Anglers have been asked to report any sighting of Pacific pink salmon in Irish rivers and waterways over the coming months.
The non-native species unexpectedly appeared in unprecedented numbers in multiple river systems in the southwest, west and northwest of Ireland in 2017, 2019 and 2021.
Inland Fisheries Ireland has said that as the fish predominantly have a two-year lifecycle there is potential for them to reappear in Irish rivers again this year.
A Senior Research Officer at Inland Fisheries Ireland said that the presence of large numbers of Pacific pink salmon "potentially pose a competitive threat to the survival of our native species such as Atlantic salmon and sea trout".
Dr Michael Millane said they were calling for "anglers and other water users to quickly contact us regarding any sightings".
"As these fish die after spawning, some dead specimens could also be encountered along Irish rivers," he said.
Anglers or members of the public can report encounters with pink salmon to the IFI's 24/7 phone number, 0818 34 74 24, or via info@fisheriesireland.ie.
They are also asked to photograph the fish and record the date and location it was found in, as well as its length and weight.
Anglers are also asked to retain the salmon, even in rivers that are only open for catch and release angling.
The IFI has said that their nearest staff member will arrange collection of the fish for further examination.
