The latest scientific evidence confirms that Northern Shelf cod is a combination of distinct cod populations that seasonally overlap in northern shelf waters, combining to form (at least) three biologically distinct substocks: the Southern substock, the Northwestern substock, and the Viking substock. All three substocks mix outside their spawning season. A lack of real-time genetic data means that managing these substocks separately is currently impossible.  

The southern substock is now below critical biological limits (B_lim); therefore, recent advice has called for zero catch to protect this most vulnerable component and to allow for stock rebuilding (ICES, 2025). 

The tiger team aims to strengthen the scientific basis for assessment and advice, ensuring more robust management of Northern Shelf cod. Work commenced in September 2025 and is expected to be finished in August 2026. The revised assessment and forecast developed by the team will be used as the basis for draft advice for 2027. Regular updates and opportunities for stakeholder engagement will be provided throughout this period. 

Assessing assessments  

Due to the uncertainties about the stock structure and extent of mixing between substocks, the Advisory Committee (ACOM) decided to establish a review-level benchmark of the Northern Shelf cod stock assessment. The objective of this process is to explore alternative options to provide a robust assessment for the stock complex and new ways to translate that into management advice options that reflect the complexities and uncertainties.  

This review-level benchmark allows for a focused, expert-driven evaluation of assessment models and data integration. This process is more agile than a full benchmark, enabling timely responses to urgent stock assessment issues. 

A team of technical experts 

The tiger team is a group of technical experts drawn from ICES member countries that fish Northern Shelf cod and beyond. Chaired by Steven Cadrin (US), it includes members from our Working Group for the Assessment of Demersal Stocks in the North Sea and Skagerrak (WGNSSK) and additional specialists to ensure diverse expertise and geographic representation. Selection was coordinated by ICES Advisory Committee Chair Colm Lordan in consultation with ACOM leadership and ICES Secretariat. 

The team will first review all available data and the current assessment framework. It will then prioritize improvements to assessment and forecasting methods. A short-term workplan (September 2025–August 2026) will address immediate challenges with the aim of providing a revised assessment and forecast as the basis for advice in 2027, while a medium-term plan will identify data gaps and research priorities for the next full benchmark. Throughout the process, it will provide regular and transparent updates within ICES and to external requesters and stakeholders. 

Stakeholder engagement 

The tiger team operates as a technical subgroup under Working Group on the Assessment of Demersal Stocks in the North Sea and Skagerrak (WGNSSK), and follows ICES Guidelines for Benchmarks. This approach allows the team to work efficiently on complex scientific and modelling issues. While current ICES Observer Rules do not support stakeholder observers in review-level benchmark processes, ICES is committed to transparency and stakeholder engagement in all our processes. We will schedule update meetings with stakeholders to provide opportunities for industry input at appropriate stages. The first of these will take place at 14:00 CET on 18 December. Contact the Secretariat for a meeting link​.  

For further information or to provide input, stakeholders are encouraged to contact ICES or follow updates on ICES website. ​