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The United Nations Fish Stocks Agreement requires states to recognise the special requirements of developing countries and to ensure that conservation and management measures do not place a disproportionate burden on developing countries. The aim of this article is to assess what policy arrangements are required to reduce the identified disproportionate burden. We developed a policy pathway that would allow members of tuna regional fisheries management organisations (tRFMOs) to strengthen their efforts to meet their duty to share conservation burdens more equitably. This pathway consists of policy options that were developed by using policy analysis, which is an innovative approach that provides actionable outcomes that can be used by tRFMO member states. Despite the global attention to reducing disproportionate conservation burdens, developing states are still suffering. The results of this article provide novel and timely policy options that have the potential to reduce the conservation burden carried by developing states. [ABSTRACT FROM AUTHOR]

Despite continued calls for the application of ecosystem‐based fisheries management, tactical fisheries management continues to be heavily reliant on single‐species stock assessments. These stock assessments rarely quantitatively integrate the effects of ecosystem processes on fish stock productivity. This lack of integration is ultimately driven by the complexity of interactions between populations, ecosystems and fisheries, which produces uncertainty when defining which processes to include and how to include them. Models developed using a structured hypothesis testing framework would allow formalizing uncertainties while underscoring the importance of incorporating different population and ecosystem processes to explain non‐stationary stock productivity. Here, we develop a conceptual framework for extending and comparing population dynamics models of increasing complexity. We illustrate the utility of the framework by investigating the population and ecosystem processes that most likely affected the differential recovery of two flatfish populations (American plaice and yellowtail flounder) on the Newfoundland Grand Banks over the past three decades. We found that yellowtail flounder population dynamics were primarily driven by recruitment variability, which was negatively affected by warmer climatological conditions, as indicated by an integrated regional climate index. Meanwhile, American plaice population dynamics were affected by a combination of temporal variability in recruitment and natural mortality, where natural mortality increased during colder than average conditions. By exploring hypotheses about the effects of population and ecosystem processes on population dynamics, this modelling framework will improve understanding about the drivers of shifts in population productivity while serving as a transparent and robust approach to support ecosystem‐based fisheries management. [ABSTRACT FROM AUTHOR]

Natural ecological communities exhibit complex mixtures of interspecific biological interactions, which makes finding optimal yet sustainable exploitation rates challenging. Most fisheries management advice is at present based on applying the Maximum Sustainable Yield (MSY) target to each species in a community by modelling it as if it was a monoculture. Such application of single‐species MSY policies to strongly interacting populations can result in tragic overexploitation. However, the idea of 'maximising the yield from each species separately' can be extended to take into account species interactions. This leads to a form of Nash Equilibrium, where the yields of each species are simultaneously maximised. Here we present 'nash', an R package that streamlines the computation of Nash equilibrium reference points for fisheries and other systems represented by a user‐defined multispecies or ecosystem model. We present two real‐world fisheries management applications alongside performance benchmarks. Satisfactory search results are shown across models with an approximate factor 7 increase in performance when compared to the expensive round‐robbing sequential optimisation algorithms used by other authors in the literature. We believe that the nash package can play an instrumental role in fully implementing ecosystem‐based management policies worldwide. [ABSTRACT FROM AUTHOR]

Despite progress in the management of assessed fish populations, many countries lag behind international commitments to restore overexploited stocks to healthy abundances. Here we use a mixed‐methods positive deviance approach, also known as 'bright spot' analysis, to understand what drives the successful governance of exploited species by learning from positive outliers, or 'deviants'. We use Canada as a case study, identifying factors driving the abundance of 230 commercially exploited fish and invertebrate populations, of which only 28% were classified at healthy abundance in 2022. We first applied a generalized linear model to test how diverse socio‐ecological fishery attributes relate to stock health. We found healthier stocks are positively and significantly correlated with certain management regions, more selective gears, eco‐certification, and high fishery value. Counterintuitively, healthier stocks were also associated with high inherent fishing vulnerability and the absence of reference points. We then used fishery expert surveys and interviews to investigate the social and institutional characteristics of stocks healthier than expected, given their circumstances. We found that fisheries targeting these positive outliers have lower conflict among users, balanced stakeholder involvement in data collection and decision‐making, and improved accounting of mortality sources. Lessons from these positive deviants can be applied to improve underperforming management systems that are struggling to reverse overexploitation in Canada and elsewhere. More generally, we suggest that a positive deviance approach, already used in public health, could be a promising tool to learn about successful fisheries management interventions, and the diverse actors responsible for ensuring these interventions are successful. [ABSTRACT FROM AUTHOR]

Fishers have intensively used drifting fish aggregating devices (DFADs) over the last three decades to facilitate their catch of tropical tunas. DFADs increase purse‐seine efficiency, potentially increasing tuna fishing mortality. They could also have impacts on tuna natural mortality and reproductive potential, and assessing the consequences of their presence at sea on tuna populations is a challenge. The use of DFADs results in a major increase in the number of floating objects, which are spatially heterogeneous at sea. To date, no converging scientific results exist regarding the effects of DFADs on the large‐scale movements and behaviour of tuna, mainly due to the difficulty of disentangling the respective roles of DFADs and environmental factors. Some biological indices show that tuna condition is lower when associated to a floating object than in a free‐swimming school. However, it is not clear whether this is the cause or the consequence of the association nor if it has long‐term effects on individuals' fitness. Further scientific progress requires (i) the collection of time series of indicators to monitor habitat change, individual behaviour, individual fitness, and population dynamics and (ii) experimental studies to identify the underlying behavioural and biological processes involved in associative behaviour. The extent of the modification of the surface habitat by the massive deployment of DFADs and the current uncertainty of the possible long‐term consequences on the individual fitness and dynamics of tuna populations argue for the need for increased awareness of this issue by Regional Fisheries Management Organisations regulating tuna fishing. [ABSTRACT FROM AUTHOR]

The maximum intrinsic rate of population increase (rmax) represents a population's maximum capacity to replace itself and is central to fisheries management and conservation. Species with lower rmax typically have slower life histories compared to species with faster life histories and higher rmax. Here, we posit that metabolic rate is related to the fast–slow life history continuum and the connection may be stronger for maximum metabolic rate and aerobic scope compared to resting metabolic rate. Specifically, we ask whether variation in rmax or any of its component life‐history traits – age‐at‐maturity, maximum age, and annual reproductive output – explain variation in resting and maximum metabolic rates and aerobic scope across 84 shark and teleost species, while accounting for the effects of measurement temperature, measurement body mass, ecological lifestyle, and evolutionary history. Overall, we find a strong connection between metabolic rate and the fast‐slow life history continuum, such that species with faster population growth (higher rmax) generally have higher maximum metabolic rates and broader aerobic scopes. Specifically, rmax is more important in explaining variation in maximum metabolic rate and aerobic scope compared to resting metabolic rate, which is best explained by age‐at‐maturity (out of the life history traits examined). In conclusion, teleosts and sharks share a common fast–slow physiology/life history continuum, with teleosts generally at the faster end and sharks at the slower end, yet with considerable overlap. Our work improves our understanding of the diversity of fish life histories and may ultimately improve our understanding of intrinsic sensitivity to overfishing. [ABSTRACT FROM AUTHOR]

Artificial reefs have been widely deployed with the intention of increasing fish habitat, enhancing recreational fishery opportunities and providing socio‐economic benefits to surrounding communities. Substantial work has been done to understand the ecology of artificial reefs but the efficacy of artificial reefs as a management tool hinges on socioecological feedbacks that are not well understood. Socioecological feedbacks are difficult to discern because they depend on multiple and complex interactions between fish, fishers, managers and habitats. To better understand the net effects of artificial reefs on recreational fisheries, we conducted a literature review to catalogue effects and feedbacks of artificial reefs. Our global synthesis revealed that artificial reefs may result in a net negative effect on fish populations, at least in the short‐term, as catch‐driven effects bolstering socio‐economic objectives occur more often or at greater intensities than positive biological effects. We have highlighted important effects of artificial reefs and feedbacks that need to be accounted for when considering their deployment in fishery management. There may be unintended consequences if biological benefits from habitat‐to‐fish and fish‐to‐fish feedbacks are outweighed by population losses due to greater socio‐economic benefits from fish‐to‐fisher feedbacks. Taken in concert with their semi‐permanent nature and apparent popularity with stakeholders, a view emerges of artificial reefs possibly functioning as a 'social‐ecological trap'. This work emphasizes the need for robust assessments of the effects of artificial reefs, as well as more formal decision science approaches for implementing of these structures. [ABSTRACT FROM AUTHOR]

Although most fisheries assessment and management focuses on the status of individual stocks, and regulations are commonly established as single‐species total allowable catch limits (TACs), much of the catch from global fisheries comes from mixed‐stock fisheries where species cannot be harvested separately. We show that in some fisheries where TAC and catch of demersal fish stocks are tracked, the average fraction of TAC harvested ranges from 21% to 68% overall and is declining. This is, in part, related to efforts to protect all species from overfishing, leading to 'choke species', which limit fishing pressure on other target species. While some choke species arise from a mix of low and high‐productivity species, others result from allocation processes, which can be aggravated by shifting distributions due to climate change. Underutilization of TACs can also result from market limitations, low value of individual species, undercapacity or management measures. Proposed methods for increasing long‐term yield require species to be managed in stock groups, or allowing the abundance of some stocks to fall below target reference points. We suggest that the observed low and declining aggregate harvests are due, primarily, to the focus on single‐stock sustainability measures, rather than performance of the fisheries in relation to potential overall yield. While there is a growing consensus that single‐species management should be replaced by an ecosystem‐based approach, this will require clear legislative directives regarding management of the trade‐offs involved. Time series considered in this analysis do not extend beyond 2019. [ABSTRACT FROM AUTHOR]

With growing concerns about global overfishing, market‐based eco‐certification programs like the Marine Stewardship Council (MSC) can incentivise adoption of sustainable practices. Several studies investigated drivers of improvement in market‐driven Fisheries Improvement Projects, but failed to use detailed, standardised measures of progress, or considered small samples. We considered the relative influence market, governance and fishery‐specific drivers have on MSC certification speed and success in 208 fisheries. To evaluate improvement we compared pre‐certification scores from MSC pre‐assessments—rapid high‐level audits against the MSC Standard—to scores from full MSC audits. Drivers considered included measures of pre‐assessment quality, as this initial advice might contribute to later certification success. National fishery management capacity, percentage of MSC catch and landed value were the strongest drivers of successful and rapid certification. Environmental improvements occurred for stock management, ecosystem health and governance aspects. While only 48% of fisheries with favourable pre‐assessment outcomes went on to be certified, improvements in many fisheries with lower pre‐assessment scores were observed in their lead‐up to full assessment. Random forest analyses allowed for considering multiple interacting variables simultaneously and revealed influential drivers under specific fishery contexts. For example, higher certification probability was associated with greater percentage of MSC catch under the full dataset, but not under subsets representing fisheries facing more challenging contexts for certification. Fisheries from lower/middle‐income countries had lower overall probability of certification, but this increased with higher management capacity. This suggests multiple drivers interact in instigating fisheries improvements, and MSC pre‐assessments provide valuable resources to understand this journey. [ABSTRACT FROM AUTHOR]

Spatial fisheries management is widely used to reduce overfishing, rebuild stocks, and protect biodiversity. However, the effectiveness and optimization of spatial measures depend on accurately identifying ecologically meaningful areas, which can be difficult in mixed fisheries. To apply a method generally to a range of target species, we developed an ensemble of species distribution models (e‐SDM) that combines general additive models, generalized linear mixed models, random forest, and gradient‐boosting machine methods in a training and testing protocol. The e‐SDM was used to integrate density indices from two scientific bottom trawl surveys with the geopositional data, relevant oceanographic variables from the three‐dimensional physical‐biogeochemical operational model, and fishing effort from the vessel monitoring system. The determined best distributions for juveniles and adults are used to determine hot spots of aggregation based on single or multiple target species. We applied e‐SDM to juvenile and adult stages of 10 marine demersal species representing 60% of the total demersal landings in the central areas of the Mediterranean Sea. Using the e‐SDM results, hot spots of aggregation and grounds potentially more selective were identified for each species and for the target species group of otter trawl and beam trawl fisheries. The results confirm the ecological appropriateness of existing fishery restriction areas and support the identification of locations for new spatial management measures. [ABSTRACT FROM AUTHOR]

Larger and older fish contribute disproportionately to spawning and play an important role in the replenishment of exploited stocks. Fishing often removes specific size‐ and age‐classes, with direct impacts on stock productivity and population resilience. Despite this, fisheries advice is commonly based on estimates of spawning stock biomass (SSB) and fishing mortality (F) and makes little reference to the importance of size and/or age structure. Consequently, there is a need for indicators of size and/or age structure to better inform fisheries management and help assess global sustainability goals. Here, we introduce a new age‐based indicator ABIMSY that monitors age structure relative to the equilibrium age structure at FMSY. We apply this new indicator to 72 commercially important stocks in the Northeast Atlantic, covering 26 species, which collectively contributed 86% of all commercial catches in the region in 2019. We estimate that 62% (45 stocks) currently have proportionally fewer older fish relative to FMSY conditions, whereas 38% (27 stocks) have proportionally more older fish; we also note patterns with respect to geographic area and taxonomic family. Simulation testing demonstrated that ABIMSY is responsive to overfishing and generally tracks (with high sensitivity and specificity) a common measure of stock depletion, SSB relative to BMSY. Throughout, we show that ABIMSY provides information on the age structure of exploited stocks that is complementary to conventional reference points for SSB and F. Further, the framework used to estimate ABIMSY make it well placed for integration into current advisory frameworks on fisheries management. [ABSTRACT FROM AUTHOR]

There is growing concern over the conservation status of sharks and relatives exposed to fishing mortality. The Food and Agriculture Organization of the United Nations in 1999 adopted the International Plan of Action for the Conservation and Management of Sharks (IPOA), which provides nations with advice on adopting and implementing national plans. An assessment of global national and regional plans of action on sharks (NPOAs) found: most are out of date; limited use of specific, measurable and timebound objectives and activities; no outcome objectives; and few performance assessments. This makes most NPOAs inadequate for planning and assessing efficacy. Over 33% of the annual retained catch of sharks and relatives was from countries without NPOAs and less than 12% was from countries with current NPOAs. NPOAs identified fisheries management framework deficits, ecology knowledge gaps, institutional capacity and coordination shortfalls, and budget constraints as the largest obstacles to implementation and are improvement priorities. We recommend how to amend the IPOA to better support the adoption and effective design and implementation of NPOAs for evidence‐informed conservation and management. [ABSTRACT FROM AUTHOR]

Extensive applications of fishery stock enhancement worldwide bring up broad concerns about its negative effects, creating a pivotal need for science‐based assessment and planning of enhancement strategies. However, the lack of mechanistic understanding of enhanced population dynamics, particularly the density‐dependent processes, leads to compromise in model development and limits the capacity in predicting enhancement effects. Here, we developed an individual‐based model based on dynamic energy budget theory and full life‐history processes, to understand the mechanism of density dependence in population dynamics that emerge from individual‐level processes. We demonstrated the utility of the model framework by applying it to an extensively enhanced species, Chinese prawn (Fenneropenaeus chinensis, Penaeidae). The model could yield projections reflecting the observed trajectory of population biomass and yields. The model also delineated the key effects of density dependence on the vital rates of growth, fecundity and starvation mortality. Regarding the manifold effects of stock enhancement, we demonstrated a dampened shape in population biomass and yields with increasing magnitude of enhancement, and trade‐offs between the ecological and economic objectives, that is, pursuing high benefit might compromise the wild population without proper management. Furthermore, we illustrated the possibility of combining stock enhancement and harvest regulation in promoting population recovery while maintaining fisheries yields. We highlight the potential of the proposed model for understanding density dependence in enhancement programme, and for designing integrated management strategies. The approach developed herein may serve as a general approach to assess the population dynamics in stock enhancement and inform enhancement management. [ABSTRACT FROM AUTHOR]

Recreational fishing (RF) is a large yet undervalued component of fisheries globally. While progress has been made in monitoring, assessing, and managing the sector in isolation, integration of RF into the management of multi‐sector fisheries has been limited, particularly relative to the commercial sector. This marginalises recreational fishers and reduces the likelihood of achieving the sector's objectives and, more broadly, achieving fisheries sustainability. We examined the nature and extent of RF inclusion in harvest strategies (HSs) for marine fisheries across 15 regions in 11 nations to define the gap in inclusion that has developed between sectors. We focused on high‐income nations with a high level of RF governance and used a questionnaire to elicit expert knowledge on HSs due to the paucity of published documents. In total, 339 HSs were considered. We found that RF inclusion in HSs was more similar to the small‐scale sector (i.e., artisanal, cultural, or subsistence) than the commercial sector, with explicit operational objectives, data collection, performance indicators, reference points, and management controls lacking in many regions. Where specified, RF objectives focused on sustainability, economic value and catch allocation rather than directly relating to the recreational fishing experience. Conflicts with other sectors included competition with the commercial sector for limited resources, highlighting the importance of equitable resource allocation policies alongside HSs. We propose that RF be explicitly incorporated into HSs to ensure fisheries are ecologically, economically, and socially sustainable, and we recommend that fisheries organisations urgently review HSs for marine fisheries with a recreational component to close the harvest strategy gap among sectors. [ABSTRACT FROM AUTHOR]

Fisheries science uses quantitative methods to inform management decisions that reflect cultural preferences which, in turn, indirectly influence the states of ecosystems. To date, it has largely supported Eurocentric preferences for the commodification of marine organisms under the tenets of maximum sustainable yield, whereby abundances are intentionally maintained far below their historical baselines despite broader socio‐ecological trade‐offs. In contrast, Indigenous Knowledge Systems (IKS) adhere to the principle of "take only what you need and leave lots for the ecosystem," implementing lower fishery removals to support socio‐ecological resilience. Despite the power imbalance favouring Eurocentric preferences in decision‐making, fisheries scientists increasingly recognize that the pairing of IKS and Western science, or Two‐Eyed Seeing, would lead to more holistic management goals. For recognition to transcend tokenism, meaningful collaborations and co‐governance structures underlying knowledge co‐production must carry through to legislated policy changes. Using recent co‐governance developments for fisheries management and spatial protections involving federal, provincial and Indigenous governments in Pacific Canada, we illustrate how the precautionary approach, including reference points and harvest control rules broadly applied in international fisheries, could be revised to make collaborative fisheries management compatible with IKS and improve biodiversity and fisheries protections. Our recommendations may create socio‐economic trade‐offs at different timescales for commercial fishers. Pre‐empting that challenge, we discuss IKS‐compatible economic approaches for addressing shorter term costs arising from reduced exploitation rates. Although our case study derives from Pacific Canada, the insights provided here are broadly applicable elsewhere in the world. [ABSTRACT FROM AUTHOR]

Fisheries are supposed to be for the benefit of society, producing food, providing livelihoods and enabling cultural continuity. Biological productivity goals for fish stocks operationalised through Harvest Control Rules (HCRs) are central to contemporary fisheries management. While fisheries policies often state socio‐economic objectives, such as enhancing the livelihoods of coastal communities, those are rarely, if ever, incorporated into operationalised management procedures. The lack of articulation of social objectives and lack of monitoring of social outcomes around HCRs amounts to poor public policy. In this article, we explore the potential for social HCRs (sHCRs) with reference points and agreed predefined actions to make the social dimensions of fisheries explicit. sHCRs cannot cover all social dimensions, so should be considered as one tool within a broader framework of fisheries governance. Moreover, successful sHCRs would require sound deliberative and participatory processes to generate legitimate social objectives, and monitoring and evaluation of fisheries management performance against those objectives. We introduce two potential types of sHCRs, one based on allocation of catch within biological limit reference points, and one for when fishing exceeds biological limit reference points. The application of sHCRs, we argue, can foster accountability and help avoid non‐transparent negotiations on size and distribution of the catch. Our proposal is a call to action for policy makers and fisheries managers to properly integrate social criteria into fisheries governance, and for both biophysical fisheries scientists and social scientists to do better in practical collaboration for methods and knowledge development to support this integration. [ABSTRACT FROM AUTHOR]

Reliable stock assessments are essential for successful and sustainable fisheries management. Advanced stock assessment methods are expensive, as they require age‐ or length‐structured catch and detailed fishery‐independent data, which prevents their widespread use, especially in developing regions. Furthermore, modern fisheries management increasingly includes socio‐economic considerations. Integrated ecological‐economic advice can be provided by bio‐economic models, but this requires the estimation of economic parameters. To improve accuracy of data‐limited stock assessment while jointly estimating biological and economic parameters, we propose to use price data, in addition to catches, in a new bio‐economic stock assessment ('BESA') approach for de‐facto open access stocks. Price data are widely available, also in the Global South. BESA is based on a state‐space approach and uncovers biomass dynamics by use of the extended Kalman filter in combination with Bayesian estimation. We show that estimates for biological and economic parameters can be obtained jointly, with reliability gains for the stock assessment from the additional information inherent in price data, compared to alternative assessment methods for data‐poor stocks. In a real‐world application to Barents Sea shrimp (Pandalus borealis, Pandalidae), we show that BESA benchmarks well also against advanced stock assessment results. BESA can thus be both a stand‐alone approach for currently unassessed stocks as well as a complement to other available methods by providing bio‐economic information for advanced fisheries management. [ABSTRACT FROM AUTHOR]

The status of federally managed fisheries in the United States is well monitored, but the condition of other marine fisheries, whether state‐managed, territory‐managed or unmanaged, is less understood and often unknown. We used expert surveys to characterize the management systems of non‐federally managed fisheries in US coastal marine states and overseas territories. For 311 fisheries, we estimated an overall Fisheries Management Index (FMI) and a qualitative stock status score. These measures were positively correlated, and while a wide range of research, management, enforcement and socioeconomic criteria were partially met (FMI ≥ 0.5) for 66% of fisheries, stock status was considered as partially acceptable (score ≥ 0.5) for only 45% of fisheries and acceptable (score = 1) for only 16% of fisheries. Higher FMI was typically observed in fisheries with greater commercial landed weight, value, or greater recreational catches. Fisheries from continental states had higher FMI than those from overseas territories. Invertebrates and diadromous fish species had higher FMI on average compared to those of marine fishes. Extrapolating results for surveyed fisheries to nearly 2000 non‐federally managed US fisheries while stratifying by state and importance designation (based on commercial, recreational, cultural or ecological importance), we estimate a mean overall FMI of 0.48, and estimate that only 19% of fisheries have a reliable estimate of stock status available; both measures are lower than similar estimates for federally managed fisheries. Funding or capacity constraints and information or data limitations were identified as common challenges faced by state agencies in managing fisheries under their jurisdiction. [ABSTRACT FROM AUTHOR]

Marine heatwaves are increasingly affecting marine ecosystems, with cascading impacts on coastal economies, communities, and food systems. Studies of heatwaves provide crucial insights into potential ecosystem shifts under future climate change and put fisheries social‐ecological systems through "stress tests" that expose both vulnerabilities and resilience. The 2014–16 Northeast Pacific heatwave was the strongest and longest marine heatwave on record and resulted in profound ecological changes that impacted fisheries, fisheries management, and human livelihoods. Here, we synthesize the impacts of the 2014–2016 marine heatwave on US and Canada West Coast fisheries and extract key lessons for preparing global fisheries science, management, and industries for the future. We set the stage with a brief review of the impacts of the heatwave on marine ecosystems and the first systematic analysis of the economic impacts of these changes on commercial and recreational fisheries. We then examine ten key case studies that provide instructive examples of the complex and surprising challenges that heatwaves pose to fisheries social‐ecological systems. These reveal important insights into improving the resilience of monitoring and management and increasing adaptive capacity to future stressors. Key recommendations include: (1) expanding monitoring to enhance mechanistic understanding, provide early warning signals, and improve predictions of impacts; (2) increasing the flexibility, adaptiveness, and inclusiveness of management where possible; (3) using simulation testing to help guide management decisions; and (4) enhancing the adaptive capacity of fishing communities by promoting engagement, flexibility, experimentation, and failsafes. These advancements are important as global fisheries prepare for a changing ocean. [ABSTRACT FROM AUTHOR]

Total allowable catch restrictions (hereafter referred to as catch quotas) play an important role in maintaining healthy fish stocks. While studies have identified a positive relationship between catch quota implementation and improved stock status, these methods are subject to selection bias as catch quotas are typically applied to stocks that are depleted. We address this challenge using the synthetic control method, which estimates the causal effect of catch quotas on fishing mortality and biomass by predicting a synthetic counterfactual outcome. We focus on high seas stocks (tunas, billfishes, and sharks) managed by tuna Regional Fisheries Management Organizations (tRFMOs), first providing an overview of stock status and current management measures in place. We find that implementation of catch quotas by tRFMOs has more than doubled over the past decade. Second, we predict the hypothetical fishing mortality and biomass trajectory for seven high seas quota‐managed stocks in absence of a catch quota. These "synthetic non‐quota stocks" are predicted using a weighted selection of high seas non‐quota stocks. Credibility of the synthetic non‐quota stocks is evaluated through diagnostic checks, and robustness tests assess sensitivity to study design. Five credible fishing mortality synthetic controls are predicted: three add support to the hypothesis that catch quotas successfully reduce fishing mortality, while two find that catch quotas increase fishing mortality. While our analysis is limited in scope, given that all seven quota‐managed stocks are managed under a single tRFMO, we highlight the potential for the synthetic control method in fisheries management evaluation. [ABSTRACT FROM AUTHOR]

Attention to human dimensions of capture fisheries involves understanding how harms and benefits are experienced and distributed among different groups or people. Yet, not all harms are well understood or adequately addressed. There is a general (mis)conception that gender‐based violence (GBV) is not of relevance for fisheries management or a topic within the remit of practitioners. Through a global review of capture fisheries, we illustrate how five types of GBV—physical, sexual, psychological, economic and cultural—are pervasive and can be reinforced by fisheries policies, practices and institutions. Our synthesis shows a variety of activities associated with these forms of violence, such as labour and human rights abuses, unsafe working and living conditions for children, women and men, and the cultural acceptance of various forms of discrimination. We argue GBV cannot be disentangled from other actions taken to achieve equitable social outcomes through fisheries management. We provide seven recommendations to help practitioners understand and work towards addressing GBV in capture fisheries: (1) removing gender blindness and bias by investing in gender‐sensitisation of the sector; (2) forming strategic partnerships; (3) improving policy and coordination between regulatory bodies; (4) increasing investments in labour rights and laws; (5) gender integrative programme design and implementation; (6) investing in specific programs for the empowerment of women; and (7) investing in specific programs for men seeking healthy models of masculinity. [ABSTRACT FROM AUTHOR]

We present a novel adaptation of the classic discrete delay‐difference model, a continuous delay‐differential model (cDDM), which can adequately represent population dynamics of stocks that turn over rapidly and continuously over time (e.g., small pelagic fish, small tunas, and shrimps). We used the Northern‐Central Peruvian anchoveta stock (Engraulis ringens, Engraulidae) as a case study for implementing the cDDM and conducted a management strategy evaluation (MSE) through stochastic optimization in policy space (SOPS). Our results showed that cDDM integrated with SOPS efficiently searches optimum and near‐optimum harvest control rules (HCR) and is an alternative to pre‐setting arbitrary HCRs as in traditional MSE. The cDDM showed comparable stock biomass and recruitment estimate reconstructions to more complex stock assessment models described for anchoveta. We concluded that the anchoveta stock is sustainably managed and is an example of adaptive fisheries management under high ocean‐climate variability and uncertainty. Contrary to fishery textbooks, the anchoveta's collapse was not entirely due to the 1972 El Niño (EN) but a recruitment failure preceding EN. Our reconstructions revealed that low recruitment (or recruitment failure) could still occur at high stock biomass. Anchoveta's stock biomass is larger than pre‐collapse, likely due to favourable environmental conditions (a cooling trend) and management, despite more frequent and stronger EN events. SOPS quickly revealed that harvest strategies with large base biomass (>5 mmt) lead to higher interannual stock variability and would not produce substantial increases in long‐term yield. Alternative HCRs with lower base biomass, while adjusting for productivity regimes, have similar long‐term yields without affecting the long‐term average stock. [ABSTRACT FROM AUTHOR]

Individual performance defines population dynamics. Condition index – a ratio of weight and some function of length – has been louded as an indicator of individual performance and recommended as a tool in fisheries management and conservation. However, insufficient understanding of the correlation between individual‐level processes and population‐level responses hinders its adoption. To this end, we use composite modelling to link individual's condition, expressed through the condition index, to population‐level status. We start by modelling ontogeny of European pilchard (Sardina pilchardus, Clupeidae) as a function of food and constant temperature using Dynamic Energy Budget theory. We then provide a framework to simultaneously track the individual‐ and population‐level statistics by incorporating the dynamic energy budget model into an individual‐based model. Lastly, we explore the effects of fishing pressure on the statistics in two constant and food‐limited environmental carrying capacity scenarios. Results show that, regardless of the species' environmental carrying capacity, individual condition index will increase with fishing mortality, that is, with reduction of stock size. Same patterns are observed for gilthead seabream (Sparus aurata, Sparidae), a significantly different species. Condition index can, therefore, in food‐limited populations, be used to (i) estimate population size relative to carrying capacity and (ii) distinguish overfished from underfished populations. Our findings promote a practical way to operationally incorporate the condition index into fisheries management and marine conservation, thus providing additional use for the commonly collected biometric data. Some real‐world applications, however, may require additional research to account for other variables such as fluctuating environmental conditions and individual variability. [ABSTRACT FROM AUTHOR]

Climate change is projected to affect the productivity of global fisheries. Management based on maximum sustainable yield (MSY) has been effective at eliminating overfishing in many regions. However, continuing to use yield‐maximizing targets under climate‐driven changes in productivity can result in higher anthropogenic pressure on populations subject to climate‐related stress than maintaining status quo management targets. We demonstrate this effect using a theoretical example and case studies from snow crab in the eastern Bering Sea and a global marine fisheries database. In these examples, the conservation gain (i.e. biomass in the ocean) of maintaining status quo management targets is larger than the small gain in harvest made through climate adaptation in MSY‐based management. The aggregate conservation gain of maintaining management targets increases as the harmful impacts of climate change on productivity worsen. Instead of climate‐adaptive MSY‐based targets, new management tools are needed to balance conservation and food production in ecosystems of populations displaying non‐stationary productivity. [ABSTRACT FROM AUTHOR]

Density dependence is likely to act as a regulatory mechanism in fish stocks that are recovering from overfishing. In general, density dependence in fish stocks is assumed to only occur in reproduction and early life stages and is therefore usually modelled as a stock‐recruitment relationship. Recent research shows that density dependence can also reduce individual growth in body size later in life. In this study, we show how optimal fishing effort changes with the strength of density dependence in individual growth for four stocks of North Sea flatfish species. Using size‐structured population models we show that density dependence arises due to a mechanistic link between the resource availability and life history processes at the individual level. We furthermore show that the stock response to harvesting is either driven by changes in individual reproduction when density dependence in individual growth is weak or by changes in individual growth rate when individual growth is strongly affected by density dependence. These two types or regimes are separated by a sudden shift in dynamics. It is therefore of great importance to account for density dependence in growth when managing fish stocks. [ABSTRACT FROM AUTHOR]

The implementation of ecosystem management requires ecosystem modelling within the context of a natural resource management process. Ecopath with Ecosim (EwE) is the most widely used modelling platform for investigating the dynamics of marine ecosystems, but has played a limited role in fisheries management and in multi‐sector resource decision‐making. We review 10 case studies that demonstrate the use of EwE to support operational resource management. EwE models are being used to inform tactical decision‐making in fisheries and other ocean use sectors, as well as to identify key trade‐offs, develop appropriate policy objectives, and reconcile conflicting legislative mandates in a variety of ecosystems. We suggest the following criteria to enhance the use of EwE and other ecosystem models in operational resource management: (1) a clear management objective that can be addressed through modelling; (2) an important trade‐off and a receptive policy context amenable to trade‐off evaluation; (3) an accessible and well‐documented model that follows best practices; (4) early and iterative engagement among scientists, stakeholders, and managers; (5) integration within a collaborative management process; (6) a multi‐model approach; and (7) a rigorous review process. Our review suggests that existing management frameworks are as much or more of a limitation to the operational use of EwE than technical issues related to data availability and model uncertainty. Ecosystem models are increasingly needed to facilitate more effective and transparent decision‐making. We assert that the requisite conditions currently exist for enhanced strategic and tactical use of EwE to support fisheries and natural resource management. [ABSTRACT FROM AUTHOR]

Climate change is altering the productivity of marine fisheries and challenging the effectiveness of historical fisheries management. Harvest control rules, which describe the process for determining catch limits in fisheries, represent one pathway for promoting climate resilience. In the USA, flexibility in how regional management councils specify harvest control rules has spawned diverse approaches for reducing catch limits to precautionarily buffer against scientific and management uncertainty, some of which may be more or less resilient to climate change. Here, we synthesize the control rules used to manage all 507 US federally managed fish stocks and stock complexes. We classified these rules into seven typologies: (1) catch‐based; (2) constant catch; (3) constant escapement; (4) constant F; (5) stepped F; (6) ramped F and (7) both stepped and ramped F. We also recorded whether the control rules included a biomass limit ('cut‐off') value or were environmentally linked as well as the type and size of the buffers used to protect against scientific and/or management uncertainty. Finally, we review the advantages and disadvantages of each typology for managing fisheries under climate change and provide seven recommendations for updating harvest control rules to improve the resilience of US federally managed fisheries to climate change. [ABSTRACT FROM AUTHOR]

Successful fisheries management systems tend to be underpinned by harvest strategies, specifying formally agreed data collection systems, assessment approaches and management measures used to regulate fishing pressure. While harvest strategies can be effective even in data‐ and capacity‐limited (DCL) situations, their development remains challenging in such contexts. We present a process and decision‐support tool, FishPath, to guide the identification of suitable harvest strategy component options given often debilitating conditions: (i) resource limitations and lack of technical management capacity; (ii) 'uniqueness' of DCL fisheries; (iii) the concept of harvest strategies is unfamiliar to managers and scientists, and the universe of options is hard to navigate; and (iv) the lack of an effective participatory process to identify solutions tailored to local contexts. These conditions can lead to either management paralysis or generic solutions that may be poor fits to specific conditions. The FishPath Tool uses a diagnostic questionnaire that elicits the key characteristics and specific circumstances of a fishery. It compares these with the requirements of alternative options from an inventory of possible harvest strategy components, identifies where these requirements are met and provides customised, transparent guidance on the appropriateness of component options of a harvest strategy, specific to the fishery of interest and its governance context. The FishPath Process is a facilitated multi‐stakeholder, participatory engagement process aimed to set fisheries on the path to develop a harvest strategy. The FishPath Process and Tool combine to ensure a bottom‐up, documented, transparent, replicable and efficient process. [ABSTRACT FROM AUTHOR]

Fisheries management needs to ensure that resources are exploited sustainably, and the risk of depletion is at an acceptable level. However, often uncertainty about resource dynamics exists, and data availability may differ substantially between fish stocks. This situation can be addressed through tiered systems, where tiers represent different data limitations, and tier‐specific stock assessment methods are defined, aiming for risk equivalence across tiers. As case studies, we selected stocks of European plaice, Atlantic cod and Atlantic herring, where advice is provided by the International Council for the Exploration of the Sea (ICES). We conducted a closed‐loop simulation to compare risk equivalence between the data‐rich ICES MSY rule, based on a quantitative stock assessment, and the revised data‐limited empirical management procedures of the ICES advice framework. The simulations indicated that the data‐limited approaches were precautionary and did not lead to a higher risk of depletion than the data‐rich approach. Although the catch based on generic data‐limited approaches was lower, stock‐specific optimisation improved management performance with catch levels comparable with the data‐rich approach. Furthermore, the simulation indicated the ICES MSY rule can fail to meet management objectives due to increased depletion risk when management reference points are set suboptimally. We conclude that the recent revisions of the ICES system explicitly account for risk equivalence for data‐limited fisheries management and are a major step forward. Finally, we advocate further consideration of simple empirical management procedures irrespective of data limitations due to their ability to meet fisheries management objectives with greater simplicity. [ABSTRACT FROM AUTHOR]

Fisheries governance systems designed to regulate fishing are often described as being highly diverse across countries. However, there is little systematic work that directly examines and describes the (dis)similarities across such systems, and how socio‐political and economic contexts drive such variation at a global scale. In this paper, we use 68 indicators from a novel dataset to examine the fisheries governance systems in place to constrain overfishing in national waters across 142 countries. We found that countries cluster in just two distinct governance groups which display different traits to constrain overfishing. Where one group takes a tougher stance on aspects regarding access to its fisheries resources, the other is more focused on gathering fisheries information and publicizing the data. The 10 greatest differences between groups relate to the gathering of information and monitoring of their fisheries, the effectiveness of compliance systems and the existence of policies around sustainability. On these key differences, one group consistently displays more far‐reaching governance traits. The overall governance capacity of a country and the national socio‐economic importance of fisheries are identified as potential drivers of this variation. Despite their differences, the two groups show substantial overlap for many indicators, particularly those that are inexpensive, but also for certain costly policies. These patterns prompt hypotheses of policy transfer or convergence across fisheries governance systems, most notably regarding 'low‐hanging fruit' policies. [ABSTRACT FROM AUTHOR]

Many marine species are shifting their distributions in response to changing ocean conditions, posing significant challenges and risks for fisheries management. Species distribution models (SDMs) are used to project future species distributions in the face of a changing climate. Information to fit SDMs generally comes from two main sources: fishery‐independent (scientific surveys) and fishery‐dependent (commercial catch) data. A concern with fishery‐dependent data is that fishing locations are not independent of the underlying species abundance, potentially biasing predictions of species distributions. However, resources for fishery‐independent surveys are increasingly limited; therefore, it is critical we understand the strengths and limitations of SDMs developed from fishery‐dependent data. We used a simulation approach to evaluate the potential for fishery‐dependent data to inform SDMs and abundance estimates and quantify the bias resulting from different fishery‐dependent sampling scenarios in the California Current System (CCS). We then evaluated the ability of the SDMs to project changes in the spatial distribution of species over time and compare the time scale over which model performance degrades between the different sampling scenarios and as a function of climate bias and novelty. Our results show that data generated from fishery‐dependent sampling can still result in SDMs with high predictive skill several decades into the future, given specific forms of preferential sampling which result in low climate bias and novelty. Therefore, fishery‐dependent data may be able to supplement information from surveys that are reduced or eliminated for budgetary reasons to project species distributions into the future. [ABSTRACT FROM AUTHOR]

Understanding and managing fishery selectivity to target species and desirable size are instrumental to fisheries management. China, as the world's largest producer of marine capture fisheries, has been widely perceived to possess unselective domestic fisheries. To date, this perception remains largely anecdotal and conjectural, hindering the development of evidence‐based and effective management solutions. Here, we conducted a literature review to examine the magnitude and scale of unselective fisheries in China. By collating and analysing 140 fishery‐level and 807 species‐level records from 66 peer‐reviewed publications from 2010 to 2021, we found that primary target species were absent in 59% of fisheries, while unidentifiable low‐value and juvenile mixed catch were universal. Key commercial taxa were subject to nationwide multi‐gear and multispecies fisheries, each involving an average of 3.33 types of gear and accounting for less than 25% of catch individually. The 'permissible gears' defined by the national gear regulatory catalogue were selective over target species and caught negligible by‐products, though they were used less frequently, representing only 24% of catch records. While unselective fishing can provide seafood supplies for China's large population and potentially facilitate balanced harvest, management actions are needed to control the fishing pressure on primary target species and by‐product species. Amid the ongoing fisheries management reform in China, we proposed management recommendations tailored to China's needs and social contexts, including accounting for the trade‐off between socio‐economic and ecological goals, contemplating impacts of unselective fishing when implementing TAC programmes, and strengthening fisheries monitoring to inform management at multiple scales. [ABSTRACT FROM AUTHOR]

Fishery management frequently involves precautionary buffering for scientific uncertainty. For example, a precautionary buffer that scales with scientific uncertainty is used to calculate the acceptable biological catch downward from the overfishing limit in the US federal fishery management system. However, there is little empirical guidance to suggest how large buffers for scientific uncertainty should be. One important component of uncertainty is variation among different assessments of the same stock in estimates of management‐relevant quantities. We analysed commercially exploited marine fish and invertebrate stocks around the world and developed Bayesian hierarchical models to quantify inter‐assessment variation in terminal year biomass and fishing mortality estimates, reference points, relative biomass and fishing mortality estimates, and overfishing limits. There was little evidence of inter‐assessment bias; stock assessment estimates in the terminal year of the assessment were not consistently higher or lower than estimates of the same quantities in future years. However, there was a tendency for extreme values from the terminal year to be pulled closer to the mean in future years. Inter‐assessment variation in all estimates differed across regions, and a longer inter‐assessment interval generally resulted in greater variation. Inter‐assessment uncertainty was greatest for estimates of the overfishing limit, with coefficients of variation ranging from 17% in Europe (non‐EU) to 107% for Pacific Ocean pelagic stocks. Because inter‐assessment variation is only one component of scientific uncertainty, we suggest that these uncertainty estimates may provide a basis for determining the minimum size of precautionary buffers. [ABSTRACT FROM AUTHOR]

The incidental capture by marine fisheries as bycatch poses a global threat to pelagic sharks and rays. In large, industrialized fisheries that often operate in areas beyond national jurisdiction, at least 22 threatened species of pelagic elasmobranchs are caught as bycatch, representing the majority of megafauna bycatch in tuna fisheries. Here, we investigate (1) the efficacy of the current policies of the five tuna‐related Regional Fisheries Management Organizations (tRFMOs) in mitigating elasmobranch bycatch, (2) data needed to better assess the amount and impact of elasmobranch bycatch and (3) the research necessary for the adoption of new policies. We found that tRFMOs have adopted 34 active policies that address pelagic elasmobranch bycatch. However, most policies (~76%, n = 26) are unlikely to avoid or minimize elasmobranch bycatch. Instead, most policies focus on mitigating post‐capture mortality via remediation and requiring or encouraging research and data collection. Despite the emphasis on research mandates, we find that the existence of research was not related to policy adoption, suggesting that lack of research has not historically prohibited policymaking. Overall, we suggest that current research and data transparency, though perhaps not necessary for policy adoption, are not sufficient to adequately evaluate the population‐level impacts of bycatch on many elasmobranch species in tRFMO‐managed fisheries. Given these results, we recommend a precautionary approach that involves reforms in tRFMO voting processes to facilitate the adoption of binding requirements for elasmobranch catch limits, bycatch avoidance, pre‐ and post‐capture handling and release modifications and protection of areas important to threatened pelagic elasmobranchs. [ABSTRACT FROM AUTHOR]

Environmental impacts on fisheries are pervasive, yet methods to account for them in stock assessments and management decisions vary in rigour and quality. The prevalence and efficacy of methods to account for environmental impacts are not well documented, limiting our ability to adequately respond to future environmental and climate changes for adaptive resource management. In Canada, legislation now requires that environmental conditions are considered in the management of fish stocks, yet the current extent of implementation in assessment processes is poorly understood. We assessed the use of climate, oceanographic and ecological considerations in science advisory processes for 178 stock assessments by Fisheries and Oceans Canada. We evaluated whether these considerations were included in conceptual hypotheses about broad‐scale mechanisms, quantitative or qualitative analyses, and the development of management advice on current or future stock status. Conceptual hypotheses were included in 46% of assessments; quantitative inclusions occurred in 21% of assessments, while qualitative interpretations appeared in 31% of assessments; and 27% of assessments included climate, oceanographic and/or ecological considerations in the advice. Assessments of salmonids, invertebrates and pelagic taxa more frequently made use of environmental data than those for groundfish and elasmobranchs. Comparing our findings with assessments in other jurisdictions highlighted a gap in Canada's ability to respond to environmental changes and a need to develop integrated management approaches, such as regional ecosystem assessments and approaches that combine modelling and empirical analyses, with socio‐economic analysis within interdisciplinary teams. [ABSTRACT FROM AUTHOR]

Fishes include some of the most threatened vertebrate species globally. As such, efforts to effectively conserve and manage fish populations and their habitats are vast. Here, we present conceptual tools from behavioural ecology to establish a framework for studies of fish conservation and management, connecting questions relevant to managers and practitioners with behavioural theories and methodologies. We apply predictions developed from a theory to diet choice, patch use, habitat selection, movement, and social behaviours. We present questions and issues in fisheries management and conservation for which theory, hypotheses, and methodologies would be both novel and complementary to current assessment strategies or conservation efficacy studies. In each case, theory approaches the ecological trade‐offs associated with a given behavioural trait through the lens of adaptations and fitness implications—the foundational principles of behavioural ecology. We show key methodologies used to effectively apply behavioural theory to specific hypotheses relevant to a given management question. We then compile the conceptual and methodological approaches to assemble a toolkit through which fisheries managers may assess, for example, habitat selection behaviours via novel study designs and/or new ways of interpreting commonly collected data (e.g., distribution and abundance relative to habitat type). Finally, we propose training of aquatic and marine natural resource specialists and conservation agency fish biologists be complemented with behavioural ecology theories and methodologies. [ABSTRACT FROM AUTHOR]

Fisheries management is essential to guarantee sustainable capture of target species and avoid undesirable declines of incidentally captured species. A key challenge is halting and reversing declines of shark and ray species, and specifically assessing the degree to which management is sufficient to avoid declines in relatively data‐poor fisheries. While ecological risk analyses focus on intrinsic 'productivity' and extrinsic 'susceptibility', one would ideally consider the influence of 'fisheries management'. Currently, there is no single management evaluation that can be applied to a combination of fishery types at the scale of individual country or Regional Fisheries Management Organizations (RFMOs). Here, we outline a management‐risk (M‐Risk) framework for sharks, rays and chimaeras used to evaluate species' risk of overfishing resulting from ineffective management. We illustrate our approach with application to one country (Ecuador) and RFMO (Inter‐American Tropical Tuna Commission) and illustrate the variation in scores among species. We found that while both management units assessed had similar overall scores, the scores for individual attributes varied. Ecuador scored higher in reporting‐related attributes, while the IATTC scored higher in attributes related to data collection and use. We evaluated whether the management of individual species was sufficient for their relative sensitivity by combining the management‐risk score for each species with their intrinsic sensitivity to determine a final M‐Risk score. This framework can be applied to determine which species face the greatest risk of overfishing and be used by fisheries managers to identify effective management policies by replicating regulations from countries with lower risk scores. [ABSTRACT FROM AUTHOR]

Tuna Regional Fisheries Management Organizations (RFMOs) are responsible for conservation and sustainable management of transboundary tuna resources in Exclusive Economic Zones and Areas Beyond National Jurisdiction (ABNJ). The data collected and analyses performed by tuna RFMOs are one of the main sources of scientific information supporting the management, sustainable use and conservation of biodiversity in the ABNJ. An understanding of the scope and availability of data provided by tuna RFMOs is timely, given the expected establishment of a new legally binding high seas agreement to protect marine biodiversity in the ABNJ. We examined official catch statistics and stock assessments that are accessible in the public domain for the five tuna RFMOs, and evaluated their taxonomic, spatial and temporal resolution. We found that the Atlantic and Indian Ocean tuna RFMOs report catches for a greater number of taxa compared to Pacific RFMOs. There are substantial gaps in the taxonomic resolution of sharks and rays and 'other teleosts', and only about half of the reported global catches are georeferenced, despite existing mandatory requirements. Additionally, the estimation and reporting of discards in all tuna RFMOs remains incomplete. Tuna RFMOs have made progress in implementing stock assessments for a wide range of taxa including targeted species with high economic value but also functionally important non‐target species with lower economic value. However, assessments should be expanded to cover other bycatch species. We emphasize the importance of accessible and accurate statistics, for supporting the research and societal oversight needed under any future ABNJ biodiversity treaty. [ABSTRACT FROM AUTHOR]

Meeting the objectives of sustainable fisheries management requires attention to the complex interactions between humans, institutions and ecosystems that give rise to fishery outcomes. Traditional approaches to studying fisheries often do not fully capture, nor focus on these complex interactions between people and ecosystems. Despite advances in the scope and scale of interactions encompassed by more holistic methods, for example ecosystem‐based fisheries management approaches, no single method can adequately capture the complexity of human–nature interactions. Approaches that combine quantitative and qualitative analytical approaches are necessary to generate a deeper understanding of these interactions and illuminate pathways to address fisheries sustainability challenges. However, combining methods is inherently challenging and requires understanding multiple methods from different, often disciplinarily distinct origins, demanding reflexivity of the researchers involved. Social–ecological systems' research has a history of utilising combinations of methods across the social and ecological realms to account for spatial and temporal dynamics, uncertainty and feedbacks that are key components of fisheries. We describe several categories of analytical methods (statistical modelling, network analysis, dynamic modelling, qualitative analysis and controlled behavioural experiments) and highlight their applications in fisheries research, strengths and limitations, data needs and overall objectives. We then discuss important considerations of a methods portfolio development process, including reflexivity, epistemological and ontological concerns and illustrate these considerations via three case studies. We show that, by expanding their methods portfolios, researchers will be better equipped to study the complex interactions shaping fisheries and contribute to solutions for sustainable fisheries management. [ABSTRACT FROM AUTHOR]

It is commonly accepted that no ecosystem model is the 'best', but rather that ecosystem models should be used in ensembles. This is also the case for the Barents Sea ecosystem, where we have used two different ecosystem models to explore the role of the top‐predator Northeast Arctic (NEA) stock of Atlantic cod (Gadus morhua, Gadidae) in the food web. The two models differ in complexity; Gompertz being less complex in terms of food web (7 components) and processes compared to the complex Nordic and Barents Seas Atlantis model (53 components). On the other hand, Gompertz provides thousands of stochastic realizations for each scenario, whereas Atlantis provides only one deterministic simulation. To compare the response to changes in NEA cod on two key prey species, capelin (Mallotus villosus, Osmeridae) and polar cod (Boreogadus saida, Gadidae), we perturbed the historical fishing pressure by ±50% and used the same NEA cod biomass in both models. Even though the links between NEA cod and the prey species are similar in the two models, the results from the study reveal that indirect effects through other food‐web components might be as important as direct predator–prey interactions. Differences in spatial structure and overlap between species also influence the species response to the perturbations. In this study, we focus on the mechanisms that drives the changes in the models, and advise on potential consequences for fisheries management. The two models can complement each other, and the differences between them point to areas where more knowledge is needed. [ABSTRACT FROM AUTHOR]

Chondrichthyan fishes are among the most threatened vertebrates on the planet because many species have slow life histories that are outpaced by intense fishing. The Western Central Atlantic Ocean, which includes the Greater Caribbean, is a hotspot of chondrichthyan biodiversity and abundance, but has been characterized by extensive shark and ray fisheries and a lack of sufficient data for effective management and conservation. To inform future research and management decisions, we analysed patterns in chondrichthyan extinction risk, reconstructed catches and management engagement in this region. We summarized the extinction risk of 180 sharks, rays and chimaeras, including 66 endemic and 14 near‐endemic species, using contemporary IUCN Red List assessments. Over one‐third (35.6%) were assessed as Vulnerable, Endangered or Critically Endangered, primarily due to overfishing. Reconstructed catches from 1950 to 2016 peaked in 1992, then declined by 40.2% thereafter. The United States, Venezuela and Mexico were responsible for most catches in the region and hosted the largest proportions of the regional distributions of threatened species, largely due to having extensive coastal habitats in their Exclusive Economic Zones. The quantity and taxonomic resolution of fisheries landings data were poor in much of the region, and national‐level regulations varied widely across jurisdictions. Deepwater fisheries represent an emerging threat, although many deepwater chondrichthyans currently have refuge beyond the depths of most fisheries. Regional collaboration as well as effective and enforceable management informed by more complete fisheries data, particularly from small‐scale fisheries, are required to protect and recover threatened species and ensure sustainable fisheries. [ABSTRACT FROM AUTHOR]

Recreational fisheries are diverse in scale, scope, and participation worldwide, constituting an important ecosystem service of marine and freshwater ecosystems. Management of these socio‐ecological systems is challenged by monitoring gaps, stemming from difficulties engaging with participants, biased sampling, and insufficient resources to conduct biological or social surveys of fish and human populations. In the Internet age, online data have great potential to make a meaningful contribution to recreational fisheries research, monitoring, and management. Recreational fishers in some countries increasingly use social and other digital media to share their experiences with followers, with most data freely available to web scrapers that compile databases of text (e.g. tweets, status updates, comments), photos, videos and other media that contain information about spatiotemporal activity, sentiments towards catches/experiences, targeted and bycatch species, effort levels, and more. Although the future of recreational fisheries research, monitoring and management will likely involve more digital scraping, uptake is only just beginning and there are several challenges including tool availability/accessibility, sampling biases, and making findings relevant and usable to practitioners. Despite these challenges, we envision fisheries managers will increasingly turn towards online sources of fisheries data to supplement conventional methods. We challenge scientists to work towards continued method development and validation of various digital fisheries data tools and emphasize how biases from the online behaviour of users may complicate interpretations of these data for fisheries management. [ABSTRACT FROM AUTHOR]

Livelihood diversification is increasingly central to policy advice and investments in rural development and fisheries management. For small‐scale fishing communities in low‐ to middle‐income countries, more diverse livelihoods are generally hypothesized to reduce fishing pressure and vulnerabilities to external shocks and adverse trends while enabling people to construct routes out of poverty. Yet, evidence of impacts from livelihood diversification in small‐scale fisheries remains sparse. Our examination of the peer‐reviewed literature found substantial differences in how livelihood diversification is pursued, and in the realized outcomes from the process of diversification. Studies describing diversified livelihoods were almost as likely to report that livelihoods were not improved or that outcomes were mixed (54% combined) as they were to report improved livelihood outcomes (45%). Furthermore, one of the main theoretical drivers behind the support for diversified livelihoods—ecological conservation benefits—was unexplored in over 70% of studies. Of the minority of studies that did explore ecological outcomes, most reported that ecological conditions had not improved. These findings indicate conceptual ambiguity around livelihood diversification and a lack of empirical evidence supporting its theoretical underpinnings. There remain important questions about the impacts of diversification on multidimensional poverty and ecological conservation. Future research on and investment in diversification should be both more deliberate of what diversification means and more rigorous in the evaluation of its impacts. [ABSTRACT FROM AUTHOR]

The propensity for fisheries management agencies in the United States to collect or request stakeholder‐based data has grown considerably in the last decade. While systems are in place for the review and use of biological data in management, there is far less structure to the integration of non‐economic social data. Here, we present a framework for characterizing the applicability of various forms of social data in regulatory processes, documents, and decisions. The social data landscape is presented as a simple framework for understanding the temporal, spatial, and impact scope of policy actions and how different kinds of social data can inform an array of action types and play important roles in management. We conclude with recommendations for practitioners and managers who seek to incorporate different types of stakeholder input into their processes and provide researchers with guidelines when weighing the trade‐offs of unique methodologies. [ABSTRACT FROM AUTHOR]

There is growing recognition that fisheries should be managed for all three pillars of sustainability: economic, social and environmental sustainability. Limited quantitative evidence exists on factors supporting social sustainability, much less factors that contribute to multiple dimensions of sustainability. To develop a broader understanding of the factors that influence the performance of fishery management systems in environmental, economic and social pillars, we examine 11 input factors conjectured to contribute to successful fisheries using a global dataset of 145 fisheries case studies. The analysis indicates that management approaches are cross‐cutting and contribute to multiple dimensions of sustainability to varying extents. Importantly, factors exogenous to fisheries management can be as important as fisheries management, suggesting collaboration of fisheries institutions with other public and private institutions is important for sustainable fisheries development. [ABSTRACT FROM AUTHOR]

The correct prediction of the shape and strength of density dependence in productivity is key to predicting future stock development and providing the best possible long‐term fisheries management advice. Here, we identify unbiased estimators of the relationship between somatic growth, recruitment and density, and apply these to 80 stocks in the Northeast Atlantic. The analyses revealed density‐dependent recruitment in 68% of the stocks. Excluding pelagic stocks exhibiting significant trends in spawning stock biomass, the probability of significant density dependence was even higher at 78%. The relationships demonstrated that at the commonly used biomass limit of 0.2 times maximum spawning stock size, only 32% of the stocks attained three quarters of their maximum recruitment. This leaves 68% of the stocks with less than three quarters of their maximum recruitment at this biomass limit. Significantly lower recruitment at high stock size than at intermediate stock size was seen in 38% of the stocks. Density dependence in late growth occurred in 54% of the stocks, whereas early growth was generally density‐independent. Pelagic stocks were less likely to exhibit density dependence in recruitment than demersal and benthic stocks. We recommend that both the degree to which productivity is related to density and the degree to which the relationship changes over time should be investigated. Both of these aspects should be considered in evaluations of whether sustainability and yield can be improved by including density dependence in forecasts of the effects of different management actions. [ABSTRACT FROM AUTHOR]

Recent literature and empirical research show that both trust and collaboration are of great importance for effective fishery management. The application of Machine Learning (ML) to fishery management offers exciting new opportunities for data synthesis and analysis and integrated insights across typically siloed domains. Yet, challenges remain as ML approaches provide new means of monitoring, enforcement and data analysis. Trust is among the underlying bases of collaboration, and control is the main means of shaping collaborative decision‐making techniques. As ML changes the dynamics of governance and enhances management control mechanisms, ML affects trust. ML methods are being introduced into a context that suffers a lack of transparency and trust between fishers and managers. As ML technologies continue to be used to inform fishery management and influence knowledge sharing and communication within the fishery network, forms of trust existing in the management network will be impacted differently. This article provides a concise review of a subset of potential ML applications to fishery management to explore how these emerging methods may impact forms of trust between fishery stakeholders. [ABSTRACT FROM AUTHOR]

Management of fish populations and ecosystems suffers from data and knowledge gaps, particularly with respect to how humans and nature affect dynamics at multi‐decadal and longer time scales. However, collection of new data which indicates population or ecosystem status is slow and expensive. Here we analyse c. 110 years of neglected fishery data for an overexploited top predator, swordfish, in the Mediterranean Sea. These data are available at scales of high time–space–biological resolution (i.e., sub‐weekly, sub‐regional sea; individual weights) and allow different ecological questions to be addressed than is possible with coarsely scaled data (e.g., annually resolved total catches aggregated over large sea areas). We constructed regional indicators of population status (relative abundance, mean individual size and its variability, migration phenology) covering most of the 20th century, and pre‐dating other population datasets by 50–70 years. The length and duration of these new time series allowed detection of significant multi‐annual/decadal variations in abundance and mean weight not detectable in shorter, more recent time series. These new data and evidence of multi‐annual variability in population variables improve knowledge of Mediterranean swordfish ecology. The findings provide a new basis on which further historical data recovery and analysis of contemporary data can provide new perspectives and opportunities for quantifying vulnerability of populations to exploitation and climate change. [ABSTRACT FROM AUTHOR]

Wild‐caught fish are a bioavailable source of nutritious food that, if managed strategically, could enhance diet quality for billions of people. However, optimising nutrient production from the sea has not been a priority, hindering development of nutrition‐sensitive policies. With fisheries management increasingly effective at rebuilding stocks and regulating sustainable fishing, we can now begin to integrate nutritional outcomes within existing management frameworks. Here, we develop a conceptual foundation for managing fisheries for multispecies Maximum Nutrient Yield (mMNY). We empirically test our approach using size‐based models of North Sea and Baltic Sea fisheries and show that mMNY is predicted by the relative contribution of nutritious species to total catch and their vulnerability to fishing, leading to trade‐offs between catch and specific nutrients. Simulated nutrient yield curves suggest that vitamin D, which is deficient in Northern European diets, was underfished at fishing levels that returned maximum catch weights. Analysis of global catch data shows there is scope for nutrient yields from most of the world's marine fisheries to be enhanced through nutrient‐sensitive fisheries management. With nutrient composition data now widely available, we expect our mMNY framework to motivate development of nutrient‐based reference points in specific contexts, such as data‐limited fisheries. Managing for mMNY alongside policies that promote access to fish could help close nutrient gaps for coastal populations, maximising the contribution of wild‐caught fish to global food and nutrition security. [ABSTRACT FROM AUTHOR]

Co‐management—fisher participation in fisheries management—varies across two fundamental dimensions. The most commonly addressed is a 'ladder of participation' reflecting the degree to which decision‐making is shared between government and fishers. The other dimension reflects if, and how, co‐management is implemented across the 'management spectrum' of functional components of management: (1) direction‐setting, planning and policy development; (2) harvest management; (3) compliance and enforcement; (4) ecosystem stewardship, conservation, rehabilitation; (5) research; and (6) organizational management and development. This article presents an approach to combining these two dimensions in a comprehensive manner, to better understand and assess the nuances of co‐management in practice. The approach is tested through application to fisheries of Nova Scotia, Canada, with representatives of organized fisher associations assessing the nature and extent of participation, both current and desired, for each of the six management components. This leads to insights about the fishery management components that tend to have greater or lesser fisher participation, differences in perceived levels of current and desired participation, the willingness and capacity of fisher associations to take on various management tasks and potential directions to improve fishery co‐management practices. [ABSTRACT FROM AUTHOR]