CONTROL OF FURUNCULOSIS AND ENTERIC REDMOUTH DISEASE IN SEA-RUN ATLANTIC SALMON BROODSTOCK IN THE CONNECTICUT AND MERRIMACK RIVERS

Adult sea-run Atlantic salmon Salmo salar captured and transported to Richard Cronin National Salmon Station (Sunderland, Massachusetts), Na shua National Fish Hatchery (Nashua, New Hampshire), and Whittemore St ate Fish Hatchery (Waterford, Connecticut) during 1986-1992 were treat ed with oxolinic acid and a bacterin. The bacterin was developed again st furunculosis and enteric redmouth disease. Among the 2,552 fish tha t were treated since 1986, 362 died and 65 (18%) of those fish had fur unculosis. Among 206 untreated fish that were maintained as controls, 109 died and 63 (57.8%) had furunculosis. The reduction in mortality c ould not be attributed to either vaccine or antibiotic alone without f urther study. A 3-year study was designed to investigate if adult Atla ntic salmon, undergoing the stress of migration, handling, and spawnin g, could mount a protective humoral immune response. Although the salm on were able to produce an agglutinin response, evidence was not found for production of a protective humoral response by these vaccinated A tlantic salmon.