The High Seas Treaty hits 100 ratifications

Two-thirds of the ocean belongs to no one, and until this year, no law governed it either.

The high seas — the vast blue beyond every country's waters — were a legal vacuum where anyone could fish, mine or drill and no one was responsible. The BBNJ treaty, in force since January, is the first attempt to fill that vacuum. This week at the UN General Assembly it crossed 100 parties, and the race is now on for January 2027 — when the treaty's first conference convenes, and only those who ratified get a vote.

The week's ratifications read like a coalition built for the occasion: Germany and Canada from the industrial West, Australia and Papua New Guinea from the Pacific, Zimbabwe and Brunei and Samoa from the South. One hundred parties is the threshold where a treaty stops being an aspiration and starts being a jurisdiction. The symbolism of the list is deliberate — every region, every ocean, every category of maritime interest — because a high-seas treaty that looks like a Western project will be treated like one.

The history behind the milestone is longer than the treaty. The freedom of the high seas is one of the oldest doctrines in international law — mare liberum, the free sea, argued by the Dutch jurist Hugo Grotius in 1609 against Portuguese claims to own the Indian Ocean. For four centuries, the principle held: beyond the narrow band of territorial waters, the ocean belonged to everyone, which meant it belonged to whoever had the ships. The UN Convention on the Law of the Sea, concluded in 1982, fenced off exclusive economic zones — 200 nautical miles of national jurisdiction — but left the high seas themselves, nearly half the planet's surface, essentially ungoverned. The BBNJ treaty is the first serious revision of the Grotius settlement in four hundred years.

The negotiation took the better part of two decades. Formal talks began after years of preparatory wrangling, and the treaty text was finally adopted in 2023 — hailed then as a breakthrough, and then subjected to the slow grind of ratification. Treaties do not become law when diplomats applaud; they become law when parliaments ratify, one by one, and sixty ratifications were needed just to bring BBNJ into force. It crossed that line in late 2025 and entered into force on January 17, 2026. The sprint from 60 to 100 in under a year is the diplomatic equivalent of a stampede — and stampedes have causes.

The January 2027 deadline is the quiet engine of the story. The first Conference of the Parties will make the treaty's first real decisions — where marine protected areas go, how environmental impact assessments work, who pays. Only ratified states vote. Every country still deliberating is now on a clock, and the week in New York was a rush for the door before it closes. The COP's agenda is the treaty's constitution in practice: the voting rules, the scientific advisory machinery, the funding mechanisms. Whoever is in the room in January writes the operating manual. Whoever is not, lives under it anyway.

"One hundred parties is the threshold where a treaty stops being an aspiration and starts being a jurisdiction."

For maritime nations like Indonesia — the world's largest archipelago, straddling the Pacific and Indian Oceans — the treaty is personal. The high seas are where the tuna are, where the shipping lanes run, and where the deep-sea mining companies are circling. A legal framework means a seat at the table when those decisions get made; staying out means being governed by other people's rules. Indonesia's waters touch three oceans' worth of high-seas boundary; for Jakarta, BBNJ is not an environmental abstraction but a fisheries and shipping treaty with a green cover.

The treaty's teeth are the two mechanisms: marine protected areas on the high seas, and mandatory environmental impact assessments for activities beyond national jurisdiction. Both were unthinkable a decade ago — the idea that anyone could tell a fishing fleet or a mining consortium what to do in international waters. Now it's law, for 100 parties and counting. An MPA on the high seas is a line on a map that says: not here. An EIA requirement says: not without asking. Together they are the first constraints ever placed on what humanity may do to the half of the planet nobody owns.

The MPA mechanism deserves a closer look, because it is where the treaty will be tested first. Designating a protected area in national waters is a domestic political fight. Designating one on the high seas — where no state has sovereignty and every state has rights — requires a voting procedure the January COP must invent. The scientific case will be the easy part: marine biologists have mapped the high-seas biodiversity hotspots for years, the seamounts and vents and migration corridors. The hard part is the politics: every proposed MPA will sit atop someone's fishing grounds, someone's shipping lane, someone's mining claim. The treaty's first protected areas will be chosen as much by diplomacy as by science.

The EIA mechanism is the sleeper with the longer fuse. Mandatory environmental impact assessments for high-seas activities mean that deep-sea mining consortia, industrial fishing fleets, and geoengineering experiments must clear a review before they operate. The collision everyone is watching is with the International Seabed Authority's mining code: the ISA governs mineral extraction on the deep seabed, the BBNJ treaty governs the water column above it, and the two regimes must now learn to share a jurisdiction neither fully controls. That negotiation — between the miners' regulator and the ocean's new guardian — will define the treaty's real authority.

The 30x30 target — 30% of the ocean protected by 2030 — is the number that makes the treaty load-bearing. You cannot protect 30% of the ocean without the high seas, because the high seas are most of the ocean. Every protected area designated under BBNJ is a down payment on that target; every year of delay is compound interest working against it. The arithmetic is brutal: with less than four years to 2030, and the first COP only convening in January 2027, the treaty has roughly three years to do what took the land conservation movement decades. The target will almost certainly be missed. The question is whether it is missed by a little — a credible down payment — or by a lot, which would make the treaty look decorative.

The absences matter too. The treaty's authority will be measured not by its 100 friends but by its missing parties — the major fishing and mining powers still outside. A high-seas protected area that the biggest fleets ignore is a line on a map. A mandatory impact assessment that the biggest miners decline is a suggestion. January 2027 will show whether BBNJ is a government or a club. The history of international law is unkind to clubs: treaties that the major powers ignore tend to become debating societies, however noble their texts. The ratification sprint is, among other things, an attempt to get the membership big enough, fast enough, that staying out becomes costlier than joining.

Then there is the money question, which the coverage politely underplays. Who pays for high-seas protection? The treaty's benefit-sharing provisions — the rules for dividing the proceeds of marine genetic resources, the pharmaceutical and biotech gold in deep-ocean organisms — are supposed to fund the system and compensate the South. But benefit-sharing is where every environmental treaty goes to stall: the definitions are contested, the revenues are hypothetical, and the countries expected to pay are the ones with the best lawyers. The January COP must put numbers on the promises. Until it does, the treaty's finances are an aspiration with a bank account.

For the Pacific island states — Samoa, Papua New Guinea, and their neighbors — the treaty is something else entirely: leverage. These are nations whose exclusive economic zones are vastly larger than their land, whose tuna stocks migrate through the high seas, and whose voices in global forums are routinely drowned out. BBNJ gives them a vote on the ocean they depend on. Their ratifications this week were not ceremonial. They were positional: small states securing a say before the rules get written, because they have learned, over decades of climate negotiations, what happens to those who arrive after the text is fixed.

The ratification sprint has a mechanics worth noting. Ratification is not a signature — it is a domestic legal act, and in most countries it requires parliamentary approval, which means scheduling, committee hearings, and political capital. That 40-odd states managed it in under a year, many of them during the UN General Assembly's high week when ministers are in New York and momentum is contagious, tells you how the diplomacy was organized: the treaty secretariat and its champions ran a deliberate campaign, country by country, to convert applause into instruments of ratification. The ceremony in New York — ministers handing over bound documents, photographers arranged — is the visible tip of a year of quiet parliamentary lobbying.

And the fishing question, the oldest one, remains the treaty's hardest test. The freedom to fish the high seas is the original mare liberum right, exercised for centuries before anyone thought to regulate it. The regional fisheries management organizations — the tuna commissions of the Pacific, Atlantic and Indian Oceans — already govern much of this activity, badly in some cases, adequately in others. BBNJ does not replace them. It overlays them with conservation obligations they were never designed to meet. The first time an MPA closes a fishing ground a tuna commission had left open, the treaty's authority will be tested against an industry that has ignored weaker rules for decades. The ocean's oldest freedom is about to meet its first real limit.

Western coverage celebrates the milestone as multilateralism working — the first high-seas governance framework in history, built by consensus, crossing the 100-party mark in its first year. Germany and Canada's ratifications are presented as the West putting its weight behind ocean governance, and the January 2027 COP as the moment the treaty grows teeth.

The caveat, duly noted: enforcement on the high seas has always been the hard part, and a treaty is only as strong as its compliance mechanism. The Western lens is honest about this because it has to be — the West's own distant-water fleets will be among the regulated, and Western environmental NGOs will be watching whether the MPAs have patrols or only press releases. In this telling, the treaty's credibility will be established not in New York conference rooms but on the water: the first time a protected area is violated and something actually happens.

The Western coverage also frames the sprint to 100 as a vindication of the multilateral method itself — the patient, consensus-based, UN-centered diplomacy that the last decade's geopolitics was supposed to have killed. In a year of tariff wars and summit theatrics, a treaty quietly accumulating ratifications is presented as proof that the old machinery still works when the subject is sufficiently universal. Nobody owns the high seas, so everybody could agree on them. That is either a model or an exception, and the West is betting on model.

Eastern coverage is more transactional, reading the treaty through the resource lens: who gets to fish, who gets to mine, and who sets the environmental assessments that could block both. The ratification rush is covered as positioning — states securing voting rights before the rules get written, which is rational behavior, not idealism.

The interest is in the deep-sea mining question, where the treaty's impact assessments meet the International Seabed Authority's mining code. That collision is coming, and the Eastern lens is watching it. In this telling, the BBNJ treaty is not primarily an environmental instrument but a licensing regime in waiting — and the states that will do the most high-seas mining are reading every clause for its permitting implications. The EIA provisions are parsed the way tax codes are parsed: for the exemptions, the timelines, the appeal rights.

The Eastern lens is also the most attentive to the treaty's relationship with existing institutions. The ISA, the regional fisheries management organizations, the International Maritime Organization — the high seas already have a patchwork of sectoral regulators, and BBNJ must fit among them without quite displacing them. In this telling, the January COP's real work is jurisdictional diplomacy: drawing the lines between the new treaty and the old bodies, and deciding who defers to whom. The ocean is getting a government. Governments have turf wars.

The Global South lens sees the treaty as a decolonization of the ocean. For centuries the high seas were governed by the navies that could project power onto them — which meant the West. A treaty where Zimbabwe and Samoa vote alongside Germany is, in this telling, the ocean's independence moment: the commons governed by the commoners.

The test, the South insists, is benefit-sharing. If marine genetic resources from the high seas generate pharmaceutical fortunes, who gets paid? The treaty's answer to that question will decide whether BBNJ is justice or paperwork. The South has watched this negotiation with the memory of every resource bargain that went wrong — the seeds, the oil, the minerals — and it is determined that the ocean's genetic wealth will not follow the same path: discovered by Southern waters, patented in Northern labs, sold back to the world with nothing returning. The benefit-sharing provisions are the treaty's moral core, and the South will judge the whole instrument by them.

The Southern lens also reads the ratification list politically. Zimbabwe, Brunei, Samoa, Papua New Guinea — the South was early and enthusiastic, while some of the ocean's heaviest users deliberated. In this telling, that asymmetry is the point: the countries with the least power over the high seas were the quickest to want rules for it, because rules are what the powerless have instead of navies. The January 2027 COP will test whether the rules, once written, actually bind the powerful — or whether the ocean's independence moment turns out to be independence on paper, like so many before it.