The value of sharks' lives is now widely understood to be more important than their value as products. And when you have sharks in an area, it's a sign of good health. They're top predators, which means they feed on old, sick, and slower fish, keeping an entire population healthy.

There are a lot of smart creatures out there. Dolphins, elephants, and whales are smart. And there are some really smart birds. I know some really intelligent fish. But they cannot know what humans know and are incapable of inflicting as much damage.

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

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.

Eating wildlife is probably not the smartest thing that we can do in terms of maintaining the integrity of natural systems.

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.

The end of commercial fishing is predicted long before the middle of the 21st century.