The High Seas Treaty: A New Era of Ocean Governance
- Inga
- 3 minutes ago
- 3 min read
After decades of unrestricted exploitation, international waters have a legal framework for protection. Here is what the landmark BBNJ agreement means — and what it will take to make it work.
The ocean covers 70 per cent of Earth's surface, yet for most of human history the vast majority of it has been an ungoverned frontier — open to all, protected by none. On January 17, 2026, that changed. The Agreement on Biodiversity Beyond National Jurisdiction (BBNJ), more commonly called the High Seas Treaty, entered into force, creating the first global framework for establishing marine protected areas (MPAs) in international waters.
These waters — the high seas — stretch beyond the 200-nautical-mile exclusive economic zones (EEZs) that coastal nations control and cover roughly 230 million square kilometres, or about twice the land area of Earth. For the first time, nations can now formally cooperate to designate and manage protected zones in this shared space. The implications for marine biodiversity, climate stability, and global food security are significant — though the harder work of implementation lies ahead.
What Are the High Seas?
Under the United Nations Convention on the Law of the Sea (UNCLOS, 1982), coastal nations hold authority over waters within their EEZs. Everything beyond those boundaries — the high seas — falls under the principle of freedom of navigation: open to all, owned by none.
In practice, that freedom has enabled unchecked exploitation. Industrial fishing fleets trawl continuously. Ships dump waste. Seabed mining operations extract resources with minimal oversight. Because no single nation holds responsibility, the result has been a classic tragedy of the commons — individual actors extracting maximum value from a shared resource until that resource is depleted. Coral reefs, deep-sea hydrothermal vent ecosystems, and wide-ranging migratory species have all suffered as a result.
The BBNJ treaty directly addresses this governance gap.
A Long Road to Ratification
Negotiations began in 2018 under UN auspices, driven by mounting scientific evidence of ecological collapse. The Food and Agriculture Organization estimates that roughly one-third of global fish stocks are now harvested at biologically unsustainable levels. Separately, oceans have absorbed approximately 90 per cent of the excess heat generated by climate change, leading to mass coral bleaching events and widespread acidification.
Delegates from 193 countries negotiated across 40 formal sessions over five years. The central sticking points were the sharing of economic benefits from marine genetic resources — deep-sea organisms that hold significant pharmaceutical and industrial value — and ensuring enforcement mechanisms did not create barriers to legitimate maritime trade. A final agreement was reached in March 2023.
Ratification required 60 countries to formally adopt the treaty. Momentum built through 2025, led in part by small island developing states such as Palau, whose populations face acute vulnerability to sea-level rise. The European Union, United States, and China all ratified during this period. Chile became the 60th signatory in late 2025, triggering the January 17, 2026 entry into force. As of April 2026, 92 parties have ratified, with more in process.
Core Features of the Agreement
The treaty operates through four principal mechanisms. First, it establishes a process for creating MPAs in international waters, with a new Conference of the Parties (COP) reviewing and approving proposed zones based on scientific criteria. These could include no-fishing buffers around seamounts — underwater mountains that support unusually concentrated and unique ecosystems.
Second, major industrial activities in high-seas areas — including deep-sea mining — will require environmental impact assessments (EIAs) subject to international review, rather than the unilateral evaluations that have previously applied.
Third, a benefit-sharing mechanism ensures that profits derived from marine genetic resources — the biological material collected from deep-sea organisms and used in pharmaceuticals, enzymes, and other products — contribute to conservation funding in lower-income nations.
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