TWENTY-FOURTH ANNUAL EASTERN FISH HEALTH WORKSHOP Royal Pavilion Resort, Atlantic Beach, NC MARCH 9-11, 1999 Fish Health Status Report For Virginia's Emerging Aquaculture Industry: 1993-1998 David Crosby Cooperative Extension, Virginia State University, Petersburg, VA 23806 Fish health problems in Virginia's emerging aquaculture industry vary with producer expertise, culture systems, and species. Since 1993, the number of cases presented to Virginia State University Fish Health Diagnostic Laboratory has fluctuated annually, peaking in 1995 with 73 cases and dropping to 28-30 cases per year thereafter. The casework has shifted from catfish and hybrid striped bass in production ponds and cages to tilapia inspections from recirculating systems. In 1997 and 1998, 50 percent of the casework has involved recirculating systems while from 1993 to 1996 it constituted 20 percent to 27 percent of the cases. Other species submitted to the laboratory include: ornamentals (goldfish and koi), eels, rainbow trout, summer flounder, American shad, and centrarchids. No single disease group (parasite, bacteria, fungus, and virus) has dominated as being a disease problem for fish producers in Virginia. However, parasitic problems are the main cause of disease outbreaks in cages and recirculating systems. Parasites constituted about 30 percent to 40 percent of casework submissions from 1993 to 1998. Few cases of Proliferative gill disease have been confirmed from pond reared catfish in Virginia. Typical parasitic problems have included Trichodina (common in caged reared fish), Ich, and Ambiphrya. Ichthyobodo has been identified as a commonly found parasite on the skin of fish from recirculating systems. Bacteria problems include Aeromonas hydrophila complex, Pseudomonas sp., Edwardsiella tarda, E. ictaluri and Streptococcus sp. Over the last two years, emphasis on controlling disease outbreaks has changed to preventing disease outbreaks. There has been a significant increase in requests for fish examinations for early detection of pathogens such as Streptococcus in recirculating systems. Return to 24th Annual Eastern Fish Health Workshop Return to Leetown Science Center Home Page