CE26003

Abstract

The International Blue Whiting Spawning Stock Survey (IBWSS) Spring 2026 was carried out from March to April 2026 to assess the abundance, biomass, distribution, and population structure of Northeast Atlantic blue whiting (Micromesistius poutassou). The survey was coordinated through the ICES Working Group on International Pelagic Surveys (WGIPS) and involved five research vessels from Ireland, the Faroe Islands, the Netherlands, Norway, and Spain. Acoustic data were collected using calibrated scientific echosounders and analysed using the StoX software framework, supported by biological sampling from midwater trawl catches. Despite persistent poor weather conditions that reduced survey efficiency and biological sampling effort, good spatial and temporal coverage of the core spawning areas along the continental shelf break was achieved. The estimated total stock biomass in 2026 was 3.0 million tonnes, representing a 32% increase compared with 2025, while total stock numbers increased by 34%. The stock was dominated by 2–5‑year‑old fish, and spawning stock biomass was estimated at 2.9 million tonnes. Distribution patterns were consistent with recent years, with the bulk of the stock concentrated in the Rockall Trough and adjacent shelf‑edge areas. The results are considered robust and contribute to the long‑term IBWSS time series supporting international stock assessment and fisheries management advice