For marine biologist Ayana Elizabeth Johnson, not knowing where our seafood comes from isn't just a mystery—it's a problem. She says we should reconsider what we eat and how we take it from the sea.

Transcript

MANOUSH ZOMORODI, HOST:

It's the TED Radio Hour from NPR. I'm Manoush Zomorodi. And today on the show, ways that we can help save our oceans and the fish that swim in them.

AYANA ELIZABETH JOHNSON: We need to change our relationship with the ocean. Our expectation that we will have heaps of fresh fish in the supermarket of whatever species we desire every day of the year is completely out of sync with what nature can provide.

ZOMORODI: This is Ayana Elizabeth Johnson. She's a marine biologist and also a policy analyst, a researcher, an inventor, a podcaster, all in an effort to teach us how we can save the oceans. And Ayana says globally, we have got caught 90% of large fish. Tuna, salmon, shark, swordfish - they're all in trouble. But what does that mean then for us when we go to the supermarket?

What else have we got here? They've got sockeye salmon. Does not specify...

Because knowing what's OK to buy can be confusing, even when you're trying your best.

UNIDENTIFIED PERSON #1: Some of the signs that you will see, they will tell you. Like, the snapper's rated yellow.

ZOMORODI: Oh, OK. So the snapper's rated yellow.

UNIDENTIFIED PERSON $1: It's still - but the (inaudible) rated yellow doesn't really mean it's bad. It means that there may be some concerns or harm.

ZOMORODI: Some stores have a green, yellow and red color-coded system.

And when you say some concerns or harm, what do you mean?

But can we be really sure that green is sustainable?

Wait a minute. They say they're rated, but it doesn't say what they are.

There are also terms like all natural or responsibly farmed.

There's Branzini, farm raised. And it says it's responsibly farmed.

And then there is sustainably caught.

I think that's good.

JOHNSON: Sustainable does not have a legal definition.

ZOMORODI: Got you.

JOHNSON: Responsibly and sustainably - like, these are not words that have clear standards or verification processes or oversight. It's something like 20% of seafood is mislabeled in grocery stores.

ZOMORODI: And so when you say mislabeled, do you mean, like, exaggerating the sustainability?

JOHNSON: I mean it's not even the species that they say it is.

ZOMORODI: Oh.

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JOHNSON: You mislabel seafood for profit. So you label it as whatever will get you the highest price or whatever you have a quota for. And it varies depending on the species up to, like, 40% or even 50% for things like snapper and sea bass. And, like, if it's not even the right species, like, are the other labels correct? So if the consumer does, you know, do your darndest to do your research and pick things that are sustainable, there's still a big chance that you would get it wrong through really no fault of your own.

ZOMORODI: Like, why is that? Why make it so hard for the consumer?

JOHNSON: The supply chain is so opaque, and there are so many steps in it. And we really often don't know where our seafood is coming from. And about 80% of the seafood that we eat in the U.S. is imported.

ZOMORODI: Eighty percent.

JOHNSON: It's coming from all over the world. And also, about 1 in 4 of the fish that we eat here were actually caught in the U.S. and probably sent overseas to Asia or other places to be processed and then reimported. It's not really what we think about when we think about sort of commodities trading or import and export, but it really is.

ZOMORODI: And Ayana says to keep up this complicated supply chain, industrial fishing vessels have to hunt fish by the thousands.

JOHNSON: There are these massive fishing vessels that have, like, full processing factories onboard. Often, they're staying at sea for months if not years. Often, the labor conditions are abysmal and often fishing with nets the size of multiple football fields or lines with hundreds if not thousands of hooks on them. So we're talking about, like, a massive industry not, like, a cute fishing trip.

ZOMORODI: And that means using pretty sophisticated tools to track down the dwindling fish populations.

JOHNSON: You have sonar. You have helicopters and spotter planes because we've overfished to such an extent that we have to use the most advanced technology we have available to us in order to find the fish.

ZOMORODI: And the shrimp industry uses some of the most harmful methods.

JOHNSON: Shrimp is the most popular seafood in the United States, and it's one of the least sustainable. Often, like, 10% or less of what they catch is shrimp, and the rest is thrown back dead.

ZOMORODI: And it's not just wild-caught shrimp.

JOHNSON: Farmed shrimp often destroys mangroves and other coastal habitats usually in Southeast Asia, which makes those areas more prone to storms. They use a lot of pesticides and antibiotics. Worker exploitation is a huge problem. So I would say if you're looking for just, like, a few things to cut out, give up shrimp unless you know that it's, like, you know, trap-caught pink shrimp from Oregon because those fisheries are sustainable and, like, really deliberate.

ZOMORODI: OK. So for most shrimp, farmed and wild are both bad. So maybe just don't eat it. But for other fish, is farmed better than wild?

JOHNSON: I mean, the answer is, unfortunately, it depends. We need to think about - the farmed fish, what are they eating? We're catching wild fish, small ones, to feed to farmed fish, that would be bigger ones. Eating farmed carnivorous fish doesn't really make sense, right? Like, if we think about agriculture on land, would we farm lions? Would we think that that is sustainable? Like, that is essentially what we're doing when we think about farming tuna or salmon. These are magnificent fish, which are quite high up the food chain.

ZOMORODI: OK. So then, Ayana, what would be your ideal shopping trip? Like, you'd avoid the shrimp, wild or farmed. You would avoid the bigger fish. But then what would you eat?

JOHNSON: I think the first thing I should say is, as opposed to choosing fish from anywhere in the world where you have no idea, eating U.S.-caught or locally caught seafood is a really good start. I personally support Iliamna Fish Company, this Indigenous Alaskan family that fishes for salmon in Bristol Bay, which is sustainable. Eating lower on the food chain is another really important thing, right? Instead of eating these top predators like tunas, we could be eating sardines and anchovies. That will be more sustainable. Eating farmed shellfish, eating farmed seaweed, that is something you can feel comfortable eating as much as you want, so, you know, enjoy.

ZOMORODI: I think it would be best for me to buy the small stuff, right? Like anchovies - I love anchovies - and sardines. They're a little too stinky for me, but if I want to stop eating, like, tuna steak, I got to find something else that's delicious.

Ayana Elizabeth Johnson is a marine biologist. You can find all her talks at ted.com. And please check out her podcast, "How To Save A Planet." Transcript provided by NPR, Copyright NPR.