A major fish kill on the River Ilen in west Cork's Skibbereen is under investigation.
Inland Fisheries Ireland said that it is investigating after fisheries officers were alerted to the incident by a call from a member of the public early on Wednesday morning.
Fish mortalities were detected over a two-kilometre stretch of the River Ilen, downstream from the centre of Skibbereen town.
Officers estimate that there were around 2,000 fish mortalities across several species including sea trout, salmon, eel and flounder.
Water and fish samples were taken from the scene by Inland Fisheries Ireland officers and removed for scientific analysis at an independent laboratory.
“Investigations are ongoing and Inland Fisheries Ireland is not in a position to comment on the cause of the fish kill at this stage, pending further analysis of samples taken,” the state agency said in a statement.
The River Ilen provides an important habitat for sea trout and salmon and is one of the prime angling rivers in the south-west of the country.
To report fish kills, members of the public are encouraged to call Inland Fisheries Ireland’s confidential hotline number on 1890 34 74 24, which is open 24 hours a day.