Salmonids are the family of fishes that include salmon and trout. Atlantic salmon populations have been in decline across North Atlantic since the late 1980s. A decline has also been noticed in the sea trout population along the west coast of Ireland, with an abundance of sea-lice, which has been associated with linked to intensive fish-farming activities.
Gaps in our knowledge
Relatively little is known about the marine ecology of sea trout and salmon around the west coast of Ireland. The Salmonid West Project will use acoustic telemetry to investigate the migration, distribution, habitat usage, and survival of sea trout and salmon smolts in the marine environment, with a focus on the impacts of sea lice.
A programme of fish tagging
An acoustic telemetry system consists of two main components: transmitters and receivers. Transmitters are electronic tags that broadcast a series of “pings” (sound pulses) into the surrounding water. The electronic tags are surgically implanted into fish of interest and released into the wild; a tagged fish can then be “heard” by any receiver within range, which log the data on pings received to allow analysis of each individual fish's movements.
Expanding to include topical issues
Until 2014, the Salmonid West Project focused on the National Salmonid Index Catchment on the River Erriff, Killary Harbour and the surrounding coastal waters. In 2016, the project expanded to include sea trout marine habitat in Galway Bay because of the potential risks threatened by a large salmon production unit that was planned for the area.
Acquiring the knowledge to guide planning & development
The project will determine factors that may influence the migration and survival of salmon and trout and to identify their key marine habitats. This will improve our understanding of salmonid ecology at sea and help facilitate robust environmental impact assessments for future developments, including windfarms, harbours and aquaculture.