5 Conclusion
This thesis has examined the role of the flag State in protecting marine biodiversity on the high seas and in the ABNJ, using EIA as the primary lens. The thesis has demonstrated that the BBNJ Agreement operates within the existing jurisdictional framework of UNCLOS, without creating new or additional substantive environmental duties. Instead, the BBNJ Agreement clarifies and structures the procedural dimensions of the due diligence obligations already established under UNCLOS. As analysed in this thesis, international jurisprudence supports the view that flag States must regulate and oversee activities under their jurisdiction or control in a manner that is proportionate to the potential environmental risk, reinforcing that prevention is an important principle in international environmental law.
Within this framework, EIA functions as a key procedural expression of prevention. UNCLOS establishes the obligation on flag States to assess potential environmental effects where significant harm is foreseeable, but it leaves the content of such assessments largely open. In the shipping context, there has been reliance on sectoral standards, and while this sectoral approach has produced consistent technical standards, it has not traditionally prioritised activity-specific or area-specific assessments. This represents a potential limitation of the current sectoral regime in the shipping context, but it should perhaps be balanced against the risk that a narrowly framed, solely activity‑by‑activity approach also risks overlooking precisely the forms of harm that the BBNJ Agreement intends to prevent.
The BBNJ Agreement attempts to respond to the abovementioned limitations by strengthening the procedural structure, notably through enhanced screening requirements and the introduction of the equivalency mechanism. Given the continuing centrality of flag State jurisdiction on the high seas, this added procedural structure has the potential to raise assessment standards, enhance transparency, and support EIA as a meaningful component of due diligence rather than as a minimal formality. At the same time, the BBNJ Agreement is designed to operate in coordination with existing regimes rather than to replace them. This thesis supports the view that the BBNJ Agreement reinforces, rather than displaces, sectoral governance. EIA represents an important procedural tool for environmental protection, and future sectoral assessments undertaken within the IMO framework could prove appropriate and clearly preferable to the absence of assessment altogether. However, reliance on such assessments cannot be automatic: their relevance under the BBNJ Agreement framework must depend on whether they substantively engage with biodiversity‑related risks in ABNJ, rather than merely satisfying formal procedural criteria.
The effectiveness of the procedural structure under the BBNJ Agreement will depend on how flag States apply screening and equivalency mechanisms in practice. This thesis takes the position that this balance is perhaps both the BBNJ Agreement’s principal strength and its central vulnerability. Interpretations that are either too narrow or too permissive risk, respectively, regulatory overlap or weakening the preventive function that EIA is intended to serve – and by extension, environmental protection can become weakened. These challenges are further complicated by differences in flag State capacity, enforcement practices, and political will, particularly in a global shipping context that is characterised by open registries.
On the view adopted in this thesis, an increased focus on procedural requirements is valuable only insofar as it enhances the quality of decision‑making; otherwise, it risks reducing EIA to a formal compliance exercise with limited substantive environmental effect. Against this backdrop, the thesis reaches a cautious but affirmative conclusion. The BBNJ Agreement holds genuine potential to strengthen flag State responsibilities for marine biodiversity protection in ABNJ by clarifying the procedural content of due diligence and providing a safeguard where sectoral regulation falls short. Whether this potential is realised will depend not on the existence of legal obligations, but on their implementation by flag States – through domestic regulation, administrative decision‑making, cooperation with existing institutions, and, crucially, the willingness of flag States to apply EIA rigorously where activities under their jurisdiction pose a risk to marine biodiversity on the high seas.