Fears over impact of Mayo fish escape on wild salmon
One of the fish that has been traced back to the Killary escape.
There are fears that farmed salmon that escaped from a cage on the Mayo/Galway border will breed with wild salmon and weaken the species.
There was a substantial release of farmed salmon last August from a cage in Killary Harbour on the Galway/Mayo border.
An estimated 10,000 to 30,000 farmed salmon escaped from the facility operated by Mannin Bay Salmon Company.
They were confirmed to have entered 12 rivers in Mayo and Galway but may have reached 30 in total.
Upriver migration of farmed fish was well over 100km in both north and south directions from the presumed source of the incident.
An investigation report into the escape was recently published.
Dr Seán Kelly of Inland Fisheries Ireland (IFI), who led the investigation, said: “The substantial geographical spread over which escaped farmed salmon were confirmed - in a critical region for wild Irish Atlantic salmon populations - is particularly concerning.”
While farmed fish carry diseases that can spread to the rapidly declining population of Atlantic wild salmon, interbreeding is a further concern.
Around 20pc of the escaped males were sexually mature and scientists at Inland Fisheries Ireland (IFI) fear they could have bred with wild counterparts.
“They can pose a significant threat to wild salmon populations through genetic contamination, impacting the overall ability of future salmon generations to survive in the wild,” said Dr Cathal Gallagher, IFI’s head of research.
Salmon suspected to be of farmed origin were caught by anglers in August and September 2024 in Mayo and Galway, and also at IFI’s fish trapping facility at the National Salmonid Index Catchment.
Escaped farmed salmon were initially identifiable by having an out-of-season silver appearance.
IFI thanked all anglers who presented suspected farmed salmon specimens to staff for verification at IFI’s River Erriff research station in Co Mayo.
