I've had the joy of spending thousands of hours under the sea. I wish I could take people along to see what I see, and to know what I know.

That attitude of arrogance, that attitude of "It's all about me. It's all about what I can get out of life now" - well, I'm personally driven by wanting to get out of my life the best I can achieve as a gift for those who come after me.

Our job is to keep what is working intact and not destroy what we have got.

There is a terribly terrestrial mindset about what we need to do to take care of the planet-as if the ocean somehow doesn't matter or is so big, so vast that it can take care of itself, or that there is nothing that we could possibly do that we could harm the ocean...We are learning otherwise.

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.

We still have the illusion that the ocean will recover. That even if we do have to lose sharks, people don't understand why this matters. The evidence is in front of us, and we fail to take it in and say, "Now I get it. Now I understand."

When I was 12, we moved from New Jersey to Florida. The Gulf of Mexico was literally my backyard. Every day, I could see the ocean. At low tide I went out and played in seagrass meadows that used to come right up to the shore, filled with tiny seahorses, pipefish and soft corals. There was so much life! But then I witnessed the change, the loss of the shoreline, the loss of the mangrove trees, the loss of the seagrass meadows. Shallow bay areas were turned into parking lots.