It's a tough time for seafood lovers.
Prefer your fish from the ocean? That habitat is becoming a less hospitable place every day, according to a recent international State of the Oceans report. Water is getting warmer, more acidic. Dead zones are growing. A mass extinction of certain fish and coral species could happen sooner than scientists previously thought.
Don't mind a farmed fish? Maybe you should. It often grows in conditions so dirty it requires constant antibiotics and other chemicals just to grow big enough to eat.
Plus, 84 percent of U.S. seafood is imported and poorly regulated, which is why so much of it is mislabeled, disguised as pricier fish. You could be paying $23 a pound for red snapper that's really $3 a pound tilapia.
But there's a scientist in Brooklyn, N.Y., who says he has a solution to all of these problems.
For Martin Schreibman, the key is fish poop.
Schreibman's lab on the campus of Brooklyn College in New York is full of pipes and pumps whirring and clanking.
You're hit by a fishy smell when you walk in, and you quickly see why: Jacuzzi-sized tanks, filled with tilapia.
"These guys haven't been fed today, so you can see how voracious they are," Schreibman says, tossing food pellets in the water.
His tanks are part of a system very different from a fish farm or natural ecosystem. Schreibman's worked for years to develop an advanced water-recirculation system that eliminates the need for chemicals during the growth process. It filters plain old tap water in and out of a tank, constantly circulating and removing fish waste.
Over the course of years of work, Schreibman says, "it just occurred to me and my colleagues that we can grow a lot of fish in a very small area, on land, under controlled conditions. And there are no antibiotics, pesticides or hormones."
Schreibman works primarily with tilapia, which are resilient and good for research. But he says he can tweak temperature, salinity and other factors to grow most any kind of widely consumed fish — and grow them using only about a gallon of water per fish.
Schreibman calls this method urban aquaculture. And he thinks it could catch on as people grow increasingly concerned about where their food comes from and whether it's sustainably produced.
"This is the future," he says.
Just Add Water
Schreibman didn't exactly invent aquaculture — the term is basically a catchall that refers to any alternative method of fish farming — but he's thought as much as anyone else about how to make it urban, by making his recirculation system small enough to run anywhere on a municipal water source.
His utopian city is one with Jacuzzi-sized fish tanks on every roof, giving locavore owners more than 100 pounds of fish a year.
Schreibman further sweetens the deal with something called hydroponics. By tweaking his filtration system to leave a certain amount of fish waste in the water, plants can be grown in the same tank.
"We're talking plants floating on the surface of the water, using the fish waste as nutrition," he explains.
Lettuce, herbs, bok choi and kale can all be grown this way. The plants float on a foam sheet, their roots dangling into the water below.
"Fish poop a lot," Schreibman says. "People would be amazed at how much product you can produce in a certain area."
He says lettuce heads, for instance, can be grown six inches apart and cut in about six weeks. Herbs can be snipped for cooking and continue to grow.
There are drawbacks to such a system. A hydroponic garden is more expensive than dirt. A private company in Milwaukee will sell you one for about $3,000. And you get the pleasant task of gutting your own fish.
But Schreiman thinks it will catch on.
"The people I spoke to seven or eight years ago — their eyes used to glaze over — are now hearing me speak again and they're saying, 'Oh, I get it now,'" he says.
"It's clean. It's productive. You can get a head of lettuce from seed to your plate in six weeks — from a tank in your backyard."
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GUY RAZ, host: So too much water in the Pacific Northwest: bad for wind farms, good for fish farms, Brent?
BRENT BAUGHMAN: Why not? Sure.
RAZ: That's producer Brent Baughman. Brent, welcome to the inside of the studio.
BAUGHMAN: Thank you.
RAZ: I should explain that you are here because you recently came across a story, and it was about the whole locovore thing.
BAUGHMAN: The locovore thing, right, the idea that you buy fruits and vegetables and meat raised within a hundred miles of your home.
RAZ: Right. Okay. And you met somebody who wants to take the locovore thing to the next level.
BAUGHMAN: Right. The level of fish.
RAZ: Fish. Okay.
RAZ: Do tell.
BAUGHMAN: Right. So I heard about this guy on the campus of Brooklyn College in New York.
Excuse me, is this old Ingersoll Hall?
It's kind of them big campus way out in Brooklyn.
Oh, thanks. Okay.
The guy's name is Martin Schreibman.
Dr. MARTIN SCHREIBMAN: Brent?
BAUGHMAN: Nice to see you.
SCHREIBMAN: Nice to meet you.
BAUGHMAN: I'm here.
And his specialty is something called urban aquaculture, a kind of fish production but on a much smaller scale and without all the problems that come with large-scale seafood production. A lot of commercial fish, he says, is actually imported; 84 percent of the seafood eaten in the U.S. And some studies say that maybe a quarter of fish out there is mislabeled.
SCHREIBMAN: Well, I'll tell you why. There's a very good case in point.
BAUGHMAN: In Japan, Schreibman, says...
SCHREIBMAN: They were selling red snapper, you know, for sushi, and it's $23 a pound. But they were substituting tilapia, which is like, two and a half, $3 a pound. You know, it's a profit margin and...
BAUGHMAN: The other problem is that a lot of commercial fish, if it comes from a farm, is loaded with chemicals and antibiotics. And if it comes from the ocean...
SCHREIBMAN: Major problem is there is no fish out in the ocean anymore.
BAUGHMAN: A recent international report said a lot of bleak things about the state of our oceans, including that a mass extinction could happen soon if they're not cleaned out. But Martin Schreibman thinks he has an answer.
(SOUNDBITE OF MACHINERY)
BAUGHMAN: It's in a big basement lab.
No. It smells like there aren't fish here.
SCHREIBMAN: It smells good. So...
BAUGHMAN: The ceilings here are about 25 feet high and the room is filled with pipes and pumps. But the main feature is a collection of tanks.
SCHREIBMAN: So here, these guys haven't been fed yet today. You see how voracious they are.
BAUGHMAN: The tanks are the size of a small Jacuzzi and in it some hungry tilapia. But the important part is the filtration system it uses. Schreibman has been developing it for years. It recirculates the water from any municipal water source, and it's small enough to go pretty much everywhere. That's why he calls it urban aquaculture.
SCHREIBMAN: Our systems are so designed that we could use saltwater or freshwater or anything in between. We can use temperatures close to freezing or warm temperatures. We can control daylight. We can control salinity.
BAUGHMAN: With this system, there's less risk of disease. Fish don't need antibiotics. And if your local co-op or grocery store had one of these, Schreibman says, you would know where your fish is coming from. In another part of the lab...
SCHREIBMAN: So remember we talked about the fish tank? This is the fish tank, right?
BAUGHMAN: Schreibman is using a slightly tweaked version of the same filter system to grow plants on the surface of the water in the fish tank.
SCHREIBMAN: The plants are put into cubes that sit in these polystyrene boards that float on top of the water. And the roots dangle into the water and grow, and the plants grow up...
BAUGHMAN: Schreibman says you can do this with lettuce, kale, basil, bok choy all grown on fish poop.
I think people would be amazed at how much product you could produce in a very limited area.
And it's because fish poop a lot.
SCHREIBMAN: Fish poop a lot. But you don't want them to poop too much because then you provide too much material for the plants. You have to have a delicate balance, a symbiotic relationship, and that's where the science comes in.
BAUGHMAN: But the science is tricky, and it's more expensive than a garden. Schreibman does mostly research, but there's a company in Milwaukee that will sell you a system a lot like his for 3,000 bucks. They say that'll give you about a thousand plants servings a year and about 100 pounds of fish. You do have to gut the fish yourself. But Schreibman thinks people would be willing to do that if it means knowing where your fish comes from and how it's grown.
SCHREIBMAN: The people I spoke to seven or eight years ago, they - their eyes used to glaze over and, you know, couldn't wait to get out of the room - are now hearing me speak again. And they're saying, oh, I get it now. It's clean. It's beautiful. It's productive. It's productive. You can get a head a lettuce from seed to your plate in six weeks.
BAUGHMAN: In a tank in your backyard.
SCHREIBMAN: In a tank in your backyard or in your basement or in your shower...
(SOUNDBITE OF LAUGHTER)
SCHREIBMAN: ...or your friend's shower.
(SOUNDBITE OF LAUGHTER)
RAZ: That's Martin Schreibman. He spoke to our producer Brent Baughman. Brent, absolutely amazing. You could, in theory, grow, you know, blue fin tuna in Iowa.
BAUGHMAN: If you have a bathtub.
RAZ: It's going to change my fish tacos forever.
BAUGHMAN: Good. Transcript provided by NPR, Copyright NPR.