Imagine an ocean so large that no country owns it. That is the high seas: waters beyond national borders that cover nearly half of Earth’s surface and about two-thirds of the ocean. On January 17, 2026, the new High Seas Treaty, formally called the BBNJ Agreement, entered into force after reaching the required 60 ratifications in September 2025. This matters because these huge waters face pressure from overfishing, shipping, plastic pollution, climate change, and possible deep-sea mining, while only about 1% of the high seas is currently protected. (apnews.com)

The biggest change is that the world now has its first legal framework for protecting biodiversity in international waters. The treaty creates a process for establishing marine protected areas on the high seas, and it requires environmental impact assessments for planned activities under a country’s control in areas beyond national jurisdiction. It also covers some activities inside national waters if they could seriously harm the ocean outside those borders. For countries that have joined, the agreement is now legally binding, so they must implement and enforce its rules. (un.org)

What about deep-sea mining? The answer is subtle. The new treaty does not hand mining control to a new organization. Under the law of the sea, that job still belongs to the International Seabed Authority, or ISA. But the treaty does raise the pressure for stronger environmental protection. AP reported that countries must now promote the treaty’s conservation goals when they work inside other ocean bodies, including the ISA. That means biodiversity protection can no longer be treated as a side issue in mining talks. (isa.org.jm)

And those talks are still moving slowly. In March 2026, the ISA Council continued negotiating the mining code for possible commercial deep-sea mining, but the rules were not finished. A further revised text is due by June 1, 2026, and more negotiations are planned for July. So the High Seas Treaty has not ended the argument over deep-sea mining. Instead, it has changed the rules of the conversation: from now on, any plan to use the deep ocean will face stronger legal and political demands to protect it first. (isa.org.jm)