Index Catalog // ScholarsArchive@OSU

Use of extractable lipofuscin as an age biomarker to determine age structure of ghost shrimp (Neotrypaea californiensis) populations in west coast estuaries

Creator:: Cassidy, Katelyn M.
Abstract:: Determining age in crustaceans is inherently imprecise because they molt periodically and do not retain hard structures throughout their lifespan. Morphological measurements, such as carapace length, are often used to estimate age because methods for direct ageing do not exist. However, variability in individual growth rate and molt frequency can...
Resource Type:: Masters Thesis

Transferability of models to predict selection of cover by coastal cutthroat trout in small streams in western Oregon, USA

Creator:: Andersen, Heidi V.
Abstract:: We assessed use and selection of cover by coastal cutthroat trout (Oncorhynchus clarkii clarkii) in six headwater streams in three watersheds in western Oregon, USA during the summer low flow period from 1 August and September 30, 2007. We tagged 1037 coastal cutthroat trout (>100 mm) with passive integrated transponder...
Resource Type:: Masters Thesis

The influence of fall-spawning salmon on growth and production of juvenile coho salmon rearing in beaver ponds on the Copper River Delta, Alaska

Creator:: Lang, Dirk W.
Abstract:: This thesis examined the influence of fall-spawning coho salmon on the density, growth rate, body condition, and survival to outmigration of juvenile coho salmon rearing in beaver ponds on the Copper River Delta, Alaska. During the fall of 1999 and 2000 fish rearing in ponds that received spawning salmon were...
Resource Type:: Masters Thesis

The influence of canopy type and seasons on adult aquatic insect emergence and riparian spiders in the Oregon Coast Range

Creator:: Premdas, Sharmila
Abstract:: The objective of my study was to examine differences in riparian tree and shrub composition associated with adult aquatic emergence and implications for terrestrial spiders in these sites. Seasonal abundance and biomass of adult emergent aquatic insects, riparian arthropod abundances and spider densities were compared between conifer- and hardwood-dominated sites...
Resource Type:: Masters Thesis

The effects of water withdrawals on the emergence timing, adult body mass, and total emerging biomass of aquatic insects from two northeast Oregon rivers

Creator:: Brown, Phil D.
Abstract:: 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...
Resource Type:: Masters Thesis

The effects of elevated temperature and stress on immune function in juvenile chinook salmon (Oncorhynchus tshawytscha)

Creator:: Harrahy, Laura Nicole Martini
Abstract:: Stress, including extreme or rapidly changing temperatures, are known to have deleterious effects on fish health and physiology. This thesis examines the combined effects of elevated acclimation temperature and acute handling stress on the number of antibody producing cells, plasma lysozyme concentrations, and the number of pronephric leukocytes in juvenile...
Resource Type:: Masters Thesis

The effect of landscape topography and in-stream habitat on the distribution, growth, and survival of Lahontan cutthroat trout (Oncorhynchus clarki henshawi) in a high desert watershed

Creator:: Boxall, George D.
Abstract:: Lahontan cutthroat trout (LCT) (Oncorhynchus clarki henshawi) are currently limited in their distribution to a patchwork of small isolated populations, the result of habitat degradation and natural variation in landscape and in-stream conditions. The objectives of this study were to determine how landscape level topographic features influence LCT distribution patterns....
Resource Type:: Masters Thesis

The effect of chronic exposure of chinook salmon to benzo(a)pyrene and cortisol of CYP1A1 induction and susceptibility to a microsporidian parasite, Loma salmonae

Creator:: Marie, Amarisa
Abstract:: Wild populations of fish are faced with a multitude of stressors, which may include human interaction, toxins, and disease. Benzo(a)pyrene (BaP), a known carcinogen and immunotoxin, has been reported in the stomach contents of juvenile chinook salmon, Oncorhynchus tshawytscha, in urban waterways. We investigated the impact of chronic dietary exposure...
Resource Type:: Masters Thesis

Stress induced differential gene expression in the brain of juvenile steelhead trout, (Oncorhynchus Mykiss)

Creator:: Schwindt, Adam R.
Abstract:: Gene expression profiles of tissues and cell-lines can be powerful tools for documenting the genetic response to a particular treatment, such as stressors. However, there is a paucity of information on the genetic stress response in the brain. Therefore, we attempted to profile gene expression in the brain of juvenile...
Resource Type:: Masters Thesis

Spawning, larval recruitment, and early life survival of Pacific lampreys in the South Fork Coquille River, Oregon

Creator:: Brumo, Abel F.
Abstract:: Recently, there has been concern over the decline of the Pacific lamprey, Lampetra tridentata, in the northwestern United States. However, effective management has been impeded by data gaps in basic biology, especially in the early life stages. Consequently, in 2004 and 2005 I examined reproductive ecology, larval recruitment, and lamprey...
Resource Type:: Masters Thesis

Spawning chinook salmon (Oncorhynchus tshawytscha) two years in a row : reconditioning for repeated gamete collection

Creator:: Mayer, Kent Corey
Abstract:: Spring chinook salmon, Oncorhynchus tshawytscha, in the Snake River Basin are listed as endangered under the Endangered Species Act. The typical life history of spring chinook salmon is semelparous. An experiment was performed to see if mature male spring chinook salmon parr could be reconditioned after hand-spawning and spawned in...
Resource Type:: Masters Thesis

Seasonal movement patterns and habitat use of westslope cutthroat trout in two headwater tributary streams of the John Day River

Creator:: Starcevich, Steven J.
Abstract:: Radiotelemetry was used to study the seasonal movements and habitat use of adult westslope cutthroat trout Oncorhynchus clarki lewisi in Roberts Creek and Rail Creek, headwater tributaries of the John Day River, Oregon, from September 2000 to December 2001. The objectives were to (1) describe adult cutthroat trout life history...
Resource Type:: Masters Thesis

Seasonal life history of Oncorhynchus mykiss in the South Fork John Day River Basin, Oregon

Creator:: Tattam, Ian A.
Abstract:: Understanding seasonal changes in growth, survival, and movement rates is crucial to salmonid management. These life history characteristics provide a context for evaluation of management actions. We evaluated the life history of individually marked Oncorhynchus mykiss gairdneri in the South Fork John Day River basin in Northeastern Oregon. This thesis...
Resource Type:: Masters Thesis

Seasonal influences on food availability and diet of coastal cutthroat trout in relation to riparian vegetation

Creator:: Romero, Nicolas
Abstract:: Current riparian management objectives in the Pacific Northwest promote both retention of existing conifers and conversion of hardwood-dominated areas to conifers. Although understanding of relationships between riparian vegetation and salmonid prey availability is growing, temporal variation in these relationships is poorly understood. Seasonal fluxes in availability of aquatic and terrestrial...
Resource Type:: Masters Thesis

Seasonal dynamics of a riparian food web in the Oregon Coast Range mountains

Creator:: Robillard, Amanda Lynn
Abstract:: Riparian areas are eco-tones where aquatically- and terrestrially-derived insect biomass is exchanged between habitats, presenting consumers with new sources of energy, and resulting in a reciprocal subsidy. The relative contribution of energy exchange and the resulting impacts on vertebrate riparian consumers, such as fish or birds, remains poorly understood. We...
Resource Type:: Masters Thesis

Seasonal changes in distribution of coastal cutthroat trout in an isolated watershed

Creator:: Hendricks, Steve
Abstract:: In an effort to identify seasonal distribution patterns and habitat requirements of coastal cutthroat trout Oncorhynchus clarki clarki, movement of tagged and marked individuals (35 radio-tagged, 753 PIT-tagged, and 5,322 fin-clipped) was monitored over a 14-month period in an isolated watershed in southwestern Oregon. Emigration out of the basin was...
Resource Type:: Masters Thesis

Salmon recovery in the Pacific Northwest : defining what constitutes a wild salmon

Creator:: Courter, Ian I.
Abstract:: In spite of considerable efforts to restore natural runs of anadromous salmonids in the Pacific Northwest, they remain at risk of extirpation. Along with many other factors influencing the decline, stocking from hatcheries over the past hundred years is often suggested to be a major cause. The listing of over...
Resource Type:: Masters Thesis

Salmon and marine-derived nutrient effects on primary and secondary trophic levels

Creator:: Claeson, Shannon M.
Abstract:: The purpose of this study was to understand the influence of organic material and nutrients from spawning salmon and supplemented salmon carcasses on stream food webs. My study objectives were to examine 1) assimilation of salmon-derived nutrients (SDN) by producers and consumers in the food web, 2) epilithic biofilm productivity,...
Resource Type:: Masters Thesis

Riparian vegetation composition and structure associated with channel morphology of headwater meadow streams in the Blue Mountains, northeast Oregon

Creator:: Toledo, Zachary O.
Abstract:: Relationships between the structure and composition of riparian vegetation with channel morphology were examined in three montane meadow streams in the headwaters of the Upper Grande Ronde River and North Fork John Day River in the Blue Mountains, northeast Oregon. Vegetation composition, root biomass, and channel morphology cross-sections were sampled...
Resource Type:: Masters Thesis

Responses of a threatened cutthroat trout to an introduced, invading salmonid : ecological implications for growth, stress, and behavior

Creator:: Osborne-Gowey, Jeremiah D.
Abstract:: Recent studies suggest that competition from brook trout (Salvelinus fontinalis; EBT) may have negative effects (e.g. displacement) on Lahontan cutthroat trout (Oncorhynchus clarki henshawi; LCT). Results from these studies have failed to elucidate the responsible mechanisms and have not examined if changing environmental conditions result in competitive/subordinate role reversals. The...
Resource Type:: Masters Thesis

Search Constraints

Search Results

Limit your search