Meat reared on land matures relatively quickly, and it takes only a few pounds of plants to produce a pound of meat.

Ten percent of the big fish still remain. There are still some blue whales. There are still some krill in Antarctica. There are a few oysters in Chesapeake Bay. Half the coral reefs are still in pretty good shape, a jeweled belt around the middle of the planet. There's still time, but not a lot, to turn things around.

When I write a scientific treatise, I might reach 100 people. When the 'National Geographic' covers a project, it communicates about plants and fish and underwater technology to more than 10 million people.

You don't have to touch the ocean for the ocean to touch you

The Earth is a unique system in the universe, the only planet we know of that's hospitable for humankind.

As a child, I was aware of the widely-held attitude that the ocean is so big, so resilient that we could use the sea as the ultimate place to dispose of anything we did not want, from garbage and nuclear wastes to sludge from sewage to entire ships that had reached the end of their useful life.

I find the lure of the unknown irresistible.