Three factors were found to be significantly correlated with the fluctuations and trends in silver salmon production in Oregon. Logging was found to adversely affect the runs of salmon in later years. Exceptional winter floods seem to produce poor resulting runs. Low summer water flows also appear to produce lower...
Recent successes of hatcheries in producing coho salmon have stimulated searches for additional hatchery locations in coastal watersheds. In the past hatcheries were designed with gravity flow water supplies, but in more recent years pumping the water has proven feasible. Because of the acceptance of pumping, naturally impounded waters are...
Coho salmon have been the most important variety of salmon caught commercially in Oregon. Until recently, coho were also the most common variety in most coastal streams. Based on records from salmon canneries, coho in Oregon north of Cape Blanco (near Port Orford) numbered about 1.25 million adults annually 100...
This information report contains the results of a program to distribute surplus fry to streams underutilized by the natural population. It discusses the stocking and evaluation procedures, and gives the results.
The Independent Multidisciplinary Science Team (IMST) convened 19 regional leaders in salmon management and research in a workshop on Goals for Recovery of Oregon Coastal Native (OCN) Stocks on August 4-5, 1999. The main purposes of the workshop were to 1) define the concept of recovery and 2) to identify...
Diseases caused by parasites are recognized as significant sources of mortality in wild fish populations. I assessed the impacts of multispecies parasitism on a threatened stock of juvenile coho salmon (Oncorhynchus kisutch). A crucial prerequisite to this research was proper identification of parasites, which can be difficult for species lacking...
Juvenile coho salmon (101-400 mm) were sampled by
purse seine off the Pacific Coast from Waatch Point,
Washington to Four Mile Creek, Oregon, out to 30 mi
offshore, during the months of May, June, and September in
1982 and 1983. Sea surface temperature, surface salinity,
surface chlorophyll-a concentration, and Secchi...
We evaluated the effectiveness of using hatchery coho salmon Oncorhynchus kisutch presmolts to rebuild wild populations in Oregon coastal streams. Juvenile and adult populations were monitored in 15 stocked and 15 unstacked streams from summer 1980 until summer 1985. During the summers following the planting of presmolts, the number of...
Juvenile salmonids display highly variable spatial and temporal movement patterns that are influenced by density dependent (e.g., competition, predation) and density independent (e.g., genetics, stream discharge, physical habitat conditions) factors. The effects of these factors differ with fish life history stage, but will ultimately affect how salmonids utilize freshwater nursery...
During a tagging operation conducted in 1951 on the Alsea River, 1,142 adult silver salmon were tagged with plastic Petersen-type tags and stainless steel jaw tags. An attempt was made to determine whether tagged fish released in different apparent conditions suffered differential mortalities. Under the hypothesis that the recovery of...
This study was designed to provide information about the juvenile life history of coho salmon, Oncorhynchus kisutch, in the Tenmile Lakes in Oregon by 1) classifying scales of spawning fish and outgoing smolts (1+), 2) assessing the contribution of juvenile life history types to the returns of adults (3₂) and...
For Pacific salmon, the evolution of local adaptations depends upon the species' propensity to return, or "home", to natal streams at time of reproduction. Pacific salmon use olfactory cues to guide homing behavior, yet little is known about the genetics of olfaction in salmon. In this study, I use putatively...
Loss of lowland estuarine and freshwater off-channel habitats along the Pacific Northwest coast has contributed to the decline of salmonid populations. These habitats serve as nursery grounds for juvenile salmonids providing them with food, winter shelter, and a transition zone between freshwater and saltwater. Lowland areas have undergone anthropogenic alterations...
The typical coho salmon life history has been characterized by juvenile fish that spend their entire first year in freshwater habitats before migrating into estuaries as smolts. However, reports of early migrating coho fry (age 0), including migration downstream to estuarine habitats, date back to the 1960s. Until a few...
Salmon survival and eventual recruitment success have long been thought to be determined within the first summer following ocean migration. Juvenile growth during this period is largely influenced by ocean conditions such as temperature, prey availability, abundance, and quality. Shifts in these conditions due to climatic perturbations are particularly prevalent...
Gives standard spawning data for salmon in Oregon and adds information "to document straying of private hatchery coho salmon from Oregon Aqua-Foods'(OAF) facility at Yaquina Bay. . . The program was conducted in response to concerns by fisheries managers and the public on the possible long-term effects of interbreeding wild...
This Technical Report of the Independent Multidisciplinary Science Team (IMST) focuses on the technical and scientific issues involving (a) management of coho salmon harvest by the State of Oregon and Pacific Fisheries Management Council and (b) the analysis of salmonid population dynamics under the Oregon Plan for Salmon and Watersheds....
Increasing the abundance of salmon in coastal Oregon rivers and streams is a high priority public policy objective. Salmon runs have been reduced from pre-development conditions (typically defined as the 1 850s), but it is unclear by how much. Considerable resources have been allocated to restoring salmon runs, but it...
Over-winter growth of juvenile salmonids may be linked to ocean survival and thus species persistence. Diet, growth, and prey available to juvenile coho, Oncorhynchus kisutch, were examined from December 2004 to April 2005 in four tributaries of the West Fork Smith River (WFSR), Oregon. Juvenile coho growth rate and condition...
from the summer dry season to the winter wet season. Such movement that connects summer and winter habitats may be particularly important for coho salmon, O. kisutch, because availability of overwintering habitat can limit freshwater survival for this species. Here, I describe basin-scale variability in the spatial pattern of fall...
The goal of the Oregon Plan is to restore wild coho and wild steelhead runs. Under the federal Endangered Species Act, wild coho salmon along the Oregon Coast are listed as Threatened and wild Oregon Coast steelhead are a candidate for listing. Although cormorants have been hazed at the Nehalem...
The effects of beaver (Castor canadensis) on stream morphology, riparian zones, and coho salmon (Oncorhynchus kisutch) fry in Cape and Cummins Creeks, Oregon, were examined using stream surveys, vegetation transects, and coho salmon fry counts in 1987. The basin around Cape Creek has been extensively logged since the late 1940's....
Many contemporary fisheries and wildlife issues are complex, messy, and divisive. Most share a set of common characteristics including a lack of comprehensive scientific information, a limited understanding of biological processes, a scarcity of agency staff, time, money, and a tendency for differences over policy preferences to end up as...
Tidal marshlands in the upper estuary ecotone provide essential habitat for
juvenile salmonids. In this environment, salmonids grow rapidly and acclimate to
saltwater. Worldwide, tidal marshes have been diked and drained to provide
agricultural and residential land. Tide gates are one-way doors integrated into
dike systems that prevent saltwater flooding...
Aquatic ecological investigation is expanding to encompass considerations of
multiple scales across large landscapes. Much of the analysis included in this work
focuses specifically on coho salmon (Oncorhynchus kisutch) in multiple subbasins on
the Oregon coast. Coho salmon were chosen for an investigation of spatial scales,
network connections, and life...
Field investigations were implemented to study the interrelationships between streamflows and salmonid production during the summer-fall low flow period in two natural stream channels. Elk Creek, near Cannon Beach in Clatsop County, was the site selected for intensive investigation.
Construction of streamflow control and diversion facilities was completed in November...
This report on departmental activities describes "physical stream and lake surveys, spawning fish surveys and individual investigations of particular human activities which might affect the well being of the salmon resource. The advent of federal cooperation has allowed an expansion of activities to include intensive collection of data on streams...
Artificial propagation has been a prominent part of the management of salmonids in Oregon since the late 1800s, and will continue to have an important role to play in the recovery of wild stocks of anadromous salmonids in Oregon. Hatcheries and reviews of hatchery programs have been controversial and are...
Evidence for reduced reproductive success (RS) of wild spawning hatchery-reared fish invites serious consideration with regard to the detrimental effects on subsequent generations of wild populations. Mate choice was evaluated as a potential mechanism contributing to these observed RS differences using a previous pedigree of wild spawning hatchery-reared and wild...
To best manage Eagle Creek National Fish Hatchery and minimize any negative impacts that the current hatchery program may be having on Endangered Species Act-listed salmonids in the Eagle Creek Basin, I determined if wild fish are being displaced from preferred habitats by hatchery salmonids Oncorhynchus spp. This thesis had...
Outreach is a key element in natural resource public participation processes in order to create an engaging, thoughtful, and productive environment for citizen involved decision-making. This project examined the utility of a needs assessment as an initial outreach tool within the context of the National Oceanic and Atmospheric Administration Fisheries...
The fitness of female Pacific salmon (Oncorhynchus spp.) with respect to breeding behavior can be partitioned into at least four components: survival to reproduction, competition for breeding sites, success of egg incubation, and suitability of the local environment near breeding sites for early rearing of juveniles. Accordingly, breeding sites should...
Large wood (LW) pieces are recognized as an important habitat component for salmon freshwater habitat. As such, they are often used in stream habitat restoration practices despite a lack of knowledge about their impacts on spatial and temporal hydraulic characteristics relevant to fish habitat. In this thesis we present results...
Visual estimation techniques were used to quantify habitat characteristics,
habitat type (pool, riffle) use and longitudinal distribution of steelhead
(Oncorhynchus mykiss), cutthroat trout (0. clarki), and coho salmon (0. kisutch)
in spring, summer and fall in 8.8 km of Cummins Creek, a basin in the central coast
of Oregon. Fish...
Coho salmon (Oncorhynchus kisutch) migration and spawning are unique components of the salmon life cycle because they require synchrony of behavior with other individuals as well as with acceptable fluvial conditions. As with other organisms that exhibit group mating behavior, it is likely that environmental cues trigger coho salmon movement...
The Ocean Salmon Management Program is responsible for obtaining fishery and biological data, analyzing these data and recommending appropriate management options for the ocean fisheries. Proposed management options are designed to achieve the optimum use of the salmon resource on a sustained basis. The ocean salmon recreational fishery is now...
Many stakeholders involved with stream restoration in the Pacific Northwest have discussed the potential benefits of using beaver dam construction activities (Castor canadensis) as a management tool to improve degraded stream habitat for anadromous salmon species. In addition, there has been growing interest in using nuisance beavers, primarily controlled by...
In addition to standard spawning surveys for coho salmon, this report contains additional sampling in the Yaquina River, at the Salmon River Hatchery and tributaries of Coos Bay "to document straying of private hatchery coho salmon from the Oregon Aqua-Foods (OAF) facility at South Beach, Yaquina Bay, and Anadromous, Inc.,...
Large wood has been utilized in many restoration projects to improve in-stream habitat in the Pacific Northwest for salmon. However, the benefits of this practice remain the subject of ongoing debate and evaluation of these projects has scarcely been done for non-salmonid species such as lamprey. In this study we...
Projected intensification of drought as a result of climate change may reduce the capacity of streams to rear fish, exacerbating the challenge of recovering ESA-listed salmon populations. Without management intervention, some stocks will likely go extinct as stream drying and fragmentation reduce juvenile survival to unsustainable levels. To offset drought-related...
1. Globally, river systems have been extensively modified through alterations in riverscapes and flow regimes, reducing their capacity to absorb geophysical and environmental changes.
2. In western North America and elsewhere, alterations in natural flow regimes and swimways through dams, levees, and floodplain development, work in concert with fire regime,...
Better fisheries management is often given as one justification for research on improving forecasts of fish survival. However, the value gained from expected improvements in forecast skill in terms of achieving management goals is rarely quantified as part of research objectives. Using Monte Carlo simulations of population dynamics, we assessed...
The aims of this study were first, to test the hypothesis that metrics of fish growth and condition relate positively to parasite species richness (S[subscript R]) in a salmonid host; second, to identify whether S[subscript R] differs as a function of host origin; third, to identify whether acquisition of parasites...
The effects of three levels of dissolved oxygen (8, 5 and 3 mg/l)
upon the feeding, growth and bioenergetics of juvenile coho salmon,
Oncorhynchus kisutch (Walbaum), were determined in laboratory
studies. Experiments with individual fish were conducted during the
summer, fall and spring to measure rates of food consumption,
standard...
This research was initiated to investigate the effects of various
parameters on the immune response of juvenile coho salmon to Aeromonas
salmonicida. The antibody response and development of protective
immunity in juvenile coho salmon were followed after a single
intraperitoneal injection of formalin killed A. salmonicida cells emulsified
in Freund's...
Effects of inbreeding coho salmon (Oncorhynchus kisutch) on
survival during early life history, growth, feed efficiency, and
resistance to gas bubble disease were studied. No effect of inbreeding
could be associated with either F=0.25 or F=0.125. Tetraploidy
may help explain the absence of inbreeding depression at these
levels.
Coho salmon smolts (Oncorhynchus kisutch) were transported at low and high densities. (12 and 120 g/L) for short and long periods (4 and 12 h). Because smolts can be transplanted directly to seawater, half of the fish in each treatment were transported to tanks containing seawater and half to tanks...
Immunity in juvenile coho salmon (Oncorhynchus kisutch) was
evaluated after immunization against vibriosis by parenteral, oral or
immersion methods. Relative levels of immunity were determined by
protection of fish from experimental water-borne challenges with
Vibrio anguillarum and by serum agglutination titers. Coho salmon
eggs were exposed to bacterin during artificial...
This study was undertaken to quantitatively evaluate the
relationship between silvering of the skin of juvenile coho
salmon, due to the deposition of the purines guanine and
hypoxanthine, and adaptation to seawater. It was hypothesized
that maximum purine deposition occurs at the time these fish
normally enter seawater, that the...
Eight scale characters of known hatchery and wild coho salmon
(Oncorhynchus kisutch) were compared, and a linear discriminant
function was used to determine if hatchery and wild adult coho
salmon could be correctly identified by their scales. Eighty-two
percent of the hatchery and 89% of the wild fish were correctly...
The objective of this research was to study the effects of increased water temperature characteristic of clearcut watersheds of Pacific coastal streams upon the growth rate of juvenile coho salmon. The natural temperature fluctuations of the stream were used in the study of growth of underyearling fish held in aquariums...
Rates of birth, death and population change were calculated for Cyclops sp. and Diaptornus forbesi in Soap Creek Ponds V-VIII near Corvallis, Oregon during the interval April, 1968 to April, 1969. An egg ratio method was used in calculating these rates. Duration of development of the eggs of both species...
Freshwater (FW) and seawater (SW) acclimated yearling coho salmon, Oncorhynchus kisutch, were subjected to severe confinement stress in FW, SW, or a medium (1/3 SW) that was approximately isosmotic to the fish's blood. Chronic stress caused osmotic imbalances in FW and SW, but not in 1/3 SW. In SW, blood...
Large numbers of coho salmon (Oncorhynehus kisutch) fry move downstream shortly after emergence from the gravel in many spawning tributaries. In three small coastal streams of Oregon about eight times more juveniles leave the tributaries as newly emerged fry than as smolts one year later. Because these early emigrants comprise...
Behavior and survival in fresh water were studied for three brood years of coho salmon in Sashin Creek, Alaska, from October 1963, until September 1966. Investigations of spawning adults were conducted to determine numbers of spawners, distribution on the spawning grounds, effects on pink salmon, age composition, redd life, fecundities,...
Coho salmon (Oncorhynchus kisutch) were exposed to sublethal levels of a water-soluble fraction (WSF) of Cook Inlet crude oil for periods ranging from 18 to 31 days, at four acclimation temperatures. The fatty acid composition of phospholipids extracted from muscle, gill, liver, and brain tissues, and, at three of the...
Multiple analytical techniques were used to evaluate the impact of multiple parasite species on
the mortality of threatened juvenile coho salmon (Oncorhynchus kisutch) from the West Fork Smith
River, Oregon, USA. We also proposed a novel parsimonious mathematical representation of
macroparasite distribution, congestion rate, which i) is easier to use...
Laboratory studies were conducted on the food consumption, growth, and bioenergetics of juvenile coho salmon (Oncoynchus kisutch) held at various swimming velocities and dissolved oxygen
concentrations at 15 C. Food consumption and growth of salmon fed to repletion on housefly larvae (Mus domesticus) were reduced by increasing activity at and...
The growth and food consumption of juvenile coho salmon [Oncorhynchus kisutch (Walbaum)] exposed to natural and elevated fluctuating temperatures were studied in the laboratory with wild fish
collected from a salmonid rearing stream. Control temperatures were similar to the temperature regime of a natural stream and the elevated temperatures were...
Data from the coho salmon migration were examined from three streams of the Alsea Watershed Study, conducted on tributaries to Drift Creek, Oregon, from 1959 through 1973. With the migration season defined as November 1 through May 31, the mean seasonal smolt count was 2022 fish in Deer Creek, 665...
Phenotypic similarities of coho salmon (Oncorhynchus kisutch)
stocks from Oregon, Washington, and California were compared using
agglomerative and divisive cluster analyses. The phenotypic characters
evaluated included the following: 1) the isozyme gene frequencies
of transferrin and phosphoglucose isomerase; 2) the life history
characters time of peak spawning and proportion of...
The metabolic clearance rate (MCR) of plasma radioactivity after a
single intracardial injection of ³H-cortisol was elevated during the
Spring in yearling coho salmon, Oncorhynchus kisutch. The reasons for
this increase in MCR are not clear, but graphical analysis suggested
that there may be a seasonal correlation between MCR and...
Ninety-six hour acute toxicity bioassays were employed to
determine the tolerance of juvenile coho salmon to chlorinated
stabilized kraft mill effluent (SKME). In addition the effect of
chlorinated SKME on the growth of juvenile coho salmon in six and
ten day experiments was studied.
Results of the acute toxicity tests...
Natural and gabion modified habitats containing coho salmon
(Oncorhynchus kisutch) were observed and measured seasonally in East
Fork Lobster Creek, a fifth order stream in western Oregon. Coho
salmon usually inhabited backwater and secondary channel pools in
winter. Large wood debris complexes and undercut banks were the
primary sources of...
The timing of two events in the early life history of coho salmon--emergence from
the gravel and entry into the ocean--is presumed to have evolved to ensure maximum
survival during these transition periods. Anthropogenic disturbances may disrupt the
timing of these events to the detriment of salmon populations.
Multivariate analyses...
This report summarizes the 1979 ocean salmon fishing season off the Oregon coast. Troll fishery landings were obtained directly from commercial fish receiving tickets supplemented with a survey of fish buyers to obtain the most up-to-date estimate of total landings. Recreational catch and effort were obtained from creel census survey...
The nature of the interaction between juvenile coho salmon, Oncorhynchus kisutch (Walbaum), and fall chinook salmon, 0. tshawytscha (Walbaum), was studied in Sixes River, Oregon. Seining, snorkeling, and tagging were used to determine distribution and patterns of growth of these two species in the stream environment. Experiments conducted in flowing-water...
The purpose of this study was to characterize Cytophaga
psychrophila isolates obtained from coho fingerlings with low temperature
disease collected at selected hatcheries in Oregon. In
addition, cultures thought to be related to this bacterium were
isolated from Siletz Hatchery water, deformed juvenile and spawning
adult coho salmon, rainbow and...
Interest is expanding for the potential role of estuaries, particularly seagrass and salt marsh habitats, to sequester carbon, mitigate ocean acidification, and support abundant fisheries. The important functions of estuaries are part of a broader set of ecosystem services, or benefits to humans, which are regulated by ocean and watershed...
This project was initiated in an attempt to control furunculosis
(Aeromonas salmonicida) in a production hatchery rearing coho salmon.
An oral vaccine was prepared and administered to 520,000
juvenile coho salmon (Oncorhynchus kisutch) at the Siletz River Salmon
Hatchery prior to the onset of a predictable naturally occurring
epizootic of...
After parenteral immunization with Aeromonas salmonicida
cells, the agglutination activity in juvenile coho salmon (Oncorhynchus
kisutch) serum was associated with the macroglobulin serum fraction.
Antibody activity was diminished by 30 minutes exposure to 50 C
but not 45 C. Reduction with 2-mercaptoethanol and alkylation
markedly lowered but did not completely...
A growth model is developed for coho salmon which accounts for
temperatures and feeding rates typically encountered in fish hatchery
operation. Feeding rates utilized by the model ranged from
maintenance to maximum utilizable rations. The model is derived from
an empirical equation for maximum growth rate, and a theoretical
equation...
The abundance of the 1982 brood of juvenile coho salmon
(Oncorhynchus kisutch) was determined in August 1983, and January
and April 1984 at 20 study sites spread throughout Knowles Creek,
an Oregon coastal watershed. The timing of emigration of juvenile
coho from the watershed was monitored from October 1983
through...
The behavior and stream habitat utilization of juvenile hatchery-reared coho salmon (Ovicozihynchus kisutch) and wild cutthroat trout (Salmo clarki) were examined to assess the nature of interactions between the species potentially resulting from introductions of hatchery coho salmon in streams. Habitat utilization was monitored in Mill Creek, Polk Co., Oregon...
This study examines the ecology and dynamics of coho salmon (Oncorhynchus kisutch) in environments experimentally altered by logging. The objective was to evaluate processes that stabilize or regulate the populations. Two small watersheds in Oregon's Coast Range were logged in
1966, one clear-cut, the other patch-cut. A third adjacent watershed...
Juvenile coho salmon (Oncorhynchus kisutch (Walbaum)) and aquatic invertebrates were subjected to experimentally increased, but naturally fluctuating, temperatures in a model stream channel. Coho of the 1969, 1970, and 1971 year classes were reared in the heated model stream and in an unheated control stream, both located at the Oak...
Detection of L-serine and D,L-alanine by juvenile coho salmon (Oncorhynchus kisutch) was measured in a two-choice Y-trough. Threshold concentration for olfactory
detection of L-serine was 10-8 M for zero-age parr, 1O-7 M for yearling parr, 10-5 M for smolts in late April-early May, and 10-6 M for smolts in June....
Policy decisions in fishery management are becoming increasingly
complex and difficult. This is especially true for the salmon fisheries
where policy outcomes affect the productivity of the salmon
resource and the subsequent well-being of commercial fishermen, charter
boat operators, Indian fishermen, and sport anglers. The objective
of this study was...
Changes in blood calcium and phosphorus concentrations were
characterized for rainbow trout (Salmo gairdneri) and coho salmon
(Oncorhynchus kisutch) following intense exercise or exposure to
suspended volcanic ash or topsoil. Significant elevations in blood
calcium and phosphorus accompanied exercise-induced acidemia in both
S. qairdneri and O. kisutch. These elevations persisted...
Whole body sex steroid levels of coho salmon,
Oncorhynchus kisutch, were measured via radioimmunoassay
during early development and sexual differentiation.
Steroid profiles of testosterone (T), 11-ketotestosterone
(KT) , androstenedione (A), progesterone (P4) , 17β, -hydroxy-
20β -dihydroprogesterone (DHP) , and 17β -estradiol (E2) were
generated beginning with unfertilized eggs and...