Why the high seas treaty changes everything

When we think about ocean protection, we often picture coral reefs, coastlines and marine reserves close to shore. But beyond national borders lies a vast, largely invisible world known as the high seas… and until now, it was one of the least protected places on Earth. But now, the High Seas Treaty has come into force and it is landmark global agreement that could reshape the future of our oceans.

What are the high seas?

The high seas make up nearly two-thirds of the ocean and almost half of the planet’s surface. They begin beyond countries’ Exclusive Economic Zones (usually 200 nautical miles from shore), meaning no single nation owns or governs them. For decades, this lack of oversight or ownership has resulted in devastating free-for-all activities…industrial fishing, deep-sea mining exploration and shipping with really minimal regulation.

Despite being out of sight for most of us, the high seas are so vital. They help regulate the climate by absorbing carbon dioxide and heat, support migratory species like whales and tuna and play a key role in the global food system. What happens out there affects all of us.

So what exactly is the High Seas Treaty?

Formally known as the Biodiversity Beyond National Jurisdiction (BBNJ) Agreement, the High Seas Treaty was adopted in 2023 after nearly 20 years of negotiations at the United Nations. At the 2025 United Nations Ocean Conference, held in Nice France, there was a turning point for the treaty as a wave of new ratifications brought the High Seas Treaty to the brink of entering into force! (You can read more about my experience at the UN Ocean Conference and what happened there at this link).

In many ways, UNOC 2025 transformed the treaty from a piece of paper into a living framework for action.It fills a major gap in international law by creating a legal framework to protect marine biodiversity in areas beyond national jurisdiction.

So, whats in the Treaty? At its core, the treaty aims to ensure that the high seas are managed sustainably and fairly as a shared global responsibility.

One of the treaty’s most important features is that it allows countries to create marine protected areas (MPAs) on the high seas for the first time. Until now, protecting these waters at scale was nearly impossible. With the treaty in place, nations can work together to safeguard ecologically important areas from damaging activities.

The treaty also strengthens rules around environmental impact assessments. This means that before potentially harmful activities like large-scale fishing operations or seabed exploitation can go ahead, their environmental consequences must be evaluated more carefully.

Another key element is fairness. The treaty addresses how benefits from marine genetic resources (such as organisms that could be used in medicine or biotechnology) are shared. This is especially important for ensuring that developing countries are not excluded from the scientific and economic gains linked to ocean biodiversity and that these swaths of oceans be used for good.

Why does it matter for oceans?

The ocean is under immense pressure. Overfishing, climate change, pollution, and habitat destruction are pushing marine ecosystems to their limits. Scientists warn that without urgent action, ocean health will continue to decline, with consequences for food security, coastal communities, and the climate.

The High Seas Treaty is a crucial tool for meeting the global goal of protecting 30% of the ocean by 2030. It provides the legal backbone needed to move from promises to action, especially in areas that were previously ungoverned.

Just as importantly, it signals a shift in how we think about the ocean: not as an endless resource, but as a living system that needs care, cooperation, and long-term thinking.

What does the future hold?

The treaty’s adoption was historic and now it has officially been ratified! This means the sufficient number of countries (60 to be exact) have formally approved the Treaty and now it can be entered into force. But now comes the real work: implementation A.K.A turning words into real protection.

Of course many challenges remain. Enforcement on the high seas is really complicated and political will can waver. But there is real momentum! Governments, scientists, NGOs and ocean advocates are increasingly aligned around the need for stronger ocean governance.

The High Seas Treaty marks the beginning of a new era. One where international cooperation protects the ocean not just for today, but for generations to come.

It’s a reminder that even in the most remote corners of the planet, collective action can make a difference.

Hope for the oceans is, at least a little bit, restored.