Commission Decision of 25 February 2016 setting up a Scientific, Technical and Economic Committee for Fisheries, C(2016) 1084, OJ C 74, 26.2.2016, p. 4–10. The Commission may consult the group on any matter relating to marine and fisheries biology, fishing gear technology, fisheries economics, fisheries governance, ecosystem effects of fisheries, aquaculture or similar disciplines.
This document contains the report of the STECF EWG 25-06 carried out at the JRC (ISPRA, Italy) in hybrid mode during 16-20 June 2025 aiming at revising several issues affecting the stock assessment of hake in GSA 1-5-6-7 in the Western Mediterranean Sea. The group was tasked to review the Input Data for the assessment (TOR 1): catches at age and estimation procedures, survey index, and any auxiliary LPUEs presented to the group, including the review of the model of growth and other biological information required for the assessment. Next, it was also requested to review the stock assessment itself (TOR 2), including if data were available through an ad hoc Data call, an update of the past year assessment with the new data supplied by member states until 2024.
Overall, the group covered the most important issues included in its TORs. Concerning the review of the input data and procedures (TOR 1): the entire MEDITS survey series; including the BALAR Spanish survey in GSA 5 East (2002 – 2006); revising some standardized LPUEs from selected Spanish fishing fleets in GSA 5 and 6, targeting the adult fraction of the population; and revisiting the sex ratio by length and the changes in effort by fleet.
Growth models were revised with the help of the ad hoc contract results, and the current growth model (Mellon-Duval et al. 2010) was retained, both for the sex combined analysis and by the first time by sex (with separate growth models by sex). Some methodological proposals for improving the slicing method to estimate the catches at age were made and preliminarily explored. Natural mortality was reviewed according to the EWG 25-01 guidelines.
Finally, the a4a model for the assessment of hake in GSAs 1–5–6–7 was reviewed and updated (TOR 2), along with an update to last year assessment, including data made available until 2024. However, due to time limitations, some of the improved procedures for obtaining catches by age and for assessments modelling were only just started and were left for further exploration. The benefits and limitations of other assessment models were briefly discussed.
URIARTE Andres;
PAZ SAMPEDRO M.;
RINCON HIDALGO Margarita;
2025-12-17
Publications Office of the European Union
JRC145140
978-92-68-35189-5 (online),
1831-9424 (online),
EUR 40589,
OP KJ-01-25-659-EN-N (online),
https://publications.jrc.ec.europa.eu/repository/handle/JRC145140,
10.2760/4074549 (online),
