In the strictest sense, researchers are growing fish at a new facility at the College of Agriculture and Life Sciences Lake Wheeler Road Field Laboratory, but what they're really doing is trying to spawn an industry.
Working with Carolina Power & Light and the Electric Power Research Institute, the College has developed a project designed to demonstrate the feasibility of aquaculture, or fish farming, in Piedmont North Carolina. The Electric Power Research Institute is a nonprofit research organization to which many utilities belong.
At the heart of the project is a 4,000-square-foot metal building named the CP&L Fish Barn. The building is located on a 4 ½-acre site within the Lake Wheeler Road Field Laboratory, where College and power company officials gathered in mid-October to dedicate and officially open the facility.
CP&L and the Electric Power Research Institute provided $250,000 to build the CP&L Fish Barn. CP&L will operate the facility with technical assistance from N.C. State. The site has been leased to CP&L for the project s duration. The facility is to be donated to North Carolina State University at the conclusion of the demonstration. The project is designed to last at least three years.
While aquaculture appears to hold consider economic potential for North Carolina, it is also the kind of industry that power companies like because the power demand for aquaculture operations is usually fairly constant, said Dr. Alex Hobbs, CP&L project engineer. High or low spikes of power usage are unusual.
Hobbs and Dr. Tom Losordo, a North Carolina Cooperative Extension Service aquaculture specialist, oversee day-to-day operation of the CP&L Fish Barn. Losordo has been experimenting since 1990 at a similar but smaller facility with technology designed to make Piedmont aquaculture feasible.
What Hobbs and Losordo learn about the dos and don'ts of this kind of aquaculture will be used to produce a sort of owner's manual, a blueprint that would-be fish farmers can follow to get into the business.
The CP&L-N.C. State partnership has already paid dividends. The water in which fish are raised must be relatively warm, about 85 degrees F. Hobbs has modified a heat pump to pull heat out of the air in the building and use it to warm the water. The water stays the temperature that fish like, while the building, which can become quite warm and humid, is cooled to a temperature and humidity more to the liking of the people who work there.
Fish farming has not flourished in the Piedmont because the abundant water supplies usually needed to raise fish are typically unavailable. The CP&L Fish Barn gets around this problem by recirculating the water in which fish are raised.
Water for the CP&L Fish Barn is provided by a well that supplies approximately 10 gallons per minute, which Losordo said is typical of Piedmont wells. Water flows through various filters that remove fish waste and ammonia before returning to the tanks in which fish are raised. The water must also be oxygenated.
Prolonged failure of any of this filtering or recirculating equipment could result in the loss of the fish in the tanks. Water quality is monitored by a computer, programmed to notify facility personnel, who all wear pagers, should any of the equipment fail.
The facility contains six tanks. Two are quarantine tanks, which are isolated from the remaining four. In an effort to keep disease out of the facility, fingerlings go first to one of these quarantine tanks, then the other, before finally being moved to one of the four 15,000-gallon tanks in the barn's main area. All the tanks are circular and use Norwegian technology that Losordo has refined to collect fish waste at the center of the tank.
While water is recycled, the same water cannot be used forever. The system uses and loses about 5,000 gallons of water per day, Losordo said. The water the system loses is diverted first to a combination filtering-composting unit, then to a nearby pond. Waste captured in the filtering-composting facility is composted to create a dry fertilizer. While it may contain more nutrients, water entering the pond should be as clean as when it first entered the barn. The nutrients in the water may fuel the growth of algae in the pond, but Losordo said the pond will be stocked with fish that eat algae.
While it should be possible to grow a number of different kinds of fish at the facility, the first crop is Tilapia, a mild-tasting fish that is particularly hardy and seems well-suited to aquaculture. Plans call for approximately 11,500 pounds of fish to be harvested every six weeks. The facility should produce about 130,000 pounds of Tilapia annually.
Losordo said fish from the barn will be sold live to wholesale markets in the Northeast, perhaps in New York City or Philadelphia.