Benchmark workshop on Northern Shelf cod stocks (WKBCOD)

The North Sea cod stock was last benchmarked in 2021 including a workshop on Stock Identification of North Sea Cod (WKNSCodID) reviewing the population structure information on the cod in the North Sea and adjacent waters. The workshop concluded that the North Sea includes different stock components of Viking and Dogger cod, and that the Dogger cod population extends to the West of Scotland (6.a.N). However, it was not possible to develop spatial approaches in time for the benchmark in 2021 because of (1) unexplained discrepancies between spatially disaggregated data and the data as used in the current North Sea assessment; and (2) the constraint that the 6.a stock was not included in the benchmark process. Nevertheless, the North Sea cod assessment was improved by revising the survey indices, biological data, and SAM assessment model configuration, thus lessening the data and assessment issues that had triggered the benchmark process. ICES recommended that further work be conducted on a data call to consider the different stock components as well as inclusion of the West of Scotland cod stock in the evaluation. This stock was last benchmarked in 2020 at WKDEM (ICES, 2020). Several pre-data meetings were conducted with the data providers to ensure that the data asked for in the data call met the requirement of the stock assessors, and were realistic to provide for the relevant countries. The data set on landings for the substocks components covering 1995– 2021 were evaluated at the data evaluation meeting and was found appropriate to use for the assessment. Presently the North Sea cod time series starts in 1963 and it would therefore be beneficial if the landings by substock could be extended further back in time. For the landings data covering the time period 1963–1995, ICES has a historic database with information on annual cod landings by area. It was decided to investigate if these data could be converted into landings by substock with some country specific assu