Working Group on the Integrated Assessments of the Barents Sea (WGIBAR)

<p dir="ltr">Key objectives of the Working Group on the Integrated Assessments of the Barents Sea (WGIBAR) are to perform an integrated assessment of the Barents Sea (BS) ecosystem, taking into account climate change and anthropogenic impacts, and to provide ecosystem information to various bodies and working groups. The annual report “Ecosystem status summary” has been updated, which provides an overview of the groups assessment and is relevant to: the ICES Working Groups on Stock Assessments; the Arctic Council; the Joint Russian–Norwegian Fisheries Commission; the Norwegian Ministry of Climate and Environment and Norwegian Management Plan. The working group concluded that<b>:</b></p><p dir="ltr">· The BS has experienced a warming trend since 1990s, with record warm year in 2016 followed by a cooler period again (2017–2022). During 2024, temperature and sea ice conditions progressed similarly to the long-term mean conditions until a marine heat wave occurred at the surface in August-September. This pattern with high temperatures during late summer, but not during winter, has developed during the last 4–5 years.</p><p dir="ltr">· The total mesozooplankton biomass in autumn 2024 was similar to the preceding years in most of the BS. However, in several subareas in the Norwegian sector, where size-fractioned biomass is available, the biomass of the mid-size fraction (typically representing older stages of large copepods like <i>Calanus</i> spp.) has been very low since 2020, while during the same period the smallest size-fraction has been increasing markedly.</p><p dir="ltr">· The 2023-year classes of cod (cod.27.1-2) and herring (her.27.1-24a514) from stock assessments were strong, while survey-based estimates of 0-group haddock and polar cod and 1-group capelin indicate above average recruitments. The estimated total biomass of 3.3 million tonnes in 2023 was record high for the survey and dominated by herring and polar cod.</p><p dir="ltr">· Total biomass of the main pelagic species during 1986–2020 has fluctuated between ca. 0.5 and 9 million tonnes; largely driven by fluctuations in the capelin stock. In the last two years by herring from the 2021 and 2022 year-classes. In 2024, the total biomass of pelagic fish increased and was highest since 2014 due to strong recruitment of capelin and polar cod.</p><p dir="ltr">· Compared 2020, the demersal stocks are in worse condition. Cod and haddock have declined from record high levels 2012–2014, due to high fishing pressure and poor recruitment, especially in 2018–2020. Recently, the recruitment of haddock has improved, and the stock is expected to increase, whereas the SSB of cod is below the precautionary level, and still in decline. The BS is at the border of the distribution area of the declining saithe stock (pok.27.1-2). Greenland halibut female spawning stock is below the precautionary level, and declining, and the total stock is in a rapid decline. The beaked redfish stock is above precautionary level and appear to be stable. The golden redfish stock (reg.27.1-2) is depleted. Based on the demersal survey in the Barents Sea, long rough dab appears to be in good condition.</p><p dir="ltr">· The snow crab population distribution and abundance have increased since 2021</p><p dir="ltr">· The distribution of megabenthos in 2014 may show a decreasing biomass and abundance trend, particularly in the eastern BS. This may indicate a long-term change caused by either climate change or/and other large scale ecosystem shifts. Expansion north and northeast of boreal species, in addition to several new boreal species recorded recently in the SW, points toward increasing temperature as a likely cause to observed changes.</p><p dir="ltr">· The centre of gravity of the most common species shifted northward for several species the last 11 years. In the same period, the abundance of pelagic surface feeding birds has decreased.</p><p dir="ltr">· White-beaked dolphins were the most frequently observed marine mammal species during the 2024 ecosystem survey, although in lower abundance than in previous years. Aggregations of humpback whales in areas East of Svalbard commonly overlap with capelin distribution.</p><p><br></p>