The true extent of damage caused by a 400,000 litre slurry spill won’t be known for weeks according to Ballinderry Rivers Trust, but so far it has killed 57 juvenile trout.
The incident, which took place last Wednesday, polluted around three miles of the Ballinderry River before it reached Lough Neagh.
And whilst the full impact is not yet known, the trust’s manager Mark Horton, told the MAIL it could kill every creature living within that stretch of river, and has called on landowners to look at what they can do to prevent it from happening again.
“We’re not sure exactly what caused the spill,” he said. “We just know that it was an above-ground slurry store, and that it was pretty much empty by the time that the landowner realised.
“In terms of its impact,” he went on, “it’s hard for us to know that just at the minute because the river was in flood when it happened — which means that we couldn’t get out and see if there were any fish killed.”
But Mr Horton explained that, even if the flooded state of the river diluted the threat, the true impact of the spill won’t be known for at least three weeks, when baby fish should have hatched from their eggs on the river bed.
“When slurry gets into the water it’s not actually the slurry that kills the creatures in the river, it’s the bacteria in the slurry that consumes the oxygen in the water,” he said.
“You don’t see the impact of a pollution event at the point where the pollution happened, because it takes a while for all that oxygen to get sucked out.”
When asked whether anything could be done to protect the fish, Mr Horton said there was no remedy for slurry spills — and has called on farmers to prevent this happening again.
As well as potentially killing flies and fish in the affected part of the Ballinderry River, it could also have a knock-on effect on otters and birds like kingfishers and herons, which rely on fish to survive.
“What’s important now is that we work with people to make sure that it doesn’t happen again,” he said.
Meanwhile DCAL Inland Fisheries have advised Department of the Environment (DOE) that 57 juvenile trout were found dead in a small river downstream of the farm, which has been classed a medium severity fish kill.
A DOE spokesperson said: “The Northern Ireland Environment Agency is continuing to investigate the circumstances of this incident and is carrying out a detailed survey of the surrounding waterways.
“A clean-up of slurry from the farm is still ongoing.”