Workshop on the Development of Quantitative Assessment Methodologies based on Life-history traits, exploitation characteristics, and other relevant parameters for data-limited stocks (WKLIFE XIV)

The objective of the fourteenth Workshop on the Development of Quantitative Assessment Methodologies based on Life-history traits, exploitation characteristics, and other relevant parameters for data-limited stocks (WKLIFE XIV) was to further advance methods for stock assessment, stock status evaluation, and catch advice for data-limited stocks. A central focus was on developing robust advice rules that align with the ICES advisory framework, the concept of risk-equivalence, and the principles of sustainable fisheries management.

Participants from 12 countries contributed 35 presentations, alongside discussions and focused working sessions on data-limited topics. Two promising approaches for stock status estimation and catch advice for category 4–6 stocks were further refined during the workshop. Both approaches depend on reliable catch (or landings) information and length data, either by defining rules based on observed trends in these data or by incorporating length-derived indicators as proxies for fishing mortality within biomass dynamic models. Suggested methods were applied to data from stocks with different life histories. Experts on Nephrops stocks highlighted challenges with the approaches used for Nephrops and discussions on shellfish stocks emphasized crossovers for fish and shellfish stocks and considerations of spatial indicators.

Progress was also made on harvest control rules and biomass threshold rules, confirming the recommendations from last year’s workshop to use more precautionary rules for low-productivity stocks, such as deep-sea species. Participants showed the potential impact of not accounting for time-varying productivity and discussed ways these could be incorporated into biomass dynamic models. Biomass limit reference points (Blim) could be improved by basing them on the time needed to rebuild. Case studies and applications from Japan provided additional perspectives on the implementation of data-limited methods in different contexts.

WKLIFE XIV also hosted a dedicated half-day session on a collaborative ICES-FAO deep-sea fisheries (DSF) project. Several case study stocks were introduced within this framework, providing a platform for shared learning and dialogue. Finally, the workshop outlined plans for the development of an open-access GitHub repository to host data-limited methods supported by WKLIFE, with the aim of increasing transparency, accessibility, and guidance for users across the ICES community and DSF project regional fisheries management organisation partners.