ecological disaster faces the Ounavarra River in Co Wexford, after the biggest spillage in the eastern region this year destroyed plant and animal life. It has resulted in the death of thousands of fish.
An agricultural spillage into the Bracken River, a tributary of the Ounavarra, is believed to be responsible.
Sgt John O'Riordan, chairman of the local Ounavarra Angling Club, predicted yesterday that the spillage would destroy the whole ecosystem down to the sea at Courtown Harbour.
"It's by far the biggest spillage to hit the area. It is going to kill everything in the river for the next few weeks, and it's slowly working its way down to Courtown Harbour."
He said that the spillage first came to attention around noon on Friday at Smith's Cross, Springmount, on the Gorey side of Ballycanew. It had serious implications for the future of the river and the angling club.
Officers from the Eastern Regional Fisheries Board have examined the devastation, and samples have been taken for analysis.
Up to Monday afternoon, some 4,000 dead fish were taken from the river.
One local fisherman said yesterday that they had taken another 4,000 from the affected area.
Another fisherman said gannets were now eating the fish.
The dead fish include large numbers of wild salmon, white trout, brown trout, lampreys, stone loach and minnows.
Wexford County Council environment officer Mr Eamonn Hore confirmed yesterday that the pollution had made its way down the river system and out to sea.
"It's very serious, and the river will take years to recover."
Mr Hore did point out, however, that oxygen levels were back up in areas where the pollution passed through, and that another tributary, the Banoge, was unaffected.
He added that the county council would be seeking prosecutions under Section 12 of the Water Pollution Act.
Fisheries environment officer Mr Donnachadh Byrne confirmed that the spillage was "easily the biggest one in the eastern region this year", with about 6km of the Ounavarra and 5km of the Bracken affected.
He said he presumed the river would recover, but it would take a long time.
Meanwhile people are being warned not to eat any fish from the river.