RAISING ROCKFISH:
The Promise of Aquaculture in Maryland

By Jack Greer

Tony Mazzaccaro is up to his armpits in striped bass. Literally. Standing in a pond brimming with stripers, he tugs on a buoyed line, corralling fish into a net, like any good fisherman. But the fish that thrash in this net are hybrid striped bass, a cross between stripers (rockfish) and white bass - and unlike fish in open waters, Mazzaccaro already owns them. Today he is moving the fish from one pond to another, only one of many acts of husbandry he must undertake before the fish are finally ready for market. (The net he holds guides the fish to a mechanized fish ladder, which turns like a giant screw and lifts the fish into another pond.)

[Hybrid Striped Bass and Tony Mazzaccar]

With the filling of his new ponds, Mazzaccaro has joined the ranks of fish farmers in the Mid-Atlantic, and he has done so in a big way. His farm in Somerset County, Maryland, which he has named "HyRock," represents one of the best financed operations in the region, according to Don Webster, Sea Grant Extension agent for the University of Maryland. "It's state of the art," Webster says. And, he says, "A lot of people are watching Tony."

People are watching HyRock Farm in the same way that they have been watching aquaculture in Maryland and in the U.S. for more than a decade, with some skepticism, some curiosity, and considerable anticipation about its future.

Taking a Chance

The outlook for aquaculture in Maryland is promising, according to the Maryland Department of Agriculture (MDA). The value of Maryland aquaculture products increased from $7 million in 1990 to $10.3 million in 1991 to $12.8 million for 1992, with an unofficial estimate of some $18 million for 1993, according to Roy Castle at the MDA's aquaculture once.

So far, hybrid striped bass still remains a relatively small player in Maryland's growing aquaculture industry. In 1992, finfish aquaculture - including hybrid striped bass, catfish, trout and tilapia - represented about 14 percent (or about $1.8 million) of Maryland's aquaculture products. The king and queen of aquaculture in Maryland remain ornamental fish and aquatic plants, which together account for nearly 70 percent of the value of the state's aquaculture industry.

Even counting ornamental fish and plants, aquaculture as a whole occupies a small niche in the state's economy, representing only a fraction (about one percent) of the gross income from Maryland agriculture, which in 1990 was estimated at some $1.35 billion.

Still, according to Reggie Harrell, researcher at the University of Maryland Center for Environmental Science and a Sea Grant aquaculture specialist, raising hybrid striped bass may be a chance worth taking. "The production of hybrid striped bass [in the U.S.] has gone from 1 million pounds in 1992 to 4 million pounds in 1993 to a projected 6 to 10 million pounds this year," he says.

Choosing Different Paths

Exactly how the finfish aquaculture industry will grow in Maryland remains open to debate. "Most growers on the Eastern Shore," says Harrell, "will use ponds." Many land owners already have farm ponds or could construct them without too much difficulty. In addition to ponds, Harrell expects to see net pens - nets that aquaculturists could float not only in ponds but also potentially in the open waters of the Bay and its tributaries - and closed systems that recirculate and filter water like giant aquariums.

Both netpens and closed systems have their "pluses and minuses," according to Yonathan Zohar, researcher and aquaculture coordinator at the Center of Marine Biotechnology (COMB) in Baltimore - one of five centers in the University of Maryland Biotechnology Institute. Zohar runs an experimental closed system aquaculture facility in Fells Point, where he delights in growing fish right in the city of Baltimore.

"That's the beauty of closed systems," Zohar says. "You can put them anywhere. We are growing fish in the best water possible," he says.

According to Zohar, water that leaves the aquaculture facility is also "very clean." The system exchanges about 15 percent of the water every week, he says. Suspended solids can be gathered on fine screens and then collected as sludge that can be used as fertilizer on farm fields.

The difficulty with closed systems, Harrell points out, is that they are expensive. "They are capital and technology intensive for the average person," he says. According to Harrell, there are likely to be only a few large businesses interested in sizable closed system operations in Maryland.

That may be true, says Zohar, but he points to examples in other states that are already up and running, like AquaFuture in western Massachusetts. "AquaFuture is the best I've seen," he says.

Western Massachusetts may not seem like fish country, but it is just fine for growing hybrid striped bass, according to Roscoe Perham at AquaFuture. "We're two hours from Boston and four hours from New York," he says. "We can supply live fish to an arc that stretches from Toronto around to somewhere south of Washington, D.C." Mobility is important, he says, since no single market can "absorb" their output of hybrids.

AquaFuture's output amounts to some 1.2 million pounds of hybrid striped bass a year, says Perham. Using giant tanks forty feet long, AquaFuture raises its hybrids in densities of about one half pound per gallon. The closed system allows for control of temperature, water quality and other environmental factors, but there have been some disease problems.

"We have had some disease introduced from fish that come from the wild," he says. Those fish come primarily from fish growers in Arkansas and Texas. According to Perham, AquaFuture would like to spawn fish on site and have complete control of their broodstock. "We are working on closing the life cycle," he says.

At present, researchers and aquaculturists alike generally seek spawning stripers in coastal rivers each spring, stripping them of the eggs and sperm they will use to hatch fry in controlled conditions. The conventional method involves shocking fish with electric probes dangled from an open boat. But like any fishing expedition, the results can be hit or miss. "This was not a good year," Harrell says, referring to his and others' attempts to capture brood stock in the Chesapeake this spring.

To avoid this uncertainty, Zohar and other researchers are developing means to induce spawning in captive stocks. "We want to be like chicken farmers," Zohar says. "Imagine if you were a chicken farmer and you had to go out into the woods and fields and hunt for wild eggs before you could raise your chickens." This, he says, would be ridiculous. "We need to get away from reliance on wild brood stocks."

Closed systems can switch to support other species as well, such as mahi mahi or salmon - by lowering the temperature, for example. "The growers said they were interested in black sea bass," Zohar says, "so we're going to look at that species as well." And flounder could be another fish on the horizon. "With any fish, we have the same needs," says Zohar, "to spawn regularly, and not depend on the wild stocks."

In Open Waters

For most fish growers in Maryland, especially those who do not plan to spring for large closed system operations, growing hybrid striped bass in ponds remains one of the best bets - or, potentially, in netpens, as they do with salmon in Chile, Norway, Scotland and elsewhere.

Reggie Harrell is among those examining the potential for pond culture and netpen culture in Maryland. And while closed systems like those at AquaFuture aim at densities of one-half pound per gallon, Harrell says he wants to aim for three-quarters to one pound per gallon. That, he says, will assure a more stable profit.

Zohar has worked with netpens as well, in Maine. "The water is very cold and stormy, and regulation is tough," he says. "It's hard to get permits."

Getting permits in Maryland for netpen culture could also prove tricky. Right now, according to Webster and Harrell, the state has awarded only two permits, including one for Pintail Point Farm. At Pintail, Sea Grant Extension specialists and the Maryland Department of Natural Resources have undertaken a project to study not only the practicality of raising fish in open water pens, but also to document the effects such intensive culture could have on water quality and on the health of the Bay bottom.

Potential effects on open waters like the Bay are what led Zohar to concentrate on closed systems. "You already have a nutrient problem in the Bay," he says. He feels that closed systems are best, especially in the U.S., where environmental concern is strong. He points out, however, that culturing oysters, with their large filtering capacity, may actually help remove excess nutAents that can lead to Bay-fouling algae blooms.

But exactly what effect netpen culture may have in an ecosystem like the Chesapeake Bay remains largely unknown. "We just don't have data for estuaries like the Chesapeake Bay," Harrell says. The information generated by the Pintail Point project will be extremely valuable for helping us understand what those effects may - or may not - be.

Both Zohar and Harrell are optimistic about the future of aquaculture in this country. There is one way in which Zohar feels that aquaculturists may have chicken farmers beat, and that is "diversification," he says. Chicken (and turkey) farmers have a limited range of species to choose from, but there are many kinds of fish and seafood appropriate for aquaculture. "Diversification of species is essential," says Zohar. "Striped bass will top out, then people will look to other species as well. And," Zohar adds, "though we are using hybrids now, this may not be necessary in the future, once we perfect the genetic selection of pure striped bass."

For Zohar and Harrell, the question is not whether aquaculture will be done, but when and how much. For fish farmers like Tony Mazzaccaro the time, they hope, is now.

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		Contents of this issue	Other Issues

RAISING ROCKFISH: The Promise of Aquaculture in Maryland

Taking a Chance

Choosing Different Paths

In Open Waters

RAISING ROCKFISH:
The Promise of Aquaculture in Maryland