Working Group on North Atlantic Salmon (WGNAS)
WGNAS met to consider the status of and threats to Atlantic salmon in the North Atlantic Salmon Conservation Organisation (NASCO) commission areas: West Greenland (WGC), North American (NAC), and Northeast Atlantic (NEAC). Many updates are provided for 2021 and 2022 as WGNAS was not able to address all terms of reference (ToRs) in 2022. Information on the catch and exploitation, including salmon caught and released, and nominal harvest, as well as tagged and marked fish releases are provided by country and jurisdiction. Emerging threats are presented, including the first report of Infectious Salmon Anaemia (ISA) in Iceland, red skin disease in Europe, and Norway is evaluating new offshore farming sites. New scientific advancements reported on include non-lethal Gyrodactylus treatment, homewater return rate estimation methods, and genetic tools to understand the reproductive success of salmon that have been caught and released. ICES did not conduct a full assessment for salmon in NEAC because the Framework of Indicators (FWI) did not indicate that the forecast estimates of abundance for the four NEAC stock complexes had been underestimated.
WGNAS was asked to provide information on three key issues in 2023, namely:
1. the causes of variability in return rates between rivers within regions of the North Atlantic, concluding that factors at river-specific, regional and oceanic scales interact to affect marine survival rates and maturation schedules, and it is unlikely that a single factor alone accounts for temporal variations and the decline of wild salmon in the North Atlantic;
2. the current state of knowledge on freshwater and marine predation by cormorants, concluding that cormorants can have substantial impacts on salmon abundance in areas where cormorant populations have increased or declines in other cormorant prey abundance have occurred, an issue of special concern where salmon populations are already threatened or endangered; and,
3. an evaluation of the risk of salmon bycatch occurring in pelagic and coastal fisheries, and effectiveness and adequacy of current bycatch monitoring programmes, concluding that ICES ability to evaluate the risk of bycatch is limited because few pelagic fisheries are screened for bycatch and screening covers small proportions of catch. To advance our capacity to evaluate such risks, a series of data deficiencies, monitoring needs and research requirements are identified.
Looking forward, a Bayesian life-cycle assessment model and data inputs were discussed in connection with the 2023 benchmark.
Published under the auspices of the following ICES Steering Group or Committee