Publication Abstract

The objective of the thirteenth Workshop on the Development of Quantitative Assessment Methodologies based on Life-history traits, exploitation characteristics, and other relevant parameters for data-limited stocks (WKLIFE XIII) was to further develop methods for stock assessment, stock status, and catch advice for stocks in ICES categories 2–6, focusing on the provision of sound advice rules adhering to the ICES advisory framework and principles for fisheries management. The meeting comprised of 22 presentations from participants, and discussions and working sessions on data-limited topics. A living document with frequently asked questions (FAQ) on the data-limited advice rules developed by WKLIFE was drafted to supplement the technical guidelines and help implementation. Work on improving the method to provide advice for ICES stocks in categories 4-6 is ongoing and an empirical approach that uses catch and catch length data to estimate stock trends was explored and shows promise but is not yet ready for application. For the ICES Stock Category 2 approach with the surplus production model SPiCT, simulations were conducted to evaluate the performance of (1) lower fractiles on the predicted catch distribution in the short-term forecast for biennial advice and (2) advice constraints when transitioning to a SPiCT assessment. Based on this work, it is recommended to change to a lower fractile for vulnerable species in the ICES technical guidelines. Additionally, the inclusion of length data into SPiCT was trialled to make it applicable in more data-limited situations without biomass indices. Furthermore, work was presented on spatial indicators, stock-specific simulations for data-limited stocks to tune harvest control rules, a review of existing information and recommendations that could help improve data collection for certain deepwater stocks, the application of methods to species with specific life-history traits, the use of SPiCT and empirical harvest control rules in Japan, and multi-species considerations to help reconstruct fishing histories for data-limited stocks. A collaborative project between FAO and ICES on data-limited approaches providing synergies is currently being developed with input from WKLIFE. The ICES technical guidelines for ICES stocks in categories 2 and 3 were reviewed during the workshop and further clarifications were suggested.

Patrícia Amorim, Paul Bouch, Ella Brock, Liese Carleton, Wendell Medeiros Leal da Silva, Rufus Danby, José De Oliveira*, Niall Fallon, Simon Fischer*, Jan Horbowy, Laurence Kell, Peter Kidd, William Lart, Tanja Miethe, Tobias Mildenberger, Mitsuyo Miyagawa, Tine Nilsen, Carl O’Brien*, Marta Cousido Rocha, Maria Soto Ruiz, Lucas Santos, Rehab Farouk Abdelfattah Soliman, Anthony Thompson, Robert Thorpe*, Rui Vieira*, Nicola Walker*, Tatsunori Yagi, Fabian Zimmermann

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