Econometric analysis of the nexus between fisheries and human behaviours

<p dir="ltr">How do the interactions between human activities and fisheries shape the sustainable use of fisheries resources? The understanding of this nexus is crucial, as it directly affects preserving invaluable resources and the viability of fisheries. This relationship is complicated by feedback and confounding effects over time, region, and space, leading to endogeneity challenges within the coupled human and natural system (CHANS) framework. Such complexities can result in incomplete understanding of the relationship between fisheries and human behaviours. Considering the critical role of fisheries in providing livelihoods and food security, particularly in coastal communities, it is essential for policymakers to accurately understand these interactions for effective fisheries management.</p><p dir="ltr">This thesis aims to explore this nexus between human behaviour and fisheries resource, and its implications for sustainable fisheries management. The objective of this thesis is to apply econometric analysis to establish causal relationships in this complex system. By designing multiple natural experiments, this thesis addresses two key aspects. Firstly, it disentangles the reciprocal effects and feedback loops, which controls the bidirectional influence where human activities affect fisheries resources, and conversely, these resources shape human behaviour. Secondly, it controls for both observable and unobservable confounders within this system, including socio-economic factors, regulatory and institutional differences, and variations in fishing technologies.</p><p dir="ltr">The first two essays focus on human responses to ecological and management shocks in fisheries resources. The first essay investigates the impact of catch levels from both industrial and non-industrial fisheries off the Indonesian coast on conflicts in the area. This analysis explores spatial interactions and spillovers by examining land-based conflicts within a 100 nautical mile radius of ocean-based fishery catches. To establish causality and mitigate the reverse impact of conflicts on fisheries, the essay utilises variations in chlorophyll-based ocean productivity as an exogenous shock on fisheries. Furthermore, the first essay considers the role of illegal fishing and the severity of conflicts. The second essay explores the effects of marine protected areas (MPAs) in international waters on adjacent fishers' behaviours, using the Ross Sea MPA in Antarctica as a case study. This analysis assesses whether the MPA is effective in deterring fishing efforts, using a natural experimental design that leverages the geographical boundaries of the regulatory area as a treatment. It also examines potential displacements and spillovers of fishing efforts near the MPA boundaries. Moreover, the second essay investigates the implications of this deterrence on vessel behaviour near the MPA by analysing their at-sea non-fishing hours. This draws from the comparisons between untreated fishers in the Antarctic Peninsula region and those in the Ross Sea area. Building on the topics explored in the first two essays, the third expands the scope to further aspects of fishery exploitation, examining how fishing access among states and its influence on global fish trade. The third essay uses network analysis to unravel the relationship between fishing access and trade, taking into account the number of participants, partnerships, and economic values. It also incorporates community information from the fishing access network as an exogenous variable, enabling an analysis of the causal effects of fishing access on fish trade.</p><p dir="ltr">The findings in this thesis highlight the importance of sustainable fisheries management. It is essential to include the knowledge of interactions between fisheries resources and human behaviours in decision-making. The results demonstrate that inadequate fisheries management, in both industrial and non-industrial catch scenarios, can lead to violence in local communities. This tendency is more pronounced with illegal fishing, which notably escalates conflict onset. Although most conflicts driven by fisheries are relatively peaceful protests, there remains a potential for these disputes to escalate into more violent forms, including terrorism. The findings from the second essay of this thesis suggest that MPAs, with effective enforcement, well-defined boundaries, and legitimate regulations, can successfully deter fishing efforts in international waters. This is achieved without leading to spillover of fishing efforts or increased concentration along the boundaries. However, policymakers should also consider the potential costs of marine conservation, as conservation policies can lead to an increase in non-fishing activities among fishers, potentially raising the operational costs. Finally, the findings highlight that fishing access can negatively affect fish trade. While the economic value of fishing access is substantially greater than that of trade, this situation presents a risk of states that are resource-rich but weaker in institutional capacity being over-exploited by more powerful fishing nations. This imbalance could limit the opportunities for smaller fishing states to develop their own fisheries industry, advance their value-added chains, and engage effectively in trade.</p>