I find the lure of the unknown irresistible.

Look at the bark of a redwood, and you see moss. If you peer beneath the bits and pieces of the moss, you'll see toads, small insects, a whole host of life that prospers in that miniature environment. A lumberman will look at a forest and see so many board feet of lumber. I see a living city.

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

Our insatiable appetite for fossil fuels and the corporate mandate to maximize shareholder value encourages drilling without taking into account the costs to the ocean, even without major spills.

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.

The Exxon Valdez spill triggered a swift and strong response that changed policies about shipping, about double-hulled construction. A number of laws came into place.

Globally sharks have been killed for their fins, for their cartilage, for their livers, for their meat. But mostly what has driven some species of sharks to near extinction - including the hammerhead shark - is the new luxury taste for shark fin soup.