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The ICES Working Group on Southern horse mackerel, anchovy and sardine (WGHANSA) assessed the status of anchovy in Atlantic Iberian waters (ane.27.9a; western and southern components) and horse mackerel in Atlantic Iberian waters (hom.27.9a) in the May meeting. The status of anchovy in Bay of Biscay (ane.27.8), sardine in southern Celtic Seas and the English Channel (pil.27.7), sardine in Bay of Biscay (pil.27.8abd) and sardine in Cantabrian Sea and Atlantic Iberian waters (pil.27.8c9a) will be assessed in the November meeting. The status of jack mackerel in Subdivision 10.a.2 (Azores grounds) (jaa.10.a2) won’t be assessed this year, since the advice is provided biannually. The stock of anchovy in Bay of Biscay (ane.27.8) has been above Blim since the reopening of the fishery in 2010. SSB in 2023 has been estimated as the second highest of the historical series. Recruitment (age 1 biomass at the beginning of the year) in 2024 is estimated above the average of the time-series. Harvest rates (catch/SSB) have been stable in the last years. The stock of anchovy in Atlantic Iberian waters (ane.27.9a) is composed by the western component (distributed in areas 9.a North, Central–North, and Central–South) and the southern component (distributed in area 9.a South). The advice is provided for the two components separately for the management calendar from July to June next year. Based on the MSE work developed for each component, the advice is based for the first time on constant harvest rate rules. For the western component, the combined PELACUS and PELAGO acoustic biomass estimate is used as an indicator of stock development and the advice is based on the stock indicator for 2023, multiplied by a constant harvest rate of 0.25, with no biomass safeguard. For the southern component, the relative SSB from an analytical assessment conducted with GADGET is used as the index of stock size development and the advice is based on the stock indicator for 2023, multiplied by a constant

Fisheries have a crucial contribution, with animal protein supply and economic income, to the subsistence and blue economy of several human societies of the Atlantic Ocean, the second largest water body in the planet. However, an accurate distribution of commercial fish across the Atlantic and through the water column is still unknown. The wide use of Species Distribution Models (SDMs) for marine fish mapping generally faces two shortcomings: (i) ignoring the vertical dimension of the ocean; and (ii) ignoring the ecological niche theory in the model fitting. Our aim is to develop 3D habitat models of the main commercial fishes across the Atlantic Ocean, accounting for 67 % of the total biomass catches, to provide an enhanced spatial representation of the environmental niche of the fish species. In particular, here we (1) explore the macroecological patterns testing if latitudinal-vertical distribution of main commercial fish species follows the isothermal distribution across the Atlantic ocean; (2) apply a novel 3D modelling approach incorporating depth dimension into the environmental data and based exclusively on public species occurrence data; (3) use Shape-Constrained Generalized Additive Models (SC-GAMs) to build SDMs in accordance with the ecological niche theory (GAM-NICHE model), avoiding potential model overfitting and hence allowing automatic model selection; and (4) estimate potential fish catch biomass in the 3D space based on the species probability of occurrence. Our results indicated that latitudinal-vertical distribution follows the prevailing isothermal distribution in the ocean, confirming that an accurate representation of stock distributions needs 3D modelling and incorporate explicitly depth dimension into the environmental data. The species response curves to 3D environmental gradients for the 30 main commercial fish species of the Atlantic yielded very good model accuracy performance (78–98 %). The developed 3D models of fish occurrence probab

This report investigates how key environmental variables influence the recruitment process of target fish stocks. Understanding how the environment affects recruitment may allow more accurate predictions of fish stock dynamics under scenarios of environmental change and in particular their response to global warming, supporting the development and implementation of robust management policies. Case studies from the four Seawise case study regions have been analysed, and the main results obtained so far are summarized below. In the Baltic Sea, the Gulf of Riga spring spawning herring showed effects of spawning stock biomass on individual weight of age-1 fish, with prey abundance in May and previous year feeding period temperature also playing significant roles. The explanatory power of the final model was moderate. Higher weight of herring is achieved at higher prey densities, lower SSB levels and lower temperatures during the main feeding season of age-0 fish. Recruitment of Western Baltic cod and herring showed decreasing reproductive potential at increasing temperature. In the North Sea, the effects of temperature, salinity, currents, chlorophyll and zooplankton on recruitment of cod, haddock, saithe, whiting, plaice, sole, sprat and herring were investigated using a semi-automated, machine learning framework. The incorporation of environmental signals in recruitment predictions showed improved predictions over a stock recruitment model without environmental effects in six out of the eight stocks. For small pelagic foirage fish, four stock-recruitment models were fitted for three sandeel stocks and the North Sea sprat stock Linear regressions revealed various relationships between recruitment and environmental variables. Short-term time scales based on monthly averages produced a noisier and less consistent pattern for most stock. In the Western Waters, Bayesian online change point detection models were applied to thr

Incorrect Affiliation In the published article, there was an error regarding the affiliation for Jasper Van Vlasselaer. Instead of: 13 Spanish Institute of Oceanography (IEO-CSIC) (Palma), Ecosystem Oceanography Group (GRECO), Palma de Mallorca, Spain, he should have: 11 Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), Fisheries and Aquatic Production, Oostende, Belgium. In the published article, there was an error regarding the affiliation for Luc Van Hoof. Instead of: 14 Department of Marine Sciences, University of the Aegean, Mytilene, Greece he should have 3 Wageningen Marine Research, Wageningen University and Research, Ijmuiden, Netherlands The authors apologize for this error and state that this does not change the scientific conclusions of the article in any way. The original article has been updated.

To effectively future-proof the management of the European Union fishing fleets we have explored a suite of case studies encompassing the northeast and tropical Atlantic, the Mediterranean, Baltic and Black Seas. This study shows that European Union (EU) fisheries are likely resilient to climate-driven short-term stresses, but may be negatively impacted by long-term trends in climate change. However, fisheries’ long-term stock resilience can be improved (and therefore be more resilient to increasing changes in climate) by adopting robust and adaptive fisheries management, provided such measures are based on sound scientific advice which includes uncertainty. Such management requires regular updates of biological reference points. Such updates will delineate safe biological limits for exploitation, providing both high long-term yields with reduced risk of stock collapse when affected by short-term stresses, and enhanced compliance with advice to avoid higher than intended fishing mortality. However, high resilience of the exploited ecosystem does not necessarily lead to the resilience of the economy of EU fisheries from suffering shocks associated with reduced yields, neither to a reduced carbon footprint if fuel use increases from lower stock abundances. Fuel consumption is impacted by stock development, but also by changes in vessel and gear technologies, as well as fishing techniques. In this respect, energy-efficient fishing technologies already exist within the EU, though implementing them would require improving the uptake of innovations and demonstrating to stakeholders the potential for both reduced fuel costs and increased catch rates. A transition towards reducing fuel consumption and costs would need to be supported by the setup of EU regulatory instruments. Overall, to effectively manage EU fisheries within a changing climate, flexible, adaptive, well-informed and well-enforced management is needed, with incentives provided for innovations and ocean liter

The ICES Working Group on Mixed Fisheries Methodology (WGMIXFISH-METHODS) met to progress work on the improvement and development of the mixed fisheries advice. In this report the group provides a summary of the work completed in 2022. The work addressed included improving workflows for the advice process, presenting methodological advances, developing new ecoregions and responding to issues encountered during WGMIXFISH-ADVICE 2022. Additionally, plans for a second scoping workshop were discussed and the contribution of WGMIXFISH to mixed fisheries information in the Fisheries Overviews was reviewed. A key methodological advance used data on quota exchanges between countries to update the Min mixed fisheries scenario to address concerns over choking behaviour in fleets that generally do not entirely consume their initial quota allocation. This update is predicated on the assumption that when TAC changes become restrictive, the usual quota exchanges will become less likely. An Irish Sea model has been in development for several years and a mature version was presented. A formal review process has been initiated to evaluate this model with a timescale consistent with incorporating this ecoregion into the formal mixed fisheries advice process for 2022. To help improve the understanding of the main outputs from the mixed fisheries model a new design for the headline “advice” plot was approved at this meeting. This new design presents the results from each mixed fisheries scenario for a particular stock. This should enable stakeholders to draw easier comparisons between the different scenarios presented for their stock of interest. Future work ahead of next year’s meeting will focus on finalising the plans initiated at this meeting for a second scoping workshop and refining the contribution of WGMIXFISH to mixed fisheries information presented in the Fisheries Overviews.

The Workshop on the Iberian Sardine Management and Recovery Plan, chaired by Manuela Azevedo (Portugal), met in Lisbon, Portugal, 1–5 April 2019 to evaluate if the management and recovery strategies jointly proposed by the Portuguese and Spanish administration meet the client´s objective and are precautionary according to ICES precautionary criterion. The request also asked for the re-examination of the Biological Reference Points (BRPs) for the Iberian sardine stock. The working group decided to keep the current BRPs, Blim of 337.4 thousand tonnes and FMSY of 0.12year-1, corresponding to the scenario of medium stock productivity, because the updated estimates as well as the estimates from the analysis of the effect on the BRPs of the assessment retrospective showed that both were within confidence bounds (95%) of the current adopted reference points. The working group also estimated BRPs considering the recent low stock productivity to be in the period 2006–2017 as specified in the request. Blim_low was estimated to be 196.3 thousand tonnes and FMSY_low was estimated to be 0.032year-1, corresponding to the scenario of low stock productivity. The estimated BRPs were used to set the biomass and fishing mortality reference levels of the catch rules and also, following the ICES guidelines for the evaluation of management plans, the basis to compute performance statistics of the management strategy evaluation under each operating model.

This paper describes a methodology that combines meta-population theory and stock assessment models to gain insights about spatial heterogeneity of the meta-population in an operational time frame. The methodology was tested with stochastic simulations for different degrees of connectivity between sub-populations and applied to two case studies, North Sea cod (Gadus morua) and Northeast Atlantic sardine (Sardina pilchardus). Considering that the biological components of a population can be partitioned into discrete spatial units, we extended this idea into a property of additivity of sub-population abundances. If the additivity results hold true for putative sub-populations, then assessment results based on sub-populations will provide information to develop and monitor the implementation of finer scale/local management. The simulation study confirmed that when sub-populations are independent and not too heterogeneous with regards to productivity, the sum of stock assessment model estimates of sub-populations’ SSB is similar to the SSB estimates of the meta-population. It also showed that a strong diffusion process can be detected and that the stronger the connection between SSB and recruitment, the better the diffusion process will be detected. On the other hand it showed that weak to moderate diffusion processes are not easy to identify and large differences between sub-populations productivities may be confounded with weak diffusion processes. The application to North Sea cod and Atlantic sardine exemplified how much insight can be gained. In both cases the results obtained were sufficiently robust to support the regional analysis

Global patterns of planktonic diversity are mainly determined by the dispersal of propagules with ocean currents. However, the role that abundance and body size play in determining spatial patterns of diversity remains unclear. Here we analyse spatial community structure - beta-diversity - for several planktonic and nektonic organisms from prokaryotes to small mesopelagic fishes collected during the Malaspina 2010 Expedition. beta-diversity was compared to surface ocean transit times derived from a global circulation model, revealing a significant negative relationship that is stronger than environmental differences. Estimated dispersal scales for different groups show a negative correlation with body size, where less abundant large-bodied communities have significantly shorter dispersal scales and larger species spatial turnover rates than more abundant small-bodied plankton. Our results confirm that the dispersal scale of planktonic and micro-nektonic organisms is determined by local abundance, which scales with body size, ultimately setting global spatial patterns of diversity.

Demographic connectivity in sardine population

In this work a scenario-based two-stage stochastic programming model is proposed to solve a microgrid’s tertiary control optimization problem taking into account some renewable energy resource’s uncertainty as well as uncertain energy deviation prices in the electricity market. Scenario generation methods for wind speed realizations are also studied. Results show that the introduction of stochastic programming represents a significant improvement over a deterministic model., Peer Reviewed, Postprint (published version)