NPR.

Hi, Planet Money. This is Haley calling from Boston.

I went to my local Whole Foods recently and splurged on what I thought was sustainably caught tuna.

And then I see when I get home in tiny print that it is wild caught in the USA, great, but it's packed in Thailand.

And I started thinking about all the miles that my tuna had traveled to get to me and my Whole Foods in Boston.

And my question is, is it worth buying this supposedly sustainably caught tuna, even though it has traveled

who knows how far around the globe to get to me? What is the environmental impact of this tuna?

Yes, that question means that it is time once again to answer questions from our listeners.

Hello and welcome to Planet Money. I'm Jacob Goldstein.

First question of the day comes from Haley. It's about tuna, a delicious fish, and Emma Peasley, you are here to answer this question.

Hello, yes. So I talked to a fish economist to get to the bottom of this one.

I'm Chris Anderson. I'm a professor of fishery economics in the School of Aquatic and Fishery Sciences at the University of Washington.

So the first thing Chris says is that it is cheaper to pack the tuna in Thailand than in the US.

And it's worth mentioning here that there have been labor issues at Thai fish packing plants in the past.

Okay.

Also, Chris says it just doesn't cost as much as you think to ship things across the ocean and back.

Ocean shipping is really cheap, really cheap. And it's really cheap because the boats that do it are really efficient because they move so much stuff.

So cheap packing and cheap shipping. That's why they send tuna across the ocean and back.

But Haley's real question is about the environmental cost.

Right. This idea of food miles, right? This idea that you want to know how many miles your food has traveled by the time it gets to your plate.

And the idea there is the farther it's traveled, presumably the worse it is for the environment, the bigger the carbon footprint.

Right. But Chris says food miles actually aren't a great proxy for the environmental footprint.

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