For centuries, people have farmed fish inland as a way to supplement their catch from the ocean and today about half the world’s seafood supply comes from aquaculture. In light of concerns about best practices, some new businesses are moving the process back off shore and into deep waters where fish have space to grow in a natural habitat. We consider innovations in aquaculture and the advantages of focusing on faster maturing species in over-fished regions.


  • Dan Stone Journalist, National Geographic magazine
  • David O'Brien Deputy Director, NOAA Fisheries Office of Aquaculture


  • 13:37:12

    MR. KOJO NNAMDIWe tend to imagine the fish we eat being hauled from the depths of the ocean caught up in big nets or snagged on the end of lines dropped from boats miles off shore and brought to market by fishermen in bright yellow rain gear. In reality, about half of the world's seafood supply comes to market through aquaculture, fish that is bred, grown and harvested in controlled environments. It's a centuries-old tradition for which modern innovations and best practices with a focus on environmental preservation and foot safety are being developed around the world in order to meet growing market demands at a time of overfishing.

  • 13:37:47

    MR. KOJO NNAMDIHere to discuss the ups and downs, which can include sharks, of farm fishing is Dan Stone. He's a journalist for National Geographic magazine where he also contributes to the blog Onward. Dan, thank you for joining us.

  • 13:37:59

    MR. DAN STONEHi, Kojo.

  • 13:38:00

    NNAMDIAnd David O'Brien is the deputy director of NOAA's Fisheries Office of Aquaculture. David O'Brien, thank you for joining us.

  • 13:38:07

    MR. DAVID O'BRIENThank you, Kojo.

  • 13:38:08

    NNAMDIYou can join the conversation. Give us a call. Do you pay attention to where your fish comes from? Tell us what your preferences are and how you keep track at 800-433-8850, or send email to David, the history of aquaculture goes back centuries. What does it typically entail and where is it most common?

  • 13:38:27

    O'BRIENWell, globally most aquaculture takes place in Asia. About 90 percent of all the world's aquaculture comes from Asia, about 70 percent from China alone. The rest of the world really is largely importing those aquaculture products. That being said, there is aquaculture in South America, Europe and some in the U.S. and Canada as well.

  • 13:38:45

    NNAMDIWhat's the distinction, if one is to be made, between aquaculture in general and marine aquaculture?

  • 13:38:51

    O'BRIENWell, aquaculture, in a very general sense, just growing anything in water. It could be fresh water, it could be marine waters. So for example, in the U.S. there's a lot of catfish farming and trout farming in fresh water environments. Marine aquaculture is in the coastal ocean and more and more are going offshore.

  • 13:39:08

    NNAMDIDan, you recently traveled to a fish farm off the shores of Panama that's a bit of an outlier. What's unique about that enterprise and what did you find there?

  • 13:39:17

    STONEThis was the largest open ocean fish farm in the world.

  • 13:39:21

    NNAMDIPaint a picture of it.

  • 13:39:24

    STONEThis is about eight miles off the north coast of Panama in the very warm waters of the Caribbean. And an American man named Brian O'Hanlon wanted to start a fish farm somewhere where he could let the fish live in their natural habitat. So he's growing a fish called cobia in a very unique way and creating these very large pens, probably about the size of a circus tent that sits submerged in the water. And the fish essentially get flushed with clean ocean water every day all day, all night. And they live in their natural habitat to the extent that they could swim naturally while still confined to allow the efficiency of farming.

  • 13:40:05

    NNAMDIThis is a pretty capital intensive endeavor, is it not?

  • 13:40:08

    O'BRIENExtremely. And what they've had to do -- I mean, again, this is eight miles off the shore of a fairly remote country, and all that infrastructure, all these ships, all the boats, the nets. And then you have to get the fish out to the nets and bring them back when it comes time for harvest to ship all over the world. Very capital intensive and that is also one of the reasons that Mr. O'Hanlon started this project in Panama as compared to the U.S. and other countries.

  • 13:40:35

    NNAMDIHow many other Americans are joining Mr. O'Hanlon in doing this? Is he the only one?

  • 13:40:38

    O'BRIENHe has about -- a staff of about eight to ten Americans and a couple...

  • 13:40:42

    NNAMDIBut he's the only operation doing that.

  • 13:40:44

    O'BRIENYeah, oh, I mean, between the hatchery and all of the operations out to the facility, there are about a dozen Americans, a few hundred local people, Panamanians who help him run the operation.

  • 13:40:56

    NNAMDIGlobally fish consumption is up even as concerns about overfishing continue to grow. Just how important are these aquaculture practices to the world food supply, first you, David, and then Dan. First you Dan and then David.

  • 13:41:09

    STONEI think as the population increases, one theme that we're exploring at National Geographic this entire year is how to create more food from the same number of resources. Wild farming has always -- wild fish farming has always been very attractive as a way to get fish but it's not always the easiest or the most efficient. There are drawbacks also with aquaculture and onshore fish farming. But what we went to see was an idea that marries the two, growing fish in their natural habitat in still an efficient way that it can be done cost effectively.

  • 13:41:46

    NNAMDIAnd you, David.

  • 13:41:47

    O'BRIENWell, I think, you know, aquaculture has, as you said, Kojo, at the beginning, it's now about half the world's seafood supply. If you go back even 20 years, it was a small fraction of that. Basically looking at the global seafood supply, for the past 20 or even 30 years, wild fisheries have reached a plateau, about 85 or 90 million metric tons, that's globally. And since that time, the demand for seafood has continued to rise beyond that. And the world has moved towards aquaculture. So now it is continuing to grow at a quite rapid pace while wild fisheries really doesn't have too much more room to grow.

  • 13:42:18

    O'BRIENIt does have room to be more sustainable and could maybe add a little more to our bottom line but basically everyone expects that the only real seafood increases will come from aquaculture. And in the U.S. currently we've been basically satisfied to import all of our seafood, about 90 percent currently, but there's more and more interest in growing more in the U.S.

  • 13:42:41

    NNAMDIDavid O'Brien is the deputy director of NOAA's Fisheries Office of Aquaculture. He joins us in studio with Dan Stone. He's a journalist for National Geographic magazine where he also contributes to the blog Onward. If you have questions or comments for us, have you visited a fish farm or worked in the industry, share your experience with us, 800-433-8850. Do you think the U.S. should ramp up aquaculture production to help mitigate overfishing? You can also send us an email to

  • 13:43:10

    NNAMDIDavid, if global aquaculture production's way up and the U.S. imports a good deal of its seafood, what does NOAA hope to see in terms of developing the industry here?

  • 13:43:21

    O'BRIENThat's a good question, Kojo, and something we actually asked ourselves a few years ago when we were asked by our leader at the time, Dr. Jane Lubchenco, you know, what is our mission with respect to aquaculture? We went around and talked to a large number of constituents around the country and we heard a lot of different opinions. But they really fell into two different camps.

  • 13:43:38

    O'BRIENOne is the idea that there's a lot of opportunity there for aquaculture. There's fishermen who are out of work, other culture communities that need more employment. We have the largest coastal zone in the world. Why are we importing so much seafood? Why can't we grow more here and keep those jobs -- keep the guys like Brian O'Hanlon, for example, growing fish in the U.S. and not importing it all?

  • 13:43:59

    O'BRIENThe other thing we heard quite a lot is that even if you want to ramp up production, we must do it sustainably. And that is -- that carries through everything we do. Our experience has been, and that of others around the world has been that those two ideas are quite compatible with each other. And that if aquaculture is managed correctly, as it generally is here in the U.S., it can be done quite sustainably.

  • 13:44:21

    NNAMDIOn to the telephones. Here we go to Mary in Silver Spring, Md. Mary, you're on the air. Go ahead, please.

  • 13:44:28

    MARYYes. Thank you. Well, I'd like to point out that fish farming is not an efficient way to provide food because the fish -- most of these fish -- species require fish to be fed to them. And that takes an astronomical number of fish from the oceans to be fed to them. Also the United Nations and the World Health Organization have pointed out that we should be moving away from a meat-based diet toward a plant-based diet. And I believe Mr. O'Hanlon's operation that National Geographic was glorifying, it would not even be allowed in U.S. waters for environmental reasons.

  • 13:45:06

    NNAMDIConcerns, David, about people having farm-raised fish, especially from overseas, tend to center on sanitary conditions and food safety issues. As you respond to our caller, Mary -- and I'll ask Dan to respond to -- what role does NOAA have either on its own or in partnership with other agencies to put safeguards in place?

  • 13:45:24

    STONEWell, if I could address the fish meal issue, this is actually a good example -- it's a question we get quite a bit. If you look at the development of fish meal over the past -- sorry, fish food over the past say 20 years or so, there's been an awful lot of progress made. If you look maybe 15, 20 years ago a typical salmon diet, for example, might have, you know -- the large majority would be fish meal and fish oil. Right now it's down to about 10 percent with the rest being soy and other plant-based products.

  • 13:45:53

    STONEAt the same time, fish like tilapia, which in the wild are herbivorous, often have a little fish meal and fish oil in there just to -- in the farmed environment to help them grow faster. So the distinction between carnivore and herbivore in the farmed environment really is quite blurry. It's often very different from what you find in the wild.

  • 13:46:12

    STONEBut that being said, there -- the fish meal question is one that we are addressing and NOAA together with the USDA and a whole bunch of other folks around the world have been working very hard to reduce the amount of fish meal required to raise a pound of salmon or cobia or anything else, and had a lot of success.

  • 13:46:28

    NNAMDIDan Stone, our caller seems to be suggesting that this is not sustainable.

  • 13:46:32

    STONEAt the moment the way fish efficiency is measured is with a feed conversion ratio, what David was talking about. How many pounds of food it takes to produce one pound of fish that we eat. Salmon is currently the most efficient in terms of that ratio, about 1.2 pounds of food per pound of fish we eventually harvest. Cobia is around 2.0.

  • 13:46:51

    STONEBut what's interesting, for all of the fish we eat, including salmon, carp, sea bass, tilapia and cobia, the number has been coming down over time. These fish have become more efficient to produce. And with the caller's -- with respect to what Mary said about the World Health Organization, the WHO does recommend the transition to plant-based diets. But keep in mind, people are eating more fish now than they ever have been. That number is going up. It's not going down. And finding a solution or finding people who have some ideas for how to solve this issue, I think those are the people that we want to take a skeptical and a very interested look at.

  • 13:47:27

    NNAMDIMary, thank you very much for your call. I'm glad you brought up cobia, because that's the particular variety of fish that you swum with, so to speak...

  • 13:47:33


  • 13:47:33 Panama. What exactly is cobia and what makes it a good candidate for farming?

  • 13:47:38

    STONECobia is an Atlantic fish that does very well in warm water. So that's why it grows very well in the Caribbean off the coast of Panama and Central America. What's most notable about cobia is how quickly it grows. The salmon that you eat for dinner generally takes between two and three years to reach maturity before it's harvested. Cobia grows two about full size in about a year, a little more, a little less. And that translates into a more efficient food structure, feeding structure and when you can harvest.

  • 13:48:10

    STONECobia's other attributes that attract chefs as well are the fact that it's a very high-quality meat. It can be served sashimi grade in raw sushi. And it doesn't really taste fishy. So if you're talking about providing more protein to more people, it doesn't have a fishy taste quite like carp or sea bass you'd find there.

  • 13:48:31

    NNAMDIDavid, what's the typical life cycle for a fish or mollusk raised through aquaculture two, three years as Dan was saying?

  • 13:48:38

    O'BRIENWell, it varies quite a bit depending on the species. That's certainly typical for a number of species. But, as you said, cobia is one of those -- potentially those wonder fish that can grow very rapidly to market size. And, you know, one of the issues we have sometimes is the market size for say a farmed salmon or a cod is quite a bit smaller than what would be allowable to be caught in the wild.

  • 13:48:59

    O'BRIENSo sometimes those issues on the regulation side, on the enforcement side with how do you manage for species in the wild, you might need a certain size limit but for the farmed version, they can be raised to a much smaller size.

  • 13:49:12

    NNAMDIIt's my understanding that some U.S. fish farms, including some nearby us in Virginia are working with cobia as well. What other fish are typically farmed in the U.S.?

  • 13:49:22

    STONEFor fish, cobia is one of the emerging species. The main fish species that is raised in the U.S. is salmon, both in New England and also in the northwest. There is some species of amberjack in Hawaii. And there's probably a few others as well, but not too many. It's really mostly shell fish and salmon are the main species in the marine environment in the U.S. Within the freshwater side there's also catfish and trout are two of the major species.

  • 13:49:46

    NNAMDI800-433-8850. Would you be apt to try less familiar varieties of fish like cobia if they could be harvested sustainably? Give us a call, 800-433-8850 or send email to Here is Brian in Washington, D.C. Brian, you're on the air. Go ahead, please.

  • 13:50:06

    BRIANHi. I just wanted to speak a little bit about a more evolved system, which is the aquaponics. I'm working on a project that's currently on hold here in the district, but I designed a system where you're growing plants, fish and fresh water prawn all in an ecosystem. And I wonder if your guests could speak to the combined aquaponics.

  • 13:50:30


  • 13:50:31

    O'BRIENSure, yeah. That raises two responses. Aquaponics typically means in a sort of tank-based environment. And there is a lot of work going on trying to develop aquaculture for marine species in tank-based environments. And there are some folks having some success with that. One of the issues there is that the energy cost of moving all that water around with pumps can be quite expensive. There's also issue of some waste discharge, not into the ocean but into land-based environments. So it's certainly not a silver bullet by any means but there's certainly room for improvement there. And I think that's going to continue to grow.

  • 13:51:07

    O'BRIENThe other issue is this idea of raising multiple species together. And that goes back thousands of years to China. But in the marine environment we're starting to see more and more of that. There's folks who are growing salmon alongside kelp and various shellfish species in what's called integrated multi-trophic aquaculture, basically different species eating different parts of the food chain, but all in close proximity to each other.

  • 13:51:30

    O'BRIENAnd in theory it seems to be actually working out pretty well, at least in experimental sites where any residual waste from the salmon farms, for example, might be taken up by the shellfish or the kelp providing extra product and also providing some -- basically some natural filtering capability.

  • 13:51:44

    NNAMDI800-433-8850 is our number. Do you pay attention to where your fish comes from? Tell us what your preferences are and how you keep track. You can also send email to Send us a Tweet @kojoshow or go to our website and join the conversation there. There's been a great deal of debate over the relative merits of farm versus wild fish in terms of nutrition, and as our earlier caller mentioned, sustainability. Starting with you, Dan Stone, what's your takeaway for consumers?

  • 13:52:16

    STONEWell, knowing which fish to buy has always been a challenge. The Monterey Bay Aquarium operates a list of which fish are most safe to eat related to their sustainability and the environments from where they come. You know, as people -- as more people require more food and fish becomes a larger part of the equation, I think it's fascinating to look at where this fish comes from and new ways to grow it.

  • 13:52:40

    STONEI mean, we will constantly have to innovate in this area specifically both in the U.S. and around the world to keep up with demand. I think demand can be kept up with but there will be new types of fish that you've never heard of and new ways of farming them that will be very new to people.

  • 13:52:55

    NNAMDIWe have links to Dan's story "Swimming With Tomorrow's Fish" his blog NOAA's Fishery page and the Monterey Bay seafood watch list on So you can find all of that there. And of course for those of you who are not familiar with NOAA or NOAA, it's the National Oceanographic and Atmospheric Administration. And back to the telephones now. Here is -- no, we won't go to the telephones yet.

  • 13:53:22

    NNAMDIDan, since we're talking about your blog, the trip you took to Panama was part of a bigger project that you're working on for National Geographic dubbed Onward. Where else have you been recently and what are you onto next?

  • 13:53:33

    STONEOver the past month we've looked at a couple major food stories. Aquaculture was one of them. Another was the role that a major drought in Brazil is playing on our coffee. The U.S. is the largest consumer of coffee. We drink the most but the U.S. produces almost no coffee. So Brazil had a drought earlier this year and we looked at how that drought and continued strange weather events is going to impact several other crops, including coffee. But we wanted to look at coffee as a highly dependent food stuff that many of us rely on every day.

  • 13:54:05

    STONEWhat we also did was we followed a truck full of strawberries from central California here to Washington, D.C. We wanted to do a story on food distribution and see that process at work, the process of thousands of trucks that cross the United States and our interstate highway system every day and bring fresh produce to our supermarkets. And we saw that process.

  • 13:54:28

    NNAMDIBack to the issue of fish, we go to Liz in Silver Spring, Md. Liz, you're on the air. Go ahead, please.

  • 13:54:35

    LIZHi, Kojo. I'm so glad you took my call. Thank you. I'm a minister and I preach on this a little bit because I think there are ethical implications to fish farming that just need to be part of our equation. Salmon, for example, lives in the wild ordinarily, very long lives full of adventure, right. They start in the rivers, they go out in the ocean, they swim around. They can live eight to ten years. They can finally come back upstream to spawn. And it's an extraordinary cycle of life. Salmon who are fished live a very, very short time in a completely different way.

  • 13:55:05

    LIZAnd if we follow a trajectory of fish farming without considering things like are we stewards of our environment, eventually we end up with animals who have no existence except to be food, which on a macro level, if that's what happens to, you know, more and more fish on the planet, eventually starts to have kind of disturbing ethical implications. And I don't mean to be soft about this but I think once you start to get into this as an enormous industry that may eventually dominate the animal life on the planet utterly, you need to think about these things.

  • 13:55:36

    NNAMDIIs this something that you have given thought to, David O'Brien?

  • 13:55:40

    O'BRIENWell, I think that's a -- I mean, I certainly appreciate where she's coming from. I think it's a personal ethical decision about what you feel about animal rights and whether animals should be wild or in farms. Certainly fish are like cows, chickens, pigs and lots of other farmed animals. We do farm them. We've made that choice as a society. I think it's up to us to at least serve our role at NOAA to make sure it's done sustainably and safely and try to do it in such a way that helps encourage some domestic jobs be produced in the meantime.

  • 13:56:10

    NNAMDIIs this a philosophical question that you have dealt with, Dan Stone?

  • 13:56:13

    STONEAbsolutely. And, you know, we've looked at how protein is created in National Geographic magazine this entire year. And the truth is, the world is eating protein and needs to eat a lot more protein. If we were to remove aquaculture from the equation I think you'd see a larger shift toward livestock raising. There's ethical concerns there as well.

  • 13:56:33

    STONEThe idea of the entire world turning its meat and protein diet from 60 miles per hour to zero I think is unrealistic, as admirable such of you, you know, might be for the rights of these animals.

  • 13:56:47

    NNAMDIHere is Janice in Washington, D.C. Janice, your turn.

  • 13:56:51

    JANICEHi. I just wanted to tell you about my new book "The Pescetarian Plan." And I looked at -- it's a diet book that we -- another -- I live in Washington, D.C. I'm a nutritionist and Sidra Forman is the chef, and we created fabulous fish recipes. And you can be a vegetarian on Sundays, a vegan on other days and a pescetarian, which is a vegetarian who eats seafood, on other days.

  • 13:57:18

    JANICESo we really did look at the environmental -- the mercury issues. We have a huge chart that tells you the high Omega 3 fish and the low mercury fish And I just wanted to let you guys...

  • 13:57:31

    NNAMDI...plug your book among other things. Thank you very much for your call. We are just about out of time. Dan Stone is a journalist for National Geographic magazine where he also contributes to the blog Onward. Dan, thank you for joining us.

  • 13:57:45

    STONEThanks, Kojo.

  • 13:57:46

    NNAMDIDavid O'Brien is the deputy director of NOAA's Fisheries Office of Aquaculture. David, thank you for joining us.

  • 13:57:52

    O'BRIENThank you, Kojo. And if I could I'd also recommend people go to if they want to find more information on health and sustainability of seafood.

  • 13:57:58

    NNAMDIAnd we'll provide a link to that website at our website The Kojo Nnamdi Show is produced by Michael Martinez, Ingalisa Schrobsdorff, Tayla Burney, Kathy Goldgeier, Elizabeth Weinstein and Stephannie Stokes. Brendan Sweeney is the managing producer. Thank you all for listening. I'm Kojo Nnamdi.

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