Salmon hatcheries have been utilized throughout the Pacific Northwest for many decades to mitigate losses, supplement natural spawning populations, and to provide tribal, sport and commercial fishing opportunities. Currently, there is substantial debate on their efficacy and the potential threats hatchery-reared salmonids pose to natural populations. These concerns have lead...
One of the biggest hurdles for a juvenile salmonid (Oncorhynchus mykiss) is migrating downstream from freshwater spawning grounds to the ocean. Juveniles from wild broodstock were reared from the South Santiam River for more than 1 year at the Oregon Hatchery Research Center (OHRC) in Alsea, OR. The fish were...
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David L.G. Noakes
One of the biggest hurdles for a juvenile salmonid (Oncorhynchus mykiss) is
Numerous populations of salmon and trout undergo extensive migrations, migrating from freshwater to the sea and throughout ocean basins. Years later they return to their natal streams with remarkable accuracy and precision. The outward migration is accomplished without the benefit of following experienced migrants or prior individual experience. Evidence suggests...
Understanding the origin and nature of intra specific biodiversity enables us to better conserve and manage animal populations. Biological diversity is seen at different scales and for different traits such as behavior, morphology, physiology, and life history. Behavior is especially important since behavioral changes are believed to precede changes in...
I conducted a study to identify potential spawning habitat for anadromous salmonids above a 60-year-old hydropower dam in the headwaters of the North Umpqua River in Oregon. Like many other historical salmonid-bearing rivers, little documentation exists for anadromous fish presence above potential natural obstacles upstream of Soda Springs Dam. My...
Hatcheries whose purpose is to provide for a recreational fishery must minimize impacts on wild fishes. Management to reduce hatchery and wild interactions is especially important on river systems that contain Endangered Species Act (ESA) listed species. I examined adult hatchery summer steelhead, Oncorhynchus mykiss, behavior, current management and a...
Anadromous salmonid populations in the Pacific Northwest have declined over the past 150 years. In 1999, wild spring Chinook salmon (Oncorhynchus tshawytscha) were federally listed as threatened within the Willamette Basin, OR. Currently, practices to restore wild populations in the upper Willamette Basin involve trapping wild adults at the base...
A number of steelhead (Oncorhynchus mykiss) populations are at risk throughout Oregon, including five populations that are federally listed as threatened or endangered. However, little is known about behavior and survival of these fish as they transition from freshwater to seawater. We investigated whether estuarine survival varies on a temporal...
The ability to non-destructively assess fish condition and subsequently track fish behavior and survival can be vital in understanding natural and anthropogenic stressors and sources of mortality, especially in populations of fish listed as threatened or endangered. I investigated the use of a quick, non-lethal, external examination technique to assess...
Rapid adaptation and evolution based on standing genetic variation and novel mutations is likely to be one of the primary ways that species survive the widespread anthropogenic environmental changes expected of the next century. Three-spined stickleback (Gasterosteus aculeatus) are known to be capable of extremely quick, dramatic adaptation in response...