Tuesday, January 27, 2015

27/01/2015: How to farm a better fish

In a dark, dank warehouse in the Blue Ridge foothills of Virginia, Bill Martin picks up a bucket of brown pellets and slings them into a long concrete tank. Fat, white tilapia the size of dinner plates boil to the surface. Martin, president of Blue Ridge Aquaculture, one of the world’s largest indoor fish farms, smiles at the feeding frenzy.

Each day Mr Martin sells 12,000 pounds of live tilapia to Asian markets from Washington, DC, to Toronto, and he’s planning another farm on the West Coast, National Geographic reports


“My model is the poultry industry,” he says. “The difference is, our fish are perfectly happy.”

“How do you know they’re happy?” I ask, noting that the mat of tilapia in the tank looks thick enough for a man to walk on.

“Generally they show they’re not happy by dying,” Martin says. “I haven’t lost a tank of fish yet.”

An industrial park in Appalachia may seem an odd place to grow a few million natives of the Nile. But industrial-scale fish farms are popping up everywhere these days. Aquaculture has expanded about 14-fold since 1980. In 2012 its global output, from silvery salmon to homely sea cucumbers only a Chinese cook could love, reached more than 70 million tons—exceeding beef production clearly for the first time and amounting to nearly half of all fish and shellfish consumed on Earth.

Population growth, income growth and seafood’s heart-healthy reputation are expected to drive up demand by 35 percent or more in just the next 20 years. With the global catch of wild fish stagnant, experts say virtually all of that new seafood will have to be farmed.

“There is no way we are going to get all of the protein we need out of wild fish,” says Rosamond Naylor, a food-policy expert at Stanford University who has researched aquaculture systems.

“But people are very wary that we’re going to create another feedlot industry in the ocean. So they want it to be right from the start.”

There are good reasons to be wary.

The new ‘blue revolution,’ which has delivered cheap, vacuum-packed shrimp, salmon, and tilapia to grocery freezers, has brought with it many of the warts of agriculture on land: habitat destruction, water pollution, and food-safety scares. During the 1980s vast swaths of tropical mangroves were bulldozed to build farms that now produce a sizable portion of the world’s shrimp.

Aquacultural pollution—a putrid cocktail of nitrogen, phosphorus, and dead fish—is now a widespread hazard in Asia, where 90 percent of farmed fish are located. To keep fish alive in densely stocked pens, some Asian farmers resort to antibiotics and pesticides that are banned for use in the United States, Europe, and Japan. The US now imports 90 percent of its seafood—around 2 percent of which is inspected by the Food and Drug Administration. In 2006 and 2007 the FDA discovered numerous banned substances, including known or suspected carcinogens, in aquaculture shipments from Asia.

Nor have fish farms in other parts of the globe been free of problems. The modern salmon industry, which over the past three decades has plunked densely packed net pens full of Atlantic salmon into pristine fjords from Norway to Patagonia, has been plagued by parasites, pollution, and disease. Scottish salmon farms lost nearly 10 percent of their fish in 2012 to amoebic gill disease; in Chile infectious anemia has killed an estimated two billion US dollars’ worth of salmon since 2007. A disease outbreak in 2011 virtually wiped out the shrimp industry in Mozambique.

The problem isn’t the ancient art of aquaculture per se; it’s the rapid intensification of it. Chinese farmers started raising carp in their rice fields at least 2500 years ago. But with that country’s aquacultural output now at 42 million tons a year, fish pens line many rivers, lakes, and seashores. Farmers stock their ponds with fast-growing breeds of carp and tilapia and use concentrated fish feed to maximize their growth.

“I was very influenced by the green revolution in grains and rice,” says Li Sifa, a fish geneticist at Shanghai Ocean University. Li is known as the ‘father of tilapia’ for developing a fast-growing breed that’s become the backbone of China’s tilapia industry, which produces 1.5 million tonnes a year, much of it for export.

“Good seeds are very important,” Li says.

“One good variety can raise a strong industry that can feed more people. That is my duty. To make better fish, more fish, so farmers can get rich and people can have more food.”

How to do that without spreading disease and pollution? For tilapia farmer Bill Martin, the solution is simple: raise fish in tanks on land, not in pens in a lake or the sea.

“Net pens are a total goat rodeo,” says Martin, sitting in an office adorned with hunting trophies.

“You’ve got sea lice, disease, escapement, and death. You compare that with a 100 percent controlled environment, possibly as close to zero impact on the oceans as we can get. If we don’t leave the oceans alone, Mother Nature is going to kick our butts big-time.”

Martin’s fish factory, however, doesn’t leave the land and air alone, and running it isn’t cheap. To keep his fish alive, he needs a water-treatment system big enough for a small town; the electricity to power it comes from coal. Martin recirculates about 85 percent of the water in his tanks, and the rest—high in ammonia and fish waste—goes to the local sewage plant, while the voluminous solid waste heads to the landfill. To replace the lost water, he pumps half a million gallons a day from an underground aquifer. Martin’s goals are to recirculate 99 percent of the water and to produce his own low-carbon electricity by capturing methane from the waste.

But those goals are still a few years away. And though Martin is convinced that recirculating systems are the future, so far only a few other companies are producing fish—including salmon, cobia, and trout—in tanks on land.

Eight miles off the coast of Panama, Brian O’Hanlon is going in the exact opposite direction. On a calm day in May the 34-year-old president of Open Blue and I are lying at the bottom of a massive, diamond-shaped fish cage, 60 feet beneath the cobalt blue surface of the Caribbean, watching 40,000 cobia do a slow, hypnotic pirouette above us. The bubbles from our regulators rise up to meet them; one pauses to stare into my mask. Unlike Martin’s tilapia or even the salmon in a commercial pen, these eight-pound youngsters have plenty of room.

O’Hanlon, a third-generation fishmonger from Long Island, grew up with New York City’s famed Fulton Fish Market as his playground. In the early 1990s the collapse of the North Atlantic cod fishery and the import tariffs imposed on Norwegian salmon bankrupted the family business. His father and uncles kept saying that the industry’s future was farmed fish. So as a teenager, O’Hanlon started raising red snapper in a giant tank in his parents’ basement.

Now, off Panama, he operates the largest offshore fish farm in the world. He has some 200 employees, a big hatchery onshore, and a fleet of bright orange vessels to service a dozen of the giant cages, which can hold more than a million cobia. A popular sport fish, cobia has been caught commercially only in small quantities—in the wild the fish are too solitary—but its explosive growth rate makes it popular with farmers. Like salmon, it’s full of healthy omega-3 fatty acids, and it produces a mild, buttery, white fillet that O’Hanlon claims is the perfect canvas for picky chefs. Last year he shipped 800 tons of cobia to high-end restaurants around the U.S. Next year he hopes to double that amount—and finally turn a profit.

Maintenance and operating costs are high in offshore waters. Although most salmon operations are tucked in protected coves near shore, the waves over O’Hanlon’s cages can hit 20 feet or more. But all that rushing water is the point: He’s using dilution to avoid pollution and disease. Not only are his cages stocked at a fraction of the density of the typical salmon farm, but also, sitting in deep water, they’re constantly being flushed by the current and the waves. So far O’Hanlon hasn’t had to treat the cobia with antibiotics, and researchers from the University of Miami have not detected any trace of fish waste outside his pens. They suspect the diluted waste is being scavenged by undernourished plankton, since the offshore waters are nutrient poor.

O’Hanlon is in Panama because he couldn’t get a permit to build in the US.  Public concerns over pollution and fierce opposition from commercial fishermen have made coastal states leery of any fish farms. But O’Hanlon is convinced he’s pioneering the next big thing in aquaculture.

“This is the future,” he says, once we’ve said goodbye to the cobia and are back aboard his orange skiff.

“This is what the industry is going to have to do in order to keep growing, especially in the tropics.” Recirculating systems like Martin’s, he says, will never produce enough biomass.

“There is no way they can scale up to meet the market demand. And to make one profitable, it’s like a cattle feedlot, where you cram so many fish in you’re just trying to keep them alive. You’re not providing the best environment possible for them.”

Read more HERE.

The Aquaculturists
This blog is maintained by The Aquaculturists staff and is supported by the
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