What Is the High Seas Treaty and Why It Matters

The Ocean's Last Frontier

Stand at any coastline and look toward the horizon. A few hundred kilometers out, national law effectively ends. Beyond the 200-nautical-mile exclusive economic zone (EEZ) that surrounds every coastal state lies the high seas — vast stretches of open ocean that belong to no country, governed by no single authority, and until recently, largely unprotected.

These international waters cover roughly 64 percent of the ocean's surface and represent over 90 percent of Earth's habitable space by volume. They are home to creatures ranging from luminescent deep-sea squid to filter-feeding whale sharks, and they generate weather systems, absorb carbon dioxide, and produce much of the oxygen we breathe. Yet for most of modern history, they were, in the words of ocean advocates, the Wild West of the planet.

That changed on January 17, 2026, when the Agreement on the Conservation and Sustainable Use of Marine Biological Diversity of Areas Beyond National Jurisdiction — universally known as the BBNJ Agreement or the High Seas Treaty — entered into force after decades of negotiation.

Why the High Seas Needed Their Own Treaty

International maritime law has existed for centuries, but it was never designed with biodiversity in mind. The 1982 UN Convention on the Law of the Sea (UNCLOS) established EEZs and general principles of ocean use, but it created no binding mechanism to protect marine life in areas beyond national jurisdiction.

The result was a governance vacuum. Fishing fleets could drag the ocean floor in international waters with limited oversight. Deep-sea mining exploration expanded with minimal environmental review. Companies could collect and patent genetic material from rare deep-sea organisms — often discovered using publicly funded research — and share none of the benefit with the broader world. All of this was, technically, legal.

Marine biologists had long sounded alarms: the high seas contain some of the most ecologically important habitats on the planet, including deep-sea hydrothermal vent ecosystems and mid-ocean seamounts that serve as nurseries for commercial fish species. Without formal protections, these environments were quietly degrading.

How the Treaty Works: Four Pillars

The BBNJ Agreement was adopted at the United Nations in June 2023 after nearly 20 years of negotiations. It finally reached the required 60 ratifications in September 2025, triggering its entry into force the following January. As of early 2026, more than 80 countries had ratified it.

The treaty rests on four core mechanisms:

• Marine genetic resources (MGR) and benefit sharing: Companies and researchers who collect genetic material from deep-sea organisms must share the resulting scientific and commercial benefits with all nations under an equitable framework. This prevents wealthy states from monopolizing discoveries made in waters that belong to everyone.
• Area-based management tools (ABMTs) and marine protected areas (MPAs): For the first time, any country or group of countries can formally propose a marine protected area on the high seas. Proposals undergo scientific review and are approved by a Conference of the Parties (COP). This is the mechanism that makes the global "30x30" target — protecting 30 percent of the ocean by 2030 — achievable in international waters, where most of the unprotected ocean lies.
• Environmental impact assessments (EIAs): Activities on the high seas — including deep-sea mining, cable laying, and research — must now be assessed for their potential ecological impact before proceeding. A global standard replaces the patchwork of voluntary guidelines that previously existed.
• Capacity building and technology transfer: Developing nations, which often lack the ships and equipment to conduct deep-ocean research, receive support to participate meaningfully in ocean science and governance. The treaty explicitly requires gender balance and the engagement of Indigenous Peoples and local communities.

The 30x30 Goal and Why It Matters

The High Seas Treaty is closely linked to the Kunming-Montreal Global Biodiversity Framework, adopted in December 2022, in which 196 countries pledged to protect 30 percent of both land and ocean by 2030. Currently, only about 8 percent of the ocean enjoys formal protection — and the vast majority of that is within national waters. Without a treaty governing the high seas, the 30x30 ocean target was mathematically unreachable.

Scientists estimate that protecting strategically chosen high-seas areas could safeguard the habitats of more than 80 percent of threatened marine species and, by reducing pressure on fish populations, actually increase global catch by over eight million metric tons annually — a counterintuitive but well-documented effect of recovery zones.

Challenges Ahead

Critics note that the treaty's real test will come in implementation. Enforcement on the high seas remains difficult; no global coast guard exists to police compliance. The first BBNJ Conference of the Parties has yet to be scheduled, and the machinery for approving MPAs is still being built during preparatory meetings running through spring 2026.

Major fishing and shipping nations will face pressure to genuinely restrict their activities — something that has proven difficult in previous ocean governance efforts. And the United States, despite helping negotiate the treaty, had not ratified it as of early 2026, a notable gap given American influence in international maritime affairs.

Still, the entry into force of the High Seas Treaty marks a genuine inflection point. For the first time in history, the world has a legal architecture capable of protecting the open ocean — not just the coasts. Whether that architecture delivers on its promise depends on political will, scientific rigor, and the sustained attention of a global public that rarely sees what lies beneath the waves.