• If effectively implemented, experts say the treaty could change the high seas from a largely unregulated frontier into a shared space of benefits
• Analysts warn that challenges such as jurisdictional disputes and institutional tensions could complicate implementation

ISTANBUL

A vast expanse covering nearly two-thirds of the world’s oceans – waters beyond any national jurisdiction – has long remained largely unregulated, exploited and overlooked.

That changed on Jan. 17, when a landmark global accord known as the High Seas Treaty entered into force, marking the first legally binding framework to protect marine biodiversity in international waters and underscoring a growing recognition that what lies out of sight can no longer remain out of mind – for the sake of both humanity and the planet.

Formally titled the Agreement under the UN Convention on the Law of the Sea on the Conservation and Sustainable Use of Marine Biological Diversity of Areas Beyond National Jurisdiction (BBNJ), the treaty now counts 86 parties. It aims to conserve and sustainably manage ecosystems on the high seas and seabed areas beyond national control.

Built around four core pillars – equitable sharing of benefits from marine genetic resources, creation of marine protected areas (MPAs), environmental impact assessments, and capacity building – the agreement represents a milestone in global ocean governance.

Yet its real-world impact, climate relevance, and ability to address mounting pressures on marine ecosystems remain key questions.

Amy Swift, a research associate at the Washington-based World Resources Institute, described the treaty as a “historic step in global governance,” moving governments toward collective action to establish and enforce protected marine areas.

“The High Seas Treaty is the first legally binding instrument to protect and ensure sustainable use of the marine life residing there. Before this, there was no collectively agreed-upon set of rules for protecting the high seas – instead just a patchwork of regional initiatives and sector-specific collectives such as regional fisheries,” she explained.

Jack O’Connor, senior scientist at the United Nations University Institute for Environment and Human Security, said the agreement provides overarching coordination among previously fragmented frameworks.

“It sits on top like an umbrella over a network of existing agreements that were previously a little bit fragmented, looked at different parts of the ocean but didn’t speak to each other,” he said.

Lisa Levin, professor of biological oceanography and marine ecology at the University of California’s Scripps Institution of Oceanography, stressed that the high seas play a critical role in sustaining planetary systems.

Without protection, she warned, the world risks damaging vital processes such as carbon cycling and nutrient regeneration.

All three experts said the treaty could become a crucial instrument for achieving the Kunming-Montreal Global Biodiversity Framework’s “30x30” target to protect 30% of the oceans by 2030.

“It opens up the door to be able to more realistically protect that much of our planet,” O’Connor said.

What will the treaty actually do?

The most transformative provision may be the ability to designate marine protected areas (MPAs) in international waters – a first in global ocean governance.

“A clear mechanism for MPAs is vital to ensure the safeguarding of marine biodiversity on the high seas. MPAs have been proven to mitigate and sometimes even reverse the adverse effects of human activity and climate change on ocean areas,” she explained.

O’Connor described area-based conservation measures as huge, noting they dramatically expand the portion of the planet eligible for protection.

Levin highlighted the treaty’s environmental impact assessment framework, which will improve coordination and risk evaluation for activities in international waters.

However, she noted that decision-making authority still rests with the countries conducting those activities, and has not been handed over to an international body.

“But it certainly is a way to bring attention and more scrutiny to what people are doing in international waters,” she said.

The treaty’s benefit-sharing provisions recognize marine genetic resources – with potential applications ranging from pharmaceuticals to industrial uses and climate solutions – as part of the common heritage of humankind.

O’Connor said the capacity-building pillar is often overlooked but critical for fairness and inclusion, as it aims to expand technology transfer, scientific collaboration and participation by countries lacking access or research capacity.

Levin expressed hope for “a new era of technology transfer and sharing of scientific information that will … bring more countries into the management of oceans.”

Climate implications

Scientists reject claims that the treaty is disconnected from climate change, emphasizing the deep link between ocean health and climate stability.

“By protecting biodiversity, we can help conserve the processes that sequester carbon and keep carbon in the seafloor or keep it in deep water,” Levin said, adding that protected ecosystems can shield climate-vulnerable species.

O’Connor highlighted the ocean’s role as a critical climate buffer: “The healthier our oceans can be, the more they will be able to help us mitigate the effects of climate change.”

He warned that the remoteness of the high seas increases the risk of damage as human activity expands faster than scientific understanding.

“That is why this kind of agreement is so important because it takes this precautionary approach … We need to protect it as a first step,” he stressed.

Swift warned the oceans are approaching a “breaking point,” strained by climate change, biodiversity loss and pollution.

“We are in the midst of the most extensive coral bleaching event on record, illegal and unregulated fishing is still prominent across the globe … and mangroves and seagrasses are rapidly being depleted,” she said.

Challenges ahead

While widely hailed as a breakthrough, implementation challenges loom.

Levin warned that additional administrative burdens could affect scientific research, calling for harmonization among UN bodies.

O’Connor said the priority now is encouraging more countries to ratify the treaty and preparing for the first Conference of Parties, a meeting of the pact’s decision-making body.

He cautioned that jurisdictional disputes and institutional tensions could complicate implementation.

“The sticky point of this agreement is the question of jurisdiction – which organizations and which countries will join together on this matter of jurisdiction,” he said.

He also warned the treaty’s non-undermining clause – designed to avoid weakening existing frameworks – could create loopholes if misused.

Swift urged rapid establishment of governance and implementation tools, while stressing that developing concrete standards for the treaty’s pillars and securing stable funding remain the biggest hurdles.

“Given the current geopolitical climate, the multilateralism exhibited in establishing and enforcing this treaty should be regarded as a serious win,” she said.

“The effort that has been put in to reach this point comes from many years of negotiations, and this needs to be celebrated. Now we must focus on getting it right from the outset.”