Aquaculture renovations at Virginia Tech keep program progressive

BLACKSBURG, Va., Dec. 4, 2003 – Recent renovations at Virginia Tech's Aquaculture Center bring to the College of Natural Resources new technology, lab space, and a greater capacity to provide useful information to industry.

The Aquaculture Center has added a premier 24-tank recirculation system that allows blocks of four tanks to operate individually or linked together to form one large system, a feature unique to recirculating aquaculture systems elsewhere. "These connected systems maximize the efficient use of water, an increasingly important natural resource," explains Ewen McLean, director of the Aquaculture Center and professor of fisheries and wildlife sciences.

The systems operate by circulating water from fish holding tanks through a side process unit that converts toxic ammonia present in fish waste to non-toxic nitrate. Protein and particulate materials, including fish scales and uneaten food, are also removed with the possibility for later use to grow worms, which may be used for fish food or bait. In addition, the worms may be used to create a valuable compost. In addition to this micro-sized sewer-treatment plant, UV light is used to disinfect water that returns to the tanks.

"These renovations allow us to increase our productivity and capability," McLean said. With this new capacity, the Aquaculture Center has been able to expand its fish holding abilities, which now also included cobia. This marine fish can grow up to 12 pounds in one year, enabling two harvests each year whereas most fish cultured in the United States only allow one. The center is also exploring the possibilities for raising shrimp in recirculating systems.

Currently, the Aquaculture Center houses a freshwater assortment of tilapia, yellow perch and hybrid striped bass. McLean hopes to add Atlantic sturgeon in the near future. Marine, or saltwater, fish housed at the Aquaculture Center include southern flounder, summer flounder and cobia. Red drum have also been studied at the facility.

"The United States has a $7 billion deficit in seafood imports, second only to oil as a natural resource. With the facility's new upgrades, the Aquaculture Center will be more able to provide leading-edge research findings to industry," McLean said.

The center's renovations extend to the facility's feed room. Here, researchers tailor the fish's intake of proteins, oils, vitamins and minerals as required by each study. According to McLean, the Aquaculture Center produced 1.5 tons of food last year.

Also included in the renovations, which were financed by funds from the College of Natural Resources, an Aspires Grant from Virginia Tech, industry grants, and Virginia Sea Grant monies, are new power lines, lighting systems, water, and air lines. An office for graduate students has also been added, complete with computers, a specialized lab, meeting room-library, and kitchen amenities. Another part of the center now houses a new 72-tank, three-system recirculation unit, which allows researchers to work with smaller fish in smaller numbers. These systems provide the means to test, for example, eight different diets in triplicate.

Completing the first stage of the Aquaculture Center's renovations is a large greenhouse that is used for Ph.D. research in bioresource engineering as well as food science and nutrition. The greenhouse also supports undergraduate programs such as the department of fisheries and wildlife sciences' Principles of Aquaculture class where students use greenhouse space to design and construct their own recirculating systems in which they monitor water quality and culture aquatic animals.

Another lead researcher at the center is Steven Craig, associate professor of fish nutrition. Craig holds a joint appointment with Virginia-Maryland College of Veterinary Medicine and the college's department of fisheries and wildlife sciences. Both McLean and Craig work in close collaboration with Virginia Tech's innovative Commercial Fish and Shellfish Technologies (CFAST) program.

"The facility allows for collaborative work and the integration of programs from several of Virginia Tech's colleges. We have worked in partnership with faculty and students from the colleges of agriculture, architecture, engineering and veterinary medicine, as well as with members of our own college. Another area of growth has been providing tours for local K-5 students," McLean said.

The College of Natural Resources at Virginia Tech consistently ranks among the top five programs of its kind in the nation. Faculty members stress both the technical and human elements of natural resources and instill in students a sense of stewardship and land-use ethics. Areas of studies include environmental resource management, fisheries and wildlife sciences, forestry, geospatial and environmental analysis, natural resource recreation, urban forestry, wood science and forest products, geography, and international development.

Written by Florence Bakke, Public Affairs Intern