Sustainability scholars frequently advocate for stewardship as a strategy to foster sustainable development. Stewardship broadly refers to the wise and responsible use of nature, and is considered necessary to ensure the long-term wellbeing of humans and that of life in general. In the academic literature local resource users, like hunters, farmers or fishers, are widely acknowledged to act as stewards of the natural environments their livelihoods depend upon. Research shows that this group of people often are able to use natural resources in a sustainable manner, and that their knowledge of how to do so can improve natural resource management. However, research also emphasizes how different local resource users have different potential to steward natural environments. There is thus a need to better understand what stewardship among local resource users entails more concretely as well as when and how it fosters environmental sustainability. In this thesis, I study stewardship in the case of Swedish Baltic small-scale fisheries. I conceptualize stewardship as an interaction between fishers and the social-ecological context in which they are embedded. This conceptualization implies that stewardship does not exist or emerge from within fishers themselves, but is created, formed and realized through fishing practices. I further define and analyze stewardship using a framework composed of three dimensions: care, agency and knowledge. My findings are contained in four papers. Paper I presents a theoretical model of how local resource users respond to social and ecological change, and shows the model’s empirical relevance. Paper II gives an overview of the diversity and development within present-day Swedish Baltic small-scale fisheries. Paper III investigates the historical development of a Swedish fishery that targets the critically endangered European eel (Anguilla anguilla). Paper IV focuses on fishers’ knowledge and assesses how this knowledge can be applied in fisheries science and management. The papers collectively demonstrate the contextual nature of stewardship and showcase how stewardship varies over time as well as between fishers. The findings illustrate the ambiguous link between stewardship and environmental sustainability, they support the notion that fishers’ knowledge can improve fisheries management, while also suggesting that future research needs to pay more attention to how stewardship is empirically manifested. Overall, the thesis advances the understanding of stewardship by highlighting the social-ecological dynamics of local resource use.

Can Swedish small-scale fisheries escape decline and live up to their attributed potential to make fisheries more sustainable? Here we address this question by highlighting diversity within these fisheries. Through a specific focus on the Baltic Sea, we demonstrate that small-scale fisheries, defined by scale of operation, are neither sustainable nor unsustainable and have different social and ecological impacts. Based on our analysis we discuss general opportunities and challenges for future development of Swedish small-scale fisheries. Opportunities exist in connection to the creation of niche-products and branding fish as a local and/or exclusive commodity, while major challenges are linked to complexity and extensiveness of regulations, lack of recruitment of new fishers, and ecological sustainability of fishing practices. We argue that attention to diversity in Swedish small-scale fisheries has to be the starting point for meeting future challenges and fulfilling their attributed potential as a sustainable primary production sector.

Unsustainable fishing can be surprisingly persistent despite devastating social, economic, and ecological consequences. Sustainability science literature suggests that the persistence of unsustainable fisheries can be understood as a social-ecological trap. Few studies have explicitly acknowledged the role of historical legacies for the development of social-ecological traps. Here, we investigate why fishers sometimes end up in social-ecological traps through a reconstruction of the historical interplay between fishers’ motivations, capacities, and opportunities to fish. We focus on the case of a Swedish fishery targeting the critically endangered European eel (Anguilla Anguilla) in the Baltic Sea. We performed the case study using a unique quantitative data set of social and ecological variables that spans over eight decades, in combination with earlier literature and interviews with fishers and fisheries experts. Our analysis reveals that Swedish archipelago fishers are highly dependent on the eel to maintain their fishing livelihood. The dependence on the eel originates from the 1930s, when fishers chose to intensify fishing for this species to ensure future incomes. The dependence persisted over time because of a series of changes, including improved eel fishing technology, heightened competition over catch, reduced opportunities to target other species, implementation of an eel fishing license, and the fishers’ capacity and motivation to deal with dwindling catches. Our study confirms that social-ecological traps are path-dependent processes. In terms of management, this finding means that it becomes progressively more difficult to escape the social-ecological trap with the passage of time. The longer entrapment endures, the more effort it takes and the bigger change it requires to return to a situation where fishers have more options so that unsustainable practices can be avoided. We conclude that fisheries policies need to be based on the premise that unsustainable fishing emerges through multiple rather than single causes.

Blue Growth is a relatively new term that is meant to realize economic growth based on the exploitation of marine resources, while at the same time preventing their degradation, overuse, and pollution. This article discusses the relevance and usefulness of this new concept for the development of capture fisheries, a sector where growth largely seems impossible without ecological devastation. An analytical distinction between intensive and extensive growth is used to argue that certain development trajectories of capture fisheries might qualify as Blue Growth. Such trajectories of growth are illustrated with the development of the Swedish bleak roe trawl fishery in the Bothnian Bay and Norwegian whitefish fishery in the Barents Sea. Comparison of the cases highlights aspects that Blue Growth advocates might want to include if they choose to consider capture fisheries as a relevant economic activity. These aspects include: a) adding value through certification; b) technological development to make more efficient use of resources used up in the fishing operation, and to upgrade their fish as commodity; and c) specialization.

Whether and how capture fisheries can increase catches and be sustainable at the same time i sa pertinent question for fisheries in the Global North. To ensure sustainable development of these fisheries, it is essential for fisheries management to pay attention to fishers’ behavior. Yet, the academic debate is polarized and features several received wisdoms. On one extreme, fishers are portrayed as “roving bandits”, and on the other extreme, fishers are portrayed as “stewards” of marine environments. In reality, fishers are neither roving bandits nor stewards,but can act as such depending on the circumstances in which they are situated. The aim of this thesis is therefore to contribute to a more nuanced understanding of fishers’ behavior, by focusing on the concept of stewardship, which has in recent years gained significant scholarly attention but requires further empirical and theoretical underpinning. The aim is addressed by the following research question: When and how are fishers in the Global North prevented from acting as stewards of marine environments? To answer this question, the thesis conceptualizes stewardship as the outcome of the interactions between fishers and the social-ecological conditions they live through and within, and applies sociological theory to analyze when and how stewardship is materialized into fishing practices. The thesis uses a mixed-method approach in order to study Swedish coastal fisheries in the Baltic Sea (SCF). The results are presented in two papers. Paper I presents some general features of SCF, discusses diversity in fishing practices, and outlines barriers and opportunities for sustainable development of SCF. Paper II provides an analysis of when and how some coastal fishers have ended up in a situation where they persistently continue to fish a critically endangered species. The results suggest that the fishers lack the motivation and the ability to act on the few existing opportunities for stewardship of marine environments. As a whole, the thesis argues that fishers are reluctant to change their way of organizing their fishing practices and proposes that this might be a general feature within fisheries in the Global North. In summary, the thesis demonstrates how the fishers’ reluctance is a response to certain social-ecological conditions, and from their particular position in these conditions. The thesis further illustrates the advantage of using a mixed-method approach to study interactions between fishers and social-ecological conditions. These interactions and their historical dynamics explain why some fishers act as stewards, others as roving bandits, and the vast majority as probably something in between.

A substantial amount of scientific effort goes into understanding and measuring compliance in fisheries. Understanding why, how and when fishers follow or violate rules is crucial for designing effective fishery policies that can halt overfishing. Non-compliance was initially explained almost exclusively with reference to economic and self-interested motivations. More recently, however, most explanations involve a combination of economic, social, political and environmental factors. Despite this recent development towards more holistic explanations, many scientists continue to frame the issue in binary terms: fishers either follow rules, or they don't. In this article we challenge this binary interpretation and focus attention on the diversity of fishers' dispositions and perceptions that underpin compliant behaviour. To this aim we construct a typology of fishers' responses towards regulation and authorities, thereby developing conceptual tools to understand different motivations and attitudes that underlie compliance outcomes. For this purpose, we identify the motivational postures of 'creativity' and 'reluctance', and then highlight their empirical relevance with an interview study of Swedish fishers. Reasons for studying the quality and diversity of fishers' motivations and responses are not purely academic. Conceptualizing and observing the quality of compliance can help policymakers and managers gauge and anticipate the potentiality of non-compliant fishing practices that may threaten the resilience of marine ecosystems.

Social-ecological (SE) traps refer to persistent mismatches between the responses of people, or organisms, and their social and ecological conditions that are undesirable from a sustainability perspective. Until now, the occurrence of SE traps is primarily explained from a lack of adaptive capacity; not much attention is paid to other causal factors. In our article, we address this concern by theorizing the variety of human responses to SE traps and the effect of these responses on trap dynamics. Besides (adaptive) capacities, we theorize desires, abilities and opportunities as important additional drivers to explain the diversity of human responses to traps. Using these theoretical concepts, we construct a typology of human responses to SE traps, and illustrate its empirical relevance with three cases of SE traps: Swedish Baltic Sea fishery; amaXhosa rural livelihoods; and Pamir smallholder farming. We conclude with a discussion of how attention to the diversity in human response to SE traps may inform future academic research and planned interventions to prevent or dissolve SE traps.

Predicting growth is critical in aquaculture, but models of growth are largely missing for mud crab species. Here, we present the first model of natural growth in juvenile and adult mud crabs Scylla serrata from East Africa using a stepwise growth function based on data on intermoult periods and growth at moult from field mark-recapture, pond and laboratory studies. The results showed a sigmoid growth pattern in carapace width and suggest that S.serrata in East Africa will reach 300g and sexual maturity similar to 9.9months after settlement, and a commercial size of 500g after 12.4months. Analyses of the literature identified several issues with the common praxis to compare standard growth measures between aquaculture studies with different initial size or growing periods. Using the new growth function to estimate the proportional difference between modelled and obtained growth as an alternative method, we show that growth rates of S.serrata cultured in cage systems, which are dominant in East Africa, was <40% of the estimated natural growth and growth obtained in pond systems. The analysis also indicated that growth rates of S.serrata in Southeast Asia was over 50% higher compared with similar culture systems in East Africa, and that different species of mud crabs had large differences in growth rates. This study shows that growth in the present mud crab aquaculture systems in East Africa is below their expected potential. Further work is needed to identify the factors behind this observation.

Scholars frequently argue that fishers’ rich understanding of marine environments can contribute to fisheries science and thereby improve management of fisheries. It is, however, challenging to integrate fishers’ knowledge (FK) with scientific knowledge. The aim of this paper is to explore to what extent FK is commensurable with scientific objectives and procedures that require generalizability and parsimony. To pursue this aim, we performed interviews with a group of fishers who participated in an earlier Swedish study in which FK was used to map locations of fish spawning grounds along the Swedish Baltic coast. By interviewing these fishers again we were able to identify and assess aspects of FK that were left implicit in the earlier study and whether or not these can complement the maps drawn. Based on our results we discuss the value of these aspects of FK for scientific understandings of marine environments.