Angler describes 'chemical smell' at fish kill scene
A fish kill is being investigated on the Three Mile Water near Newtownabbey in County Antrim.
The number of fish affected has not been confirmed but the source of the pollution has been identified.
David North from Mossley Mill Angling Association, which manages the Three Mile Water, told BBC News NI that "a mile and a half of the river is dead".
He described a "chemical smell", with "dead fish in every pool".
Stormont's Department of Agriculture, Environment and Rural Affairs (Daera) said it received a report indicating there was "agricultural effluent" in the river on Wednesday.
The Northern Ireland Environment Agency (NIEA) has deployed water quality inspectors to assess the impact on the river.
The NIEA is now carrying out a joint investigation with Daera's Inland Fisheries staff.
The Three Mile Water flows through Newtownabbey via Monkstown into Belfast Lough.
The river is known for its trout and salmon.
It is understood many of both have been killed, from young fish to mature adults.
"The fish are dead, the invertebrates in the water are probably dead," Mr North told BBC News NI.
"Anything that feeds on the fish - otters, kingfishers and herons will go somewhere else. They can't stay on the river if there's no feeding," he explained.
"It's just a disaster," he added.
The Three Mile Water has been the site of several fish kills in recent years.
In 2015, a local angling group said hundreds of trout and salmon were affected in what the NIEA described at the time as a "moderate" incident.
In June 2021, the remains of several hundred trout were recovered from the river, many of them of spawning age, due to suspected pollution.
Then just over two months later, a pollutant with a "significant quantity of a detergent" spilled into the waterway, resulting in a major fish kill.