Never again will we have this good a chance as we now have to find an enduring place for ourselves within the natural systems that keep us alive. It's a sweet spot in history. That's why this is such a critical time.

What we put into the atmosphere in terms of burning fuel is unprecedented.

Far and away, the greatest threat to the ocean, and thus to ourselves, is ignorance. But we can do something about that.

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.

Ice ages have come and gone. Coral reefs have persisted.

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.

There is this sweet spot in time when we have an opportunity to stop killing sharks and tunas and swordfish and other wildlife in the sea before it's too late.