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.

We are all together in this, we are all together in this single living ecosystem called Planet Earth. As we learn how we fit into the greater scheme of things, and begin to understand how the system works, we can plan ahead, we can use the resources responsibly, to show some respect for this inheritance that goes back 4.6 billion years.

Ten percent of the big fish still remain. There are still some blue whales. There are still some krill in Antarctica. There are a few oysters in Chesapeake Bay. Half the coral reefs are still in pretty good shape, a jeweled belt around the middle of the planet. There's still time, but not a lot, to turn things around.

Far and away, the greatest threat to the ocean, and thus to ourselves, is ignorance. But we can do something about that.

The oxygen cycle, the nitrogen cycle, the carbon cycle, the water cycle - all of these are linked to the existence of life in the sea.

With every drop of water you drink, every breath you take, you're connected to the sea. No matter where on Earth you live.

Life in the ocean makes Earth hospitable. We are sailing along in the universe and we have a blue engine that is making everything alright.