When I first ventured into the Gulf of Mexico in the 1950s, the sea appeared to be a blue infinity too large, too wild to be harmed by anything that people could do.

I've spent thousands of hours under water. And even in the deepest dive I have ever made, 2.5 miles (about 4 kilometers) down, I saw trash and other tangible evidence of our presence.

We are blessed with a place that is open to the universe and, despite this, supports this very thin envelope of air we call atmosphere, which holds just the right amount of oxygen for us to breathe.

If I seem like a radical it's because I have seen things that others have not.

The concept of 'peak oil' has penetrated the hearts and minds of people concerned about energy for the future. 'Peak fish' occurred around the end of the 1980s.

Only two percent of the ocean is fully protected right now.

We still have 10 percent of the sharks. We still have half of the coral reefs. However, if we wait another 50 years, opportunities might well be gone.