The World Heritage Centre has urged the planet’s governments to expand its World Heritage programme to include sites in international waters.

In an effort to preserve high seas ecosystems, the UN body said in a new Unesco report that deep water sites in the two-thirds of the world’s seas that sit outside of national borders needed protection under international law.

“Just as on land, the deepest and most remote ocean harbours globally unique places that deserve recognition,” said World Heritage Centre director Mechtild Rössler.

Unesco currently lists more than 1,000 sites on its World Heritage register, with protection of these sites largely left up to the individual country’s governments. Among those sites, 47 marine areas including the Great Barrier Reef and the Galápagos Islands are listed, but the agreement doesn’t include any designation for sites not within national boundaries.

According to the report, in light of the growing understanding of the value of high seas marine ecosystems, locations such as a “thermal dome” near Costa Rica and the Atlantic’s Sargasso Sea of seaweed should be designated as World Heritage sites.

In order to enact such a change in the UN system of World Heritage designation, its members would have to agree on new legal and bureaucratic structures, with co-operation from multiple governments on site protection.

“Nothing in the inspirational vision of the 1972 World Heritage Convention suggests that nature or culture heritage should be excluded from this protection,” said the report. “Indeed, it would be strange if more or less half of the world were to be excluded from what is indicated as ‘World Heritage’.”

To read the full report, click here.