Wild fish populations are typically infected with a variety of micro- and macroparasites that may affect fitness and survival, however, there is little published information on parasite distribution in wild juvenile salmonids in three upper tributaries of the Willamette River, OR. The objectives of this survey were to document (1)...
The purposes of this report are to describe the quality of shallow ground water in alluvial aquifers of the Willamette Basin and to identify relationships between shallow ground-water quality and various natural and anthropogenic factors. Several natural and anthropogenic factors (soil characteristics, cumulative thickness of clay above open interval of...
Land use alters the physical and biological structure of stream ecosystems and potentially alters their capacity to process nitrogen (N), an essential nutrient that has nearly doubled in abundance on the biosphere
during the past century from human activities. In this dissertation, I quantified uptake and transformation of nitrate (NO₃⁻)...
Reservoir systems in the western US are managed to serve two main competing purposes: to reduce flooding during the winter and spring, and to provide water supply for multiple uses during the summer. Because the storage capacity of a reservoir cannot be used for both flood damage reduction and water...
This report reviews and summarizes available information on aquatic biological communities in the Willamette Basin through 1995. Specifically, the report describes (1) the distribution, abndance, and trends of three taxonomic groups--algae, macroinvertebrates, and fish--and, to a lesser degree, other selected semi-aquatic taxa (i.e., taxa frequenting but not living wholly in...
Storage of water for water quality control is one of the alternative
means of achieving water quality objectives. Authorities in
the field of water quality management disagree regarding the use of
precious water for the dilution of wastes.
The costs of achieving water quality objectives by treatment
of wastes at...
Fresh-water benthic river algae were collected from selected
sites in Willamette River tributaries; two sampling sites were in the
Yamhill River system and four sampling sites were in the Santiam
River system. Twelve samples were taken at each collection site in
the Yamhill River system at approximately monthly intervals from...
There were 21 days with observations during 30 January-21 May 1974. Herons were already displaying on January 30, so nesting activity can occur much earlier than has been supposed. A yearling was often seen at the nests, but most nesting activity was by adults. Although eggs were laid in at...
The purpose of this research is to investigate how stakeholders involved in collaborative watershed groups in Oregon work with each other to form ideas and take action. Most collaboration efforts include encouraging a high level of trust with a great value placed on relationships and partners, being open and flexible,...
The main theme of this research is the application of geographic techniques in a study involving environmental monitoring and analysis of the associations between landscape and in-stream characteristics in the Pacific Northwest. The geographic techniques used in this study include (1) geographic information systems (GIS) coupled with statistical analysis and...
The Willamette River and its floodplain in northwest Oregon have changed dramatically since European settlement. At one time, the river was a vast complex system of braided channels with a broad floodplain forest; it has now been simplified by channelization and dams, and the forest has been removed to support...
A novel mode of shallow aquifer management could increase the volumetric potential and distribution of underground, freshwater storage: Shallow aquifer storage and recovery (SASR). In this mode, water is efficiently stored in basin fill aquifers with strong hydraulic connection to surface water. Regional numerical modeling can provide a linkage between...
The littoral zones of seven reservoirs in the southern Willamette Valley of Oregon were sampled with a boat electroshocker during the summer months of 1995 and 1996. Shoreline substrates were inventoried before sampling sites were randomly selected. Sampling sites consisted of 9 of 12 possible habitat types including four substrate...
To better understand the impact of land use on stream nutrient export, a synoptic sampling of 57 sub-basins within the Willamette River basin was conducted during winter baseflow conditions (February 2009). I assessed whether stream dissolved organic carbon (DOC), NO₃⁻ and Cl⁻ and specific ultra-violet absorbance (SUVA) values were correlated...
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...
In the fall through spring of 2002/03 and 2003/04, the composition of fish and amphibian communities were examined in intermittent streams in the upper Willamette river basin in western Oregon. I recorded standard aquatic habitat variables and water nutrient concentrations (nitrate and phosphate) and correlated them with fish and amphibian...
This report presents information concerning the water and related land resources of the Middle Willamette River Basin and is the result of a cooperative study by the U. S. Department of Agriculture and the State Water Resources Board of Oregon.
The State Water Resources Board of Oregon is making a...
Alternative futures studies provide a way for policy-makers and stakeholders to investigate the future impacts of different management strategies by providing representations of possible outcomes. An alternative futures study was undertaken by the Pacific Northwest-Ecosystem Research Consortium for the Willamette River Basin, Oregon, USA, to determine how this regional system...
This dissertation examines learning driven adaptations in salmon recovery efforts and water resources management in Oregon. The case study utilizes a framework highlighting the connections between human and natural systems. Semi-structured interviews are used to analyze interactions between rural riparian landowners and watershed council staffs living and working in Oregon’s...
Shifting climate patterns in the Columbia River basin are affecting snow pack, and, as a result, stream flow throughout the region. In the Oregon Cascades, ever growing populations, and their associated activities, place increasing stress on an already over allocated hydrologic system. Political pressures, including the possibility of renegotiation or...
Juvenile Chinook salmon (Oncorhynchus tshawytscha) exhibit an array of life history tactics in Oregon's Willamette River Basin, yet we do not know to what extent it is driven by phenotypic plasticity or whether it is predetermined and how conditions in the early rearing environment may affect phenotype expression. We have...
Pacific lamprey Entosphenus tridentatus is a valuable icon and traditional food source for Indigenous people of western North America. Native Americans have utilized traditional ecological knowledge (TEK) since time immemorial to guide their ways of life, transmitting cultural values and natural history to further generational knowledge. Pacific lamprey are in...
The primary goal of this research was to identify the impacts that individual agricultural land uses have on fish communities in small streams located in the Willamette Valley of western Oregon. The diverse nature of the land use features of the valley provided a challenging but useful system for the...
First introduced to the USA in 1958, Myxobolus cerebralis, the parasite responsible for whirling disease in salmonids, has since spread across the country causing severe declines in wild trout populations in the intermountain west. Recent development of risk assessment models used to assess the likelihood and consequences of exotic parasite...
A rapid expansion of population and industrialization in recent
years has created new and difficult problems in water resources
management. Prudent management of water quality will require that
more efficient methods be developed for evaluating large volumes of
data on complex river systems, and tabulating the results in a form...
It is no longer possible in any area of the United States to formulate
water resources plans for single purpose projects as has been
done in past years. No longer can one of our greatest natural resources,
water, be used solely for navigation, power generation,
irrigation, or controlled for reducing...