The United Nations is hoping an international conference that got underway Monday will bring fresh momentum to protracted efforts for a global agreement on protecting the world’s oceans.

The five-day U.N. Ocean Conference in Lisbon, Portugal has drawn senior officials and scientists from more than 120 countries to the Atlantic port city in Southwest Europe, as well as activists dismayed by the failure to come up with international rules that might ensure ocean sustainability.

No comprehensive legal framework covers the high seas. Oceans cover some 70% of the earth’s surface and provide food and livelihoods for billions of people. Some activists refer to them as the largest unregulated area on the planet.

In his opening remarks at the conference, U.N. Secretary-General Antonio Guterres urged countries to show “unity and togetherness around the issues of the sea.”

“Sadly, we have taken the ocean for granted, and today we face what I would call an ocean emergency,” Guterres said. “We must turn the tide.”