IT is estimated that hundreds and possible thousands of fish may have been killed on a minor tributary of the Bandon River, south of Dunmanway, near Curraghalicky Lake.
Inland fisheries Ireland (IFI) is currently investigating the fish kill and the species affected include brown trout, juvenile salmon and bream.
IFI officers attended the site on Monday evening following a report from a local angler. Initial investigations indicate a significant algal bloom as the cause of the incident.
Efforts are ongoing to assess the extent of the fish kill and an aerial survey of the lake is underway.
Cork County Council has taken water samples from the lake and river and is liaising with the IFI in their investigation.
Members of the public can report instances of illegal fishing, water pollution of invasive species by calling Inland Fisheries Ireland’s confidential hotline number on 1890 34 74 24 or 1890 FISH 24.