June 8 marks World Oceans Day, a day when environmental leaders call attention to the importance of the planet’s oceans in everyday life. Creative Commons

World Oceans Day is about putting a spotlight on one of Earth’s most vital resources, including the things that threaten its future. The United Nations has called the oceans the “heart of the planet,” underscoring the vital role the oceans, which make up nearly two-thirds of earth’s surface, play in sustaining life.

The first World Oceans Day was marked in 2002. The U.N. has dubbed this year’s theme “healthy oceans, healthy planet,” calling attention to the importance of maintaining marine ecosystems. The oceans face countless manmade threats, not least among them pollution, overfishing and rising sea temperatures caused by global warming.

World leaders, including U.S. Secretary of State John Kerry, have recognized the importance of World Oceans Day. “Protecting the ocean is a task too big for any government or institution to handle alone,” Kerry said in a statement. “Choosing sustainable seafood, carpooling or public transportation more often, picking up litter, and reusing products are just a few small ways that we can all help to protect the ocean we share.”

Here are 11 quotes and sayings to celebrate World Oceans Day.

1. “We are tied to the ocean. And when we go back to the sea, whether it is to sail or to watch, we are going back from whence we came.” -- John F. Kennedy

2. "The sea has never been friendly to man. At most it has been the accomplice of human restlessness." -- Joseph Conrad

3. “One drop of water helps to swell the ocean. … None are too small, too feeble, too poor to be of service. Think of this and act.” -- Hannah More

4. “Ocean is more ancient than the mountains, and freighted with the memories and the dreams of Time.” -- H.P. Lovecraft

5. “How inappropriate to call this planet Earth when it is quite clearly ocean.” -- Arthur C. Clarke

6. “Ocean is a mighty harmonist.” -- William Wordsworth

7. “The least movement is important to all nature. The entire ocean is affected by a pebble.” -- Blaise Pascal

8. “In every outthrust headland, in every curving beach, in every grain of sand there is the story of the earth.” -- Rachel Carson

9. “The three great elemental sounds in nature are the sound of rain, the sound of wind in a primeval wood, and the sound of outer ocean on a beach.” -- Henry Beston

10. “Faith is knowing there is an ocean because you have seen a brook.” -- William Arthur Ward

11. “Limitless and immortal, the waters are the beginning and end of all things on earth.” -- Heinrich Zimmer