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Forage fish populations often undergo large and rapid fluctuations in abundance. However, most of their predators are buffered against such fluctuations owing to their slower pace of life, which allows them to maintain more stable populations, at least during short periods of food scarcity. In this study, we investigated top‐down processes exerted by seabirds on forage fish stocks in five contrasted marine ecosystems, compiling numerous data sets on seabird counts, diets, energetic needs and prey energy content and abundance. Off Norway, South Africa, Peru, Sweden and Scotland, we found that predation pressure—estimated as the proportion of a fish stock consumed by seabirds—was generally low (median = 1%), but increased sharply at low levels of prey abundance. When prey biomass decreased below 15–18% of its maximum recorded value, predation by seabirds became a source of important additional pressure on prey stocks (~20% of prey biomass is consumed by seabirds). An earlier empirical study advocated for keeping forage stocks from falling below a threshold of 33% of long‐term maximum prey biomass in order to safeguard seabird breeding success, but here we further suggest that a threshold of 18% should be considered as a limit not to be exceeded for the sake of the forage fish themselves, and below which extra cautious management of fisheries may be required. Nevertheless, despite exceptionally high rates of predation on some occasions, predation pressure was not correlated with prey dynamics, suggesting an absence of prey entrapment due to seabirds alone in these five ecosystems. [ABSTRACT FROM AUTHOR]

Conflicts of interest between resource extraction and conservation are widespread, and negotiating such conflicts, or trade‐offs, is a key issue for ecosystem managers. One such trade‐off is resource competition between fisheries and marine top predators. Managing this trade‐off has so far been difficult due to a lack of knowledge regarding the amount and distribution of prey required by top predators.Here, we develop a framework that can be used to address this gap: a bio‐energetic model linking top predator breeding biology and foraging ecology with forage fish ecology and fisheries management.We apply the framework to a Baltic Sea colony of common guillemots Uria aalge and razorbills Alca torda, two seabird species sensitive to local prey depletion, and show that densities of forage fish (sprat Sprattus sprattus and herring Clupea harengus) corresponding to the current fisheries management target BMSY are sufficient for successful breeding. A previously proposed fisheries management target for conserving seabirds, 1/3 of historical maximum prey biomass (B1/3), was also sufficient.However, the results highlight the importance of maintaining sufficient prey densities in the vicinity of the colony, suggesting that fine‐scale spatial fisheries management is necessary to maintain high seabird breeding success.Despite foraging on the same prey, razorbills could breed successfully at lower prey densities than guillemots but needed higher densities for self‐maintenance, emphasizing the importance of considering species‐specific traits when determining sustainable forage fish densities for top predators.Synthesis and applications. Our bio‐energetic modelling framework provides spatially explicit top predator conservation targets that can be readily integrated with current fisheries management. The framework can be combined with existing management approaches such as dynamic ocean management, marine spatial planning and management strategy evaluation to inform ecosystem‐based management of marine resources. [ABSTRACT FROM AUTHOR]

Despite improved knowledge and stricter regulations, numerous fish stocks remain overharvested. Previous research has shown that fisheries management may fail when the models and assessments used to inform management are based on unrealistic assumptions regarding fishers' decision‐making and responses to policies. Improving the understanding of fisher behaviour requires addressing its diversity and complexity through the integration of social science knowledge into modelling. In our paper, we review and synthesize state‐of‐the‐art research on both social science's understanding of fisher behaviour and the representation of fisher decision‐making in scientific models. We then develop and experiment with an agent‐based social–ecological fisheries model that formalizes three different fishing styles. Thereby we reflect on the implications of our incorporation of behavioural diversity and contrast it with the predominant assumption in fishery models: fishing practices being driven by rational profit maximizing. We envision a next generation of fisheries models and management that account for social scientific knowledge on individual and collective human behaviours. Through our agent‐based model, we demonstrate how such an integration is possible and propose a scientific approach for reducing uncertainty based on human behavioural diversity in fisheries. This study serves to lay the foundations for a next generation of social–ecological fishery models that account for human behavioural diversity and social and ecological complexity that are relevant for a realistic assessment and management of fishery sustainability problems. [ABSTRACT FROM AUTHOR]

Many natural resources have degraded and collapsed despite being managed under rigorous institutional frameworks set up to ensure rational exploitation. Path dependency of dysfunction institutions has been suggested as an explanation for such undesired outcomes. We explore the role of path dependency in natural resource management by studying a 100-year evolution of Swedish fisheries. We rely on three main types of original longitudinal data collected for the period 1914-2016: (A) policy documents, (B) government spending on management and subsidies, and (C) catch and fleet data. Our analysis contrasts the periods before and after the Swedish entrance into the European Union (1995) because this marks the year when fisheries policy became beyond the direct influence of the Swedish government. We uncover four pieces of evidence suggesting the existence of a path dependent dynamic in the pre-EU period: (1) despite increasing insights on the vulnerability of fish stocks to overexploitation, national policy goals in relation to fisheries continuously promoted incompatible goals of social and economic growth but without any reference to the sustainability of the biological resources; (2) the same policy instruments were used over long periods; (3) actor constellations within the fisheries policy subsystem were stable over time; (4) neither political regime nor macroeconomic variables and fisheries performance (industry production, oil price, landing values) could explain observed temporal variation in subsidies. We conclude that key policy actors in the pre-EU period formed an "iron triangle" and thereby prevented necessary policy changes. These national reinforcing feedbacks have been weakened since EU entrance, and the indicators for path dependency show broader involvement of stakeholders, a shift in spending, and policy goals that now explicitly address ecological sustainability. [ABSTRACT FROM AUTHOR]

Sustainable fisheries management plays a critical role in supporting healthy marine ecosystems and the livelihoods of millions of people. An emerging view on fisheries management emphasizes the need to manage fisheries as complex social-ecological systems. Yet, our understanding of the outcomes of fisheries management from a social-ecological perspective is limited in comparison to that provided by either the biophysical or the social perspective alone. In the Baltic Sea, management interventions focused on ecosystem recovery contributed to unintended changes from 1996 to 2009 in the fishing strategy diversity practiced by Swedish fishers. We evaluate how the changes in strategy diversification affected the capacity of Swedish fishers to adapt to future ecosystem changes. To do this, we constructed and analyzed social-ecological fisheries networks. Our analysis confirmed the previously reported development of a narrower combination of fishing strategies among large-scale fishers, parallel with a diversification in small-scale fishers' strategies. However, the results demonstrated that switching fishing strategies has, in fact, increased in magnitude, and the fishers were more equally distributed in different fishing strategies in 2009 than in 1996. Further, we detected a development toward lower ecological dependency between fishing strategies within the community, although the strategies remained connected through ecological interactions. In conclusion, our analysis of the social-ecological interdependencies suggests that the previously reported changes in the fishing strategy diversity increased the adaptability of the Swedish Baltic Sea fishers to changing ecological conditions. On the other hand, the changes may have made the Baltic Sea more vulnerable to poor management. This empirical study emphasizes the importance of a social-ecological approach on fisheries research and management. Our results show that appreciating the complexity and changing nature of fisher behavior is crucial when assessing fisheries management outcomes, and when designing policies that aim to maintain adaptability in the uncertain and dynamic fish industry. [ABSTRACT FROM AUTHOR]

The study and classification of fishers' behaviour remains a much debated topic. There is a tension between detailed empirical studies, which highlight the variety and diversity of fisheries, and the parsimony and generalization required to satisfy science and policy demands. This study contributes to this debate. The first section reviews quantitative methods currently used for classifying fishing practices. The review uncovers significant weaknesses in quantitative classification methods, which, we argue, can be improved through the complementary use of qualitative methods. To this purpose, we introduce the concept of 'fishing style', which integrates quantitative classification methods with qualitative analysis. We explain the scientific premises of the fishing-style concept, outline a general methodological framework and present a fishing-style analysis of Swedish Baltic Sea fisheries. Based on these results, we conclude that it is possible to classify fishing practices in a relatively uniform and limited number of styles that can highlight the rich, empirical diversity of fishers' behaviour. We therefore propose that fishing-style analysis, based on an integration of quantitative and qualitative methods, can be an important step towards more effective and sustainable fisheries management. [ABSTRACT FROM AUTHOR]