When oceanographer and marine biologist Sylvia Earle was just three years old, in 1938, her parents took her to the beach, and she got knocked over by a wave. “The ocean got my attention,” she says. Shortly after she turned twelve, her family moved from New Jersey to Florida, where, to her delight, her backyard was the Gulf of Mexico. She became fascinated by ocean life, and as a young scientist in the 1960s she joined exploratory expeditions to the Indian Ocean and the Galápagos Islands. On one mission she was the only woman among seventy men. In 1970 she spent two weeks in the Tektite II underwater laboratory, working closely with four other female scientists. The press called them “aquababes.”

But Earle never let sexist attitudes get in the way of her quest to explore and protect the planet’s oceans. Now in her early eighties, she has logged more than seven thousand hours underwater (more than a year’s worth of waking hours), and when it comes to climate change, she knows how high the stakes are. “Our very lives depend on a healthy, stable ocean,” she says.

Earle has become one of the world’s fiercest advocates for preserving the earth’s blue regions. She has been called “Her Deepness” by The New Yorker. Time magazine named her a “hero for the planet” and put her, wearing her wet suit, on the cover of a 2017 issue celebrating trailblazing women. The first woman to serve as chief scientist for the U.S. National Oceanic and Atmospheric Administration (NOAA), she also founded the advocacy group Mission Blue (mission-blue.org). Her goal is to preserve 30 percent of the planet’s oceans by 2030. To accomplish this, she proposes a planetary network of aquatic refuges she calls Hope Spots and describes as a “blue necklace of protected treasures” (deephope.org). In the 2014 Netflix documentary Mission Blue Earle says of her work, “I see things that others do not, a different world, a world that’s changed enormously just in my lifetime.” More recently she was featured in the National Geographic film Sea of Hope: America’s Underwater Treasures.

After more than sixty years of diving, Earle is still entranced by what she finds below the surface. She describes navigating an undulating forest of yellowish kelp, saying, “I felt like a dancer, these golden scarves surrounding me.” For her, environmental preservation isn’t a “liberal or conservative challenge — it’s common sense.” U.S. presidents from both major parties have praised her. When George W. Bush dedicated a marine national monument protecting the seas surrounding Hawaii, he said Earle “sat me down and gave me a pretty good lecture about life.” Barack Obama, as he walked along a Hawaiian beach with Earle, said, “I’m in awe of anybody who has done so much for ocean conservation.”

I visited Earle at Deep Ocean Exploration and Research (DOER), the laboratory she founded in 1992 in Alameda, California, on the shores of San Francisco Bay. DOER builds state-of-the-art submersibles and other equipment to bring back samples from the ocean’s depths. It designed a robotic arm for the Deepsea Challenger capsule that film director James Cameron used to descend more than thirty-five thousand feet below sea level. (Earle turned over management of the lab to her daughter and son-in-law in 1997.)

At the time we met, DOER was being forced to relocate because the Alameda Marina was being turned into condominiums. “This is a working waterfront,” Earle said indignantly. “Where will people put their boats?” Wearing a cobalt-blue jacket the color of a healthy ocean, she invited me into her second-story office, and we talked with the thrum of motors from the lab in the background.

Despite the calamities befalling her beloved seas, Earle remains hopeful. Her precise language and passionate voice make those around her pay attention, but she doesn’t lecture — she wants people to discover the wonders of the oceans for themselves.

511 - Sylvia Earle


Shapiro: When you were in college, working women were expected to be teachers or nurses. Would you give me a sense of what the atmosphere was like for women in science in those days?

Earle: Things have changed a lot with respect to what roles are available to women. It’s not as rigid as it once was — at least, in some parts of the world.

I have become more philosophical about it over the years. I suppose everybody faces challenges in trying to achieve whatever it is they want to do in life. You’re too tall, or you’re too short. You’re too fat, or you’re too thin. You’re too old, or you’re too young. Your skin isn’t the right color, or you speak with an accent. You can’t hear too well, or you can’t see. Everybody has something that serves as a barrier. One way or another, people have found ways to overcome obstacles — or even turn those obstacles into an advantage.

Being a woman in a profession where men typically dominate is mostly a disadvantage, but there are times when, if you’re the only woman in a place, you get noticed. You stand out not just because you’re doing a good job but because you’re a woman doing a good job. It also makes you work harder, and maybe you stand out for that reason.

So I didn’t consider it a particular disadvantage being the only woman, except when it came to career advancement. Then it was clearly a man’s world. As a student at Duke University I was told that even though I was qualified, I would not be considered for a well-paying assistantship, because the young male candidates would soon have the responsibility of supporting a family, and I was just going to get married and rely on a man for economic security. For me to be a scientist was considered an accomplishment, but for men it was a profession. This attitude still persists. Women are not expected to be as professionally motivated or to stick with a job the way a man would.

One common factor for people who do succeed is a love of what they’re doing, a refusal to accept the reasons others give for why they can’t do something. I met a man who was an opera singer, and he’d been scorned in his youth for wanting to sing. It was viewed as a girly activity. But he persisted.

You have to have a sense of humor. It’s your suit of armor. Make a joke of the idiots who want to put you in a box.

Shapiro: When you joined an expedition to the Indian Ocean, you were the only woman.

Earle: They needed a botanist, and I was trained as a botanist, so they invited me to join. There were seventy men and me. When the group gathered in Mombasa, Kenya, at the beginning of the expedition, we were interviewed by the daily newspaper there. The reporter took particular interest in interviewing me. The headline the next day was: “Sylvia Sails Away with Seventy Men.” It wasn’t about the science or the nature of the expedition. But I didn’t have a problem with it, largely because of that suit of armor called a sense of humor.

The big problem all of us shared was how to explore the Indian Ocean from a single ship. Though 220 feet long, our vessel was a tiny speck in the middle of this vast ocean. We were equipped with scuba gear, which was a gift, because scuba was new in 1964. But we did not have a submarine. We had nets and dredges that we used to scrape the ocean floor. Imagine trying to understand San Francisco by dragging a net through the streets from an airplane high in the sky. You would know nothing of the music or the arts or Golden Gate Park.

Shapiro: It’s like trying to put together a puzzle with just a few pieces.

Earle: Right, and you have no idea what the picture is supposed to look like.

Later, after astronauts walked on the moon for the first time, in 1969, the idea of being an “aquanaut” — of living underwater — caught the public’s imagination. I was at Harvard University at the time. There was a notice on the bulletin board announcing an opportunity for scientists to live underwater for two weeks. In a previous experiment four men had lived for two months at fifty feet, proving it could be done.

The U.S. Navy, NASA, the Department of the Interior, and General Electric together built the Tektite II underwater laboratory in Lameshur Bay in the U.S. Virgin Islands. When they put out this invitation to the scientific community, there was no mention that the project was for men only. So some women did apply, which came as a surprise to the powers that be in Washington, D.C. The head of the program, Dr. James Miller, said — and I wasn’t there, so this is secondhand — “Well, half the fish are female, and half the dolphins, and half the whales. I guess we could put up with a few women.” And they did.

But they were concerned about the appearance of having unmarried men and women living together. The nature of the scientific project I had proposed would have placed me with four male ichthyologists — fish experts. I was the botanist. I wanted to work with them to study the ecology of the fish and the plants on the coral reef around the laboratory, but I wasn’t allowed. I had to conduct the project on my own. They selected four other women, and the five of us shared a living space.

Still, men and women were living in close proximity underwater. “Hanky-Panky on the Reef” was one of the headlines. They called the other women and me aquabelles, aquachicks, aquababes, and — the best one — aqua-naughties. We didn’t really care what they called us, as long as they let us go. We were there as scientists. All of the aquanauts across the board were just trying to do their jobs. For the women’s team, this meant we needed to be out in the water a lot, watching fish in their natural state. Some of the other experiments didn’t require as much time in the water. By the end of the project it turned out that the women had spent the most time exploring the environment in diving gear — ten to twelve hours a day. Some people accused us of trying to show the guys up. C’mon. You have to laugh or cry. Better to laugh.

Shapiro: Your approach sounds like the way Jane Goodall studies chimpanzees in Tanzania.

Earle: Yes, you go out and watch the animals.

Shapiro: And sit with them until they get used to you.

Earle: Yes! One of the things that changed for me was that I got to know individual fish. I suppose I knew that no two living creatures are exactly alike, but I hadn’t thought to apply this knowledge to fish.

Shapiro: Was this when you realized that an eel could have a personality?

Earle: And an attitude, and a behavior that’s different from the eel who lives fifty yards away. Fish have homes; they’re homebodies. They may swim around, but they come back to the same place repeatedly. Parrot fish make beds in the ocean floor and cover themselves with a blanket of sand. And then in the morning they shake themselves off, get up, and move around.

Shapiro: I’ve heard that octopuses will decorate their dens with shells.

Earle: For sure. You know when you’ve found an octopus lair, because when they catch a tasty morsel, they bring it home to eat and toss the shells outside. Maybe they do select pretty or shiny shells, or maybe it’s a trash heap.

Shapiro: So you realized that fish and other sea creatures have personalities.

Earle: And faces. They’re individuals. Their markings are different. I had a real wake-up call with Sir Peter Scott, one of the founders of the World Wildlife Fund and a well-known bird-watcher, naturalist, writer, and painter. I visited him at his home, and on the easel in his living room was a canvas filled with the faces of swans. His home was on the marsh, and the swans came right up to his big picture window. He got to know every one of them, and many of the other local waterfowl.

It’s also true with sea creatures. If you line up a school of herring, you can see differences in the patterns on their scales. The callosities [large calluses] on right whales are distinctive and make it possible to distinguish one from another. The patterns of the white and black speckles on the tails of humpback whales are so distinctive that a photo gallery of tails has been developed. The undersides of manta rays, orcas’ dorsal fins, the spots on whale sharks — these are all being photographed and entered into computer databases so researchers can match them. If you send in a photo of a particular whale shark, you can find out where that animal has been and possibly where it is.

For me it was a revelation to get to know those parrot fish, those groupers, and the barracuda who made an appearance right by the picture window of the underwater laboratory. There was also an eel we called Puff the Magic Dragon.

Jane Goodall was given a hard time by some loftier-than-thou scientists who accused her of “anthropomorphizing” gorillas by giving them names and describing their personalities. Her response was: That’s nonsense. It’s my response, too. Why should we doubt that we have characteristics in common with other living creatures? Whether we’re talking about bacteria or elephants or pine trees, the basic recipe for the chemistry of life is the same. We share more than 96 percent of our DNA with chimpanzees. We even have a lot in common with clams and oysters. And it’s a good thing, too. When we digest clams, they become a part of us. The chemistry of life, the flow of nutrients from the sea, to the land, to the whole earth — it’s what sets our planet apart from dead planets elsewhere in the solar system.

A lot of people excuse their bad behavior toward fish by saying, “Oh, they don’t feel pain.” That’s absurd. Fish have all the equipment we do to feel pain. Don’t make up stories to try to spare your conscience. You either choose to inflict pain on other creatures, or you don’t. But do they feel pain? Of course they do. Do they have emotions? Do they have a social structure? Do they bond with one another? Absolutely. It’s a smallness on our part, a narrowness of spirit and mind and heart, to think we are so special. Why not be thrilled that we have so much in common with other creatures?

Humans today are empowered with knowledge that did not exist even fifty years ago and that gives us the gift of responsibility; we have an opportunity not to lose this extraordinary living planet.

A lot of people excuse their bad behavior toward fish by saying, “Oh, they don’t feel pain.” That’s nonsense. Fish have all the equipment we do to feel pain. Don’t make up stories to try to spare your conscience. You either choose to inflict pain on other creatures, or you don’t.

Shapiro: So you’re saying the responsibility to protect nature is not onerous but an opportunity we should be grateful for?

Earle: Exactly. Imagine if we did not know. Most people choose not to take advantage of this most precious knowledge we have, which no other generation before us could have. It’s the key to our survival. It’s an opportunity that will never come again. Why aren’t we excited about being able to take what we’ve got and turn it to our long-term advantage? We can be the saviors of humankind. I say humankind because life will go on with us or without us. It did before, and it can after. It just won’t be the same assemblage of life. We’re already altering pieces of the puzzle. We’ve lost a lot of species due to our actions. When we destroy a coral reef, we lose its residents, all the unique species that evolved there and nowhere else in the universe. Some species of lizard fish have a very limited range. Shrimp-like creatures called stomatopods have unique eyes that see a much broader spectrum of light than humans can — the broadest spectrum we’ve been able to identify in any creature. So we destroy the reef, and we lose that piece of the puzzle. We’ll never have a complete picture again.

We don’t deliberately try to hurt the ocean, but we have. We are. We poison it with chemicals that don’t exist in nature. We’ve put into the ocean this avalanche of waste: plastic debris, old fishing gear, and so on. Turtles eat plastic and die. A sperm whale came ashore in California a few years ago with 450 pounds of trash inside it. Many baby albatrosses on Midway Atoll never get to fly because their well-intentioned parents bring back bits of plastic and stuff them down the gullets of the baby birds, thinking they are feeding them something nutritious. The young can’t regurgitate the plastic, and their intestinal tracts and stomachs get so jammed up that they starve to death. We are talking about tens of thousands of birds that never get to reach maturity. It’s a wonder any of them make it.

Fishing, too, is depleting the oceans of wildlife. Look at the sharks killed for their fins or cartilage or for sport. Look at the grouper and snapper and tuna caught and sold to consumers. My goodness. For humans, tuna is an acquired taste. A hundred years ago few people ate tuna. Bluefin-tuna populations in the Pacific have been reduced to 2.7 percent of what they were in 1980. There are still some adult tuna out there, but they’re smaller than before and less common. The price goes up as the supply goes down, however, so it remains profitable to catch bluefin tuna.

In the Atlantic the numbers are a little stronger. In 1990, when I was the chief scientist at NOAA, 90 percent of the North Atlantic adult-tuna population had already been extracted. When you’re down to 10 percent, isn’t it time to stop? Just stop, unless your goal is to exterminate them. If we really want to have an ocean without bluefin tuna, then we should keep killing them at the current rate, because there isn’t any way for nature to keep up with that level of extraction.

We kill tuna because there’s a market for the fish. We kill them because of that wonderful human characteristic called greed. We just can’t resist. The only hope is for people who care to say, I will never eat tuna again. We don’t need to eat it. For those for whom it is necessary sustenance, I say, OK. Native people who catch and consume the fish locally to feed their families — that’s different. That is not likely to deplete the ocean of wildlife. But when you catch fish to send to market on the other side of the world because you are going to get a hundred thousand dollars for one fish, that’s not sustenance; that’s a luxury. We are fostering the extinction of creatures that belong somewhere other than on our plates.

Shapiro: And tuna are top-of-the-food-chain fish. We know from what we’ve seen on land that when you take away top predators, the entire ecosystem suffers.

Earle: The world we inherited had wolves, bears, big cats, eagles, owls. But then we overruled the wisdom of nature, saying, Wolves should be shot because they might eat my cows’ calves. We killed them instead of respecting that we all have a place within the fabric of life. We have to survive, true, but do we have to exterminate, annihilate, reduce other creatures to near or total extinction just because they don’t happen to suit our idea of what life should be like? Maybe we will regret losing some of the species we have deliberately caused to disappear over the ages. We’re very close now with elephants and rhinoceroses. We still have buffalo only because we took action to save the last ones. We almost exterminated sea otters, and now they’re coming back. There are still elephant seals because a few managed to survive until we decided to stop killing them.

Shapiro: They’ve come back spectacularly on the California coast.

Earle: Only because we consciously gave them a break. We could have killed every last one. We have the power to kill every blue whale, every gray whale, every humpback — every whale, period. But for now we have determined that they’re more valuable to us alive than dead. And we are beginning to understand that intact nature, intact forests, intact coral reefs have a value that transcends markets. Short-term use is not as important as our long-term existence.

Shapiro: The Trump administration has talked about reducing ocean sanctuaries.

Earle: Preservation of these areas started under President George W. Bush. This is not a partisan issue. This is a matter of human survival. It’s the better part of human nature to think beyond our immediate desires.

Our failure to value nature is one of the gaps in our thinking. The value of a live tuna isn’t just aesthetic. The ocean has been the great stabilizing factor of nature, and we are destabilizing it.

Shapiro: It’s our foundation.

Earle: The ocean is the foundation of life itself — the living ocean. It isn’t just rocks and water; it’s this amazing collection of life. We had nothing to do with making it, but we are having a lot to do with destroying it. We are cutting great swaths through the fish populations, extracting 100 million tons a year or more.

The ocean is the circulatory system of the planet, and we are the beneficiaries of it. We think that all the ocean is good for is being a dump site and a place to extract minerals, or oil, or gas, or fish, or shrimp — you name it. Or we use the ocean for transportation or to wage war. But with every breath you take, the ocean assists you, wherever you are, even if you never see it. You never see your heart either, but I’ll bet you’re glad it exists.

Shapiro: You’ve called menhaden the “most important fish in the sea.” We use menhaden for fish-oil supplements and pet food.

Earle: And fertilizer.

Shapiro: Could we get those same oils from plants?

Earle: Absolutely. In fact, the menhaden get the oil from phytoplankton — microscopic ocean plants. They don’t make the oils; they consume them and store them. So we can bypass the fish and go straight to the phytoplankton. And some companies, instead of killing the fish and squeezing the oil from them, are growing the plants that make the oil and harvesting it directly. They do it inland, in tanks in Kentucky, for heaven’s sake.

Shapiro: I know you don’t eat fish. Do you eat any meat?

Earle: I used to. I don’t anymore.

Shapiro: Are there responsible ways of occasionally eating seafood?

Earle: Eat low on the food chain, and give up wild animals.

Shapiro: So don’t eat wild salmon?

Earle: That’s worst of all. Wild salmon have essentially been annihilated. A few places remain where the wild populations are pretty healthy: Alaska and parts of Russia. But here in California, conservationists are happy when three wild salmon come back up the rivers. And the Atlantic salmon is greatly depleted in its natural habitat. Whether it’s the European side of the Atlantic or the East Coast of the U.S., the streams are just a tiny trickle of what they were a hundred years ago. It’s the dams. It’s contamination of the rivers. It’s straightening the rivers, which eliminates the best spawning places. We’ve really done a number on wild salmon. Give them a break. Nobody should eat them except native populations with long histories and cultural traditions.

But here’s the thing: armed with new technologies, even a few people can eliminate what remains of these greatly depleted populations. The native Alaskans are allowed to kill a limited number of whales for religious or cultural purposes. But I think they should give up using exploding harpoons and fiberglass boats and all the methods that are not traditional.

The ocean really needs us to take care of it, which means we have to make choices. I wish we could have made these choices fifty years ago, but we didn’t know then what we know today. Fifty years from now, we likely won’t have the same choices. Think about the doors that are closing, the species that are being eliminated, the chemistry that is changing, the planet that is warming, the ice that is melting. We haven’t responded fast enough to hold the planet steady. Now is the time to act.

Shapiro: It’s been more than sixty years since you started exploring the ocean. That’s such a short time in the history of the earth, but so much has happened.

Earle: I sometimes tell people that I come from a different planet. My friends say, Oh, we knew that. [Laughter.] But actually I did come from a place that doesn’t exist anymore. Earth has changed so much in the last few decades that even young people have witnessed changes that would normally occur on an almost geologic timescale. It’s especially visible in coastal areas, where humans tend to live — and for good reasons: transportation, food, quality of life. People love to be near water.

Shapiro: How did you feel at the age of twelve when your family moved to Florida?

Earle: We lived right on the Gulf of Mexico, and my backyard was this big, beautiful body of water, shallow enough at low tide that I could go out and explore the grassy underwater meadows and see the creatures living there. At high tide I’d go out with just a face mask and sometimes an inner tube so I could float along.

I got acquainted with many creatures that I couldn’t identify: spider crabs and little snails — we call them bubble snails. I’d ask my teachers at school what they were, but my teachers didn’t know either. I couldn’t even find these creatures in books. I’d thought that libraries contained everything I needed to know. I realized then that we have much of the ocean left to explore.

Shapiro: We’ve been to the moon. We’ve sent crafts deep into outer space. Yet the vast majority of the ocean hasn’t been explored. Is it the last frontier in some ways?

Earle: I think there will always be frontiers. Each time you make a new discovery, you see how much more there is to learn. Every new way of looking and seeing and understanding leads to more questions that need to be answered. We have plenty to discover, even within our own bodies. Until relatively recently we didn’t understand the importance of our microbiome — the many microscopic creatures who live inside us and on our skin, and who make our lives possible.

And the ocean — ah, think of all the creatures in the sea. Think of the biome there. We’re talking millions of species that grow and adapt quickly. There is constant change. When we inadvertently change the ocean, we change the nature of that biome, which in turn changes the chemistry of the planet. We’re only just beginning to understand what we’re getting into when we alter the nature of nature.

Shapiro: We mostly think about the larger sea creatures, but the foundation of ocean ecology seems to be microorganisms like plankton, which are so tiny that we don’t notice they are disappearing until half of them are gone. By then the species that depend on them are tremendously affected.

Earle: Think of the discoveries just in my lifetime about the living world: Where do we come from? How old is the earth? We’ve learned more about these big questions in the last half century than in the entire rest of history, because new technologies have increased our ability to gather data and connect the dots and crunch the numbers. We can see, for example, the correlation between burning fossil fuels and CO2 emissions, the consequences of putting too much carbon dioxide in the atmosphere, the release of methane, the greenhouse-gas phenomenon. That was unknown when I was a child. Some scientists might have suspected it, but now we have clear evidence of the cause-and-effect relationship between human activity and the changes to polar ice, ocean currents, habitats, the generation of oxygen, the capture of carbon. We can see what the smartest people in times past could not, because the evidence was not visible to them.

We have acquired this knowledge maybe just in time to save us from ourselves. This is good news. The bad news is that unless we do something, we are headed for trouble. Human extinction is a real possibility.

You’ll hear some big thinkers, like inventor Elon Musk, say we have to make an escape plan for humankind. We have to think about “terraforming” Mars — changing its environment to make it habitable. That idea has a lot of appeal, but first we have to get there. It’s not realistic to think that billions of people, or even a few thousand, could make the leap in this century. And when we do, we’re on a barren planet. There’s no life-support system. There is water, but no ocean. There may be microbes, but not the 4.5 billion years of fine-tuning Earth has experienced. Our best chance of surviving in this solar system is to work with what we’ve got, to acknowledge the problems we’re causing and change our behavior. We’re not going to manage nature, but we can certainly manage ourselves in such a way that we give nature a break.

We’ll never be able to go back to the way things were when I was a kid, let alone how the earth was a thousand years ago. And we may not be able to avoid some terrible consequences for humankind. But if we act now, we may see a turnaround within the century. We have the power. We know what the problems are. It’s a matter of getting enough people motivated.

Shapiro: The oceans and the planet in some ways are very resilient. If you create an ocean sanctuary and give it a chance, life seems to come back.

Earle: That’s because much of the ocean is in pretty good shape — for now. It can absorb some disasters. The Exxon Valdez oil spill in 1989 was horrendous. I went to Prince William Sound [in the Gulf of Alaska] on several occasions after the spill, and it was devastating. Those poor sea otters. And the impacts are still being felt. If you dig down deep enough on the cobblestone beaches, the oil is still there. Bacteria do slowly turn it into other compounds, but it’s not going to just disappear. Life had been moving along there as it had been for millennia — thousands of millennia, actually — and then abruptly there was a change, and now everything is different. Think about Europe after World War II. Most European countries look pretty good today, but if the war had not happened, they would be very different. Some scientists have theorized that humans, as agents of change, are as powerful as the asteroid that struck the earth 65 million years ago and ended the era of dinosaurs. This is a remarkable time to be alive, in terms of discovery and exploration and technology, but also terrible environmental losses.

Shapiro: Strong constituencies and powerful people are working against efforts to save the ocean or reduce carbon emissions. They say we need the jobs, or we need the development. Some say it’s all “God’s will.”

Earle: I love the thinking of [biologist] E.O. Wilson with respect to religious beliefs about nature. If, as many religions would have it, a higher power created the earth and all the creatures who live on it, including us, then isn’t it arrogant to think we have a right to destroy that creation; to think we know better than God — or whatever power you believe is behind creation? Methodically, willfully, and without understanding the consequences, we have unraveled the amazing fabric of life that is vital to our existence.

This is not a matter of religion. It is not a matter of belief. It’s a fact. We know where oxygen comes from. We can detect it and measure it. Green plants generate oxygen and capture carbon. It’s a process that began 3.5 billion years ago. And we know that oxygen creation and carbon capture take place mostly in the ocean through phytoplankton, bacteria, and other organisms. Just like the leaves, grass, ferns, and mosses on land, the ocean is part of the glorious green mantle of the earth.

Many religions speak of a paradise, a Garden of Eden, that we have destroyed in ways that, on the one hand, have created prosperity, but, on the other hand, have undermined our capacity to exist. If we continue to destroy the environment, we will destroy ourselves.

This is not about jobs. Jobs come from prosperity. If we destroy natural systems, then poverty, scarcity, and wars will follow. Protecting the natural world is a security issue. We need a living planet to be secure.

Maybe you saw the film or read the book The Martian, about the astronaut who gets left behind on Mars. Think how grateful he was to find potatoes in the food supplies when he was alone and trying to survive. And he realized that to grow a potato garden, you have to have water and bacteria and temperatures within a certain range. We have all that here on Earth. All we have to do is respect it and protect it.

Yes, we have to take from the natural world, whether it’s trees for houses or animals and plants for food and clothing. But there’s a limit. We can’t just exploit the whole planet for short-term gain.

Think of any big city. Now imagine you put a dome over it. Don’t let anything out or in. How long could it last? Where will the oxygen come from to replenish what’s being consumed? Where will the water come from? Where will the emissions from all the cars go? Where will the food come from?

The planet is a contained system like that domed city. In just a short time we’ve managed to change the chemistry of the atmosphere, increasing the amount of carbon dioxide and methane and nitrous oxide. The ocean has been a great buffer against the excess CO2 we’ve generated, but when carbon dioxide is absorbed by the ocean, it’s turned into carbonic acid. As a result, the ocean is becoming measurably more acidic. This is not good news. All the life in the ocean — from microbes and phytoplankton to fish and whales — is like an orchestra playing away. It’s taken 4.5 billion years to get this orchestra to play in harmony, and here we come along and consciously disrupt it. What are we thinking? Why would we do such a thing?

We came very close, in the twentieth century, to killing whales to the point of no return. Some whale species may yet go extinct due to our predation over the past hundred years, when we were armed with technologies that made it easy to hunt whales and reduce them to oil and fertilizer. We’re doing that now with fish — using advanced techniques to kill them on an industrial scale. Before we became such capable killers, we were causing only gradual depletion, gradual extinctions. Now we are killing on an unprecedented scale. We are taking big bites out of the fabric of life and, in the process, breaking the molecular cycles that keep the environment stable. The evidence is clear. Still, it’s hard for people to think about what tomorrow will bring so long as we have a planet that’s somewhat comfortable today. We can still breathe. But there have been storms of greater intensity, because we are altering the basic planetary processes that govern the weather.

Shapiro: On land, when there’s a strip-mining operation, you can see the desecration. In the ocean we’re not seeing it, because it’s not happening on the surface. And with climate change we won’t feel the full consequence of what we’re doing today for twenty-some years.

Earle: Meanwhile there are things we can do to soften the blow. We can plant a lot of trees — and not just any trees but trees that are native to an area. And we can stop destroying mature, old-growth forests, which have so much biological complexity. Planting pine forests that get harvested for paper is of little value compared to maintaining healthy forests. Mature forests in Georgia and North Carolina are currently being turned into paper or real-estate developments. We need to treasure marshes, treasure forests, treasure every bit of the wild. The knowledge is there. Anybody can access it. Why are we not seeing the value of nature?

National parks — which some say are the best idea this country ever had — were put in place just over a century ago as safe havens. [President] Teddy Roosevelt and others at the time who loved nature could see that, unless we took action and embraced wild places, they would be turned into farms and cities, the trees cut, the wildlife gone. It was an aesthetic concern, a desire to preserve beautiful landscapes — the works of God, if you will, that no human could create. It’s beyond our capacity to create Yellowstone or the Grand Canyon. What we didn’t know a hundred years ago is that we should protect these places not just because they’re beautiful, and not just because we don’t know how to bring them back once they’re gone, but also because they are the underpinnings of our life-support system.

The ocean comprises the great majority of that life-support system. It shapes climate and weather and holds the planet’s temperatures steady. It’s where most of the life on earth exists. It’s where most of the oxygen is generated. It’s where a great amount of the carbon is captured. The atmosphere above, the ocean below — it’s one big system. Until recent decades the ocean had been largely unaffected by human activity. Yes, we had significantly reduced the populations of whales and some fish, but altering the chemistry of the ocean is something new. Even oil spills have a tiny impact compared to the effects of burning fossil fuels.

The acidification of the oceans is setting in motion other processes. It changes what can live in the water, increasing the number of organisms that favor an acidic environment and decreasing the number that do not. A new ocean ecosystem is arising as a consequence. We have measured a sharp decrease in oxygen in the ocean over the last fifty years. If the ocean has less oxygen, then less is going into the atmosphere as well. I don’t want to mess around with my oxygen-generating system. Ask any astronaut how important your oxygen-generating system is. Shouldn’t this be the highest priority of every man, woman, and child — to be able to breathe? To have a planet where we don’t have to walk around with oxygen tanks on our backs?

The ocean is the foundation of life itself — the living ocean. It isn’t just rocks and water; it’s this amazing collection of life. We had nothing to do with making it, but we are having a lot to do with destroying it.

Shapiro: Speaking of oxygen tanks, you often encourage people to go scuba diving and snorkeling.

Earle: Yes, get out there and get wet — no child left dry.

Shapiro: But can the ocean handle many more people using it for recreation?

Earle: If we treat it with respect. There’s a carrying capacity to any place, but if you visit it the way you would someone’s home, you can minimize the harm. You don’t wreck the furniture when you go to someone’s home. Right now we too often visit the ocean to deliberately cause harm. Take sportfishing — catch and release. Doesn’t that hurt your psyche somehow, to see an animal struggling for its life? And then you break its jaw getting the hook out, and you throw it back in the ocean. You release it, so you feel good about yourself, but you tortured that animal. Boy, where did that come from: going out and causing something pain and calling it a good time? I have never quite understood that, even when I was a kid.

When you go fishing or hunting, you enter nature with a mind-set of “Let’s go kill.” How about: “Let’s go live”? I can take a walk in the woods. I don’t have to kill something to justify it. Maybe my goal is to find a pileated woodpecker or a certain kind of mushroom — not to eat it but to respect it, to wonder how many millions of years have gone into creating the kind of mushroom that lives in the roots of that tree. Is it bioluminescent? What kinds of insects are living in its gills? The quest for knowledge can be never-ending, because when you find out one thing, you want to know more. It’s the joy of being a human: we’re curiosity with arms and legs.

Shapiro: Do you think you were born with this curiosity?

Earle: All kids are born curious — and not just human children. Look at a kitten, a puppy, a young deer, a baby fish. They’re always exploring. Kids are natural scientists. They want to know everything. Scientists are like kids who never really grow up, never stop exploring, never stop wondering what’s next: Who is this? How does it live? Where does it come from? Where is this beetle going when it flies off? Let’s find out.

Shapiro: And you’re still exploring, still searching?

Earle: Yes, because I’m still breathing. I hope to continue doing so for a good long time.

I was just diving in Mexico a couple of weeks ago, into a cenote [a natural pit or sinkhole]. The entrance was at a cave, and there were bats and swallows living near the top. The cave went back some distance and was filled with water. So we dove into this tunnel, and at various points we saw sunlight coming through, and we came out at another cenote. It was extraordinary, like swimming through a cathedral.

Shapiro: Was this in the Yucatán?

Earle: Yes, and I was on Easter Island earlier this year. I get to go to some exotic place about once a month. In October I’ll be in the Mexican village of Cabo Pulmo, where the fishermen saw for themselves the impact of overfishing and decided to stop. The grandparents in the community remembered when the fish were this big [holds arms wide], and you could just walk to the shore and catch plenty for your family and to share. In recent years they had to work longer hours and travel farther offshore for fewer fish. So they had a crazy idea: stop fishing and figure out other ways to generate income. They promoted diving to attract tourism. The village didn’t have fancy hotels or amenities, but the villagers used their fishing boats to take divers out. Then they worked with the Mexican government to officially designate the area as a national marine park.

It’s been more than twenty years now, and you can see the difference. I started diving there maybe five years ago, and they actually have grouper. In most of the coral reefs in the Gulf of California, grouper are the first species to go, because they’re big, friendly fish. Spearfishermen can just swim right up to them. It’s like shooting a cow. Nothing in groupers’ experience has prepared them for predation by smart primates who put bait in the water and use nets. We have just about stripped the ocean of snapper and grouper and sharks. The shark fishermen have demolished life in the Gulf of California and elsewhere because of the global appetite for shark-fin soup and because sharks are good game fish. They have tournaments to see how many pounds of sharks they can kill.

But in Cabo Pulmo you actually see sharks. And a giant school of jacks has set up residence in the area. It’s astonishing. You go five miles down the coast, outside the protected area, and the coral reefs are deserted.

You see parrot fish in Cabo Pulmo. Parrot fish have become the latest food fad. Once, nobody would eat them; now they are prime targets for restaurant menus. It’s just sad. This is not tradition. This is: We’ve cleaned out the grouper. We’ve cleaned out the snapper. Sharks are getting harder to catch. What’s left? Let’s go after the parrot fish. I’ve never eaten parrot fish, but I’m told that they’re not as desirable as catfish or tilapia or carp.

Maybe forty years ago a scientist named Bill Ballantine somehow convinced the local people in Leigh, New Zealand, to stop killing fish and create a preserve. Not only did the area recover significantly, but the waters immediately surrounding it had more fish, too. The safe haven created a spillover effect.

Some governments create protected marine areas so there will be better fishing, but that’s not a good motivation. It’s like saying, Let’s create national parks so we can kill more birds. Every argument you can make for protecting wild birds, you can make for wild fish, too. It’s just that we haven’t quite matured in our thinking. Most people don’t even think about fish other than as food.

I think there’s plenty of reason for hope. Billy Causey, a regional director for NOAA, started out catching fish to sell to aquariums. Today he’s one of the most ardent voices for conservation in the country — in the world. He still likes to eat fish, but he does not favor large-scale extraction or commercial fishing that eliminates big predators for luxury dining. For one thing, it hurts the valuable tourism economy in the Florida Keys, where he lives. The tourism value of sportfishing is small compared to the value of maintaining healthy waters and a healthy reef. You don’t go to Florida to see a dead ocean; you go to see a vibrant living system. How do you maintain that? Don’t kill all the fish. Lobsters are essentially gone from Florida waters except in areas where they’re protected. Some parts of the Caribbean are still able to produce enough lobsters, but nothing like when I first went to the Florida Keys in the 1950s. You’d see the bristly antennae poking out from every crevice and cranny underwater. Now you have to really look.

Sportfishing is encouraged, however, inside the Florida Keys National Marine Sanctuary. Even President George W. Bush asked why they call them “sanctuaries” if you may fish inside them.

Shapiro: But Papahānaumokuākea near Hawaii is not a sanctuary; it’s a marine national monument, right?

Earle: Yes, that’s a monument, fully protected. That was a breakthrough. Monuments work; managed areas do not. What works is deliberate safe havens. You just respect whatever’s there: the lobsters, the shrimp, the poor, beleaguered squid that have little protection anywhere else.

In the 1990s Causey was a proponent of working with the fishermen, getting them to stay away from breeding areas, feeding areas, seagrass meadows, and nurseries where the juvenile fish hang out. It took a legal battle to designate areas throughout the Florida Keys where the fishermen by law had to respect the fish. Causey was burned in effigy and had his tires slashed. His life was threatened, because he was seen as taking away the fishermen’s livelihoods.

Fast-forward to today, and the fishermen say Causey’s strategy does work. They understand that if we want to have fish, we can’t just kill them all. We’ve got to protect the most vital areas.

Nations around the world are catching on: Chile, the UK, the Republic of Palau. Eighty percent of Palau’s exclusive economic zone is fully protected. The inner 20 percent is managed. That’s where local fishing can take place. But the fishermen cannot intrude on the favorite dive sites that tourists pay big bucks to photograph, because they form the basis of the island nation’s economy.

The trend was moving in the right direction — until Trump. But it’s not over yet.

Shapiro: You’ve explored a great deal of the world’s oceans. Is there a place you still haven’t been but want to go?

Earle: I do want to explore the deepest part of the ocean, the Mariana Trench. Maybe I’ll have to build my own submarine first.

All the life in the ocean — from microbes and phytoplankton to fish and whales — is like an orchestra playing away. It’s taken 4.5 billion years to get this orchestra to play in harmony, and here we come along and consciously disrupt it. What are we thinking? Why would we do such a thing?

Shapiro: Have you been in many submersibles?

Earle: I’ve used more than thirty kinds. My first was in the Deep Diver in 1968. My next couple of dives were made in the Johnson-Sea-Link submersibles launched in 1969 and 1970. The front compartment was a clear sphere for the pilot, copilot, and an observer, and the aft compartment was a chamber that you could open up and swim out of, into the ocean.

I love submarines. I have a passion for the ocean, snorkeling, holding my breath, scuba diving, living underwater — bring it on. I love it all. It’s our world; it’s mostly blue. What’s holding anybody back?

Less than 10 percent of the ocean has been explored, and the best is still ahead. The submersible Deep Rover brought back images from Antarctica of communities of life a thousand meters down: coral reefs, sponges, giant sea spiders, arthropods the size of your fist, sea stars the size of a washtub — giant creatures living where the water, if it were fresh, would freeze. It’s cold there, and it’s dark, but it’s teeming with life that has adapted to that environment over hundreds of millions of years. We humans are crippled in our ability to think about time because we have such a short life span in the grand scheme of things. Imagine being able to live as long as some deep-sea sharks. One Greenland shark is four hundred years old. Think about what civilization was like four centuries ago, and this shark was alive then and is still cruising around. How would you like to be as old as a redwood tree or some of the deep-sea corals that are thousands of years old? We are here and then we’re gone, except for what we leave for the future. But we are armed with this knowledge, and we can make choices that deep-sea corals cannot, that even elephants cannot. Only we have that power.