Projected intensification of drought as a result of climate change may reduce the capacity of streams to rear fish, exacerbating the challenge of recovering ESA-listed salmon populations. Without management intervention, some stocks will likely go extinct as stream drying and fragmentation reduce juvenile survival to unsustainable levels. To offset drought-related...
1. Globally, river systems have been extensively modified through alterations in riverscapes and flow regimes, reducing their capacity to absorb geophysical and environmental changes.
2. In western North America and elsewhere, alterations in natural flow regimes and swimways through dams, levees, and floodplain development, work in concert with fire regime,...
Better fisheries management is often given as one justification for research on improving forecasts of fish survival. However, the value gained from expected improvements in forecast skill in terms of achieving management goals is rarely quantified as part of research objectives. Using Monte Carlo simulations of population dynamics, we assessed...
The aims of this study were first, to test the hypothesis that metrics of fish growth and condition relate positively to parasite species richness (S[subscript R]) in a salmonid host; second, to identify whether S[subscript R] differs as a function of host origin; third, to identify whether acquisition of parasites...
The effects of three levels of dissolved oxygen (8, 5 and 3 mg/l)
upon the feeding, growth and bioenergetics of juvenile coho salmon,
Oncorhynchus kisutch (Walbaum), were determined in laboratory
studies. Experiments with individual fish were conducted during the
summer, fall and spring to measure rates of food consumption,
standard...
This research was initiated to investigate the effects of various
parameters on the immune response of juvenile coho salmon to Aeromonas
salmonicida. The antibody response and development of protective
immunity in juvenile coho salmon were followed after a single
intraperitoneal injection of formalin killed A. salmonicida cells emulsified
in Freund's...
Effects of inbreeding coho salmon (Oncorhynchus kisutch) on
survival during early life history, growth, feed efficiency, and
resistance to gas bubble disease were studied. No effect of inbreeding
could be associated with either F=0.25 or F=0.125. Tetraploidy
may help explain the absence of inbreeding depression at these
levels.
Coho salmon smolts (Oncorhynchus kisutch) were transported at low and high densities. (12 and 120 g/L) for short and long periods (4 and 12 h). Because smolts can be transplanted directly to seawater, half of the fish in each treatment were transported to tanks containing seawater and half to tanks...
Immunity in juvenile coho salmon (Oncorhynchus kisutch) was
evaluated after immunization against vibriosis by parenteral, oral or
immersion methods. Relative levels of immunity were determined by
protection of fish from experimental water-borne challenges with
Vibrio anguillarum and by serum agglutination titers. Coho salmon
eggs were exposed to bacterin during artificial...
This study was undertaken to quantitatively evaluate the
relationship between silvering of the skin of juvenile coho
salmon, due to the deposition of the purines guanine and
hypoxanthine, and adaptation to seawater. It was hypothesized
that maximum purine deposition occurs at the time these fish
normally enter seawater, that the...