Judy Woodruff: Marine biologist Sylvia Earle has spent more than four decades at the forefront of ocean exploration. And, at 83, she shows no signs of slowing down.

Earle was the first female chief scientist of the U.S. National Oceanic and Atmospheric Administration, and was named Hero of the Planet in 1998 by “TIME” magazine.

In tonight’s Brief But Spectacular, she reflects on her passion for the ocean and the planet.

Sylvia Earle: The ocean got my attention when I was about 3 years old.

A wave sneaked up behind me and knocked me off my feet. And my mother, kind of the mother of all mothers, instead of racing out to take me out of the ocean forever, saw the big smile on my face and let me run back in. And I have been running back in ever since.

Two words of instruction, breathe naturally, and over the side, I went. It took a few seconds, no more, before I felt like I belonged there. Four decades ago, I had a chance to do some research.

Narrator: There is a new tool in the sea. It can withstand pressure up to 2,000 feet. Dr. Sylvia Earle is a marine biologist. Her question, can scientists use the JIM suit for dives over 1,000 feet? If successful, she will be the first woman to walk the seafloor beyond 1,000 feet.

Sylvia Earle: We cooked up this idea of going on the nose of the submarine, like the ornament on the hood of a car, together down to the bottom of the ocean, and then I would step off at the maximum depth we could go, which turned out to be about 400 meters, 1,250 feet.

Creatures with lights down the side, they looked like little ocean liners. There are various kinds of jellies and crustaceans and little squids and the fish. It’s like diving into a galaxy of these lights.

What’s hard is getting people to understand why the ocean matters to them. If the ocean dried up tomorrow, life would also dry up. That’s where most of the action on Earth is. It’s 97 percent of the water on Earth.

They should know that, with every breath they take, every drop of water they drink, the ocean is touching them.

You should treat the ocean as if your life depends on it, because it does.

My name is Sylvia Earle, and this is my Brief But Spectacular take on why the ocean matters to all of us.

Judy Woodruff: She’s amazing.

And you can find additional Brief But Spectacular episodes on our Web site,