ICES advises that catches for mackerel in the Northeast Atlantic and adjacent water in should be no more than 782,066 tonnes in 2023
The International Council for the Exploration of the Seas (ICES) has issued its advice on the recommended total allowable catch for Mackerel (Scomber scombrus) in subareas 1–8 and 14, and in Division 9.a (Northeast Atlantic and adjacent waters) in 2023.
ICES advises that when the MSY approach is applied, catches in 2023 should be no more than 782,066 tonnes down on the 794,920 tonnes recommended in 2022.
In the quality of assessment, the ICES found that the only available catch data from Russian Federation for 2021 was total catch by ICES division from ICES preliminary catch database, and no Russian catch samples were available.
Historically, preliminary catches are comparable to ICES final estimated catch. There were adequate samples from other fishing nations operating in the same areas which were used to estimate catch-at-age and weight-at-age. The inclusion of a new year of data modifies the relative weight of the different data sources in the assessment, which leads to revisions of the perception of the stock. In 2022, there has been an upwards revision of SSB and a downwards revision of fishing mortality for the period 2007 to 2017, and a revision in the opposite direction for the most recent SSB and F estimates. The relative weights of the data sources in the assessment are dependent on both the length of the time-series and the consistency of the information. With the new data included this year, the influence of the tagging data in the assessment model increased slightly. The abundance index for age 0 from the IBTS surveys could not be updated, and no value was available for 2021; however, this has no effect on the advice. The SSB index from the 2022 mackerel egg survey used in this year’s assessment is a preliminary value, and it is 26% larger than the previous estimate in 2019. The final value will be used in next year’s assessment. The stock assessment and the short-term forecast include ages from 0 to 12. The abundance estimates at ages 0 and 1 are highly uncertain, and year-class strength only becomes apparent when fish enter the fishery at age 2 to 3. Therefore, this year, recruitment is presented for age 2.