The Shannon Regional Fisheries Board has said there was a "very significant" fish kill as a result of the Derrybrien landslide in south Galway last year.
Commenting on the publication of a consultancy study into the cause of the landslide, the board said it would not accept a claim by the ESB subsidiary, Hibernian Wind Power, that the fish kill in the Lough Cutra system was not as extensive as was originally estimated.
Mr Eamon Cusack, chief executive of the Shannon Regional Fisheries Board (SRFB), said preliminary estimates showed that 50 per cent of a total stock of 100,000 fish in the Owendalulleegh river had died as a result of the pollution.
The fatalities included trout, eels, perch and lamprey. The Owendalulleegh river is part of the Lough Cutra catchment.
Scientific assessments are still being carried out on the extent of the kill following the bogslide of October 16th last year, which ran for more than a mile and a half through Coillte afforestation and into the river system.
Mapping of the river's lower stretch was carried out by SRFB and ESB International staff several weeks ago, and a full electro-fishing programme will be conducted in March and April when the waters have receded after winter rain.
Some of the stocks can only be replenished naturally, such as eels, perch and lamprey, but there will be a rehabilitation programme for trout. The SRFB said that its board would discuss possible court action, and the rehabilitation measures, in the coming weeks.
Mr Cusack noted that the board was still awaiting a copy of Hibernian Wind Power's consultancy study on the landslide, which was published on Thursday.
Hibernian Wind Power said yesterday it accepted that the kill was "significant", and was in discussions with the fisheries board in relation to rehabilitation.
The report, commissioned by the company, identified construction on the 60 megawatt wind farm at Derrybrien in the Slieve Aughty mountains as the major cause of the slide.
The company has accepted this finding. It has undertaken to implement the 17 recommendations drawn up by Applied Ground Engineering Consultants (AGEC) before work resumes.
