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...
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 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...
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...
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...
The cellular dynamics of the intestinal epithelium in the coho
salmon, Oncorhynchus kisutch, has been studied to determine the effects of temperature and whole-body X-irradiation.
In vivo experiments utilizing colchicine mitotic inhibiting technique and tritiated
thymidine (³H-TdR) radioautography were employed in order to
evaluate the kinetics of the cell population....
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...
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...
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...
Experiments were carried out in fall and winter, 1990
and spring and summer, 1991 , to determine growth and
mortality of juvenile Pacific oysters {Crassostrea gigas)
in effluent from cultured coho salmon {Oncorhynchus
kisutch) , and effluent from salmon in which the red
macroalga Palmaria mollis was cultured. Ambient sea...
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...
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.,...
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...
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...
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...
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...
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...
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...
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....
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 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...
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...
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...