| |
|
SPRING/SUMMER 1999 ARCHIVE Clemson Recognized as Leader in Orthopaedic Bioengineering Clemson University Mathematics: The Next National Champion? Clemson University, Southeast Leader in Invention Income Where the Rubber Meets the Roador Off-Road Clemson Students Win NSF Awards Professor Receives National Math Award Thomas Green Clemson Academy Welcomes Three New Members Dow Chemical Pledges More Than Half-Million Dollars to Film-Related Research Catfish: Improving Environment and Economy ACES Reunion and BBQ is Coming!  |
Catfish: Improving Environment and Economy It's hard to call a channel cat beautiful, but the fact that these fish are loved can't be denied. Baked, fried or stewed, they're found on menus all over the country.
In conventional ponds, fish culture and waste management interact within an essentially uncontrollable, "static" body of water. Consequently, the two functions are difficult to manage optimally. The Aquaculture Research Initiative at Clemson University developed an approach that physically separates the two processes to allow for operator-controlled, efficient operation. The application is known as the Partitioned Aquaculture System (PAS). PAS transforms the traditional earthen pond into linked processes where fish production and waste treatment are optimized through computer monitoring and regulation. The system couples high-density raceway culture of fish with paddle-wheel-driven, high-rate algal growth basins. The algae controls organic and nitrogenous wastes, allowing 100 percent reuse of culture water in self-contained, self-oxygenating units. This approach allows increased fish production on less land with little or no environmental impact because the wastes are treated internally. The fish culture is also enhanced because the PAS affords better inventory controls, health management, predator regulation, feeding and harvesting, which all serve to lower costs. Because of its modular nature, the PAS can be scaled to meet a wide range of production goals. It is designed to use less water than conventional pond systems, which expands its application to sites with restricted water resources. Limited environmental impact of the system contributes to its operation under more stringent discharge regulations. Development of the system called for a team approach with each member providing special skills, insights, abilities and training. D.E. Brune is the process and environmental engineer; J.A. Collier, the mechanical design engineer; T.E. Schwedler, the fish culturist and health specialist; A.G. Eversole, the shellfish biologist; and Michael Hammig, the agricultural economist. Since 1995, research was conducted on six replicate PAS units, approximately one-third of an acre in size. To date, the systems have yielded production levels that exceed conventional technologies by almost 400 percent, while improving feed efficiency by 25 percent. Well-managed farms generally produce 4,000-5,000 pounds per acre. The PAS units have produced 15,000-17,000 pounds per acre.
While this performance has generated considerable interest from both current fish growers and prospective farmers, the economic feasibility of a commercial-scale system has remained uncertain -- until now. A two-acre commercial-scale system designed to produce 20,000 pounds per acre per year has been constructed and should produce the first crop of fish by this fall. The system should provide the engineering, production and economic performance data necessary to confidently present this new technology to the agriculture community. |
[an error occurred while processing this directive]
Pond-reared catfish account for
nearly half of the total U.S. aquaculture production. Over the
last 30 years, this industry has grown from $100 million annually
to $1 billion according to 1997 USDA figures. This market expansion
has led to scientific investigation to find ways to improve methods
and practices in both the environmental and economic arenas.