Working Group for the Bay of Biscay and Iberian Waters Ecoregion (WGBIE)

The Working Group for the Bay of Biscay and Iberian Waters Ecoregion (WGBIE) assesses 17 demersal fish stocks within ICES divisions 3.a to 9.a. WGBIE is tasked with conducting assessments of stock status using analytical models, or data-limited methods (DLS) to provide catch forecasts and a first draft of the ICES advice for 2026. All 17 stocks are scheduled for regular advice provision in June 2025. All the planned Terms of References (ToRs), both generic and specific to WGBIE, were covered. All the data requested by ICES had been provided ahead of the meeting and did not cause any delay in the assessment process of the WGBIE stocks.

Age-structured assessment models were conducted for the northern and southern megrim (meg.27.7b–k 8abd* and meg.27.8c9a), the four-spot megrim (ldb.27.8c9a) and sole (sol.27.8ab). Length-based models were applied to Northern and southern hake (hke.27.3a46–8abd and hke.27.8c9a), northern black-bellied anglerfish stocks (ank.27.78abd), and both white anglerfish (mon.27.78abd and mon.27.8c9a). An age–length structured model is used for the Bay of Biscay sea bass (bss.27.8ab). Length-based and biomass trends-based methods were used to assess the pollack (pol.27.89a), sole (sol.27.8c9a), and whiting (whg.27.89a). Two category 5 data-limited stocks are assessed with only catch data: southern seabass (bss.27.8c9a) and four-spot megrim (ldb.27.8c9a). The six Nephrops stocks usually evaluated in WGBIE were moved to a new Nephrops working group (WGNEP).

All forecasts and assessments were made following the ICES framework for category 1 (11 stocks), category 3 (4 stocks) and category 5 (2 stocks) and in agreement with the corresponding stock annex.

Three stocks were benchmarked prior to the WGBIE meeting (bss.27.8ab, mon.27.8c9a and ank.27.8c9a) all of them assessed with the Stock Synthesis age and length structured model. WGBIE will propose to include the stock of pollack (pol.27.8ab) in the next round of benchmark workshop. Some model improvements were presented for hake.27.8c9a and sol.27.8c9a. However, it has not yet been decided how these changes could be implemented into the assessment (through an simple update of the stock annex via an external review process or through a standard benchmark workshop)..

In 2020, the migration of assessment to TAF (Transparent Assessment Framework) was initiated by ICES on some specific stocks. WGBIE have started this migration with five stocks (hke.27.3a46–8abd and sol.27.8ab, sol.27.8ab, hke.27.8c9a and meg.27.7b–k 8abd). WGBIE will continue to add more stocks to the system.

Other points and issues raised during the meeting include: to continue and expand research collaboration with the genetic working group (WGAGFA) and support the continuity of genetic sampling collection and implement Management Strategy Evaluation technique for data limited stocks.

During the meeting, some time was allotted to present different exploratory analyses aimed to eventually improve the quality of their respective assessment and projections. This was mainly in response to the progressive increase of the retrospective patterns. The preliminary results are promising although further work is needed.

*Along the Advice Drafting Group (ADGBBI), after the WGBIE, some concerns were raised about the meg.27.7b–k 8abd stock status and the model quality and the advice is postponed until Autumn 2025.