PAUL RENO - RESEARCH FOCUS 2000

Dr. Reno and his team work on the effects of infectious diseases on finfish and shellfish populations. Research is integrated with the Department of Microbiology, OSU; the University of Idaho; Oregon Department of Fish and Wildife; the Washington Department of Fish and Wildlife; the Nevada Department of Conservation and Natural Resources; the California Department of Fish and Game; and other agencies throughout the West. Particular areas of research are:

-- Diseases of finfish: They have performed laboratory experiments to assess the factors involved in the initial dissemination of two important fish pathogens; Aeromonas salmonicida, the agent of furunculosis in salmon and ornamental fishes, and infectious hematopoietic necrosis virus, the agent of IHN in salmon and trout. They determined the threshold (minimum) density needed to initiate disease and mortality in chinook salmon and rainbow trout. This can be used in hatcheries to disperse fish to low enough densities to prevent epidemics and in determining the potential effects of pathogens on populations of wild fishes. This could have significant economic benefits if it alleviated the direct loss of fish or reduced the use of antibiotics to treat bacterial disease of fishes.

-- Modeling of diseases: They have begun to construct models to estimate the risk of causing diseases in wild populations of fish by the introduction of a single infected individual to a susceptible population. These have been drawn up around rivers in northeastern Oregon and adjacent Nevada for whirling disease of salmonids. The use of risk assessment models of disease will help in determining where and if potentially infected fish can be released. The economic benefits of this project are not yet estimated, but its influence on distribution of fish could be considerable.

-- Inactivating Vibrio parahemolyticus: They have carried out experiments with Dr. Michael Morrissey in Astoria on the ability of high hydrostatic pressure to inactivate the agent of human shellfish poisoning, Vibrio parahemolyticus. They found that at pressures of 45,000 psi the bacteria could be completely eliminated from oysters which had been exposed to the bacteria by bath immersion. Counts were reduced from greater than 10,000 per gram of tissue to undetectable levels by using this method.

-- Whirling disease: They have begun experiments designed to determine what the effects of transfer to seawater have on the progress of whirling disease in chinook salmon and steelhead. The fish are being held in a specially designed quarantine facility to prevent the potential dissemination of the spores to the outside. Fish will be transferred to seawater within the month.