Anthropogenic effects on watersheds are important in explaining the decline of Pacific Northwest salmon stocks. Associations were tested between thirteen anthropogenic variables in 202 watersheds in Washington, Oregon, Idaho and California and the stock status of summer, spring and fall Chinook Onchorhynchus tshawytsha, coho O. kisutch, and winter steelhead O. mykiss. Summer Chinook had the hig...

During February 2000, two trout farms, situated in NW Greece, reported unusually high losses of hatchery reared rainbow trout fry and fingerlings. Live fish and chilled samples of diseased whole fish were delivered to a veterinary laboratory in Athens for diagnostic investigation. Infections with the fungus Ichthyophonus hoferi as well as the Gram negative bacterium Aeromonas hydrophila were di...

To reduce mortality in the by-catch of commercial salmon fisheries, techniques are being explored to revive fish before live release and improve survival. By measuring blood and muscle variables, we demonstrated that capture of coho salmon (Oncorhynchus kisutch) by commercial trolling methods resulted in severe exhaustion and stress, e.g., muscle lactate reached 46.1 mmol·kg–1 while muscle phos...

Many Appalachian streams historically dominated by Brook Trout Salvelinus fontinalis have experienced shifts towards fish communities dominated by Rainbow Trout Onchorhynchus mykiss. We used empirical estimates of biomass and secondary production of trout conspecifics to evaluate species success under varied thermal regimes. Trout populations were sampled in 13 Appalachian streams from Maryland...

The kinetics of pyruvate reduction by LDH isozymes in the presence of NADH is said to be an ordered bisubstrate reaction characterized by Michaelian concentration dependence (Borgmann et al., 1975). If the reaction is ordered, no cooperativity can occur between the two substrates (NADH and pyruvate) (Neet, 1995). Experiments with fish LDH showed, however, that this enzyme might display two type...

Oncorhynchus mykiss have a diverse array of life history types, and understanding the relationship among types is important for management of the species. Patterns of gene flow between sympatric freshwater resident O. mykiss, commonly known as rainbow trout, and anadromous O. mykiss, commonly known as steelhead, populations are complex and poorly understood. In this study, we attempt to determi...