International Council for the Exploration of the Sea
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Working Group on Commercial Catches (WGCATCH; outputs from 2020 meeting)

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posted on 2024-01-25, 07:56 authored by ICESICES

WGCATCH contributes to ensure the quality of commercial catch data, which underpins stock assessments and advice. In order to achieve this, the group documents sampling schemes and estimation methods, establishes best practice guidelines and provides advice on the uses of commercial fishery data. The group also evaluates how new data collection regulations, or management measures, may alter the way data needs to be collected and provides guidelines about biases and disruptions induced in time-series of commercial data. At this year´s WGCATCH meeting, all the proposed Terms of References were covered although some tasks were prioritized due to virtual nature and limited time available at the meeting.

Work under ToR a), guidelines and best-practices for catch sampling and estimation, mainly focused on the planning of work for the next three-year term.

The work carried out under Small Scale Fisheries (SSF) subgroup, continued to review developments in sampling and estimation practices for collection of fishing activity variables (landings by species and fishing effort) and biological data (discards, length and age distributions, other biological parameters) in small-scale fisheries (SSF), with the objective to ensure that the collection of fishing data from SSF across Europe is sufficient for main end-users needs, harmonised and comparable and to improve their quality. Based on the risk assessment methodology developed in 2018–2019 to evaluate the SSF transversal data quality, this evaluation was updated. In addition, the differences in data quality were also compared with the transversal data collected from the Large Scale Fleet and also with the scientific estimates obtained from scientific surveys.

Fishing effort data are regularly used by numerous ICES working groups, including WGBYC, and are one of the fundamental components in the production of bycatch mortality estimates and risk assessments, and along with bycatch rates estimated from sampling programmes and abundance estimates help to improve our understanding of the impacts of fishing activity on many non-commercial and protected species populations and in the development of bycatch management measures. Under the work carried out by the subgroup dealing with Protected, Endangered, and Threatened Species (PETS), the main focus during this year´s meeting was to analyse the differences found between the Regional Data Base (RDB) and WGBYC data base regarding effort data. With this aim in mind, a questionnaire was sent to all WGCATCH members about 3 weeks before their meeting in November 2020. Based on the responses provided, a first analysis of the results was realized to identify what are the main reasons for these discrepancies. The results of this analysis allowed to identify some possible measures (e.g., improvements in the data call) to avoid these differences in effort estimates as far as possible.

In addition, and in order to streamline the data handling towards Advice on incidental bycatch, ICES has developed a Roadmap, which was presented in plenary at the meeting by Henn Ojaveer. The roadmap gives the list of key expert groups in the process and outlines their main expected roles and tasks. WGCATCH feeds into the internal workflow and system for creating the evidence base for the bycatch advice by developing sampling protocols.

WGCATCH continued to support the development of the RDBES, ToR d), e.g. the proposed series of practical workshops on estimation procedures will support the future development of estimation methods within the RDBES. Further, WGCATCH has played an active role in developing and reviewing the updated RDBES codes for none-probabilistic methods for selecting a sample. The purpose of the new codes is to communicate the diverse ways of past and present none-probabilistic selection with a few numbers of code that unambiguous inform on method used and convey relevant information to end-users.

Under the ToR e), ‘Collaborate in the advisory process, liaising with assessment groups and benchmarks on commercial catch issues’, ToR e), the involvement of WGCATCH in the development of a check list for benchmarks for topics relevant for commercial catches e.g. LPUE / CPUE was discussed and accepted. A recommendation for data calls including commercial catches, which could raise the quality of commercial catch data in future assessments and benchmarks, was formulated, including a time line for data requests and involvement of data submitters and WGCATCH. Further, the former work on how to communicate relevant information about sampling design and estimation to end-users was picked up based on a recommendation from WGNSSK.

And, as always a lot of presentation from other ICES expert groups was held in plenary to inform on other relevant work within the community, ToR f).

Finally, the group discussed the possibility of including a special issue under the ICES Journal of Marine Science, considering the topics that are worked on within WGCATCH. The chairs will make the first contacts with the editors of this journal about how to launch WGCATCH research topics to start developing the proposal.


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)

Kirsten Birch Håkansson; Estanis Mugerza

Contributors (Authors)

Maciej Adamowicz; Mikel Basterretxea; Kirsten Birch Håkansson; Ângela Canha; Mary Christman; Liz Clarke; Thomas Cloâtre; Bram Couperus; Jessica Craig; Sébastien Demanèche; Laurent Dubroca; Josefine Egekvist; Jon Elson; Ana Cláudia Fernandes; Giorgos Gitarakos; Gildas Glemarec; Kieran Hyder; Allen Kingston; Sara Konigson; Maksims Kovsars; Anne-Mette Kroner; Uwe Krumme; Karolina Molla Gazi; Estanis Mugerza; Dália Reis; José Rodriguez; Sven Stötera; Ioannis Thasitis; Kostas Toloumis; Sofie Vandemaele; Rita Vasconcelos; Jon Helge Vølstad; Julia Wischnewski; Lucia Zarauz



Recommended citation

ICES. 2022. Working Group on Commercial Catches (WGCATCH; outputs from 2020 meeting). ICES Scientific Reports. 4:26. 95 pp.

Publication language

  • en

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  • PDF