In this June 9, 2015 file photo, tourists stand in front of huts that form part of the Lady Elliot Island Eco Resort where a turtle digs for food amongst the coral in the island's lagoon, north-east of the town of Bundaberg in Queensland, Australia. (PHOTO / REUTERS)

NEW YORK – The United Nations has adopted the world's first treaty to protect the high seas and preserve marine biodiversity in international waters, marking a milestone after nearly 20 years of effort, UN Secretary-General Antonio Guterres announced Monday.

The adoption followed an agreement reached in March by more than 100 countries on the of text of the High Seas Treaty, also known as the Biodiversity Beyond National Jurisdiction treaty, after more than 15 years of discussions and five rounds of UN-led negotiations.

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The treaty will take effect after 60 countries ratify the agreement, according to the UN

In approving the text, member states have "pumped new life and hope to give the ocean a fighting chance”, Guterres said in a statement.

The agreement will be open for signature in New York for two years starting Sept 20, the day following a summit on the UN sustainable development goals. It will take effect after 60 countries ratify the agreement, according to the UN.

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A school of fish swims at Isle de Madelaine off Senegal's capital Dakar, July 24, 2007. (PHOTO / REUTERS)

The pact is a key plank in efforts to put 30 percent of the world's land and sea under environmental protection by 2030, a goal set in December.

Among other provisions, the legally binding agreement would govern sharing benefits derived from marine genetic resources beyond national jurisdictions, creating protected areas on the high seas and establishing a framework for assessing environmental damage.