（Singapore, 10.02.2026）A major global ocean agreement has quietly entered into force, but its implications could extend well beyond environmental protection and into one of the world’s most strategically sensitive and economically vital regions: the South China Sea.
The High Seas Treaty, formally known as the Biodiversity Beyond National Jurisdiction (BBNJ) agreement, took effect on January 17 after more than two decades of negotiations. It establishes a legally binding framework to protect marine biodiversity in areas beyond national jurisdiction, covering nearly half of the Earth’s surface and more than 60 per cent of the global ocean.
While the treaty is designed to safeguard ecosystems and regulate the use of shared ocean resources, analysts warn it could also open a new legal and diplomatic front in the South China Sea — a region already marked by overlapping territorial claims, rising maritime confrontations, and significant economic interests.
From conservation pact to strategic tool
The BBNJ agreement is the most significant development in ocean governance since the 1982 United Nations Convention on the Law of the Sea (UNCLOS). Among other provisions, it allows for the creation of marine protected areas on the high seas and sets rules for sharing benefits derived from marine genetic resources, which are increasingly valuable for biotechnology, pharmaceuticals and advanced research.
However, in contested waters such as the South China Sea, conservation mechanisms may take on a strategic dimension. Legal experts note that although the treaty does not address sovereignty disputes or grant new territorial rights, it introduces new global norms that could influence how claimants frame their positions.
Instead of directly challenging sovereignty claims — an approach that has often led to stalemate or escalation — states may emphasise environmental protection and biodiversity obligations. By proposing conservation measures or highlighting ecological risks, countries could indirectly constrain rival activities such as fishing, marine research or commercial exploration.
This shift could gradually change the nature of competition in the South China Sea, moving it away from overt power projection and towards legal positioning and narrative control. Over time, countries that are seen as aligning with international norms on sustainability and environmental governance may gain greater credibility and influence in shaping outcomes.
China’s support and its red lines
China has been a key participant in the treaty process, signing the agreement in 2023 and formally ratifying it last October. More recently, Beijing announced its bid to host the treaty’s permanent secretariat, a move widely interpreted as an effort to strengthen its voice in global rule-making.
Chinese officials have presented their support for the treaty as evidence of the country’s commitment to multilateralism and responsible global leadership, particularly at a time when the international order is under strain from trade protectionism, geopolitical rivalry and uncertainty over US policy direction.
At the same time, Beijing has been clear about its limits. China maintains that it has “indisputable sovereignty” over major island groups in the South China Sea and insists that no waters in the region should be considered high seas. From Beijing’s perspective, any attempt to apply marine protected areas or conservation rules to disputed waters would amount to a challenge to its claims.
As a result, China pushed hard during negotiations to ensure the treaty excludes disputed maritime areas from its scope and prevents international courts or tribunals established under the agreement from exercising jurisdiction over such waters. Chinese legal scholars have described marine protected areas as one of the most sensitive issues in the treaty, particularly in relation to the South China Sea.
Beijing has signalled that territorial sovereignty remains a firm red line, and that it would respond diplomatically to any move it believes crosses that boundary.
Legal uncertainty meets economic reality
For Southeast Asian claimants, the treaty presents both opportunity and risk. The Philippines, which ratified the agreement last year, has seen public discussion about whether the BBNJ framework could reinforce its legal standing following its 2016 arbitration victory under UNCLOS — a ruling that invalidated China’s expansive maritime claims, though Beijing rejected it.
Some legal advocates in Manila argue that conservation-based mechanisms could add another layer of legal support by restricting certain activities under the banner of environmental protection rather than sovereignty. Vietnam and other claimants are expected to proceed more cautiously, aiming to ensure that the treaty’s mechanisms are not used to legitimise unilateral actions or unlawful claims.
Beyond diplomacy, the treaty has clear financial and commercial implications. The South China Sea is a crucial artery for global trade, carrying roughly one-third of global shipping by value. Any new legal ambiguity affecting fishing rights, seabed research or commercial access could raise operating risks for shipping companies, energy firms and insurers.
The treaty’s emphasis on marine genetic resources also highlights the growing economic value of ocean biodiversity. As companies increasingly look to the seas for innovation, questions around access, benefit-sharing and regulation will become more prominent for investors and policymakers alike.
Much will now depend on how the treaty is implemented. Proposals for marine protected areas must undergo scientific review, stakeholder consultation and approval by the treaty’s conference of parties, with key implementation rules expected to be finalised later this year.
The High Seas Treaty does not resolve the South China Sea disputes. But by introducing new legal norms and conservation tools, it reshapes the environment in which those disputes unfold. For governments, businesses and investors, the evolving legal landscape adds yet another layer of complexity and risk to one of the world’s most important maritime regions.
