For nearly half a century, Sylvia Earle has been exploring the world’s oceans, taking part in more than 400 expeditions and spending thousands of hours under the sea. An explorer-in-residence at the National Geographic Society and former chief scientist at the National Oceanic and Atmospheric Administration, Earle has broken many barriers in the world of deep-sea exploration.
In 1970 she led the all-female Tektite II expedition during which she and four other women spent two weeks living in a small structure under the sea. In 1979, she descended to 1,250 feet in a dive suit, setting a women’s depth record and also walking untethered on the sea floor at a lower depth than any person ever has. In addition, she holds the women’s record for a solo dive in a submersible vehicle, reaching a depth of 3,280 feet.
Now, drawing on decades of oceanographic work, Earle has written a book
in which she reflects on the profound changes she has witnessed in the world’s oceans and offers her thoughts on how to restore the health of a badly over-taxed marine environment. In The World is Blue, Earle describes the two-pronged assault on the seas: what we are pulling out of the oceans, through unfettered industrial fishing, and what we are putting into the oceans through pollutants, fertilizers, and growing amounts of carbon dioxide that are leading to a dangerous acidification of the sea.
In an interview with Yale Environment 360, Earle discussed how humanity needs to begin looking at fish in the same way we view wild creatures on land, how the current system of aquaculture — in which carnivorous predators such as salmon are raised — is folly, and how the massive influx of carbon dioxide into the world’s oceans is altering a precious balance that has existed for millions of years.
She also talked about ways to undo the damage we have already done to the oceans. Chief among these remedies is the creation of a large, global network of marine protected areas — what she calls “hope spots” — where the giant bluefin tuna and hundreds of other endangered species can rebuild their decimated numbers. In addition, she supports expanded aquaculture in which herbivores, such as tilapia, are raised in closed systems that do not contaminate the ocean with pollutants, parasites, or disease.
The world’s oceans, Earle concludes, can still be redeemed, but only through swift and decisive action.
“We get to choose,” she told e360 senior editor Fen Montaigne. “We either get to choose by conscious action or by default because we are complacent… thinking somebody else will look after this. But nobody else will take care of these issues.”
Yale Environment 360: Can you describe how humankind has been testing the limits of the oceans?
Sylvia Earle: It comes in two areas primarily — what we put into the sea and what we allow to flow from the land, the toxic materials that we put in our fields, our farms or backyards, golf courses, streets. It flows inexorably into the sea. There are consequences. We have changed the chemistry of the ocean — not just what goes from the land directly, but what we put into the sky that moves into the sea. Most worrisome now is excess carbon dioxide.
Parallel with that is what we are taking out of the ocean. Even now some believe that actually the ocean is limitless in its capacity to yield whatever we want to take. But we should have learned with whales. We should have learned with wildlife on the land that we have the power — through both our numbers and our technologies — to be able to find, kill, extract and market, to decimate, anything that swims in the ocean.
e360: I know that there have been studies showing that many of the top ocean predators may be down by as much as 90 percent.
“Some believe that the ocean is limitless in its capacity… But we should have learned with the whales.”
Earle: And more. [With] bluefin tuna in the North Atlantic… we’re downby 90 percent. Of course, we weren’t trying to exterminate them. All of these learned minds were directed toward trying to find a magic balance of sustainability, which turned out to be a big illusion. Look at tuna… we’re still killing them. Amazingly, we haven’t come to the realization that, like the whales, if you want them to recover from severe depletion, stop killing them. Just stop!
And here’s the thing, it’s not to feed starving millions of people, it’s to feed a luxury appetite [Sushi]. We can be the agents of destruction or we can be the agents of a positive change. It’s up to us.
We don’t have a lot of time. Maybe we’ve already signed the death warrant, the extinction warrant, for bluefin tuna. But because there are still some there, there’s cause for hope. But not if we keep killing them.
e360: Do you think that somehow humanity is going to have to begin looking at creatures in the sea more like wild creatures on the land?
Earle: They are wild creatures. We treat the natural world, historically, as our big larder. It’s definitely not infinitely renewable. Those dwindling assets have been so depleted that we really need to step back and restore and protect what remains. There are limits to what we can do to the planet without dire consequences to us.
e360: I wanted to talk about what is increasingly looming as this great problem of the acidification of the oceans, the changing chemistry.
You point out in your book that by pulling all these fish out of the ocean, that we actually are affecting the oceans’ buffering capacity to absorb carbon dioxide. Could you explain how over fishing can play a role in the ocean’s ability to absorb carbon dioxide?
Earle: We need a great deal more in the way of exploration, of doing the calculations, but it is simple. This is a no-brainer. Fish, every living thing, is a carbon container. By extracting millions of tons of ocean wildlife, it’s like clear-cutting forests. You have removed the carbon-based units.
“Our actions in just a little slim period of time have so altered the nature of nature.”
But this destruction of the great ocean food web, the destruction of thehabitats in the sea, the dredging, the trawling, that [alters] these finely tuned systems that have developed over literally hundreds of millions of years… We call it the great green engine that generates oxygen and takes up carbon dioxide at a point that is just right for life. But our actions in just a little slim period of time have so altered the nature of nature.
You have to think pretty hard about what we are doing and change our ways. And part of it relates to what we are doing to the sea, what we are taking out — the carbon based units that we are removing and the structure of the ecosystem in the seas that holds the planet steady.
e360: And then of course, [we are] pouring all of this CO2 onto the atmosphere, which is absorbed by the oceans. You write in your book that almost half of CO2 emitted every year by human activities is absorbed in the oceans. How concerned are you that we are so rapidly changing the chemistry of the sea that we could reach a point where we could see no mollusks, no shellfish, the loss of most of the world’s coral reefs?
Earle: Scientists who have been looking at the devastation of coral reefs around the world are convinced that we are on the track that leads to that, but it doesn’t have to be that way. Part of that relates to our complacency about carbon dioxide in the atmosphere, our complacency about global warming.
Carbon dioxide is part of the problem, but part of this story is the methane, which is a far more powerful greenhouse gas… A major concern in the minds of many who understand the amount of frozen methane in the deep sea is that the release of that could overwhelm all the other problems that we now face.
We have a little window of time. It’s not too late. We still have maybe half of the coral reefs around the world. They are still in pretty good shape. We haven’t killed the last whale. We still have icecaps at both poles.
But if we continue on the track that we currently are following, we will see within our lifetime, certainly within the lifetime of our children and our grandchildren, changes that will lead to a world that won’t work as well as the world that we now have. We have a chance, but the longer we wait the harder it is going to be.
e360: As a scientist, you must balance conveying the gravity of our current situation with hope. Could you talk about what you think we need to do now to help restore that balance in the oceans again?
Earle: So the greatest cause for hope is knowing that the more people really understand, the more they can respond to things. But first you have to know and care… We must do everything we can on the land and in the sea to protect the natural systems and to avoid further degradation, and to move towards restoration of forests, marshes, letting mangroves stay in place… For heaven’s sake, we must change our ways with respect to killing the fish and using these destructive fishing techniques and understanding fish as wildlife. We can’t commercially exploit wildlife in the sea any more than we can commercially exploit songbirds or little furry things on the land on a large commercial scale.
It just isn’t working. With all the subsidies that we are pouring into industrial-scale fishing worldwide, it’s still not economically a winner. If you put the value of living systems on the balance sheet, it’s certainly not a justifiable enterprise.
Having protected areas on the land like national parks — we’ve only protected about 12 percent of natural systems on the land, but that gives us clean water, that gives us the resilience from natural systems on the land that we must have if we are to prosper…
By establishing networks of protected areas of the sea — I call them hope spots. Call them what you will, marine protected areas, marine sanctuaries; although what we call sanctuaries are multiple-use areas, that don’t fully protect what’s there like a national park.
What George Bush did during his administration — protecting 340,000 square miles of ocean, the reefs of the northwest Hawaiian Islands and some of the areas of the western Pacific — is a magnificent step in the right direction. We have about 4,500 protected areas in the sea, but it’s a fraction of one percent of the ocean. So we’ve got to step up to the plate while we have time, and seriously support protected areas in the sea. To do it as if our life depends on it, because it can.
e360: What percentage of crucial ocean ecosystems do you think needs to be protected? Seven or 10 or 12 percent? Even more than that?
Earle: Every ounce of ocean counts, of course. The question has been deliberated by many who really seriously want to do the right thing. Some say, well, 10 percent by 2012. That was the goal that was established a few years ago. Or by 2015, let’s have 30 percent.
If you want tuna to prosper, don’t go to the places where they are breeding and attack them.”
The numbers are all over the place. I say, look, it’s what makes the world work. It is the blue heart of the planet. How much of your heart do you want to protect? Is 10 percent of your heart enough to keep it beating? Is 50 percent?
We have to do everything we can through networks of critical areas, the breathing areas, the feeding areas. If you want tuna to prosper, for heaven’s sake, don’t go to the places where they are breeding and attack them, which is what the fishermen are now doing in the western Gulf of Mexico, or where they aggregate off the coast of North Carolina.
Those are the places, the hot spots, where we should pull out all the stops and give them a chance. Let’s go to the richest areas in the sea and not exploit them but protect them, because they give back to all of the sea, give back to our life support systems.
At the same time in our own backyard, by giving up a lawn that is heavily dependent on chemical fertilizers and pesticides and herbicides — [you can] turn them into your own little areas of hope, where you can plant native trees and wildflowers, and let them be a substitute for a green rug out there. Do your part, or do your part by not consuming the ocean wildlife that is seriously in trouble. A friend who runs Wild Aid says their motto is, ‘When the Buying Stops, the Killing Can, Too,’ — not buying things like shark fin soup and tuna.
You mentioned aquaculture. It doesn’t make sense to raise top predators such as salmon that consume large numbers of ocean wildlife and are fed tons of wild fish to get pounds of farmed fish. The equation just doesn’t function. Over thousands of years farmers have come to understand that you don’t raise carnivores if you want to feed a lot of people. You raise grazing animals or you raise plants to feed a lot of people. Not a single farmed animal on the land is a carnivore because it doesn’t make sense in the equation of the food web. If you try to get enough energy from the system to raise lions and tigers to feed large numbers of people, it just doesn’t calculate.
So why are we trying to do something different in the ocean? We are raising cod, for heaven’s sake. We are raising salmon. You should be raising things like catfish, tilapia, carp; or identifying that great swathe of ocean larvae that’s out there — even microbes have great hope. We [need to] figure out which microbes give us the oils that we want. And grow them under controlled circumstances, not in the open sea where we risk contaminating and modifying our life support systems.
Some who are in the business of agriculture are seeing more crops per drop by having closed systems. We are recycling water, a combination of plants and low-on-the-food-chain grazers. Sometimes it works — as China has been doing for more than a thousand years — to have multiple organisms living in relatively closed systems, ponds where ducks and mulberry trees and carp all have some interaction to mutual benefit.
There are solutions. At James Cook University in Australia, I was so impressed visiting there to see how they’re focusing on closed systems that really work, with marine plants and microbes and fish. We have to really use our brains to look at the suite of options out there, instead of just going for what sells today for a high price, salmon or cod or other carnivores.
e360: Can you talk about the larger ethical and moral issues that underlie these questions we have been discussing?
Earle: If we want to have livelihoods, to feed families and communities, we have to cut back on the large industrial-scale exploitation of ocean wildlife and ocean systems. Because it’s not working and in fact it’s undermining health, undermining security, undermining the economy, undermining the capacity of the world to work at all.
Maybe it’s what, in the end, will cause the changes for moral considerations, if the hearts of people, the minds of people are moved out of compassion, out of a sense of responsibility. It’s on our watch. It’s up to us to determine, will there or will there not be whales any more? Will there or will there not be tuna or coral reefs or oysters in coastal waters?
We get to choose. We either get to choose by conscious action or by default because we are complacent — that we just let things slide, to continue the way they are at present, thinking somebody else will look after this. But nobody else will take care of these issues.