On the basis of the outcomes of WKLIFE VII–X (2017–2020), WKSPRAT 2018, WKSPRATMSE 2018, and WKDLSSLS I–II (2019–2020), this workshop will focus on the following issues:
1) Test different assessment methods for data-limited short-lived species (seasonal SPiCT, depletion models, stage-based biomass models, others) and provide guidelines on the estimation of MSY proxy reference points for category 3–4 short lived species.
a) Further work on assessment methods of stock status relative to MSY concept or other reference points either with surplus production models or with simpler analyses of historical catches, the abundance indices, or others.
b) Improved fitting of SPiCT or other surplus production models for different fish and cephalopods case studies stocks accounting for their particular catch and abundance index series.
c) Further testing of SPiCT advice rules for management for short-lived species. Evaluation of the performance of these rules either alone or in combination with uncertainty caps and biomass safeguards.
2) Further explore the appropriateness of the other management procedures for short-lived species based on direct use of abundance indices (category 3) by means of Long-Term Management Strategy Evaluations (LT-MSE). This will involve:
- Revisiting, if required, the trend-based advice rules proposed in WKDLSSLS I & II, testing alternative applications, such as by shifting the uncertainty cap values in time, or testing optimal uncertainty caps allowing advice to return back up to previous fishing levels, etc.
- Further work on applying constant or variant harvest rate strategies in time instead of the trend-based rules (aligned with HCR 3.2.2 Catch rule based on applying an Fproxy in WKMSYCat34). Definition of constant harvest rates MSY proxy and how they vary with assumed catchability and uncertainty of surveys, productivity and life history assumptions and across modelling platforms.
- Further testing of best ways of defining and applying biomass safeguards.
- Testing the effectiveness of the precautionary buffer in mitigating the short-term risks associated with the harvest control rules.
3) Testing simple dynamic rules which can approach maximum sustainable harvest rates (as in Carruthers et al., 2016 and others).
4) Review Current ICES technical guidance on advice rules for stocks in Category 3 for short-lived species and drafting for WKLIFE.
