Wgibar 2018 Report
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WGIBAR 2018 REPORT ICES INTEGRATED ECOSYSTEM ASSESSMENTS STEERING GROUP ICES CM 2018/IEASG:04 REF ACOM AND SCICOM Interim Report of the Working Group on the In- tegrated Assessments of the Barents Sea (WGIBAR) 9-12 March 2018 Tromsø, Norway International Council for the Exploration of the Sea Conseil International pour l’Exploration de la Mer H.C. Andersens Boulevard 44–46 DK-1553 Copenhagen V Denmark Telephone (+45) 33 38 67 00 Telefax (+45) 33 93 42 15 www.ices.dk [email protected] Recommended format for purposes of citation: ICES. 2018. Interim Report of the Working Group on the Integrated Assessments of the Barents Sea (WGIBAR). WGIBAR 2018 REPORT 9-12 March 2018. Tromsø, Norway. ICES CM 2018/IEASG:04. 210 pp. https://doi.org/10.17895/ices.pub.8267 The material in this report may be reused using the recommended citation. ICES may only grant usage rights of information, data, images, graphs, etc. of which it has owner- ship. 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This document is the product of an Expert Group under the auspices of the International Council for the Exploration of the Sea and does not necessarily represent the view of the Council. © 2018 International Council for the Exploration of the Sea Contents Executive summary ................................................................................................................ 1 1 Administrative details .................................................................................................. 3 2 Terms of Reference a) – d) ............................................................................................ 4 3 Summary of Work plan ................................................................................................ 5 4 List of Outcomes and Achievements of the WG in this delivery period............. 6 4.1 List of relevant publications ............................................................................... 6 5 Progress report on ToRs a) –e) ..................................................................................... 8 5.1 Progress report on ToR a .................................................................................... 8 5.2 Progress report on ToR b .................................................................................... 8 5.3 Progress report on ToR c .................................................................................. 10 5.4 Progress report on ToR d .................................................................................. 11 5.5 Progress report on ToR e .................................................................................. 12 5.6 Cooperation ........................................................................................................ 13 6 Revisions to the work plan and justification .......................................................... 14 7 Next meeting ................................................................................................................. 15 Annex 1: List of participants ............................................................................................. 16 Annex 2: Recommendations ............................................................................................. 17 Annex 3: Agenda for WGIBAR 2018 ............................................................................... 18 Annex 4: New spatial time-series ..................................................................................... 20 Annex 5: The state and trends of the Barents Sea ecosystem in 2017 ........................ 69 Annex 6: Time-series used in WGIBAR ....................................................................... 208 Interim Report of the Working Group on the Integrated Assessments | 1 of the Barents Sea (WGIBAR) Executive summary The Working Group Report of the Working Group on the Integrated Assessments of the Barents Sea (WGIBAR), chaired by Elena Eriksen (Norway) and Anatoly Filin (Rus- sia), met in Tromsø, Norway, on 9–12 March 2018. The meeting was attended by 21 participants from 4 institutes and 2 countries. The group updated most of the time-series data and established additional time-series for the oceanographic conditions (currents, temperature, and salinity (1980–2017), me- so zooplankton (1989–2017) and 0-group fish (six fish species, 1980–2017), based on WGIBAR-subareas for the Barents Sea. The group discussed the 2017 state and changes of the Barents Sea ecosystem (see short summery below). The group discussed also different ecosystem models and their use in the IEA, and the group will be a platform for evaluation, testing, and development of ecosystem models. WGIBAR working group provide knowledge of the status, changes, relationships, and processes in the ecosystems to the Joint Russian-Norwegian Fisheries Commission, the Joint Russian- Norwegian Environmental Commission, the Norwegian Ministry of Climate and En- vironment and different ICES working groups. Since the 1980s, the Barents Sea has gone from a situation with high fishing pressure, cold conditions and low demersal fish stock levels, to the current situation with high levels of demersal fish stocks, reduced fishing pressure and warm conditions. The cur- rent situation is unprecedented, and the Barents Sea appears to be changing rapidly. The main points for 2017 are: • The air and water temperatures remained higher than average and typical of warm years, yet lower than temperature in 2016. In autumn, the area covered by Atlantic waters (>3°С) was large than in 2016; areas covered by Arctic and cold bottom waters (<0°С) were small but larger than in 2016. Ice coverage was much lower than normal, but higher than in 2016; the lowest value (1%) observed in September. • Spatially integrated net primary production has increased over the years. A noteworthy increase is observed in the eastern regions where sea ice cover- age has diminished over the years. An increase in ice-free areas, and length of the growing season, provide improved habitat for phytoplankton growth. • Mesozooplankton biomass during autumn was higher than in autumn 2016 in the eastern Barents Sea and on the Central Bank, but lower on the Great Bank. Zooplankton biomasses in the Central Bank and Great Bank subareas have shown declining trends since the peak in 1995. An increasing trend in krill biomass has been observed during the last decades – and the level in 2017 was above the long-term average. Amphipods are still considered to be at a low level - although some large catches were made north and east of Svalbard. Jellyfish biomass was at third highest level since 1980. • The capelin stock has recovered after a mini-collapse in 2015–2016, and the biomass of young herring is the highest since 2005. Polar cod and blue whit- ing biomass is low. Cod and haddock biomass have decreased in recent years following a peak around 2013, but is still above the long-term mean. The 2016 and 2017 year classes of haddock seem strong and could be of the same order of magnitude as the strong 2004–2006 year classes. Sebastes mentella, Green- land halibut and long rough dab biomass is stable at or above the long-term mean. • Assessments of the benthos biomass in 2017 were very high but this most likely related with overestimation of the biomass due to the technical causes 2 | WGIBAR 2018 REPORT during the benthic monitoring like in 2012. The distribution area of the inva- sive snow crab was larger than in previous years, and for the first time rec- orded northeast of Svalbard. The shrimp, Pandalus borealis, population was within the long-term mean and stable. • The summer abundance of minke whales in the Barents Sea is now about 50 000 animals and has been quite stable or increasing over the period. The sighting rate from the 2017 survey is the highest recorded which might con- firm the apparent increasing trend at present. In 2017, 1518 individuals of nine species of marine mammals were observed during the Barents Sea Eco- system Survey (BESS), August-October 2017 and an additional 46 individuals were not identified to species level. • A large-scale monitoring of marine litter performed in the joint Norwegian– Russian ecosystem monitoring surveys in the period from 2010 to 2017. Dur- ing the time-series, plastic dominated number of observations with marine litter, as 72% of surface observations, 94% of pelagic trawls, and 86% of bot- tom trawls contained plastic. In 2017, marine litter on the surface (floating) and taken by trawls dominated by plastic. Wood was registered in the 28.4% of stations, while textile, paper, rubber and metal was observed occasionally. Interim Report of the Working Group on the Integrated Assessments | 3 of the Barents Sea (WGIBAR) 1 Administrative details Working Group name The Working Group on the Integrated Assessments of the Barents Sea (WGIBAR) Year of Appointment within the current cycle 2016 Reporting year within the current cycle 2 Chairs Elena Eriksen (Norway) Anatoliy Filin (Russia) Meeting venues and dates 9-12 March 2018, Tromsø, Norway, (21 participants) 16–18 March 2017, Murmansk, Russia (25 participants) 4 | WGIBAR 2018 REPORT 2 Terms of Reference a) – d) ToR Description Background Science Duration Expected Plan topics Deliverables