High Seas Treaty

The high seas are our planet’s international waters, so-called areas beyond national jurisdiction. They cover nearly half of our planet’s surface, and make up 95% of its habitable space, home to a wealth of biodiversity from deep-sea corals to whales. To achieve the global target of protecting at least 30% of the ocean by 2030, we must establish protections for this vast ocean habitat. Before the High Seas Treaty, there was no formal way to do so.

The High Seas Treaty, which entered into force on January 17, 2026, is an essential tool that helps safeguard marine life and habitat by providing a pathway to designate area-based protections in international waters.

WHAT ARE THE HIGH SEAS?

Coastal nations have authority to protect and manage the oceans within their own exclusive economic zones — but most of the ocean is outside the jurisdiction of any single country. These international waters, known as the high seas, lay 200 nautical miles from any shore, are more than two miles (3.2 kilometers) deep on average, and are home to incredible biodiversity, much of it still unstudied.

The high seas are a global common: owned by everyone and no one at the same time. They are plagued with overfishing, noise pollution, plastic debris, and other threats — and governance is challenging: a patchwork of about 20 multilateral organizations manage different areas of the high seas, with varying mandates and limited coordination.  

Without protections and proper management, the high seas face further unsustainable exploitation.

WHAT IS THE HIGH SEAS TREATY?

Governments adopted the Treaty for Biodiversity Beyond National Jurisdiction (BBNJ Agreement), also known as the High Seas Treaty, in June 2023 under the United Nations Convention for the Law of the Sea, after 19 years of negotiations. After receiving its 60th ratification, the High Seas Treaty officially entered into force on January 17, 2026.

The High Seas Treaty:

• Creates a governing body and legal process to establish area-based management measures, including marine protected areas (MPAs), to protect biodiversity on the high seas. Previously, there was no mechanism to do so; MPAs existed exclusively within country waters.¹
• Sets standards for Environmental Impact Assessments of high seas activities;
• Offers a way for countries to share the benefits from marine genetic resources (such as pharmaceutical discoveries); and
• Promotes capacity building through technology sharing, financial assistance, and knowledge sharing for developing states.

The Treaty is focused on habitat and biodiversity protection. It does not specifically mention other threats such as overfishing, deep-sea mining, or plastic pollution, and does not override other existing agreements or bodies that govern the high seas, such as the International Seabed Authority or regional fisheries management organizations. Similar to other international agreements, the Treaty is only binding for countries that have ratified it. As more countries sign, the Treaty’s power to make meaningful protections grows.

WHY IS IT IMPORTANT?

We can’t meet the global 30×30 target (protecting 30% of the oceans by 2030) without ambitious action on the high seas. By implementing the High Seas Treaty, the global community can safeguard the biodiversity found within the planet’s largest habitable space.

OCEANA AND HABITAT PROTECTION

In the countries where we campaign, Oceana has already protected more than 4 million square miles (more than 10 million square kilometers) of ocean habitat through establishing MPAs, no-take zones, and fishing restrictions that protect seafloor communities such as bans on bottom trawling.

While the High Seas Treaty was being developed, Oceana was already campaigning to protect biodiversity on the high seas through other pathways: Oceana in Chile is working through the South Pacific Regional Fisheries Management Organization (SPRFMO) to create a fisheries closure for the high seas region of Salas y Gómez-Nazca, an area that covers almost 2,000 square miles (2,900 square kilometers) and more than 100 submarine mountains that are biodiversity hot spots.²

1. The Ross Sea Region and South Orkney Islands Southern Shelf are the exception, having been established in the high seas off Antarctica by the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR), an international body dedicated to the conservation of the Southern Ocean.  ↩︎
2. This area has been recognized as an Ecologically or Biologically Significant Marine Area (EBSA) under the Convention for Biological Diversity (CBD).  ↩︎