There is a problematic interaction going on between grey seals and the small scale coastal fisheries in the Baltic. A large number of seals are by-caught and drowned each year, and the viability of the fishery is threatened by catch losses caused by the seals. Traditional mitigation methods are not sufficient, or have in some cases not been properly evaluated. Available methods of quantifying and analysing the catch losses are also insufficient. This thesis consists of three parts, each studying a different angle of this conflict. In the first part, new models for estimating catch losses are presented. In addition to the commonly used method of counting the number of damaged fish in the nets, the new models also allow for an estimation of the hidden losses. Hidden losses may be fish that are completely removed from nets without leaving any traces, fish that escape through holes in the net torn by the seals, or even fish that are scared away from the fishing gear. Such losses were found to be significant, and hence it is now clear that the traditional models seriously underestimate the total losses. The new models also allow for a deeper analysis of the interaction process. The first presented model compares catches between adjacent days (day-pairs), the second uses nets that are pre-baited before deployment, and the third relies on a detailed inspection and repair of all seal-induced damage to the net meshes. In the second part, some traditional methods of mitigating the conflict are evaluated. A commercially available Acoustic Harassment Device was tested in a field trial. AHDs were deployed at several set-traps for salmonids for three consecutive years. The damage reducing effect was persistent throughout a season, as well as over the full three-year test period, and no “dinner bell” effect was observed. When seal attacks became frequent in the 1980´s, several of the traditional salmon traps were reinforced with newly developed extra strong net materials. These materials dramatically reduced the damage to the nets, and to some degree also the catch losses. However, the losses were still substantial, and the traditional gear was gradually phased out when better solutions emerged. In the third part, new methods of mitigating the conflict are evaluated. A salmon trap was built, using net meshes which were large enough to allow seal-chased fish to escape through, but which would still guide and confine non-stressed fish. The trap was fitted with a fish chamber with a double wall of very taut netting, separating the catch from the surroundings by a fixed distance. Interference by seals was significantly reduced with this construction. Field experiments revealed that seals used their above-water vision to locate and search out buoys of the type that are used in the fisheries. Larger buoys were more readily found than smaller. A set of trials was initiated where certain geographical areas were made unattractive for seals prior to their seasonal arrival to the region, by deploying stationary AHDs. Finally, aquarium experiments demonstrated that underwater vision and hearing were equally important in seals’ detection of fish in a test box. It was also found that there was a “near zone”, within which seals stayed focused on a fish and attempted to catch it by a quick thrust of the head. These studies strongly suggest that new seal-safe fishing gear and mitigation methods should be based on, and would benefit from, an in-depth understanding and analysis of natural seal behaviour.

Coastal communities are facing unprecedented challenges as impacts of climate change continue to escalate globally. Rising sea levels, intensified storm activity, and coastal erosion are extreme climate impacts noticed frequently in coastal communities. Indigenous coastal communities in Ghana are impacted by these extreme climate impacts. In this thesis, I studied the perceived human-environment changes in Indigenous community of Akplabanya. Akplabanya community on the coast of Ghana is experiencing changes in their cultural heritage, environmental surroundings, and their climate. This thesis sought to explore adaptation dynamics within Akplabanya and offer insights into their human-environmental changes and resilience in the face of climate change. In studies that focus on Ghana, little is known about the changes of human-environment interaction in Akplabanya, or their Indigenous peoples' responses to those changes. The two objectives of this study are: 1). To identify changes in coastal human-environment interactions as perceived by the Akplabanya Indigenous community, and 2). To examine the human adaptation responses of the Akplabanya community to the changes in their coastal human-environment interactions. I used four qualitative data collection methods. Semi-structured interviews (n=61) enlisted personal experiences and insights on changing environment and adaptation responses. Key informant interviews (n=28) provided additional insights into context and history. Focused group discussions (n=3), each comprising five participants, focused the community's collective narratives on changing environment and adaptation responses. Participant observation conducted throughout data collection helped me to understand daily life of Akplabanya. Data collection occurred over a period of two months (December 2022-February 2023). I found five themes to explain Akplabanya's perceptions about the changes of coastal human-environment interactions. They are: 1). Biodiversity loss (e.g. vegetation loss), 2). Pollution (e.g. unsustainable practices), 3). Coastal climate change (e.g. coastal erosion), 4). Resource change (e.g. freshwater change), and Population change (e.g. increasing population). I also built participant responses that addressed objective 2 on themes of place, agency, collective action, institutions, coastal Indigenous knowledge, and learning. The findings built on these themes highlights changes in coastal human-environment interactions in coastal fisheries, water systems, land utilization, livestock management, architectural practices, and the preservation of Indigenous knowledge in Akplabanya. / Master of Science / Coastal communities are facing unprecedented challenges as impacts of climate change continue to escalate globally. Rising sea levels, intensified storm activity, and coastal erosion are extreme climate impacts noticed frequently in coastal communities. Indigenous coastal communities in Ghana are impacted by these extreme climate impacts. In this thesis, I studied the perceived human-environment changes in Indigenous community of Akplabanya. Akplabanya community on the coast of Ghana is experiencing changes in their cultural heritage, environmental surroundings, and their climate. This thesis sought to explore adaptation dynamics within Akplabanya and offer insights into their human-environmental changes and resilience in the face of climate change. In studies that focus on Ghana, little is known about the changes of human-environment interaction in Akplabanya, or their Indigenous peoples' responses to those changes. The two objectives of this study are: 1). To identify changes in coastal human-environment interactions as perceived by the Akplabanya Indigenous community, and 2). To examine the human adaptation responses of the Akplabanya community to the changes in their coastal human-environment interactions. I used four qualitative data collection methods. Semi-structured interviews (n=61) enlisted personal experiences and insights on changing environment and adaptation responses. Key informant interviews (n=28) provided additional insights into context and history. Focused group discussions (n=3), each comprising five participants, focused the community's collective narratives on changing environment and adaptation responses. Participant observation conducted throughout data collection helped me to understand daily life of Akplabanya. Data collection occurred over a period of two months (December 2022-February 2023). I found five themes to explain Akplabanya's perceptions about the changes of coastal human-environment interactions. They are: 1). Biodiversity loss (e.g. vegetation loss), 2). Pollution (e.g. unsustainable practices), 3). Coastal climate change (e.g. coastal erosion), 4). Resource change (e.g. freshwater change), and Population change (e.g. increasing population). I also built participant responses that addressed objective 2 on themes of place, agency, collective action, institutions, coastal Indigenous knowledge, and learning. The findings built on these themes highlights changes in coastal human-environment interactions in coastal fisheries, water systems, land utilization, livestock management, architectural practices, and the preservation of Indigenous knowledge in Akplabanya.

La surexploitation des ressources halieutiques a conduit à une crise majeure du secteur de la pêche professionnelle. Dans ce contexte, les pêcheries artisanales, et notamment les pêcheries aux petits métiers côtiers, apparaissent comme des modes d'exploitation potentiellement durables des ressources côtières. La diversité des engins utilisés et des espèces ciblées rend néanmoins complexe le suivi de cette composante importante de la pêche professionnelle. L'activité de pêche artisanale reste ainsi très peu évaluée en Méditerranée, et notamment à l'échelle d'une Aire Marine Protégée (AMP). Les AMP sont pourtant de plus en plus utilisées comme des outils de gestion de ces pêcheries, les effets des différentes mesures de gestion mises en place étant à même de bénéficier aux pêcheurs professionnels. A l'heure où le nombre d'AMP se multiplie, il apparaît alors nécessaire pour les gestionnaires comme pour les scientifiques de disposer d'indicateurs permettant de suivre l'activité de pêche professionnelle sur le territoire d'une AMP, et d'évaluer les effets de la gestion sur cette activité. Un protocole d'enquête pour le suivi de la pêche artisanale aux petits métiers côtiers a ainsi été mis en place entre juillet 2009 et juin 2010 au sein du Parc Marin de la Côte Bleue (PMCB), AMP méditerranéenne française comprenant deux réserves marines d'âge et de taille différents. Les données récoltées ont permis d'identifier sept métiers principaux pratiqués par les pêcheurs du PMCB, et de les caractériser par un groupe d'espèces cibles, un engin, un territoire et une période de pêche. L'effort de pêche et les captures ont alors pu être estimés à partir de ces métiers. / The overexploitation of fishery resources has led to a major fisheries crisis. In this context, artisanal fisheries, and in particular small-scale coastal fisheries, appear as relevant alternatives for a sustainable use of coastal resources. But the diversity of fishing gears and targeted species diversity make it difficult to assess this important component of the commercial fishery. Hence, the activity of small-scale artisanal fishing remains poorly known in the Mediterranean Sea and few studies focus on an assessment of this activity at the scale of a Marine Protected Area (MPA). MPAs are yet more and more used as management tools for these fisheries, as protection effects and targeted access regulations may benefit to commercial fishers. As many MPAs are going to be established in the short term, it seems necessary for managers and for scientists, to have indicators to monitor the artisanal small-scale coastal fishing activity within an MPA, and to estimate the effects of MPA management on this activity. A field protocol was defined and implemented between July 2009 and June 2010 within the Parc Marin de la Côte Bleue (PMCB), a French Mediterranean MPA including two marine reserves of different age and size. The collected data allowed identifying seven main métiers within the PMCB, and characterizing them by group of target species, type of gear, fishing grounds and fishing periods. Fishing effort and catch were estimated. In the Côte Bleue area, 3 512 fishing trips and 4645 fishing operations were performed by 30 active boats during the studied period, for a total of 10 300 km of immersed nets.

Small-scale fishing communities along Cambodia’s coast have relied on marine resources as a mainstay of their livelihood for decades. However, in the last ten to fifteen years, a confluence of shocks such as increased fishing pressure, the rapid rise of commercial fisheries in the Gulf of Thailand, illegal, underreported and unregulated fishing, climate change and, more recently, sand mining, have contributed to a progressive decline in catch. Such challenges demand that fishers harness social traits of adaptability, responsiveness, persistence, planning, inter alia. In other words, there is a need for fishers and their households to demonstrate resilience in the face of such challenges. Though a contested term, scholars working within human-environment relations have adopted the concept of social-ecological resilience, acknowledging that the social aspects of resilience have been relatively under-addressed. Relatedly, studies on fishers and fishing communities have shown the important contribution fishing plays in fulfilling social and psychological needs, i.e. wellbeing, and how fishing is more than ‘just’ a livelihood. While evidence for this connection between fishing and wellbeing has been shown across different regions, the nature of this relationship is not as clear for coastal communities in Cambodia. Meanwhile, Cambodia has exhibited rapid economic growth (and foreign direct investment) over the past decade. Part of this has been through the creation of Special Economic Zones (SEZs) across the country. The creation of the SEZs and thus, the resultant labour demand has catalyzed migration of Cambodians to secondary cities and to the capital, Phnom Penh. Unlike other parts of the country, the experience of the lives of people on the move from the coastal regions of Cambodia remains less understood. Through qualitative work done among three coastal fishing villages in Koh Kong province in southwest Cambodia, I aim to contribute to a better understanding of the social dimensions of resilience by using a multidimensional (material, subjective, and relational) social wellbeing framework to not only better understand how migration affects the wellbeing of those who leave and those who stay, but also the implications on fishing as ‘a way of life’. My research focuses on understanding the role fishing plays, and the degree to which it impacts the wellbeing of fishers and their households in coastal Cambodia, in the context of migration. My empirical findings problematize the notion that fishing as a way of life supplants other dimensions (e.g. material/income) as observed elsewhere by considering outmigration of villagers from the fishing village. I find that the draw of alternative economic opportunities outside the coastal village has resulted in shifting values and opinions towards fishing as a livelihood particularly by younger villagers and has catalyzed their out migration. As a livelihood strategy, migration plays a crucial role in supplementing income from fishing and, in some cases, forms a critical lifeline for the poorest households. I also show how life in the coastal fishing village is filled with trade-offs and difficult choices people must navigate and negotiate, including tensions between various aspects within subjective dimensions of wellbeing. My thesis reveals the important, and sometimes dominant, influence of subjective and psycho-social factors on coastal villagers’ resilience and how this changes the way some view fishing itself. As such this research shows that adopting a social wellbeing lens can not only result in a better understanding of the impact of migration on coastal fishing communities in Cambodia but also broaden understanding of social resilience, for villagers and migrants who are facing a sea of environmental and economic change.

Das Untersuchungsgebiet, die Nha Phu Lagune, weist eine massive Degradation der fischereilichen Ressourcen auf. Die „Rural Livelihoods“ in den Gemeinden dieser Küstenregionen sind durch diese Degradation gefährdet. Da, die Ressourcennutzungsentscheidungen einzelner Haushalte von vielen Faktoren abhängen, bedarf es eines multi-sektoralen Forschungsansatzes. Dieser ermöglicht, die Komplexität und die Diversität des Ressourcennutzungssystems und seine Nutzer, zu erfassen. Das Integrated Natural Resources Management (INRM) ist ein multi-sektoraler Forschungsansatz, der innovative und flexible Managementformen zu entwickeln versucht, um natürliche Ressourcen nachhaltig zu nutzen. Interdisziplinarität und die Betonung von Partizipation sind zentrale Kennzeichen des angewandten INRM-Forschungsansatzes. Diese interdisziplinäre Vorgehensweise berücksichtigt sowohl sozio-ökonomische und institutionelle Einflussfaktoren, z.B. Ressourcennutzer-Gruppen und bestehende Regulierungen und Gesetze, als auch biologische und produktionstechnische Einflussfaktoren, z.B. Aquakultur und Fischfangtechniken. Während eines sechs monatigen Untersuchungszeitraums unter Anwendung Partizipativer Aktionsforschung und des INRM-Ansatzes wurden 12 Dörfer im Umkreis der Nha Phu Lagune besucht. Der innerhalb der Partizipativen Aktionsforschung angesiedelte Lernzyklus generiert Wissen durch die Reflektion von gesammelten Daten, die kontinuierlich an die Beteiligten zurückgeführt werden. Die Erhebung mittels Fragebögen, halbstrukturierter Interviews, Gruppendiskussionen, Observierung, „Resource Mapping“ und Venn Diagrammen identifizierte Ursachen für die Degradation fischereilicher Ressourcen. Diese Informationen wurden dann an die Beteiligten weitergereicht, was zu neuen Erkenntnissen über alternative Ressourcenmanagementstrategien führte. Die Integration biologischer und sozio-ökonomischer Aspekte erfasste die Komplexität des Ressourcensystems Nha Phu Lagune und seiner Nutzer. Dies beinhaltet eine Vielzahl von verschiedenen Ressourcen, Akteuren, Ebenen, Institutionen, Entscheidungsstrukturen, Livelihood Strategien, Trends und assoziierte Probleme des nachhaltigen Managements natürlicher Ressourcen. / The selected study site, Nha Phu Lagoon is characterized by massive degradation of coastal fishery resources. As a result rural livelihoods in coastal communities are threatened. Since household decisions concerning resource use are influenced by several factors, a multi-sectoral approach is necessary. A multi-sectoral approach enables to comprehend the complexity and diversity of the resource system and its users. Integrated natural resources management (INRM) is one multi-sectoral research approach that aims to develop innovative and flexible management forms to manage natural resources in a more sustainable way. The applied INRM-approach is characterized through strong interdisciplinarity and participation. Interdisciplinary means that socioeconomic and institutional aspects, e.g. resource-user groups and existing legal arrangements, are combined with biological as well as production system aspects, e.g. mangrove reforestation as well as aquaculture or gear-fishing techniques. For a period of six months participatory action research following an integrated natural resource management approach was carried out visiting 12 fishing villages around Nha Phu Lagoon. The inherent ‘learning cycle’ in participatory action research generates knowledge in a process of reflecting on the collected data that is continuously fed back to the participants. During questionnaires, semi-structured interviews, group discussions, observations, resource mappings, and Venn diagrams reasons for the degradation of fishery resources were gathered. This information was then shared with participants, which led to new insights as well as alternative resource management strategies. The integration of biological and socioeconomic aspects identified the complexity of the coastal fishery resource system Nha Phu Lagoon and its users. This includes a multitude of different resources, actors, levels, institutions, decision-making structures, livelihood strategies, trends, and associated problems in the sustainable management of the natural resources.

L'économie circulaire (EC) émerge depuis les années 2000 dans le débat public, en opposition à l'économie linéaire, modèle dominant aux limites économiques et écologiques reconnues. Cette thèse constitue une première confrontation opérationnelle de l'EC à un système socio-écologique dépendant de la pêche, le Pays de la Cornouaille en Bretagne. Le système est délimité dans sa façade maritime avec la pêche côtière, seule considérée comme production locale.L'approche est systémique, multidimensionnelle et dynamique. L'analyse comporte trois volets : le premier sur l'amont du circuit en mer, le deuxième sur l'aval du système à terre et le dernier sur le système complet. Premièrement, le coût caché des rejets est visualisé via une analyse comptable de flux de matière ("Material Flow Cost Accounting" MFCA) adaptée à la pêche, proposé comme outil pertinent pour améliorer la performance économique et environnementale des pêcheurs. Deuxièmement, l’analyse de flux révèle une forte dépendance des activités à terre vis-à-vis des importations et exportations de bioressources halieutiques malgré un apport significatif de la pêche côtière à l'économie locale. Troisièmement, des scenarii sur le sous-système Sardine, du "business as usual" a l'EC, servent à proposer une trajectoire alternative de développement basée sur un "panier" de biens et services territorialises et la construction d'une valeur territoire à partir de ressources halieutiques locales. Pour atteindre cette EC durable, il s'agira d'optimiser l'utilisation des ressources locales et diminuer les externalités négatives, en plus d'aller vers une gouvernance partagée, adaptée à l'échelle du système socio-écologique considéré. / The years 2000 have favored the emergence of "Circular Economy" (CE) in the public debate, as opposed to the "linear economy", the dominant model that led to acknowledged economie and ecological limits. Our work is a first attempt to address the CE to a fishery-dependent socio-ecological System, the Cornouaille region in Brittany. The approach is systemic, multidimensional and dynamic. It implies the identification of marine boundaries, in which only Coastal fisheries are considered as a local production. The analysis is conducted along three main axes: an analysis of the upstream part at sea (fishing), an analysis looking at the downstream value chain, on land, and a third looking at the whole System. First, a Material Flow Cost Accounting (MFCA) analysis adapted to fisheries is proposed as a relevant tool to improve economy and environmental performance of fishers, providing evidence of hidden costs of fish discards.Second, the fish bioresource flow analysis indicates a strong dependency on importation and exportation flows to maintain land-based activities depending on sea products, albeit evidence of a significant contribution of Coastal fisheries to the local economy. Third, the exploration of the sardine sub-system through scenarii, ranging between from "business as usual" to those lined with CE, shows an alternative development trajectory, based upon a potential "basket of goods and services", a "territorial value", specifically linked to local fisheries. To achieve such a sustainable CE, we would need to not only aim at a more efficient use of local marine resources and decrease negative externalities, but also advocate for a shared governance, suited to the scale of the considered localised socio-ecological System.