SEAwise Report on scoping workshops

The SEAwise stakeholder integration aims to ensure that the key issues of relevance, current ecosystem status, potential management measures are identified and prioritised for further evaluation in the project and hence that the end results are relevant to the end users. This deliverable report describes the approach taken to identify the stakeholder community, stakeholder interests and responsibility and subsequently establish ecological and social system priorities. The SEAwise consultations in the first half year of the project had the specific aims to identify key stakeholders, build trust and common understanding between SEAwise scientists and these stakeholders, identify key issues of relevance for ecosystem based fisheries advice, current ecosystem status and potential management measures, identify priorities of these key issues and evaluate how this varies between consultation methods and regions. Stakeholders were contacted through the Mediterranean Advisory Council (MEDAC), Southwestern Waters Advisory Council (SWWAC), Northwestern Waters Advisory Council (NWWAC), North Sea Advisory Council (NSAC). Pelagic Advisory Council (PELAC) and Baltic Sea Advisory Council (BSAC). Scientists participating in the project completed the same exercises for comparison. The choice of consultation method was chosen to enhance equal influence of all participants by minimising the impact of the organising scientists’ expectations and emergent group dynamics on group results. Three different approaches were used (individual consultation: 79 contributors, individual consultation in a group environment: 106 contributors and group consultation: 106 contributors). In total, 2752 key issues were identified. Six issues were identified repeatedly across regions and participant groups: climate change, MPAs, windfarms, employment and small scale fisheries. The remaining words often were identified only by either SEAwise scientists or stakeholders and there were frequent instances where one of these group identified a word in the top 10 whereas the other group did not mention the word. The results highlight the importance of scoping the key topics beyond the scientists participating in the project and the need to consider consultation methods thoroughly. Moving forward in SEAwise, the individual scoping results will be used to identify issues which interested users may first search for and the workshop cloud scoping together with the individual scoping results to identify key topics for advice. The differences between SEAwise participant and stakeholder key topics will be used in the project to raise awareness of the need to talk to end users about the advice produced in advance. This report describes results of the SEAwise project. More information about the project can be found at https://seawiseproject.org/</p

SEAwise report on the bycatch mortality risk of potentially endangered and threatened species of fish, seabirds, reptiles and mammals

The SEAwise project works to deliver a fully operational tool that will allow fishers, managers, and policy makers to easily apply Ecosystem Based Fisheries Management (EBFM) in their fisheries and bycatch of protected, endangered and threatened (PET) species is a major concern in EBFM implementation. This SEAwise report evaluates the effects of fishing on bycatch of PET species by applying a hierarchical framework that moves from qualitative to quantitative methodologies depending on species vulnerability to bycatch and data availability. By these means, this work identifies current areas of highest bycatch risk across the case studies and assesses the sustainability of bycatch levels on PET populations.The first step of this report consisted of the application of the semi-quantitative Productivity-Susceptibility Analysis (PSA) to a wide range of sensitive species across European waters, including cetaceans, bony and cartilaginous fishes and a single seabird species. PSA measures the risk of a species to over-exploitation by a fishery based on two properties; productivity, defined by the life history characteristics determining the intrinsic rate of population increase, and susceptibility, based on the interactions between population and fishing dynamics. This analysis scores species’ productivity and susceptibility attributes from 1 (low risk) to 3 (high risk) for each fishery or gear of interest, allowing a rapid screening of the species most likely affected by bycatch.Cetaceans were assessed in the Bay of Biscay and Irish waters, and in both cases, gillnets were identified as the gears with the highest bycatch risk, especially for common dolphin (Delphinus delphis) and harbour porpoise (Phocoena phocoena). Cartilaginous fishes were assessed in the Mediterranean Sea, including pelagic species such as the blue shark (Prionace glauca) and demersal species such as the longnose spurgod (Squalus blainville), the bull ray (Aetomylaeus bovinus) and the common smooth-hound (Mustelus mustelus). The blue shark, which is Critically Endangered in the Mediterranean, showed a high risk of being bycaught by pelagic longline, while demersal species were all highly threatened by bottom trawlers. A combination of elasmobranchs and teleost fishes was assessed along the North Sea, Bay of Biscay, and Celtic Seas, including common skate complex (Dipturus spp.), blonde ray (Raja brachyura), spurdog (Squalus acanthias), tope (Galeorhinus galeus), spotted ray (Raja montagui), undulate ray (Raja undulata), starry ray (Amblyraja radiata), John dory (Zeus faber), Atlantic wolffish (Anarhichas lupus) and Atlantic halibut (Hippoglossus hippoglossus). Highest bycatch risk was found for the common skate complex, spurdog and tope, showing highest bycatch risk for both beam- and otter trawls, as well as gillnets. The only seabird species analysed was the critically endangered Balearic shearwater (Puffinus mauretanicus), which showed a high risk to longlines in the Bay of Biscay.Where quantitative data were available for populations size and bycatch in e.g, ICES reports, the impact of fisheries bycatch was estimated quantitively by estimating reference points and by comparing them to total bycatch mortalities. This quantitative assessment was completed for two cetaceans and two elasmobranch species that were also included in the previous step. Bycatch impact for the common dolphin in the Northeast Atlantic and for harbour porpoise in Irish waters was found to be unsustainable, as current bycatch mortalities are above the “allowable” capture limits in both cases. For spurdog and undulate ray in the Northeast Atlantic and English Channel, respectively, the fishing pressure on the stock was sustainable, as it is below the harvest rate of Maximum Sustainable Yield (MSY). Reference points for seabirds were also estimated, but no comparison with bycatch mortality could be done due to lack of data. Additionally, quantitative assessments were produced for grey seal in the North Sea and loggerhead turtle in the Mediterranean (despite not being included in the previous step), where current bycatch rates were evaluated to be sustainable.Specific analyses were conducted for the Baltic Sea harbour porpoise with previously unused bycatch data from gillnets. Bycatch was modelled to estimate total bycatch mortality, addressing several objectives at once. On one hand, estimated total bycatch was compared with reference points, which showed that the current bycatch level was unsustainable for the population. Secondly, estimated total bycatch was compared with the results provided by previous simpler extrapolations, demonstrating that the later should not be applied when the fishery is heterogeneous due to the potential to provide biased estimates.Overall, the qualitative approaches are commonly used as a tool to identify species that are minimally affected, so the more intensive analysed are limited to high-risk species. Here, most species analysed showed-medium-high risk and therefore, all of them should have been analysed in further steps. However, many of those species lack the necessary information to conduct a quantitative assessment, and as result, the impact of bycatch at population level could only be evaluated, as seen above, for a few of them. This highlights the need for more exhaustive data collection and further research that could answer to the requirements of the EBFM.More information about the SEAwise project can be found at https://seawiseproject.org/</p

SEAwise Report on key drivers and impacts of changes in spatial distribution of fisheries and fished stocks

   An ecosystem approach to fisheries management requires the consideration of spatially explicit management measures and other impacts on species and the links between the distribution of fished species, their surrounding environment and productivity. Quantification of the spatial aspects of fisheries and ecology of commercially fished stocks may improve the accuracy of the predicted changes in fish productivity, fisheries yield and costs, benefits and selectivity.  To provide a knowledge base for spatially explicit considerations, SEAwise consulted stakeholders throughout Europe and conducted a systematic review of the scientific literature. As a first step, engagement with relevant stakeholder groups in each Case Study identified key issues of relevance to spatial management. The input from this stakeholder consultation was supplemented by a systematic literature review with careful consideration of the objectives, search terms, inclusion/exclusion criteria, the method for data/knowledge extraction and ultimately how these data and knowledge will be used. The purpose of the task was to quantify the key drivers and pressures behind the changes occurring in commercial fish stocks and fisheries distribution that have a spatially explicit content, map the relevant existing scientific knowledge and provide input to the subsequent SEAwise tasks.  The words identified by the stakeholders consulted focused on factors causing changes to the distribution of commercial fish/shellfish (climate change, MPAs, species interactions, pollution, habitats and invasive species) and fisheries (windfarms, MPAs, Marine spatial planning) as well as the other human impacts. The systematic review extracted data from 331 papers. The most frequently studied topic was the distribution of fish and the region with most papers was the North Sea with about the twice the amount of papers in each of the other regions. The most frequently studied species in the literature were cod, hake and plaice and by far the most frequently studied fisheries was demersal trawl fisheries.  Among the issues identified by stakeholders as key, the effects of environmental conditions on the distribution of fish were particularly well represented in the reviewed material. In contrast, factors determining the distribution of fisheries were almost exclusively studied in trawl fishing in the North Sea and papers on the effect of area restrictions on fish and fisheries were largely restricted to Western waters and the North Sea. While knowledge on the effects of habitats on species did exist, this was restricted to the Baltic Sea and North Sea and papers addressing this outside these areas were close to non-existent. This points to important areas for future work in SEAwise. This report describes part of the results of the SEAwise project. More information about the project can be found at https://seawiseproject.org/ </p

SEAwise Report on the key social and economic aspects of regional fisheries

Fishing is a human activity with various social and economic implications. In most countries, those implications are key factors to consider when deciding on specific management strategies. In this report, the fisheries management strategies implemented in the different European marine regions are reviewed, and relevant indicators, models and tools that can be used to predict the effectiveness of these strategies, from a social and economic point of view are identified. The objective was to identify the critical social and economic aspects of fisheries,  relevant social and economic indicators, and regionally‐relevant management measures to be considered in the evaluations of different management strategies later in the project.   The scoping consultations and systematic reviews identified a long list of potentially relevant key social and economic aspects and management measures. Among these, the most frequently mentioned items identified in scoping with stakeholders were windfarms, employment/jobs, MPAs, food supply, small-scale fisheries, local communities and pollution. The systematic review identified landings (volume or value), effort (days at sea), fuel costs, number of vessels, profit, aspects of costs, economic performance, sustainability-resilience, compliance and capacity as frequently occurring topics. The fisheries management policies most frequently mentioned were effort control, landing obligation, Individual Transferable Quota (ITQ), MPAs and TAC. Among the papers analyzed, more than 30%, concerned the Mediterranean region, followed by Western Waters, the North Sea and the Baltic Sea, indicating a higher contribution of Mediterranean studies to the conclusions. Aspects identified frequently in both scoping and in systematic reviews included MPAs and small-scale fisheries, which were all identified in both methods as frequently occurring. However, there were also aspects which appeared to be represented differently in the evaluations (e.g. employment and local communities) indicating discrepancies between the available knowledge and that sought by the end users. The report describes results from the SEAwise project. More information can be found at https://seawiseproject.org/</p

SEAwise Report on the key drivers of stock productivity and future environmental scenarios

An ecosystem approach to fisheries management requires the consideration of commercial species as components of an ecosystem and the acknowledgement of the links between their productivity and the surrounding environment. To provide a knowledge base for such links, SEAwise consulted stakeholders throughout Europe and conducted a systematic review of the scientific literature. The systematic review resulted in 2050 articles from the literature search that were screened for their tile and abstract. 516 of them were retained for data extraction. The majority of studies were conducted in the Baltic Sea and the North Sea, followed by the Western Waters, and with only a few dozen papers in the Mediterranean Sea. Cod and herring were the most studied species, temperature and more generally climate and hydrodynamics indicators were the main drivers investigated, and reproduction was the main productivity-related process. The output of the systematic review is a database of scientific articles organised by regions, species, environmental drivers and productivity-associated processes and where outcomes, but also spatial and time scales, analytical methods etc. are described in a standardised fashion. This database will be analysed in the coming months and used in the downstream tasks of WP3. The most frequently driver identified by stakeholders across regions was climate change followed by species interactions, cod, pollution, commercial fish/shellfish and plankton. Climate change effects on stocks through temperature and salinity are relatively well covered in the literature as are effects of plankton and species interaction. Studies of the effects of pollution do not occur frequently and as a consequence require a dedicated effort is made in SEAwise to remedy this. Species reported frequently by the stakeholders included cod, seabass, sardine, sole, crabs, flatfish, Norway lobster, octopus, shrimps, herring, sprat, anchovy, hake, new species (species increasing in abundance as a result of climate change as well as invasive species of commercial interest) and sandeel. Among these, more than 10 papers were retrieved for cod, sardine, sole, herring, sprat, selected flatfish, anchovy, hake and sandeel. For the remaining species, a dedicated effort must be made in SEAwise if they are to be included in stock models.  This report describes results of the SEAwise project. More information about the project can be found at https://seawiseproject.org/</p

SEAwise Report on the key species and habitats impacted by fishing

The implementation of ecosystem-based fisheries management requires knowledge on the ecological impact of fishing activities on species and their habitats – those both targeted and not targeted by fisheries. To identify which ecological impacts are key and what is known about them, SEAwise consulted stakeholders through European Advisory Councils and conducted a systematic review of the scientific literature to map the available knowledge and evidence. Specific reference was given to the bycatch of Protected, Endangered and Threatened (PET) species, benthic habitats, food webs and biodiversity, and impact from fisheries-related litter and ghost nets.  At the stakeholder consultations, sharks and/or elasmobranchs, turtles, species interactions, and seals or marine mammals were identified as top ranked in at least three out of the five regions. Other terms identified by at least two Case Study regions were: seabirds, sensitive species, benthic habitats, litter, PET species, invasive species and species interactions.  Relevant data were extracted from 549 retained papers. The majority of studies were conducted in the Mediterranean Sea, whereas only few papers reported on fishing impacts in the Baltic Sea (see figure below). Bony fish (teleosts) and benthos were the most studied ecosystem components in all Case Study regions, whereas marine mammals and cartilaginous fish were often studied in relation to bycatch of PET species.  Out of the 549 papers, most of them were related to fishing impacts on food webs and biodiversity and benthic habitats, followed by bycatch of PET species and other fishing impact studies (not related to any task). Fewest studies were related to the impact of fisheries-related litter and ghost nets. Demersal trawls were by far the most studied gear in studies on commercial fishing impacts. For recreational fisheries, hooks and lines, in particular angling, was the most studied fishing activity.  Among the items identified by the stakeholders, marine mammals, seabirds and reptiles were all covered in at least 25 papers each, indicating that there is a considerable body of knowledge even though not all areas may have information for all species. Litter was the key item that was least frequently reported on in the literature, especially outside the Mediterranean, where scientific papers were rare. As a consequence, areas outside the Mediterranean may lack information for further analysis unless a dedicated effort is made in SEAwise to remedy this. The regional differences in topics identified by stakeholder scoping did not reflect the regional amount of papers available.  This report describes results of the SEAwise project. More information about the project can be found at https://seawiseproject.org/</p

SEAwise Report on consistency of existing targets and limits for indicators in an ecosystem context

The SEAwise project works to deliver a fully operational tool that will allow fishers, managers, and policy makers to easily apply Ecosystem Based Fisheries Management (EBFM) in their fisheries. This SEAwise report investigates the consistency of existing targets and limits from the Common Fisheries Policy (CFP) and the Marine Strategy Framework Directive (MSFD). Trade-offs between different objectives (ecological, economic, social), targets and limits are highlighted. A wide range of model types (from bio-economic to full ecosystem models) has been applied to various case study areas across the North East Atlantic and Mediterranean. Although model predictions are by nature uncertain, this study provides important information on likely inconsistencies between existing targets and limits and trade-offs expected under ecosystem- based fisheries management (EBFM). The scenarios investigated include the current range of management applied in terms of the Maximum Sustainable Yield (MSY) concept (i.e. strict MSY approach vs. Pretty Good Yield (PGY) approach allowing sustainable deviations from single species FMSY point estimates). The landing obligation is a key aspect of current fisheries management and was fully considered, in particular for mixed demersal fisheries.Maintaining current fishing effort without further management measures was the least sustainable option in nearly all cases studies. This approach led to increased risk of stocks falling below critical biomass limits. Although the fishing effort adaptions needed is highly case specific, this indicates that further management measures are likely to be needed to ensure a sustainable exploitation of all stocks.Scenarios applying a strict MSY approach in combination with the landing obligation (i.e. FMSY as upper limit with fisheries ending when the first stock reaches FMSY) in most case studies led to the lowest fishing effort. This had positive effects on MSFD related indicators such as bycatch of Protected, Endangered and Threatened (PET) species, benthic impact and the Large Fish Indicator as well as global indicators such as CO2 emission or ecosystem-based indicators like catch per km2. However, this scenario often led to the lowest catches from mixed demersal fisheries due to strong choke effects because fleets had to stop when their first quota was exhausted. This reduces social indicators such as food security, employment and wages. In terms of economic performance, the gains and loses were highly case specific. Scenarios applying the Pretty Good Yield concept and allowing sustainable deviations from the FMSY point estimate when stocks are in a healthy state often outperformed the scenarios applying FMSY as strict upper limit. Such scenarios, applying a more flexible interpretation of the MSY concept, led to reduced fishing effort compared to the status quo effort, but relaxed choke situations in mixed demersal fisheries to some extent leading to higher gross profits and in some case studies also to higher catches. Hence, they may constitute a compromise between the need to attain social as well as ecological objectives. Whether the associated effort levels lead to conflicts with MSFD objectives must be analysed when more internationally agreed thresholds become available for e.g., bycatch of PET species or benthic impact.The majority of case studies exceeded suggested thresholds for the global ecosystem indicators catch per km2 or primary production even under scenarios with high effort reductions. This can be explained to some extent by the fact that these indices are mainly driven by pelagic and industrial fisheries not always part of the models applied. Nevertheless, it indicates potential conflicts with such more holistic ecosystem indicators in their current form.Additional trade-offs in terms of yield were identified within the food web if e.g., demersal piscivorous predators feed on small pelagic fish and both groups are fished. Further, in case studies where small-scale fisheries (SSF) play an important role (e.g., Eastern Ionian Sea) additional trade-offs became apparent as different scenarios led to different ratios between revenues from small scale fisheries and revenues from large-scale fisheries. This adds another level of complexity when such aspects need to be taken more into account in future fisheries management under EBFM.The modelling assumed current selectivities and catchabilities will be maintained in the future. Especially trade-offs arising from fleets having to stop fishing when their first quota is exhausted or when e.g., a threshold for bycatch of PET species is reached may be resolved by improving selectivities via technical measures (e.g., closed areas or innovative gears) in the future. Deliverable 6.8 in month 36 will test such scenarios. Furthermore, the list of indicators and their targets and limits will be updated based on research within and outside SEAwise. Predictive capability of models will be enhanced by incorporating improved biological and economic sub-models in relation to environmental change. Climate change scenarios will be run and new harvest control rules (HCRs), proposed by SEAwise, will be tested. Finally, consistent targets and limits will be proposed for implementing EBFM.</p

SEAwise Report on improved predictive models of growth, production and stock quality.

The SEAwise project works to deliver a fully operational tool that will allow fishers, managers, and policy makers to easily apply Ecosystem Based Fisheries Management (EBFM) in their fisheries and understanding how ecological drivers impact stock productivity through growth, condition and maturity is essential to this proces. In this SEAwise report, we present the predictive models of fish growth, condition and maturity obtained so far in each of the four regional case studies.The biological processes (fish growth, condition and maturity) were studied in terms of body size (weight-at-age, length-at-age), condition factor, otolith increments and size at first maturity. Underlying data were available at different levels, ranging from individual fish, to sampling haul or stock level. Accordingly, the methods employed varied across case studies to adapt to the specific features of the process under study and the available data.The methodology encompassed statistical models (linear models, generalised additive models, mixed models, Bayesian nested hierarchical models, changepoint models), otolith growth increment analyses and mechanistic models (DEB-IBM model coupled to the environment and mizer model). Some of these models were focused on detecting overall trends, including potential changepoints along the time series or identification of the main intrinsic factors. Other models explored the impact of ecological drivers such as temperature, salinity, food availability or density dependence.In the Baltic Sea, two regimes were identified in the weight-at-age time series of herring in the Gulf of Riga (1961-1988 and 1989-2020). During the first period the main driver of the individual annual growth of the fish was the abundance of the copepod L. macrurus macrurus, while the abundance of the adult stages of E. affinis affinis was the dominating explanatory variable affecting herring growth during the second period. Neither SSB nor summer temperature during the main feeding period were significant drivers of the individual growth in the two distinct ecosystem regimes.In the Mediterranean Sea, the analysis of the impact of the environmental variables on biological parameters like size at first maturity, condition factor and growth in South Adriatic Sea and North-West Ionian Sea showed some significant effects in relation to the different species/area. In most of the cases, the environmental driver was bottom temperature, although some relationships with bottom salinity and primary production were also found. The model outcomes suggested that temperatures prevailing in deeper waters were the most significant factor affecting gonad maturity of hakes, while those in the shallow zone had the main impact on the L50 of red mullets. Condition factor of hake and red mullet in the Eastern Ionian Sea were affected not only by temperature, but also by zooplankton abundance.In the North Sea, mediated length-based growth models, linear mixed models and state-space linear mixed models were applied to four gadoids, two flatfishes and one pelagic stock and their performances were assessed in terms of model fit and predictive capability. For the mediated length-based growth model approach, the best model differed across stocks, but density dependent mediation effects were significant for five out of the seven stocks. Regarding the linear mixed models, the two types of models and the different penalisation procedures led to different models across stocks. Among the additional ecological variables, surface temperature was the most frequently included in the final model, closely followed closely by SSB and to a lesser extent by NAO. Detailed otolith increment analysis was used in the development of multidecadal biochronologies of average annual growth of sole in the North Sea and in the Irish Sea. In the North Sea, the best extrinsic model of sole growth included sea bottom temperature, fishing mortality at age, and stock biomass at maturity stage, and their interactions with age and maturity stage, while in the Irish Sea, the best extrinsic model included sea bottom temperature and fishing mortality at maturity stage and its interaction with maturity stage. These results confirmed the expected positive effect of temperature on adult growth. However, in the North Sea, temperature showed unexpected negative effect on juvenile growth, which might be linked to changes in food availability and/or intraspecific competition and need to be further studied. The mizer model (package for size-spectrum ecological modelling) with environmental forcing was used to study whether warming in the North Sea is responsible for the failure of the cod stock. The simulated fish community response when recruitment and carrying capacity depended on surface temperature fitted better with the assessment data than when the environment was fixed. However, the qualitative differences remain, suggesting that temperature effects were not the main cause of the model-assessment disparity.In the Western Waters, the mediated length-based growth models developed for the North Sea case study were applied to 14 stocks in the Celtic Sea. The best model differed across stocks, but again SSB mediation was significant for most of the stocks. From visual inspection of the plots, however, it was noted that the raw data from certain stock objects showed a reduced growth compared to the model fits, requiring further analyses. The analysis on biological measurements of individuals collected at fish markets, observers at sea or during scientific cruises allowed to study temporal variations in body size and condition factor of benthic, pelagic and demersal species in the Celtic Sea and the Bay of Biscay. The linear models indicated a significant negative monotonic relationship of sizes at all ages for anchovy and pilchard, but variations in size at age were less clear and significant for benthic and demersal species. In contrast, the results of the body condition indices showed a moderate but significant decrease for all the studied 19 species over time. The in-depth analysis for anchovy in the Bay of Biscay based on research surveys confirmed the decline in the length and weight of anchovy in the Bay of Biscay and pointed to a decline in body condition toward slender body shapes. Detected associations between temperature and size became more apparent for adult age classes than for juveniles, whereas the association between anchovy size and the biomass of spawners was more important for juvenile than for adult age classes. Associations between anchovy size and chlorophyll-a concentration were in general weak. Finally, the DEB-IBM model coupled to the environment that is under development for the two main seabass stocks of the North East Atlantic will provide further insights on how growth, condition and maturation can affect the future dynamics and productivity of these stocks.Read more about the project at www.seawiseproject.org</p