International Council for the Exploration of the Sea
WGScallop Interim Report 2022.pdf (5.19 MB)

Scallop Assessment Working Group (WGScallop; Outputs from 2022 meeting)

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posted on 2024-01-25, 08:07 authored by ICESICES

The ICES Scallop Assessment Working Group (WGScallop) discusses scallop surveys, stock assessment methodologies, advances in technology, scallop aging procedures, and recent studies on scallop species to develop and improve stock assessment methods.

The group welcomed four new members this year and spent time discussing diversity and inclusion to ensure that we are doing everything possible to make this working group accessible and welcoming. This WG will continue to work with ICES to ensure that progress continues, and we are very pleased that we have several PhD students who participated in the meeting.

Several group members contributed to the review paper, “A global review of catch efficiencies of towed fishing gears targeting scallops” being published in “Reviews in Fisheries Science and Aquaculture”. This paper provides an in-depth review and discussion of the factors which influence catch efficiency, relating the considerable variation in the catch efficiency estimates (0.1 to 0.7) to scallop size and substrate type as the two most important factors.

Work on progressing a stock assessment for the Irish Sea included five intersessional subgroup meetings which involved members of the Working Group on Operational Oceanographic products for Fisheries and Environment (WGOOFE). Members of WGScallop have been using available Vessel Monitoring Systems (VMS) data and logbooks to consider various models (Vector Autoregressive Spatial-Temporal Model (VAST) and SPict) and standardized survey indices. A stock annex has been drafted for king scallops in the Irish Sea. 

Surveys continue to be integral for many of the institutes and the WG discussed the possibility of staff exchanges between surveys and have also agreed to hold an intersessional meeting to discuss survey design and related common issues. 

This was the third year of submitting a data call and there continues to be issues with the data quality. ICES Secretariat presented an overview of the Regional Database Estimation System (RDBES) and the group have agreed to use this framework. There will be a period of overlap and intersessional work will include a comparison between the datasets (WGScallop data call and RDBES).

Work continues on scallop stock connectivity, larval dispersal and genetics, and the WG were given a presentation from the Stock Identification Methods Working Group (SIMWG). The WG will continue to discuss options for mapping of VMS data and aim to draft a paper which will address the issues previously reported. The WG continues to work alongside the Workshop on Scallop Aging (WKSA) and are pleased that a workshop will be held in 2023.

The WG discussed the ToR, identified leads for each and agreed to further discuss the two interrelated ToR (B and C) considering options for combining work areas.


Published under the auspices of the following ICES Steering Group or Committee


Published under the auspices of the following ICES Expert Group or Strategic Initiative



ICES Scientific Reports





Contributors (Editors)

Lynda Blackadder

Contributors (Authors)

Rhei Ammaturo; Samantha Bampleid; Francis Binney; Lynda Blackadder; Isobel Bloor; Simone D'Alessandro; Adam Delargy; Helen Dobby; Mairi Fenton; Spyros Fifas; Eric Foucher; Ellen Grefsrud; Jessica Harvey; Natalie Hold; Jónas Jónasson; Shona Kinnear; Andy Lawler Guillermo Martin; Carrie McMinn; David Murray; Nikolai Nawri; Dave Rudders; Tiago Silva; Bryce Stewart; Kevin Stokesbury; Claire Szostek; Oliver Tully; Karen Vanstaen; Fabian Zimmermann



Recommended citation

ICES. 2023. Scallop Assessment Working Group (WGScallop 2022). ICES Scientific Reports. 5:08. 75 pp.

Publication language

  • en

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  • PDF

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