A new study published in the Nature Journal, Scientific Reports reveals the marine migration route of Atlantic salmon in the North Atlantic. Led by Arctic University of Norway, it involves co-operative research by 10 universities and institutions across Europe.
The survey required tagging 204 salmon kelts with satellite tags from seven European countries, including Ireland’s Barrow, Nore, Suir and Blackwater, and the east coast of North America, and tracked them during their oceanic migration.
Salmon travelled to oceanic fronts, but with specific patterns. Norwegian and Danish salmon migrated towards the north Atlantic between Iceland and Svalbard. In contrast, Irish salmon headed towards south and east Greenland. Despite the variation, most migrated to polar ocean frontal areas.
Salmon released further south tended to cover longer distances, with a straight-line tracked 2,400km for one salmon from the river Suir. Tagged salmon spent 80 per cent of their time foraging at the surface and performed occasional dives up to 870m.
Overall, populations closest in proximity tended to converge in their oceanic feeding area, but taken together exploited a very large part of the ocean. Given that Atlantic salmon from different geographic locations feed in distinct areas at sea, they experience different temperature regimes.
For example, Irish salmon experienced much warmer temperatures, ranging from 5 to 16°C, whereas Norwegian and Danish salmon adapted to temperatures from 0 to 11°C. These differences not only contribute to variation in growth and survival, but are likely to impact on Atlantic salmon differently with changing climate.
Southernmost populations, like those of Ireland, are more at risk than northernmost as migration distances are likely to become longer, thereby decreasing feeding time, with consequences for marine survival of different populations.
Taken together these findings suggest that a common marine factor responsible for the decline in Atlantic salmon is unlikely. Importantly, this means conservation efforts should be focused locally, such as during the freshwater phase.
One of the authors, Dr Paddy Gargan of Inland Fisheries, said: “This new research is suggesting that this type of climate change may have greater impact on salmon populations originating further south, like Ireland. This is because distances and time required to travel to feeding areas will increase if the boundary between Atlantic and Arctic waters move northward because of ocean warming.”
The full study, Redefining the oceanic distribution of Atlantic salmon, can be found at Nature.com at https://doi.org/10.1038/s41598-021-91137-y
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A group of experienced women anglers were due to complete an angling coach training course in Waterford this week, making it a first for women in Ireland to achieve this award.
As angling is predominately male dominated this is huge for women in sport and for angling coaching as numbers involved in coaching continue to dwindle.
(Full report in next week’s angling notes.)
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Organisers of the Irish Game Fair & Fine Food Festival, planned for Shanes Castle, Antrim, on July 31st-August 1st, 2021, have reluctantly declared that the fair will be postponed until 2022.
Director Albert Titterington said: “We had no option other than to postpone given the uncertainty regarding Covid restrictions going forward in Northern Ireland. Factoring in the potential new risk from the Delta variant, we had to postpone the Game Fair until June 25-26th, 2022.
“Between now and 2022 we will be implementing our ‘plan B’ to build on success of the Virtual Game Fair www.thevirtualgamefair.com. Impressively, for a relatively new internet start-up, there have been upwards of 203,000 visitors since its launch in August last year.”
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