Contents

What's Next for Fish Farmers?

Science of Closed Systems

Aquaculture in the Classroom

For More Information: Aquaculture Web Sites

Knauss Fellowships Available

Other News of Note

By Merrill Leffler

Not far from Cambridge on Maryland's Eastern Shore and miles from the Choptank River, fish circle the confines of 40-foot rectangular tanks. Though separated from the docks and deadrisers associated with fishing on the Chesapeake, for Rick Sheriff these fish represent his catch, his form of food production. Clean water continually circulates through each of Sheriff's thirteen tanks, which sit in an out-of-the-way industrial park in Hurlock, Maryland. Water quality, if all works right, is completely under his control.

In each tank here at Delmarva Fisheries 12,000 gallons of water pass through clarifiers that remove solids and then through biological filters that break down chemical wastes and leave them harmless. Unlike the turbid waters of the Chesapeake, the water in these tanks, under the building's low roof and low lighting, looks nearly transparent.

By all appearances, this is the way closed-system farming is supposed to work. Sheriff gets fingerlings from hatcheries that raise juveniles in high numbers, then nourishes them with specially formulated feeds. Filtration is key to maintaining water quality, since contaminants can not only produce off-flavors, lowering the value of his product, but can also sicken or even kill the fish - and put a serious dent in Sheriff's investment. If all goes well, depending on the species, fish will be ready for market in six to seven months (for yellow perch and bluegills) or nine months (for tilapia) or a year (for hybrid striped bass).

Although the clean tanks at Delmarva Fisheries seem on track for producing a wholesome and valuable seafood product, the record for aquaculture that relies on recirculating systems has posted as many failures as successes. The reason: raising fish for profit depends on conquering a suite of challenges, and often raising fish is not the toughest part.

"Growing fish is the least of my problems," says Sheriff. In addition to watching the tanks, feeding the fish and cleaning the water, Sheriff, like other aquaculturists, has to worry about where the next crop of fingerlings will come from, and, with low-price imports from South America and Asia, about who will buy his fish once they're ready for market.

"I concentrate on fingerling supplies and marketing," Sherrif says.

According to Sea Grant Extension specialist Don Webster, that's the right thing to do. "More aquaculture fails because of business management than system management," says Webster. Fingerlings, too, pose a major problem, according to Webster, since fish farmers must have a reliable supply of the fingerlings they want when they want to raise them.

"Rick's system can grow fish profitably," says Robert Butz, a dairy and grain farmer in western Maryland who is now farming fish in tanks, "but that's not the complete story. You need others to supply fingerlings - you need industry support when you get in trouble. This is still a frontier mentality."

Tough Times on the Frontier

The rearing of fish, shellfish and aquatic plants — known generally as aquaculture — may be the aquatic equivalent of land-based agricultural husbandry, but it lags far behind its terrestrial sibling.

Though slow to catch on in this country, the cultivation of fish is hardly new, going back at least 2000 years in China, which may be why, with its long head start, China far outpaces other countries in overall aquaculture production. That nation alone accounts for some 70 percent of farmed fish each year, while the U.S. trails far behind, a distant eighth at one percent of world production.

Most U.S. production comes from catfish grown in ponds in the Mississippi delta and salmon raised in floating cages off the coasts of Maine and Washington state. U.S. shellfish farmers also cultivate oysters on the northwest and northeast coasts, and mussels, crawfish and clams on the east and Gulf coasts. Still, all told, the U.S. imports a great deal more seafood than it exports, carrying an annual $5 billion seafood trade deficit. No wonder that the U.S. Department of Commerce's Aquaculture Plan calls for the nation to invest more of its research and expertise in raising domestic seafood products.

In Maryland and the mid-Atlantic, farmed fish production for consumption hardly registers — aquaculture's largest economic impact still comes from ornamental fish. In Maryland, the largest and most profitable aquacultural production comes from Hunting Creek in the western reaches of the state, which for eighty years has produced fish for the aquarium trade. Another important role of aquaculture in the Chesapeake region continues to be its use in proactive restoration efforts. Aquaculture has proven central to efforts to restore the Bay's shad and oyster populations, for example. At the University of Maryland Center for Environmental Science (UMCES), the Horn Point Hatchery has produced more than ninety percent of the disease-free spat used to reseed oyster bars in the Bay. Likewise, the Department of Natural Resources operates a hatchery where it has spawned some six million shad larvae for release into the Patuxent and Choptank rivers.

Recirculating systems can be located anywhere and don't depend on expensive waterfront property or unpredictable water supplies pumped from a river or bay.

DNR is using "Reproboost" technologies, implants that release hormones over a period of time that induce fish to spawn in captivity. Developed at the Center of Marine Biotechnology (COMB), part of the University of Maryland Biotechnology Institute, these time-release implants have made it possible to produce large numbers of larvae that traditional spawning techniques could not deliver.

In addition to providing juveniles for stock enhancement, researchers use hatchery-reared strains to test for disease tolerance — in the effort, for example, to manage around the oyster diseases, MSX and Dermo. Beyond this, aquaculture is now playing an important role in education as well — numbers of Maryland elementary and middle and high school teachers are using aquaculture to teach students about biology and ecology by growing fish in tanks (see sidebar, "Aquaculture in the Classroom").

Despite these important and worthwhile roles for aquaculture, the bottomline for entrepreneurs like Rick Sheriff and Robert Butz remains financial. What they bank on is a more controlled method of farming fish — not in ponds and not in netpens, where water quality and the problem of effluents can create environmental challenges — but in completely enclosed environments, recirculating tanks, that offer the kind of management and economy required for a profitable enterprise. Such systems, they argue, can be located anywhere — not only in rural areas like Hurlock or western Maryland, but in warehouses in cities like Baltimore, says Yonathan Zohar, director of COMB. They don't depend on expensive waterfront property or unpredictable water supplies pumped from a river or bay.

Pioneers like Sheriff and Butz hope to find niches in an aquaculture industry that will one day make fish production in Maryland as viable an endeavor as agricultural production has been for centuries.

On the Trail of Recirculating Systems

In research labs across the University System of Maryland, researchers are working to develop capabilities that could help turn the potential of aquaculture into a long-promised reality.

At a recent meeting at the UMCES Horn Point Laboratory, Webster and Sea Grant Extension aquaculture specialist Andy Lazur brought together university researchers with Maryland aquaculturists who hope to raise, in recirculating systems, species such as tilapia, yellow perch, hybrid bluegills and hybrid striped bass. There are other species to consider as well — including marine species like the sea bream. "What we wanted to learn," says Lazur, "were the major problems that growers face, so we could set out a course of assistance to help this fledgling industry."

The model for this kind of cooperation is well established. After all, determining research needs by bringing scientists together with farmers has been at the heart of agricultural development in the United States for more than 100 years. Aquaculture expert Reginal Harrell, Eastern Shore director of the Maryland Agricultural Experiment Station, explains it this way: "Research does the underwriting work, while Extension can demonstrate it and educate the work force." Industry then takes over, he says. "They need to make the tough decisions. But they can't afford to make the big investment and lose the animals to find out what the best answers are. Our job is to get scientifically credible answers."

Reducing the Risk of Failure

While fish farmers identified a number of problems, by far their biggest complaint was their inability to get fingerlings — their "seed" — when they needed them.

Part of solving this problem, according to Webster, is strategic. "The key to recirculating systems is flexibility," Webster says. "Growers can't focus on one species and expect to stay there. If one species becomes uneconomical, they better be able to move into something else."

And yet with the exception of a few species — tilapia in particular — growers have faced limits to their flexibility because hatcheries have not yet proven able to spawn different species on a regular basis.

Though researchers are making solid advances in university laboratories, new technologies are only beginning to make their way to commercial hatcheries, and compared with land-based agriculture, aquaculture has a long way to go. Unlike farm animals that have been genetically bred, for example, most fish species are either captured in a gravid state from spawning grounds, or they are reared in hatcheries for a short time. An entire year's production of larvae may depend on the brief spawning period of captured fish. Though several hatcheries have mastered the ability to produce tilapia year-round, that is not the case for species such as yellow perch and hybrid bluegill.

Even year-round controlled spawning of high quality tilapia fingerlings does not secure success. Though a highly tolerant warm-water species that accommodates close quarters and fluctuating water quality, tilapia, like all cultivated species, whether on land or sea, still faces the vagaries of the marketplace. This lesson became clear several years back, when a reliance on tilapia left a number of businesses in jeopardy, as low-cost imports sent prices plunging. Because they could not ride out the loss or switch to another species, a number of growers were forced out of business.

Again, as marine agent Don Webster says, it's the business part that can prove the most difficult nut to crack.

Coping with Changing Markets

When the price of tilapia plunged, Rick Sheriff switched his operation to the more profitable yellow perch. A staple of weekend fish fries in the Great Lakes, perch promised good money, especially since wild harvests in that region had fallen from 40 million to 10 million pounds a year. "The demand was there," Sheriff says. "We just couldn't satisfy it."

That demand for cultured fish can exceed supply is good news for anyone considering the aquaculture business, but the ways of the market are complex. As one might expect, other growers also wanted to sell to that lucrative market. With increasing demand on limited supplies of fingerlings from hatchery producers, the price for juveniles went up — some five times more, Sheriff says, than what he originally paid. The profit margin grew smaller, and with tilapia prices on the rebound, he's since backed off yellow perch and has now returned to farming tilapia.

Clearly, flexibility and diversification of crops is as important for aquaculture as it is for agriculture. For some fish farmers closed, recirculating systems will help remove some of the risk of otherwise uncontrolled variables, and give them the control they need to switch species when necessary.

What they do not yet have is an established industry, with easy access to supplies and materials — the farming infrastructure that has, over many years, grown up around land-based agriculture.

According to Robert Butz, it's not that recirculating systems such as his can't produce large numbers of fish. What causes him headaches is the lack of support services that can make farming fish profitable. "Look at how developed hog, poultry and cattle nutrition is," he says. "There is comparatively little development in fish nutrition compared with agriculture."

Despite the shortcomings, Butz sees fish farming itself as a form of diversification, which is why, earlier this year, he bought thirteen tank systems built by Sheriff's company. In raising fish he sees a means of diversifying his agricultural investments, and in recirculating systems he believes there is a chance to gain more control over production. Unlike raising fish in ponds or in netpens, he says, an aquaculturist using recirculating systems can better manage environmental conditions. He points out that he can raise non-indigenous species without worrying about their escape, and he doesn't have to worry about predators. He also feels that he can better manage water quality and disease.

Anytime you raise animals, says Butz, there is an environmental cost, but with closed system aquaculture that cost is very low. Though some water is discharged, he says, the amounts remain relatively small, especially when systems are properly maintained. To Butz, farming fish in recirculating tanks seems like a good way to respond to the vagaries of the marketplace, and he expects that others may well follow suit.

The Path Toward Profit

Growing fish well, say Webster and Lazur, means growing them profitably — the bottom line is what counts. To increase their potential for profitability, they say, growers need better management, a variety of species and alternative markets.

In addition to low-margin species such as tilapia, hybrid striped bass, yellow perch and bluegills, says Lazur, we have to look at higher value species such as sturgeon, sea bass and sea bream. And beyond that, he notes, the industry should not lock itself into food species. He points to attractive possibilities for raising ornamentals for the aquarium trade. What we need now, he says, is good market information that we can then link to economics.

Even beyond food production and ornamentals, there are important opportunities for aquaculturists, Lazur says — for instance, providing environmental benefits by using the natural filtering of shellfish, and perhaps integrating that with plants to treat a range of effluents. Creative use of aquaculture, he says, could lead to innovative ways to reduce nutrient loading into surface waters while producing a cash crop.

To chart the next moves for the aquaculture industry, researchers need to develop both improved means for raising a variety of species in captivity but also incisive market analyses for those species, whether food fish, ornamentals, baitfish or for restoration work. This is the information the industry needs up front, says Lazur, to know what directions make the most economic sense.

As the still-developing aquaculture industry moves into the future, Lazur cautions that everyone involved will need to keep their eye on true economic potential. "We're taking a comprehensive approach to address profitability," Lazur says. "We're in this for the long haul."

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