ICES Guidelines - Advice rules for stocks in category 2 and 3

This is a new edition of `ICES technical guidance for harvest control rules and stock assessments for stocks in categories 2 and 3', ICES Technical Guidelines, previous version: https://doi.org/10.17895/ices.pub.26056306

The new edition includes clarifications and changes to Method 1 (SPiCT) so that it aligns with the recommended calculation of catch advice based on a SPiCT; includes possibility of lower fractiles for vulnerable stocks; and alternative SPiCT HCR can be used for accepted but more uncertain SPiCT assessments. It also includes clarifications to Method 2 without changes to the methods.

Correction 05/03/25: Minor edits to table 1, section 5 and equation 6 to correct inconsistencies between equations and text description.

Stocks classified in categories 2 and 3 by the International Council for the Exploration of the Sea (ICES) are considered to be "data-limited". This document is designed to provide clear guidance on the rationale, use, and application of methods to assess stock status, provide catch advice, and short-term forecast for stocks of finfish and shellfish in ICES category 2 and 3 using either the MSY approach or the Precautionary Approach. The primary purpose of these guidelines is to outline the best available scientific methods and advice rules to manage these stocks effectively and sustainably. The intended audience includes scientists working with stock assessment and scientific advice, and other stakeholders involved in the management and conservation of marine resources. These guidelines serve as a comprehensive resource, offering detailed methodologies and advice rules that have been developed and tested to ensure sustainable fisheries management objectives in alignment with biodiversity goals.