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Geology topics

L.A. Ford

Publications and source records attributed to L.A. Ford.

12 recordsLinked to original sources
USGS1998

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), Nashua National Fish Hatchery (Nashua, New Hampshire), and Whittemore State Fish Hatchery (Waterford, Connecticut) during 1986–1992 were treated with oxolinic acid and a bacterin. The bacterin was developed against furunculosis and enteric redmouth disease. Among the 2,552 fish that were treated since 1986, 362 died and 65 (18%) of those fish had furunculosis. Among 206 untreated fish that were maintained as controls, 109 died and 63 (57.8%) had furunculosis. The reduction in mortality could not be attributed to either vaccine or antibiotic alone without further study. A 3‐year study was designed to investigate if adult Atlantic salmon, undergoing the stress of migration, handling, and spawning, could mount a protective humoral immune response. Although the salmon were able to produce an agglutinin response, evidence was not found for production of a protective humoral response by these vaccinated Atlantic salmon.

Progressive Fish-Culturist↗
USGS1994

Isolation of Aeromonas salmonicida from paddlefish, Polyodon spathula

Aeromonas salmonicida was isolated from paddlefish ( Polyodon spathula ) mortalities collected during an epizootic of furunculosis at the Spring River State Hatchery, Arkansas (USA), in 1992. Isolates of the bacterium were obtained from culture of gill and kidney tissue. This is the first epizootic of bacterial etiology to be reported in paddlefish.

Arkansas↗
USGS1994

Relationship between resistance of salmonids to furunculosis and recovery of Aeromonas salmonicida from external mucus

Fish were sampled at the Ed Weed State Fish Hatchery (South Hero, Vermont, USA) in September 1992. Aeromonas salmonicida was common, with concentrations as high as 10 5 to 10 7 colony-forming units per gram of mucus, and readily recovered from most mucus samples obtained from furunculosis-sensitive populations of brook trout ( Salvelinus fontinalis ), lake trout ( Salvelinus namaycush ), and Atlantic salmon (Salmo salar) . The pathogen was the predominant microorganism and accounted for greater than 85% of the total number of bacteria isolated from the mucus of these fish. By comparison, A. salmonicida was recovered only from two rainbow trout ( Oncorhynchus mykiss ), and bacterial frequencies did not exceed 10 3 colony-forming units per gram of mucus. The pathogen was not recovered from the mucus of steelhead ( O. mykiss ) or Rome brown trout ( Salmo trutta ) selectively bred for resistance to furunculosis, even though there was widespread contagion throughout the hatchery and fish were cultured on a common, unprotected water supply.

Journal of Wildlife Diseases↗
USGS1992

Detection of Aeromonas salmonicida the mucus of salmonid fishes

Mucus of salmonids was evaluated as a source for nonlethal detection of the pathogen Aeromonas salmonicida in fish. The bacterium was readily isolated from mucus on dilution plates when Coomassie Brilliant Blue agar was the primary plating medium. Kidney samples from the fish that served as sources of mucus were similarly processed. Infection was detected in 56% of mucus samples from lake trout Salvelinus namaycush that were undergoing an epizootic of furunculosis, but only 6% of the kidneys from these fish were positive for the pathogen. Only 1% of asymptomatic brown trout Salmo trutta sampled at another fish hatchery had A. salmonicida in their mucus, and none had a kidney infection. Combined results from the examination of two pools of Atlantic salmon Salmo salar reared at a third hatchery indicated that 37% of these fish had mucus infections caused by A. salmonicida , but only 4% of the kidneys were infected.

Journal of Aquatic Animal Health↗