The ICES Scallop Assessment Working Group (WGScallop) collates and analyses scallop land-ings data, scallop surveys and methods, scallop ageing procedures and advances in technology in order to further develop and improve appropriate stock assessment methods.

Collated data from the 4th annual data call were reviewed and compared to data from the Re-gional Database Estimation System (RDBES). Further intersessional comparison work will be undertaken and if the two datasets match, then RDBES data can be used routinely and WGScal-lop will no longer issue an annual data call.

Fisheries independent surveys are critical for many stock assessment methods. The WG held an intersessional meeting on survey design and will continue further discussions during 2024. The first staff exchanges on scallop surveys occurred during 2023 and a list of surveys with available spaces for staff exchange have been compiled for 2024.

Scallop larval dispersal models have progressed in Scotland and Northern Ireland. Connectivity work among locations in the Irish Sea found that no significant spatial genetic differentiation among populations at the scale of ~ 400 km. There was however a significant genetic differenti-ation within samples that may be temporally linked to spring and autumn spawning. This hy-pothesis will be investigated using stable isotope analysis of king scallop shells from these two genetically distinct groups.

The Workshops on Scallop Aging have now concluded, and an update is provided.

WGScallop decided to combine two existing terms of reference,ToR B and ToR C, which are closely related and focus on developing stock assessment methods for scallops. A table was pro-duced to highlight the international range of scallop stocks, current data and methods utilised, and a “road map” of best practice was suggested. An intersessional subgroup will meet to further discuss and consider options for a workshop.

New research on modifications to traditional dredge gear,i.e. skid dredges and n-viro dredges, to increase harvesting efficiency and decrease environmental impacts was presented. In addi-tion, invited guests presented novel alternative harvesting methods involving pot fishing and suction methods.