Current State of the Oceans | Sea of Hope: America's Underwater Treasures

People today should really understand that the ocean underpins everything that people care about. If you like to breathe, you'll listen up because most of the oxygen in the atmosphere is generated out there in the ocean. The ocean shapes temperature, climate, weather. It's where most of the water is, and all life, people very much included, need water.

So when rain falls out of the sky, it doesn't matter where on the planet you are, the ocean is touching with you. They should also know that just in a relatively short period of time, my lifetime, more change has taken place in the ocean than during all preceding human history. Changes, some of them good. I mean, we've learned more about the ocean since the middle of the 20th century. During all preceding history, we have technology that enables us to get high in the sky and look at the whole world and see that it's mostly blue.

We can dive deep into the sea. James Cameron, National Geographic explorer-in-residence, filmmaker, many things—he was one of three people, only three, who have ever been to the deepest part of the ocean. And it's only seven miles down. But at least we have the technology that makes that possible. For the first time in history, access to the ocean is now as never before a reality.

We can go high in the sky, but we're still a little behind the curve in terms of exploring this part of the universe, Earth's ocean. We need to know that the ocean was in trouble and that there are things that can be done now to reverse the decline of coral reefs. About half of them, since I began exploring the ocean in the 1950s, I have either disappeared or they're in a state of serious decline.

Ninety percent of many of the fish are gone. They didn't just evaporate; we've eaten them. And we've also, through the methods used for capturing fish to take to market, have caused some real problems, like clear-cutting forests. We've clear-cut the ocean and left whole ecosystems in disarray.

Fifty years ago, we thought there was nothing that we could do to harm the ocean. The ocean is so big, so vast, so resilient. It was thought that the ocean is simply too big to fail, and a lot of people still think that. And that has to change because the ocean, as big and vast and resilient as it is, is not infinitely so. We only have a little bit left to restore what has been lost.