Rousseau_whole_thesis.pdf (18.49 MB)
Predicting the future of global seafood production
thesisposted on 2023-05-28, 10:03 authored by Rousseau, Y
Understanding the impact of global fisheries on ecological and human systems is intimately linked to the yield of the ocean, the combination of marine resources and how to access them, i.e. fishing fleets. A major current limitation is the lack of integration of fishing fleets with ecological data, critical for understanding the sustainability of global fisheries. To address this research gap, I collected and classified 151 countries legal definitions of fishing sectors according to language, technology or fishing vessel characteristics. Based on these definitions, I reconstructed the global engine power, vessels number and fishing effort from 1950 to 2015, separating industrial and artisanal sectors. The fishing effort was then mapped, leveraging on existing mapped catch data, and compared with satellite tracking. Various models have attempted to express the global ocean's yield, but the uncertainty was found to be vast, due to disciplinary shortcomings. Lack of harmonization of terms, particularly in fishing sector, impede the comparability of studies, and require further examination. These sectoral-specific hurdles reflected in the fishing fleets, the rate of change varying vastly between sectors. Globally, vessel numbers, engine power and fishing effort have increased in almost all regions since the 1950s. Only the most developed countries showed signs of stabilization and fleet reduction. Conversely, the global catch per unit of effort has decreased drastically since the 1950s, highlighting the strain on marine resources and hinting at future declines, particularly in Southeast Asia. Mapping of the effort confirmed the disparate nature of global fishing and highlighted the lack of detail of the artisanal sector. Future work is required to improve estimates of fisheries efficiency. A better understanding of the global yield and the links between fisheries and the oceans might be facilitated by integrating fleets in models, which this thesis has described in detail.
Rights statementCopyright 2019 the author Chapter 3 appears to be the equivalent of a pre-print version of an article published as: Rousseau, Y., Watson, R. A., Blanchard, J. L., Fulton, E. A., 2019. Defining global artisanal fisheries, Marine policy, 108, 103634 Chapter 4 appears to be the equivalent of a pre-print version of an article published as: Rousseau, Y., Watson, R. A., Blanchard, J. L., Fulton, E. A., 2019. Evolution of global marine fishing fleets and the response of fished resources. Proceedings of the National Academy of Sciences, 116(25), 12238‚Äö-12243