Hundreds of fish killed by farm slurry in Somerset river
More than 1,600 fish have died in a Somerset river polluted with slurry, the Environment Agency has said.
Large numbers of fish were spotted "in distress or dying" in the River Frome last week.
The agency said slurry released from a farm had reduced water oxygen levels to 2%. They would normally be above 90%.
Ian Withers, from the agency, said: "We're pretty confident that all of the fish in about four or five miles of the river were killed."
The agency said it had received a number of reports of a "large fish kill" in the River Frome on 12 May.
It is investigating how slurry from the farm ended up in the water and was "currently collating all of the evidence" before deciding its "enforcement response".
Some 1,600 trout, bream and pike were counted by fisheries officers who worked to restore oxygen levels in the river.
But with "many more" fatalities either washed downstream or eaten by wildlife, Mr Withers said it was a "conservative estimate".
"There were certainly more than that, but we will work with the farm - the source of the slurry - to make sure we know what happened, that we've identified the exact cause and make sure that it won't happen again," he said.
The pollution is being treated as a category one incident - the most serious - by the agency.