Small low-head diversion dams are capable of removing much of the flow of a river, often resulting in increased water temperatures and habitat loss. Warmer temperatures have been shown to accelerate aquatic invertebrate growth and development, and discharge reductions can reduce instream habitat, suggesting that water withdrawals may alter both...
Forest soils contain a substantial portion of global terrestrial carbon stores. Forest management can influence the soil carbon pool and how soil organic matter functions. The long-term productivity of forests is an ongoing goal where land managers utilize biomass and timber. A site-specific understanding of intensively managed forests can ensure...
Summer mortality of farmed Pacific oysters causes financial losses for shellfish growers, and selective breeding to improve survival of offspring is a promising way to reduce losses. This dissertation has two objectives to assist the development of tools for use in selective breeding programs.
Objective 1: Identify candidate genes for...
Observations of the Oregon coast’s physical oceanography over the last few decades have revealed falling dissolved oxygen levels associated with seasonal upwelling, as well as rising water temperatures. In extreme cases, these changes have been associated with die-offs, redistribution, and decreased abundance and diversity of benthic fish and invertebrates. Many...
Pacific salmon (Oncorhynchus spp.) face numerous challenges associated with climate change. Most research has emphasized the potential effects of elevated summer water temperatures; however, climatic changes are also projected to significantly alter incubation and rearing habitats during the late autumn, winter, and spring months ("the incubation period"). Along the southern...
I evaluated hypotheses related to growth as a driver of depth use and diel vertical migration by bull trout (Salvelinus confluentus) in a thermally stratified reservoir. I applied a bioenergetic model to evaluate growth of bull trout in relation to potential patterns of diel depth use by bull trout in...
Pacific lamprey, Entosphenus tridentatus, have shown recent and rapid declines in abundance. These anadromous fish return to streams where they mature, spawn and die. It has been inferred that Pacific lamprey enter freshwater and reside for ~ 1 year before spawning. This long exposure to the freshwater environment may affect...
All streams in Oregon that are inhabited by salmon and trout have a statemandated
water temperature standard. However, temperatures of many streams,
especially during summer months, exceed the seven-day average maximum
temperature parameter (200 C for redband trout inhabited streams) accepted by the
Oregon Department of Environmental Quality. To date,...
The effect of anthropogenic disturbance on river systems is gaining attention, and concerns about the state of freshwater natural resources are increasing globally, as are efforts to restore habitat that has been degraded by disturbance. In rivers, non-point source pollution affects the physical characteristics of the habitat and the endemic...
Since the early 1990s, declines in northern spotted owl (Strix occidentalis caurina) populations have been documented through extensive field surveys and range-wide demographic analyses. Although loss of late-successional forest has been credited as the primary cause for spotted owl population declines, environmental variation has also been shown to influence vital...