65 farmed salmon have been caught in five rivers in counties Mayo and Galway.
Inland Fisheries has confirmed that 65 salmon have escaped from salmon farms and have turned up on the Delphi, Erriff, Newport, Bunowen and Kylemore/Dawros rivers.
Analysis on some of the fish has shown that several male fish were mature on capture and had the potential to spawn - this would have an impact on the integrity of the native salmon stock.
Salmon farm owners are obliged under their licence conditions to report all escapees to the Department of the Marine, but the Dept has confirmed that no such report has been received.
Inland Fisheries Ireland is cautioning against the renewal of licences where conditions are not being adhered to.