by Karl H. Kazaks
RIDGEWAY, VA — Blue Ridge Aquaculture (BRA) is already the world’s largest sustainable indoor fishery — yet it’s poised to get even bigger.
BRA is looking to add a facility somewhere in the western U.S. to reach markets in that part of the country in addition to the eastern markets it already serves. What’s more, the company is more than five years into a research program to develop commercial indoor shrimp production, which would give it an extra product to sell along with the live tilapia it currently produces.
BRA was originally known as Blue Ridge Fisheries, and grew catfish, producing Grade A catfish filets. At the time, the company was buying rather than hatching fish to raise. One shipment of catfish came mixed with tilapia.
“The tilapia did better,” said Darin Prillaman, operations manager. “They’re more domesticated. They’ve been farmed for millennia,” including by Hebrews and Egyptians 2,000 and 3,000 years ago.
So when the company reorganized as Blue Ridge Aquaculture in 1993, they decided to switch their focus from catfish filets to live tilapia.
“Tilapia are a more natural fish for high density production,” Prillaman said.
And he means it when he says high density: at harvest the density of the grow tanks is such that there will be a one and three-quarter pound tilapia per every gallon of water, in tanks holding up to 50,000 fish a piece.
Whereas before the facility could produce 1.5 million pounds of catfish per year, now the same facility can grow 4.3 million pounds of tilapia per year.
The technology behind BRA’s production facility is part of what makes the operation sustainable.
The indoor, low-light (to prevent algae growth) facility recirculates 2.6 million gallons of water in 42 concrete grow tanks, replacing just 15 percent of that water each day. Many fisheries are designed to have a continuous supply of new fresh water. The water at BRA can be reused because the facility is outfitted with an array of RBCs (rotating biological contactors).
RBCs were created to provide biological treatment for wastewater treatment plants. The units, which look like large cylindrical filters, slowly rotate in an area separate from the grow tanks. As they come into contact with the facility’s water supply, microbes which populate throughout the RBCs help decontaminate the water. The water BRA does release is treated at a local municipal plant.
In addition to keeping the water it uses to raise its tilapia clean, BRA also has to keep it oxygenated, to allow its fish to breathe. BRA oxygenates and ozonates its water by pumping it down into the ground 33 feet, where at the extra atmosphere of pressure oxygen more easily dissolves into the water.
“The secret to being intensive is to have plenty of oxygen for them to breathe,” Prillaman said.
Blue Ridge Aquaculture is sustainable not only for its water management strategy but also because of its nutritional planning. They use only one pound of fishmeal per eight pounds of tilapia grown — much lower than in other fisheries like salmon. The bulk of the 20,000 pounds of feed they use each day is soybean meal, wheat, rice, and corn.
“For a lot of fisheries, fish meal is largest ingredient,” Prillaman said. BRA, he added, can even grow tilapia with zero fishmeal if market conditions demand.
Also, the fact that BRA is economically viable — it has been able to survive for two decades in an industry where attrition is regular — is part of what makes it sustainable.
The genetic pool at BRA has been closed since 1997. BRA operates its own nursery and hatchery. Each week it collects some 250,000 eggs, about 2,000 per female. Brood stock is rotated about every six months.
It takes about nine months to raise tilapia to harvestable size. In the first few weeks of life, they are fed 20 percent of their body weight. But because they are so small at that stage, the quantity fed is relatively small. Over the life of a fish, it takes only 1.5 or 1.6 pounds of feed to make one pound of tilapia. The amount of protein in the feeds starts at 50 percent for young fry and is stepped down as the fish age, to 45 percent, 40 percent, and finally 36 percent.
As part of BRA’s genetic program, Prillaman and his team have selected the fastest growing, calmest, whitest fish.
“No one else has this color fish,” Prillaman said. Tilapia can also appear gray.
The white color of their fish is highly prized in the markets BRA serves. They sell their live fish primarily to Asian markets in the Northeast — New York, Toronto, Boston, Montreal, and Philadelphia. A truck goes to New York every two days.
When the fish are harvested, they are screened to make sure they are the right size. Fish that aren’t big enough are kept at the facility until they get bigger.
Counting truck drivers, Blue Ridge Aquaculture has 35 employees. Someone is on hand at the facility around the clock. “If a pump goes out,” Prillaman says, and oxygen levels in water start to decrease, “you’ve only got two or three minutes before you risk mortality.”
Jim Franklin, the company’s vice president, is excited at the prospect of growing and marketing shrimp.
“The market is right,” he said. “The demand is definitely there — and we’ve got the management. We need to develop the technology side, how to cultivate shrimp that grow well in an indoor system.”
The company has been undertaking large-scale research and development into Pacific white shrimp production since early 2008. “We have to learn their physiological and nutritional requirements,” Franklin said.
Once that progress reaches a point where commercial production is viable, BRA will reach another milestone — not just the world’s largest sustainable indoor fisheries, but also the largest facility of its type able to produce two different species of seafood.
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