What we once used as weapons of war, we now use as weapons against fish.

Photosynthetic organisms in the sea yield most of the oxygen in the atmosphere, take up and store vast amounts of carbon dioxide, shape planetary chemistry, and hold the planet steady.

When some people look at a shrimp they think, "Hmm. Delicious." When I look at a shrimp I think, "You're a miracle, absolutely incredible. Your ancestors have gone back hundreds of millions of years." And to develop a thing as simple as a shrimp cocktail, you have to calculate the hundreds of millions of years that have preceded that moment where you're sitting there with your sauce and fork poised.

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.

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.

Everyone has power. But it doesn't help if you don't use it.

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.