Status of the Tana/Teno River salmon populations in 2022
Research report
Åpne
Permanent lenke
https://hdl.handle.net/11250/3041641Utgivelsesdato
2023Metadata
Vis full innførselSamlinger
Sammendrag
Anon. 2023. Status of the Tana/Teno River salmon populations in 2022. Report from the Tana/Teno Monitoring and Research Group nr 1/2023.
This report is the sixth status assessment of the re-established Tana/Teno Monitoring and Research Group (MRG) after the 2017 agreement between Norway and Finland. After a summary of salmon monitoring time series in Tana/Teno, we present an updated status assessment of 8 stocks/areas of the Tana/Teno river system. All stocks are evaluated in terms of a management target defined as a 75 % probability that the spawning target has been met over the last four years. A scale of four years has been chosen to dampen the effect of annual variation on the status.
Assessing the stock status is answering the question about how well a salmon stock is doing, how many salmon were left at the spawning grounds and how many should there have been. The question about how many salmon should spawn has been addressed by the defined spawning targets for the different populations (Falkegård et al. 2014). The unprecedented situation in 2021 and 2022, when a total moratorium of salmon fisheries was put in place both in the Teno/Tana river system and in large areas in Tanafjord and in adjacent coastal areas, meant that in contrast to the several alternative ways of estimating the spawning stock used in earlier years (Anon. 2020), only direct counts of ascending and spawning salmon were used in the assessments in 2021 and 2022 because of the absence of salmon catches.
The map below summarizes the 2019-2022 stock status of the evaluated parts of the Tana/Teno river system. Symbol colour designates the management target, defined as probability of reaching the respective spawning targets over the last four years. The management target was classified into five groups with the following definitions:
1) Probability of reaching the spawning target over the last four years higher than 75 % and attainment higher than 140 % (dark green color in the summary map below)
2) Probability higher than 75 %, attainment lower than 140 % (light green)
3) Probability between 40 and 75 % (yellow)
4) Probability under 40 %, at least three of the four years with exploitable surplus (orange)
5) Probability under 40 %, more than one year without exploitable surplus (red)
Based on the status assessment, seven of the eight evaluated areas had a management target below 40 %, and six of the areas were placed in the worst (red) status category with no exploitable surplus in at least two of the last four years.
Of the stocks with poor status, the most important thing to note is the status of the upper main headwater areas of Kárášjohka, Iešjohka and Anárjohka/Inarijoki (evaluated in last years report) and of the Tana/Teno main stem. These areas, which constitute 84 % of the total Tana/Teno spawning target, have had consistently low target attainment and low to none exploitable surplus over several years.
To conclude, the situation for different salmon stocks of the Tana/Teno system in 2022 continued to show an overall negative status with very low spawning stocks and low estimates of pre-fishery abundance. The numbers of large MSW salmon were particularly low, in line with what was predicted for 2022. Overall low returns of 1SW salmon continued, and it is therefore expected that the return of MSW salmon will continue to be low also in 2023 and that there likely will not be any sustainable surplus available.
Given the critical red status category for 6 of 8 assessed areas, the biological advice, based on the recommended stock recovery procedure given in Anon (2022), is that no exploitation should take place for stocks placed in the red category. until the forecast indicates the return of an exploitable surplus and status categories increase to at least orange.