Since the middle of the 20th century, more has been learnt about the ocean than during all preceding human history; at the same time, more has been lost.

No water, no life. No blue, no green.

We couldn't go to the moon on whale oil. We don't have the capacity yet to consider doing such things as harnessing current sunlight. We're burning ancient sunlight in order to get us to where we now are. But it's costly.

Since I began exploring the ocean in the 1950s, 90 percent of the big fish have been stripped away. Tuna, sharks, swordfish, cod, halibut, you name it, the numbers have just collapsed. Also, about half of the coral reefs are gone, globally, from where they were just a few decades ago.

Even if you never have the chance to see or touch the ocean, the ocean touches you with every breath you take, every drop of water you drink, every bite you consume. Everyone, everywhere is inextricably connected to and utterly dependent upon the existence of the sea.

We want to think of ourselves as truly special creatures that are unique in the universe and, well, we are. And we have that capacity to wonder, to question, and to see ourselves in the context of all of life that has preceded the present time, and all that will go off far into the future, one way or another.

I have lots of heroes: anyone and everyone who does whatever they can to leave the natural world better than they found it.