ALLISON AUBREY, HOST:

This got us wondering about shrimp and other seafood we see at the store. How do we know when it's best to buy farm-raised versus wild or domestic rather than imported seafood? And how do these seemingly simple choices leave a larger footprint around the world?

To find out more, we're joined now by Barton Seaver. He's the director of the Healthy and Sustainable Food program at Harvard University's School of Public Health and the author of "Two If By Sea." Hey there, Barton.

BARTON SEAVER: Hey. It's wonderful to be here with you, Allison. Thanks.

AUBREY: So one of the reasons that there's demand for this farmed shrimp we just heard about in New York is that many shoppers have heard stories about imported shrimp that make them hesitant to buy it, for instance, revelations about slave labor in Thailand last year, as reported by the AP. Remind us what exactly was uncovered there.

SEAVER: What was uncovered was a horror story. People kind of shanghaied into service, you know, eight years, 20 years one woman was held in captivity. Fishing off these boats, the fish from those boats then, you know, ended up in our largest and some of our most prestigious grocery stores, restaurants and retailers here in America.

AUBREY: So I'm imagining that there have got to be better ways, more sustainable ways of producing shrimp. We just heard about shrimp farmed in indoor tanks. I know there are other methods used in aquaculture, too, so I'm wondering are these newer methods more sustainable? Do you think that aquaculture or farming fish rather than fishing fish is going to be a big part of the future of seafood?

SEAVER: Well, farming fish is already here to stay. We're about equal right now in terms of how much farmed fish we eat versus how much wild fish we eat. I think it's the greatest opportunity ahead of us right now. You know, we're in a situation where we're constantly sort of under the anxiety of whether or not we live in a world managed for abundance or one managed for scarcity.

And as we run out of fresh water, as we, you know, are being run out of arable land as populations rise, where are we going to get food? Well, hey, how about 70 percent of the planet that we don't currently use much of? And aquaculture just presents so much untapped potential. And, you know, we're getting so smart about it, too.

And, you know, a lot of the bad press that agriculture has gotten - yeah, hey, I mean, it was deserved. There were some pretty bad abuses, you know - levied upon ecosystems. You know, the farmed salmon industry, for example, you know, sort of the poster fish of all that's bad - that industry really as a global industry is only just under 50 years old. Industries evolve, and farming of fish has evolved very rapidly and is now at a point where by a host of different methods, we are now producing very high quality, very necessary, very healthful food.

AUBREY: So how is it that we as consumers can know what we're buying? Is there a way for us to know that the seafood is being produced sustainably? I mean, where do we go for the answers?

SEAVER: Well, you know, there are some certifications that do audits that include fair labor practices, and, you know, part of the almost instantaneous reaction from the industry after this expose was to put into place some standards requiring that some of these shrimp farmers consolidate their operations so that these dark crevices in which crime and crimes against humanity can happen disappeared.

We have to also acknowledge that we have some responsibility in this. It's our insatiable demand for shrimp that has created an economy that is a race to the bottom, where the only competition is about quantity and price. And so if we're not willing to pay the true price of what that farm cost to raise, well, then the company passes it down and passes it down until it hits the weakest of us which is the laborer. And, you know, I don't think that's something we need to feel guilty about. That's not the purpose of dinner. I think rather we should feel inspired about this. Hey, we got a wakeup call. We have an opportunity as consumers to make a real difference in people's lives.

AUBREY: Barton Seaver is the director of the Healthy and Sustainable Food program at Harvard University's School of Public Health and the author of "Two If By Sea." Thanks, Barton.

SEAVER: Pleasure being here. Thank you so much. Transcript provided by NPR, Copyright NPR.