Marine Institute says fish either migrated to the sea or ‘succumbed’ to predatory mammals.
Marine mammals, including seals and dolphins, are believed to have consumed a significant portion of the 7,000 to 8,000 farmed salmon that escaped from a damaged pen in Killary Harbour, Co Galway, earlier this year, according to an unpublished preliminary report by Ireland’s Marine Institute, cited by the Irish Independent.
The report suggests that empty stomachs in recaptured fish indicate they struggled to adapt to wild feeding conditions. Most of the escaped salmon are thought to have either migrated out to sea or fallen prey to predators.
The escape occurred on August 11 when a well-boat treating salmon for amoebic gill disease caused a tear in the net of one pen during poor weather conditions. The Mannin Bay Salmon Company, operating under Docon Ltd of Co Mayo, estimated the loss at 7,000 to 8,000 salmon, each weighing between 1.5 and 2 kilograms.
The damaged net was repaired and replaced, but the incident was reported to the Department of Agriculture, Food and the Marine on August 13—outside the required 24-hour reporting period.
Inland Fisheries Ireland (IFI) confirmed the recapture of 59 escaped salmon through traps and nets in nearby rivers, including the Erriff and Delphi. Additional efforts by the Marine Institute involved specialist nets west of the site. However, low recapture numbers have been criticized by NGOs, including Salmon Watch Ireland, which argued the lack of a coordinated recapture plan contributed to the shortfall.
Galway Bay Against Salmon Cages (GBASC) described the escape as “massive,” alleging up to 30,000 fish may have escaped, potentially impacting wild salmon populations in nearby rivers.
The Marine Institute reported low sea lice levels on the affected farm and found no lice on a sample of 30 fish from the pen during an August 21 inspection, suggesting minimal risk to wild salmon populations. It also dismissed concerns raised by Salmon Watch Ireland over potential antibiotic-related risks to human health from escaped fish.
However, Salmon Watch Ireland questioned the Marine Institute’s assertion that escaped salmon are unlikely to inter-breed with wild stocks, citing international evidence of inter-breeding in Norway.
