Conversation With Sylvia Earle, Part One: You'll Never Eat Tuna Again

Known affectionately as Her Deepness, Sylvia Earle is a renowned oceanographer, environmentalist and pioneer for women, and is a National Geographic Explorer-in-Residence. She's also the founder of the Deep Search Foundation (DeepDeep.org), which seeks to explore and protect our planet's oceans. Water covers 70 percent of the Earth, which explains the title for her latest book, The World is Blue: How Our Fate and the Ocean's Are One. In this two-part series, Tonic's Annie Scott talks with Earle about a variety of subjects, from threatened species to what humans can do to save the earth's oceans.

We don't think much about the health of the ocean when we eat fish. I didn't before, but after spending a morning on the phone with Sylvia Earle, I will never eat tuna again. In the words of Her Deepness, "Not knowing that you have a problem is the worst problem of all."

The problem is that our ignorance is damaging the well-being of our oceans. We don't need to waste any time feeling bad or guilty about it, but we do need to act. You've probably already guessed what I'm about to say: you shouldn't eat tuna. Nobody should. When you hear the simple logic of this, you won't believe how foolish we've been. Tuna fishing is on trial. Just last Sunday, officials announced a major reduction in how many bluefin tunas can be caught in Atlantic and Mediterranean waters — a step many conservationists say isn't enough to avoid a complete fishery collapse.

Earle's logic goes like this: We know that we've poured enough crap into the oceans to actually change their pH levels — we've made the oceans more acidic. Fish eat plants with toxins and imbalanced pH levels. Carnivorous fish eat these other fish. At the top of the fishy food chain? Tuna: the dirtiest food.

"Whatever kinds of tunas you're talking about," says Earle, "albacore, yellow fin, blue fin — they're all top predators, and they have the highest concentrations of the things in them that you do not want in you: the mercury."

"When you think about the economics of farming, it doesn't make sense to raise wolves or tigers or lions. It's just too expensive. They eat meat. And they're low on the food chain compared to tunas, which don't just eat meat — I mean, they eat fish that eat fish that eat other fish that eat other fish that eat other fish. There would certainly be ten or fifteen steps to get to a fish that a tuna will consume."

Yes, you read that right. A tuna is far higher on the food chain than a lion. King of the Jungle doesn't come close to Chicken of the Sea.

Earle went on: "It's not just tunas, it's also swordfish, it's cod. Most of the fish that we eat are high on the food chain, and every step of the way, the concentration of toxins and things we put into the ocean get accumulated, accumulated, accumulated and concentrated, so the highest concentrations of fire retardants, of the heavy metals including mercury, of pesticides and herbicides, are in the fish that we choose to eat. Oblivious to this, most people haven't even thought about it."

Like, say, pescatarians — "vegetarians" who don't eat meat but will eat fish, thinking it's more humane?

"What a joke," said Earle. "It's on us."

So are there are any safer, kinder alternatives? Yes, says Earle. US-farmed catfish and tilapia, for example, are fish that feed on plants and have controlled sources. When it comes to fish farming, Earle is open to the idea, as long as it's done right.

One might be surprised, however, to hear what isn't done right.

"Wild salmon, of course, are top-of-the-line carnivores that follow the same recipe I've just described for tunas, but the farmed ones are fed wild fish," Earle says. "When you look at what it takes to make a pound of tuna, think in terms of a hundred thousand pounds of plants. Not two pounds of plants [like catfish need]."

And eating tuna isn't just toxic for the consumer, it's dangerous for the species. About 90 percent of them are gone, a reality that Earle compares to the results of cutting old growth forests on the land.

In order to "maintain the integrity of the Antarctic ecosystem, we stopped harvesting penguins for their oil. We've stopped shooting egrets down to use as decoration for our hats. We're more evolved than that. Aren't we?

"We look to those who killed the last dodos, the last great hawks and say, 'Why did you do that? What were you thinking?' That's not too distant in our past. Future generations will look at us and say 'How could possibly eat tuna? Didn't you realize how important they are? How there's so much we can learn from them, how they move through the water, how they communicate ... and you ate them?' They'll think that we are neanderthals," she says.

Don't feel bad; that's a waste of time. Just start making changes. You can still get your omega 3s; in fact, supplement manufacturers like Martek are finding ways to raise the very plankton that are providing those healthy fats for fish in the first place.

"I think there are many smart things we can be doing," she says, "harnessing the power of small creatures to either generate the omega 3s or generate the proteins or generate other things that would make sense for us to incorporate into our diets — directly, instead of running through fish that are so much more important alive than dead."

Sounds good to us.

Stay tuned to Tonic for more about how we can help protect our oceans, and please spread the word.

Photo of Sylvia Earle by John Shearer/WireImage. Bluefin tuna photo by Yai&JR via flickr.