Mote Marine Laboratory

Turning Fish Into Gold: Aquatic Alchemy

By: Alison Koch

Starting life as a tiny, slimy bubble of an egg, a mature female Siberian sturgeon can produce $2,000 worth of caviar in one shot. The impressive marketability of her 40,000 eggs is prized enough that humans have scavenged the oceans to reap the rewards, forcing the world's stock of these wild fish to unprecedented levels of depletion.

Farming in a New Era

A dirt road winds through a meadow, bypassing moss-covered trees, horses grazing nearby and a still, serene pond. From the outside, Mote Aquaculture Park still has the feel of an old-Florida farm, with wooden pegs marking the entrance and picket fences lining the way.

The buildings are strictly modern-era farm — 11 huge shotgun-style metal-framed structures — but what’s inside them really blasts visitors into a new farming era. This new farm isn’t about cows or pigs or chickens. It’s about the United States’ up-and-coming food favorite: fish.

The USDA predicts that the country’s fish consumption will increase 6.8 percent by the year 2020 as more people seek protein alternatives for healthful reasons. At the same time, consumption of traditionally farmed foods like beef and pork is expected to decline by 3 percent.

Mote Aquaculture Park is designed to cater to the novel and increasing demands. Wood frames and red paint take a backseat to steel and concrete. Stalls give way to aquarium-style tanks. Seventeen miles from the coast, Mote is breaking environmental and economic ground with new freshwater and saltwater crops.

“Figure out how to practice aquaculture inland, with recycled water, and we’d be on our way to raising most of our own seafood — clean, fresh and reasonably priced,” says Dr. Kevan Main, who heads up Mote’s Center for Aquaculture Research and Development.

In a world where oceans are already fished unsustainably and nations like the United States rely on seafood imports to meet growing demand, Mote Aquaculture Park is using the revelation of ocean science to seed a new generation of fish farming. The goal? New -- and sustainable -- levels of production and profit.

A Finite Resource

Once a Siberian sturgeon egg is fertilized, it take seven to 10 days to hatch and become a larval fish. Ordinarily the growing fish would be fed zooplankton, like brine shrimp. Mote scientists have found that they can substitute a specialized, high-quality diet that includes fish meal or oil to produce a healthy, high quality fish stock.

Oceans — once thought to be an inexhaustible resource — are facing a crisis. Fishermen have suspected it for decades. Their catches have leveled off since the late 1980s, despite ever-improving techniques and a worldwide fleet that has doubled since 1970.

Now, scientists are beginning to confirm the crisis with hard data. Fish that were once considered plentiful have suffered huge declines. The Pew Oceans Commission found that 30 percent of the world’s fish populations that it studied are being fished unsustainably — fish are being caught faster than they can reproduce.

The future may be especially grim for the United States, one of the world’s top five seafood consumers along with China, Japan, India and Indonesia, according to a 2003 study by the United Nations’ Food and Agriculture Organization. While the United States ranks as the third largest consumer, it is only the 10th-largest producer. China, India and Indonesia produce billions more pounds of seafood than they eat — exporting the rest. Japan and the U.S. each import about half the seafood they consume.

And that was in 2003.

Now the U.S. imports closer to 70 percent of its seafood consumption, says Steve Rappaport, editor of Fish Farming News, a national magazine that focuses on the aquaculture industry. The economic impact has been devastating, with the U.S. trade deficit in seafood — at $9 billion — standing second only to its trade deficit in oil.

New Life for the Fishing Industry

On average, it takes 1.5 pounds of feed to produce 1 pound of sturgeon for consumtion. It takes 7 pounds of feed to produce 1 pound of beef.

“Growing more of it (fish for food) in the U.S. would not only keep that money from going to other countries, it would recycle it in the U.S.,” says Dr. Kevin Fitzsimmons, past-president of the World Aquaculture Society. After all, U.S. aquaculture feed contains American grains and it follows that increased aquaculture would equal a growth in U.S. grain sales, along with increases in equipment sales and training provided by U.S. technical engineers and manufacturers.

Main hopes Mote’s innovations will revolutionize the U.S. seafood industry and the aquaculture industry at large.

Aquaculture was created more than 3,000 years ago as a pond-based system; not much has changed since then. China still uses ponds to grow 67 percent of the world’s aquaculture yields. And although the United States is responsible for only 1.4 percent of the world’s total aquaculture production, it also relies heavily on the ancient Chinese techniques.

In these ponds, the water supply is pumped from natural sources, cleansed by live organisms, and pumped back out again into the natural sources.

“What you have to be concerned with, of course, is that runoff from the ponds be properly controlled,” says Rappaport. “If you are using any medication, there are going to be residues in the water.”

Excess food and waste also constantly threaten to pollute the surrounding environment, he adds. Pond experts try to reduce these pollutants by decreasing food supply and adding absorbents. Rappaport says that pond systems — when managed properly — have minimal environmental impacts. But there is always a risk of water or stock contamination. And excessive water usage is almost guaranteed.

To bypass these environmental hazards, Mote is creating a unique water-recycling system. Both freshwater and saltwater purification require common steps: solids removal, nitrification and aeration. Nitrification removes ammonia from wastes and aeration oxygenates and degasses water. The result is freshwater so clean that only 5 percent of it must be disposed of and salt water that is infinitely reusable with zero disposal.

While avoiding pollution and reducing water requirements, the filtration system also allows Mote to avoid the second complication with pond-cultures: the high cost of land near water.

Ponds require large areas, so they must be built on less expensive land. Given current technology, the land must be near a water source. In the United States, where coastal properties sell for millions of dollars, inexpensive waterfront is hard to come by. And previous U.S. pond-cultures that have taken advantage of undeveloped land have resulted in the destruction of cotton fields in some areas.

“Mote is developing high-intensity recirculation systems which, as they are perfected, allow for high densities in relatively small areas, so you don’t have a need for as much land,” says Rappaport. With cleaner, more oxygenated water, a greater number of animals can live in a smaller area. “With Mote working to develop and perfect very low water loss in its systems, even the amount of water available becomes less of a limiting factor.”

Main’s goal is to create new aquaculture systems that can be built almost anywhere, not just near the water. That’s something the state of Florida — which depends on beaches and the tourism dollars they draw for income — is watching closely. “With population growth, the supply of food is going to rely more and more on the inland facilities,” says Sherman Wilhelm, Director of Aquaculture at the Florida Department of Agriculture and Consumer Services. “So, Mote is leading the pack in aquaculture technology.”

Though high-tech, Mote’s system must still be manageable for farmers. Expensive land is not an option, nor is overwhelmingly complex science. Mote scientists have computerized their entire process. Machine-operated feeders feed the fish. Computer probes keep track of dissolved oxygen and temperature. If the systems malfunction, computers will send phone messages to farmers or will sound an alarm. For a fast-paced, low-maintenance business world, Mote’s technology fits right in.

Making the Model Work
Mote’s initial 1998 stock was harvested for meat in 2003 and 2004 and managers turned to Germany to boost their soon-to-be self-sustaining stock. Their purchase was 40,000 eggs — just enough to milk one foreign female dry, without harming her and without importing her or any others to the United States.

While they are learning to perfect their techniques, Mote scientists need to work with a lucrative fish like the expensive caviar-producing Siberian sturgeon. “We want to be profitable,” says Jim Michaels, manager of Mote’s Sturgeon Demonstration Program. “We’re starting with a high-priced species to make the economic model work.”

So far, they’ve made great progress, Main says. “We’ve experimented with salinity, fish density and temperature. All have a huge impact on how many fish we can raise, and therefore cost.”

By 2012, Michaels expects to have a standing stock of more than 440,000 pounds of fish and an annual harvest of more than 165,000 pounds of meat and nearly 10,000 pounds of caviar. Mote is also raising Pacific white shrimp for food. “Both have very high market values,” says Main.

By developing a way to commercially raise sturgeon and shrimp, Main and her colleagues hope to help save wild fish and bring food production back into the United States. They also want to contribute to a more global objective: putting fish back into the world’s oceans. “The goal is to rear a wild juvenile fish that can be put back in the ocean. Lots of them. The most snook we’ve raised in a year is 20,000. We need to hit 100,000 a year to make a dent” in wild populations, says Main.

Learn more about: Aquaculture, Mote Sturgeon, Mote Sturgeon Products

Reap what you sow. Aquaculture done right is a remedy for the world's food supply problem. And just as undeniable is the importance of your support for one very progressive aquaculture program.