Backgrounder: World Oceans Day

World Oceans Day, a UN-designated day held annually on June 8, aims to arouse people's consciousness to preserve oceans on Earth.

Oceans are vital to human survival, as they not only generate most of the oxygen, but also provide abundant resources and regulate Earth's climate. However, as oceans are under constant threat nowadays due to human activities, more people are urged to take actions to protect them.

This year's theme is "Healthy Oceans, Healthy Planet," the same as last year, and the UN is encouraging a special effort to curb plastic pollution.

According to the UN, plastic pollution is a serious threat as it degrades very slowly and pollutes waterways for a very long time. It also impacts the health of aquatic animals, and may even do harm to the health of human beings.

"Urgent action on a global scale is needed to alleviate the world's oceans from the many pressures they face, and to protect them from future dangers that may tip them beyond the limits of their carrying capacity," UN chief Ban Ki-moon quoted a UN website dedicated to the World Oceans Day as saying.

The UN will mark this year's event with a ceremony rewarding winners of the Annual Oceans Day Oceanic Photo Competition on Wednesday at the UN headquarters.

Initiated in 1992 by the government of Canada as "The Ocean Project," World Oceans Day was officially recognized by the UN in 2008. Endi