MARTINSVILLE, Va. — It doesn’t look like a farm. From the outside it looks like any other manufacturing building in an industrial park. Step inside, however, into the humid office area and it is obvious something different is going on.
Blue Ridge Aquaculture (BRA) in Martinsville, is the world’s largest indoor fisheries. In its 100,000-square-foot facility on less than two and a half acres of land, BRA raises more than 4 million pounds of protein every year in the form of tilapia. In contrast, using the National Cattlemen’s Beef Association statistics, less than 10,000 pounds of beef could be produced on the same acreage and not in an industrial park.
Tilapia is a valuable source of protein, and it is growing in popularity. Demand for the fish quadrupled in the four years leading to 2007 and has continued to grow. The National Marine Fisheries Service ranks tilapia as the fifth most popular seafood in the United States.
BRA uses an indoor recirculating aquaculture system to grow tilapia to 1.5 pounds at harvest, with a stocking density of 1.5 gallons of water per fish. Unlike other large-scale animal production, which may require the prophylactic use of antibiotics and growth hormones to overcome stress caused by high animal densities, the tilapia actually benefit. Being packed together makes the fish less territorial and aggressive and improves health and growth rates.
“The fish grow better that way,” said Jim Franklin III, BRA vice president. “These fish are bred for this facility. We could increase the density. The density of the fish is not an issue; it’s water condition.”
BRA maintains its own brood stock on site, harvesting 400,000 to 500,000 eggs every week. Over time the fish have adapted to thrive in the conditions provided by BRA. When the eggs hatch, the fry are moved through a series of nursery tanks before ending up in one of the facility’s 42 grow-out tanks. It takes nine months to raise the tilapia to market size. BRA has a feed conversion ratio of 1.3 to 1.5, slightly lower than the industry average. There are many way to figure feed conversion ratios; BRA measures everything that comes into the farm against the product that goes out.
Each grow-out tank holds 35,000 gallons of water, and this is where the recirculating aquaculture system shines. Open system aquaculture, including ponds, net-pens and flow-through, is often criticized by environmental groups for its water consumption as well as the effluent that is discharged into the watershed. At BRA, 85 percent of the water is returned to the system with no environmental discharge.
Filtration systems are continuously operating, removing solids from the water. Beneficial bacteria convert ammonia into nitrogen-rich water. The carbon dioxide is removed and pure oxygen is injected into the water before it is returned to the fish.
“Every time you feed a fish, you’re going to have waste,” said Franklin. “When you have a large amount of waste it can be a benefit or a nuisance.”
BRA is experimenting with a variety of ways to use their waste streams. Aquaponics has been tried on a small scale, using the nitrogen rich water to grow tomatoes, peppers, herbs and lettuce. The bio-solids can be used to produce energy in a methane digester. Franklin also sees an opportunity to raise algae as a feedstock for biofuels.
“It’s good business to be environmentally conscious,” said Franklin. “Even more than that, we can use the waste for another revenue (stream).”
Upfront costs challenge some of BRA’s innovations, but the recirculating aquaculture system has more than justified the initial costs. BRA has been operating since 1993 and the lower operating costs offset the upfront costs.
“We’ve realized the costs over and over,” said Franklin.
Recirculating aquaculture’s impact extends beyond environmental concerns. Over 80 percent of the seafood consumed in the United States is imported. It is by far the most imported food consumed in the country. By contrast, about 10 percent of the red meat U.S. consumers buy is imported.
“It (seafood) is very subject to problems of contamination,” said Franklin. “Less than 5 percent of the seafood coming in is tested.”
While seafood is generally regarded as a healthy, low-fat protein, contaminants like mercury, antibiotics and hormones can offset the benefits in both imported farm-raised and wild-caught seafood.
“Wild caught is better than imported (seafood),” said Franklin. “If you put junk in, you get a low-quality product out. When products coming in have antibiotics and malachite green in them, you know the systems are sick.”
One of the benefits of BRA’s recirculating aquaculture system is the tight control they are able to maintain over the entire life of the fish.
“The only thing that goes into the tanks is what we put in,” said Franklin.
It obviously works for the fish. BRA has a less than 2 percent mortality rate. The industry standard is 10 percent.
“Balance is everything,” said Franklin. “A well-balanced system keeps our costs low.”
It also keeps the fish healthy. Blue Ridge Aquaculture sells 10,000 to 20,000 pounds of live fish every day to distributors in New York, Boston, Washington D.C., and Toronto. They support about 40 employees at both their Martinsville site and in research and development. Subsidiaries include Rolling Rivers Live Haul, the Virginia Shrimp Farm and Virginia Cobia Farms, a joint venture with MariCal.
For more information, visit www.blueridgeaquaculture.com.