Spring Chinook salmon, Oncorhynchus tshawytscha, are transported above dams in the Willamette River to provide access to blocked spawning habitat. However, 30-95% of these transplants may die before spawning in some years. To varying degrees, salmon in other tributaries--both blocked and unblocked--have similar prespawn mortality (PSM). Our study determined if...
Histology is often underutilized in aquatic animal disease screening and diagnostics. The agreement between histological classifications of infection and results using diagnostic testing from the American Fisheries Society's Blue Book was conducted with 4 common salmon pathogens: Aeromonas salmonicida, Renibacterium salmoninarum, Ceratomyxa shasta, and Nanophyetus salmincola. Adult Chinook salmon (Oncorhynchus...
Spring Chinook Salmon Oncorhynchus tshawytscha are transported above dams in the Willamette River to provide access to blocked spawning habitat. However, 30–95% of these transplants may die before spawning in some years. To varying degrees, salmon in other tributaries—both blocked and unblocked—have similar prespawn mortality (PSM) rates. Our study determined...
Adult Chinook salmon (Oncorhynchus tshawytscha) migrate from salt water to freshwater streams to spawn. Immune responses in migrating adult salmon are thought to diminish in the run up to spawning, though the exact mechanisms for diminished immune responses remain unknown. Here we examine both adaptive and innate immune responses as...
Pre-spawning mortality (PSM) presents a major problem for population recovery of spring Chinook salmon (Oncorhynchus tshawytscha) in the Willamette River basin. In certain reaches and years, PSM has exceeded 90%. Histology has been used as the primary diagnostic method to investigate PSM in the Chinook Salmon, and a collection of...
Stocks of salmon are declining in the Pacific Northwest. Based on region-wide studies that list and categorize the status of salmon stocks (Nehlsen et al., 1991; Huntington et al., 1994; and Nawa, 1995), I analyze the watersheds where stocks of salmon spawn for several anthropogenic variables, most of which are...
Using a probability-based neighborhood sample of urban African American youth and a sample of their close friends (N = 202), we conducted a one-year longitudinal study to examine key questions regarding sexual and drug using norms. The results provide validation of social norms governing sexual behavior, condom use, and substance...
Conceptually, the dynamics of wood in streams can be viewed in terms of input and in-channel processes. Input processes are associated with both the riparian (tree fall, bank cutting, windthrow) and upslope forests (mass failures). In-channel processes include log breakage, movement, and decomposition. A mechanistic view of these processes is...
Headwater streams and wetlands are integral components of watersheds that are critical for biodiversity, fisheries, ecosystem functions, natural resource-based economies, and human society and culture. These and other ecosystem services provided by intact and clean headwater streams and wetlands are critical for a sustainable future. Loss of legal protections for...
The Integrated Landscape Assessment Project (ILAP) was a multi-year effort to produce information, maps, and models to help land managers, policy-makers, and others conduct mid- to broad-scale (e.g., watersheds to states and larger areas) prioritization of land management actions, perform landscape assessments, and estimate cumulative effects of management actions for...