WGCATCH contributes to ensure the quality of commercial catch data, which underpins stock assessments and advice. At this year’s WGCATCH meeting all the proposed ToRs were covered and objectives were met. The group started documenting the national estimation procedures (Section 3.2). Most of the countries use ratio estimators for their estimation. Recent discussions at WGCATCH and other EGs have increasingly highlighted that estimation techniques currently used by many countries to process commercial catch data may not be the most up-to-date and/or ignore sampling design and/or are far from transparent and/or involve significant levels of ad-hoc decisions. Therefore, WGCATCH recommends a series of practical workshops on estimation procedures for the next 3 years to produce best practice guidelines for choosing methods and variables used to raise commercial sampling data. Under ToR a.3, the sample size thresholds used for national data provision were documented. WGCATCH discussed extensively use of specific thresholds, however, it is not possible to come up with a single universal rule to be ap-plied across all countries and stocks. Instead, WGCATCH advises that specific analytical steps are taken during the benchmark process to test and evaluate the impacts of applying or not thresholds to national data before providing the data to the assessment. Intersessional work was carried out to develop tools to be used by the data submitters and stock coordinators to under-stand and summarise the quality and quantity of the data provided to Intercatch (Section 3.3).

The work developed under SSF, ToR b), continued to develop best practice guidelines on SSF data collection, with quantitative analyses on the coverage/completeness of fishing activity. PCA analysis was carried out of data incompleteness issue or over-declaration to build a risk’ map where each country*area is positioned (Section 4.2). The sub-group reviewed the proposed CL and CE data formats from RDBES core group to accommodate ‘scientific’ and ‘official’ estimates to cover SSF data gaps. One of the main issues with this proposal was the lack of transparency that needs to be addressed (Section 4.4). The strengths and weakness of using ERS for monitoring SSF were also assessed (Section 4.3).

Under ToR c), sampling and estimation of by-catch species, the main focus during this year’s meeting was to review the definitions of sorting, hauling and slipping processes for each gear type and how to implement in on-board protocols (section 5.2); and a detailed description on how to sample protected species on-board commercial vessels (Section 5.3). The RDBES structure was also reviewed to assess if it is suitable to accommodate the necessary information for WGBYC needs (Section 5.1).

WGCATCH continued to review the work developed under the RDBES. The documentation of the current estimation procedures will contribute to the prioritization of the estimation methods to be implemented as standard methods in the RDBES system. The series of practical workshops, proposed by WGCATCH, on estimation procedures for the next 3 years to produce best practice guidelines for choosing methods and variables used to expand commercial sampling data will also contribute to the development of the RDBES, as they will focus on the best statistical meth-ods to expand the commercial sampling data.

Given that this is the third year of the current term of WGCATCH, future needs in line with the ICES objectives and Science plan were identified and a future work plan was proposed.