Highlighting the centrality of the marine environment to human well-being, Secretary-General Ban Ki-moon stressed the collective global responsibility to protect the world's oceans.

"We need to preserve the productivity and essential ecosystem functions of the oceans as a basis for a prosperous and sustainable future for all," he told the Pacem in Maribus XXXIII International Conference on Oceans, held in Beijing, China.

In a message delivered by Under-Secretary-General for Legal Affairs Patricia O'Brien, Mr. Ban noted the theme of this year's Conference, "Oceans, Climate Change and Sustainable Development," spotlights just how important oceans are and the many benefits that are derived from them.

Oceans – which cover about two-thirds of the Earth's surface – generate most of its oxygen, absorb carbon dioxide emissions, provide food and nutrients, regulate climate, and supply fishing and other marine resources for income.

"Perhaps most significant is the role that oceans play in regulating the global climate – generating oxygen and absorbing carbon dioxide from the atmosphere," said the Secretary-General.

He pointed out that among those on the front lines of climate change are coastal communities, particularly people living in small island developing States.

"Halting the decline of coastal ecosystems such as mangroves, salt marshes and seagrasses, can help to mitigate the adverse impacts of climate change while providing numerous social and economic benefits to hundreds of millions of people," he said.

As the world is becoming increasingly aware, he noted, the many benefits of the oceans to human well-being are not limitless and, in some cases, are in peril.

Mr. Ban said that with so many people depending on the oceans, it is vital to pursue universal participation in the 1982 United Nations Convention on the Law of the Sea.

Known as the world's "constitution for the oceans," the treaty provides the legal framework within which all activities in the oceans and seas must be carried out.

In 2008 the General Assembly decided to make World Oceans Day, which was already celebrated by many countries, into an officially-recognized UN annual observance on 8 June to raise global awareness of the threats to the oceans.