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P.V. Haner

Publications and source records attributed to P.V. Haner.

24 records · Page 2Linked to original sources
USGS1996

Incidence of Renibacterium salmoninarum infections in juvenile hatchery spring chinook salmon in the Columbia and Snake Rivers

From 1988 through 1992, we assessed the prevalence (frequency of occurrence) and severity (degree of infection) of Renibacterium salmoninarum (RS) among fish in marked groups of Columbia River basin and Snake River basin hatchery spring chinook salmon Oncorhynchus tshawytscha before release and during their seaward migration. During the study, prevalence of RS infection decreased (from >90% to <65%) in six of the eight hatchery groups. We attributed this decrease to changes in hatchery practices that reduced vertical and horizontal transmission. Fish from Snake River hatcheries had a higher prevalence of infection when sampled at dams (mean >90%) than in the hatchery (mean <70%), but there were no differences in similar comparisons of Columbia River fish. Although prevalence and severity of RS infection were not correlated in the groups studied, it appears that fish from the Snake River were more severely infected than those from the Columbia River. Some groups of Snake River fish had higher severity of infection at dams than in the hatchery, but infection in fish from Columbia River hatcheries did not change. These differences between Snake River and Columbia River fish might have resulted from differences in river conditions and the distances from hatcheries to dams.

Oregon, Washington↗
USGS1990

Assessment of smolt condition for travel time analysis. Annual report 1989

The Water Budget is a volume of water used to enhance environmental conditions (flows) in the Columbia and Snake rivers for juvenile salmonids during their seaward migration. To manage the Water Budget, the Fish Passage Center estimates travel times of juvenile salmonids in index reaches of the main-stem rivers, using information on river flows and the migrational characteristics of the juvenile salmonids. This study was initiated to provide physiological information on the juvenile salmonids used for these travel time estimates. The physiological ability to respond to stressors was evaluated by measuring concentrations of plasma cortisol, glucose, and chlorides before and after a 30-s handling-stress challenge test. As in 1988, most groups responded satisfactorily to the challenge. The scope for response was compromised among two groups of juvenile chinook salmon that were trucked to release sites and in steelhead from one hatchery after unusual marking and transportation protocols were used. The development of smoltification was assessed by measuring gill Na+-K+ ATPase activity and plasma thyroxine concentrations. Mean ATPase activities of marked hatchery groups of juvenile chinook salmon and steelhead changed little during the month before release and rose sharply for about the first 20 d of the migration after release. Mean plasma thyroxine was highest during the first 20 d after release. Mean gill ATPase activity of spring chinook salmon from the migration-at-large peaked at about the 90th percentile of passage at Rock Island and Lower Granite dams, and at about the 50th percentile of passage at McNary Dam. Mean gill ATPase activity of wild steelhead was higher than gill ATPase activity of hatchery steelhead at Rock Island Dam, the Snake River Trap, and Lower Granite Dam, but not at McNary Dam. This was attributed to a time-dependent relationship between increases in ATPase activity and the number of days fish migrated before recapture. Correlations of gill ATPase activity and/or plasma thyroxine concentrations with condition factor, morphology, or skin guanine concentration may be useful as non-lethal indicators of smoltification for inclusion in a smoltification index. Prevalence of bacterial kidney disease in spring chinook salmon was generally higher than in 1988, ranging from 81-100% using an enzyme-linked immunosorbent assay (ELISA) method. Fish from Snake River hatcheries had more severe infections than those from mid-Columbia hatcheries. The percentage of fish with severe infections was lower at two downstream dams than at the Snake River hatcheries of origin, suggesting a bias in dam collection facilities or that these fish ceased to migrate, either of which could lead to biases in travel time estimates.

Report↗