The workshop further develops methods for stock assessment and catch advice for stocks in categories 3–6, focusing on the provision of sound advice rules that are within the ICES MSY framework and should address the following Terms of Reference:
ToR a) Evaluate potential improvements to the performance of the WKMSYCat34 catch rule 3.2.1 (ICES 2017) as follows:
i) Investigate the impact of relative weighting of the r, f and b components of the rule on the performance of the rule;
ii) Investigate more extensively the time-lag properties of the r component, including alternative formulations;
iii) Explore the setting of appropriate reference levels in the f and b component of the rules, and the extent to which this could be done with tuning that depends on life-history traits and/or the nature of the time-series;
iv) Investigate the use of trends in an index without a reference level.ToR b) Evaluate “MSY-PA" advice rules (WKLIFE VIII; ICES 2018) for stock production models (e.g. SPiCT), and develop recommended guidelines for use in determining catch advice.
ToR c) Establish relationships between simple measures of the life-history (e.g M, K, Lmat) and %SPR reference points to estimate data-limited proxies corresponding to FMSY and Flim.
ToR d) Review and further investigate modelling approaches that incorporate both data-rich and data-limited stocks within mixed fisheries/multi-species frameworks and their ability to provide sea area-based stock assessments and catch advice.
ToR e) Review the draft report of, and recommendations from, the ICES' workshop on data limited stocks of short-lived species (WKDLSSLS) and the need for specific advice rules for these stocks.
WKLIFE IX will report to ACOM no later than 18 November 2019.