Bridging Institutional Fragmentation in Ocean Governance: Regulatory Spillover and Cooperation under the BBNJ Agreement

<title>Abstract</title> <p>The fragmented institutional landscape governing marine biodiversity in areas beyond national jurisdiction (ABNJ) poses persistent challenges for achieving coherent ocean governance. The BBNJ Agreement responds to this challenge by establishing cooperation mechanisms with existing international legal instruments, frameworks and bodies (IFBs). Among these mechanisms, Article 25(6) addresses the problem of uneven participation and institutional membership gaps across governance regimes. Unlike other coordination obligations, the legal and governance implications of this provision remain underexplored. Drawing on treaty interpretation, drafting history, and comparative analysis of the UNFSA, the CCAMLR regime and CAOFA, this article examines the legal meaning and governance implications of Article 25(6) for States Parties that do not participate in the relevant IFBs. The article argues that Article 25(6) represents a procedural coordination mechanism through which cooperation can be strengthened without extending treaty obligations beyond the consent-based limits of international law. Comparative experience suggests that the provision may influence States’ behavior through procedural engagement, transparency, reporting, and review mechanisms. Whether Article 25(6) can contribute to cross-regime coherence depends on the development of procedural guidance, COP–IFB communication channels and capacity-sensitive support.</p>