There has been a fish kill on the Owenass River below Mountmellick in Co Laois.
The local anglers claim hundreds of brown trout were found dead in a stretch of the river below a Laois County Council sewage plant.
Laois County Council has admitted that effluent from the plant is believed to have contributed to the fish kill.
The Mountmellick Anglers Association held an emergency meeting last night to discuss the issue and has called on the council to take immediate action to ensure the incident is not repeated.
The River Owenass is a tributary of the River Barrow and is regarded as one of the premier spawning areas for Atlantic salmon in the region.
