Fisheries straddling or migrating between international maritime boundaries represent a typical case of the tragedy of the commons. Over two dozen Regional Fisheries Management Organisations (RFMOs) have been created to manage these fisheries, which means it also represents a typical case of 'regime complexity' or 'governance architecture'. These literatures recognise that such institutions do not operate independently and therefore institutional functions such as attracting participants, practising their regulatory role, and performing their mandate should be understood as interdependent. This thesis proposes that we study such institutions together with actors and architectures of relations between and among them, which together I term 'governance complexes', by means of a relational approach. This relational approach combines relational theory, which posits the operation of endogenous relational mechanisms alongside exogenous explanations such as institutional design, with network methods that enable structural insights and robust inference that takes into account these interdependencies. The dissertation comprises two main parts that describe and explain the global fisheries governance complex, respectively. The first describes how the governance complex's three main components, states, RFMOs, and states participation in these RFMOs, have evolved. A topological typology utilising key network concepts is proposed and employed to show that the global fisheries governance complex is not fragmenting but becoming more overlapped and nested. The second part explains how this governance complex has evolved in terms of (1) participation, (2) practice, and (3) performance. First, it finds that while states find institutional design features such as an RFMO’s internal organisation attractive, relational mechanisms such as popularity and closure also provide important heuristics for participatory decisions in complex settings. Second, it finds that high levels of organisation also enables higher regulatory activity, but so do relational mechanisms such as coercion or imitation. Third, it proposes the concept of net effectiveness to gauge an institution’s "take-home" performance once its position in the broader governance complex has been taken into account. The result is not only an explanation of the evolution of global fisheries governance but also a developmental step towards an institutional relationalist theory of governance complexes.

Depuis le 19ème siècle et l'industrialisation puis l'expansion des industries extractives, l'accès aux ressources marines a évolué de globalement libre à un régime régulé par la Convention des Nations Unies sur le Droit de la Mer (CNUDM). Cette thèse porte sur les accords de pêche, des outils créés par les pays développés pour continuer à exploiter les stocks de poissons de pays ‘hôtes' en voie de développement. L'étude particulière des accords financés par le contribuable européen a permis de tester l'idée selon laquelle leurs clauses économiques, sociales, et environnementales se sont améliorées vis-à-vis des pays hôtes. A ce jour, peu d'études ont été publiées sur le sujet, et ce travail est donc d'importance primordiale pour les futures décisions des parties prenantes. Les chapitres 1 et 2 constituent une revue critique de la base légale de ces accords, à savoir la notion controversée de ‘surplus' devant être mis à disposition des autres pays selon la CNUDM. Les limites de leur estimation sont également discutées : dans la plupart des cas, ils sont difficiles à estimer correctement à cause de mauvaises estimations des captures réelles. Céder des surplus de stocks à des pays étrangers conduit à une diminution des captures locales difficile à justifier. Le chapitre 3 montre que depuis leur création, le niveau auquel ces accords ont été subventionnés est resté extrêmement haut (environ 75 %), et que le complément, payé par les opérateurs des flottes, a seulement représenté une fraction marginale de leurs revenus. Un déséquilibre flagrant de la distribution des bénéfices générés a donc été mis en évidence. Finalement, le chapitre 4 démontre qu'en dépit de progrès au niveau de certaines clauses sociales et environnementales, celle qui pourrait être considérée comme étant la plus importante, à savoir celle régissant l'embarquement d'observateurs à bord des bateaux, s'est continuellement dégradée. Ces résultats conduisent à l'inévitable question de la légitimité de tels accords. Bien qu'ils soient célébrés pour leur transparence, ils restent principalement bénéfiques aux intérêts européens et peu contrôlés. Aussi, compte tenu de l'expansion actuelle des flottes locales dans les pays hôtes et des réformes au niveau du commerce international, la question du futur de tels accords historiques du type ‘on paye, pêche, et part' est posée. / Since the 19th century, with the expansion and industrialization of extractive industries, maritime jurisdictions have shifted from chiefly open-access to a regime regulated by the UN Convention on the Law of the Sea (UNCLOS). This thesis examines fishing access agreements, i.e., tools designed by developed countries to continue to exploit the fish stocks of developing 'host' countries. The emphasis is on the particular fisheries access agreements funded by EU-taxpayers, and the aim is to test the common belief that their economic, social, and environmental provisions have improved over time vis-à-vis the host countries. To date, only little has been published on this topic, and thus this examination of their provisions is of paramount importance for the policy realm. Chapters 1 and 2 challenge the legal ground of such agreements, which rests on the questionable notion of fisheries 'surplus' that must be made available to other countries according to UNCLOS. Flaws in the estimation of surplus are noted: in most cases, surpluses cannot be calculated due to inaccurate catch estimates, and ceding potential surpluses to foreign countries results in hard-to-justify decreases in domestic catches. Chapter 3 argues that since their inception, the level at which these agreements have been subsidized remained extremely high (around 75%); the remainder (paid by fleets' operators) represented only a small fraction of their turnover, highlighting a gross imbalance in allocation of benefits. Finally, Chapter 4 demonstrates that despite advances in most social and environmental provisions, the one regarding the supervision of foreign vessels by observers (arguably the most critical provision of all) has declined. These results beg the question: how legitimate are such access agreements? While they are lauded for their transparency, they appear to remain mostly beneficial to European interests and poorly monitored. Also, due to the fishing expansion occurring in host countries and ongoing international trade reforms, one can only wonder whether such historical 'pay-fish-and-go' agreements still ought to continue.