The United Nations’ High Seas Treaty

Photo: Pedro Fiuza/NurPhoto Getty Images

On March 4th, following almost two decades of discussion, the members of the United Nations (UN) came to an agreement on marine conservation in the high seas. But what makes this such a historic agreement, and what does it mean for the future of marine conservation? 

The Blue Planet 

“Conserving and sustainably using the oceans, seas and marine resources” forms part of the UN Sustainable Development Goals. With oceans contributing to almost two-thirds of the Earth’s surface, and 95% of its global habitat, protecting the “blue” of the planet is fundamental to tackling the triple planetary crisis of climate change, biodiversity loss, and pollution. They also contribute $1.5 trillion annually to the global economy, and provide employment to over 50 million people.  

Oceans are considered the lungs of Earth, producing more than 50% of the planet’s oxygen, including through plants, algae, and cyanobacteria. The oceans are also essential in tackling climate change: absorbing over 90% of excess heat, and acting as effective carbon sinks by absorbing roughly one-quarter of carbon dioxide emissions annually. While there are estimated to be over 250,000 different species in the ocean and over two-thirds yet to be identified, marine biodiversity is currently being decimated, with 90% of big fish populations killed and half of the world’s coral reefs destroyed. The biggest threats include unsustainable fishing practices, changes in human coastal use (with almost 75% of the global population living in coastal areas, and only 15% of coastlines ecologically intact), deep sea mining, and climate change.  

Marine pollution disrupting ecosystems is increasingly concerning. For example, plastic pollution is rising, with plastic particles in the ocean weighing 2.3 million tonnes as of 2019 (the equivalent of 11,500 blue whales, or almost half the entire global blue whale population). While large oil spills are less common compared to the 1970s, thousands of these incidents still happen every year in US waters alone.  

The High Seas Treaty 

The high seas, also known as international waters, are defined as “all parts of the ocean that aren’t included in the exclusive economic zone, the territorial sea, or the internal waters of a country, or in the archipelagic waters of an archipelagic country.” Despite over 64% of the world’s oceans considered the high seas, only 1% of it is protected by international law.  

After five rounds of negotiations, the legally-binding High Seas Treaty was agreed under the UN Convention of the Law of the Sea (UNCLOS). This achieves a major milestone towards the Kunming-Montreal Global Biodiversity Framework – established at the biodiversity-focussed 15th Conference of the Parties (COP15) – to protect 30% of the planet and 30% of damaged ecosystems by 2030 (also known as 30X30). 

The High Seas Treaty acts to promote sustainable practices that do not damage or deplete. This includes a coordinated international approach to combat the impacts of climate change and pollution in areas beyond national jurisdiction.  

As part of its “general principles and approaches,” the High Seas Treaty also recognises the polluter-pays principle, thereby increasing accountability for the world’s worst offenders. The polluter-pays principle has been cited on several occasions for international policymaking, including the Rio Declaration in 1992, which specifically referenced the principle to “avoid degradation of the marine environment.” This is particularly important for equitable climate action, given that higher income countries have produced 79% of carbon emissions between 1850-2011, and the richest 1% of the world’s population producing twice the carbon emissions of the poorest 50%.  

A sticking point during the negotiations was the sharing of marine genetic resources, due to their potential benefits in the food and pharmaceutical industries. It was eventually agreed that this will be done in an equitable manner, in line with recent international agreements such as the Loss and Damage Fund at COP27.  

The Future 

There is still work to be done. The treaty must be formally adopted by countries and areas to be protected need to be proposed. However, the High Seas Treaty provides a historic milestone and has created momentum to preserve our blue planet.