Scallop Assessment Working Group (WGScallop; outputs from 2025 meeting)

The ICES Working Group on Scallop Assessment (WGScallop) aims to advance the assessment and understanding of scallop stocks across ICES regions through collaborative data analysis, methodological development, and strategic planning. The group’s objectives include improving survey design, refining stock assessment models, and evaluating environmental and anthropogenic impacts on scallop fisheries.This report addresses key questions related to the consistency and reliability of data submitted through WGScallop and RDBES (Regional Database and Estimation System) data calls, the development and comparison of stock assessment models, and the integration of environmental factors such as offshore wind farm development into fisheries assessments. It also explores the potential for defining scallop stock boundaries through genetic and dispersal studies.Key findings include continued discrepancies in effort data between WGScallop and RDBES data call submissions, particularly in UK reporting, which may affect the reliability of spatial analyses. Progress was made in applying SS3 (Stock Synthesis 3) and SAM (State-Space Assessment Model) models to king scallop data, with intersessional meetings supporting model development and comparison. Survey exchanges and methodological comparisons across jurisdictions have strengthened collaborative learning, and a multidisciplinary survey proposal is underway to assess wind farm impacts in the Irish Sea. Advances in larval dispersal modelling and population genetics were presented, highlighting the need for further expertise in these areas. The group also initiated work to map renewable energy developments in relation to scallop fishing activity and began drafting a report on age determination methodologies. A framework for a queen scallop review paper was agreed, with drafting to begin intersessionally.Future priorities include refining data submission protocols, expanding expertise in genetics and modelling, continuing collaborative efforts with the Stock Identification Methods Working Group (SIMWG) to inform future directions for defining scallop stock boundaries and organising intersessional work on survey standardisation and queen scallop review efforts.