“Do our smolts die in large quantities in the lower river and coastal zone and, if so, why?”
To get a clear understanding of what is happening to smolts during their migration we are developing a Tracking Programme for smolts to monitor their progress towards the open ocean).
Interest particularly in Acoustic Tracking is growing and AST is raising funds to help support local projects undertaking this important research and to gather results to give a national picture of smolt migration and impacts. The AST is working towards establishing an Acoustic Tracking Network Programme and we are fundraising to employ a Coordinator to facilitate the network of projects. Our aim is to work with international partners to move tracking research from the lower rivers and coastal areas progressively outwards towards the salmon feeding grounds.
Benefits of a Salmonid Acoustic Tracking Network include:
- Transferring knowledge and experience
- Cost saving on purchase of equipment
- Shared use of receiver arrays
- Co-operation with projects monitoring other iconic marine species such as whales, dolphins and sharks
- Sharing data to generate a national picture of smolt migration and mortality pinch points.
Environmental DNA (eDNA) Project: Understanding pelagic by-catch
For some time there has been concern about the level of accidental killing of salmon by pelagic vessels at sea during migrations from and to their rivers of origin. Previous research has shown that salmon are caught as a by-catch in pelagic vessels fishing for species such as mackerel and herring, but the extent of such catches is not known.
The AST and University College Dublin are running an innovative project to develop and pilot a pioneering technique to assess the presence or absence of salmon DNA on board ships using environmental DNA (eDNA). The method involves the analysis samples from nets or on-board water samples to identify salmon DNA shed from the fish through scale loss or from slime/bodily fluids. The eDNA collected may also provide valuable information on the origins of salmon in the by-catch, which will greatly add to our knowledge of salmon migration and distribution patterns in the ocean. Other applications for similar eDNA probes include the identification of the presence of Gyrodactylus salaris in freshwater samples or the presence of the organism on items such as anglers tackle, boats and canoes. eDNA also has the potential to assess the presence of fish farms escapees.
The AST firmly believes that ICES (the International Council for the Exploration of the Sea) has now provided convincing evidence of both direct impacts and major risks from open cage salmon aquaculture on wild salmon and sea trout stocks, in terms of both sea lice loadings and genetic introgression from escaped farmed fish.
In light of the recent scientific information on the impacts of Aquaculture the AST has revised and updated its positioning statement on salmon aquaculture. We are looking at ways to urgently and positively move forward the dialogue with the fish farming industry and Government so as to alter fish farm management practices and improve conditions for wild salmon. The full positioning statement can be downloaded by clicking here: AST Salmon Aquaculture Position Statement.