Treasures of the high seas

Signing of global treaty is a timely opportunity for governments to act in the interests of marine life

- Yvonne Gordon

The UN's high seas treaty is open for states to sign up to. It is an important development: signing the treaty starts the process for countries to ratify it, signalling their intention to comply with its provisions and to make it part of national legislation. At least 60 countries need to sign up for the treaty to come into force.

The high seas are areas of the ocean beyond national jurisdictions and, as such, have no legal protection. They cover nearly half the planet and house many unique ecosystems.

Conservationists are urging governments to act quickly. Fishing hours in the high seas rose about 8.5% between 2018 and 2022, according to estimates by Greenpeace using data from Global Fishing Watch. This figure was even higher in areas that Greenpeace had previously earmarked for protection where fishing had risen by 22.5% over the same time period. Many high seas areas are also under threat from pollution, climate change and damage from shipping traffic and deep-sea mining.

Scientists hope that when the UN treaty comes into effect, it will enable marine protected areas (MPAs) in the high seas to be demarcated. "It's absolutely critical that we start establishing MPAS... if we are going to achieve our common goal of protecting 30% of all land and sea by 2030," said Rebecca Hubbard, the director of the High Seas Alliance, a partnership of conservation organisations.

Greenpeace recommends that nations produce candidates for protection while ratifying the UN treaty to save time. The report highlights possible sanctuaries: the Emperor Seamounts of the North Pacific; the Sargasso Sea in the North Atlantic; and the South Tasman Sea/Lord Howe Rise in the southern hemisphere.

This shortlist overlaps with suggestions from other organisations. Here are five sites that scientists think should be some of the first MPAs.