The use of some age determination methods may result in the
incorrect age structure of fish populations. This in turn may lead
to incorporation of inappropriate data into models used for stock
management. Otoliths are commonly used for determining the age of
fishes, and ages based on the whole otoliths...
Fisheries models are generally built to assess the dynamics of a resource with a given fishing mortality
which level can be decided by some “decision maker” and/or which can be an observed process, e.g. times series proportional to some observed values of fishing effort. In these cases, the resource dynamics...
Discusses the removal of boulders in the Alsea River near Tidewater by blasting with dynamite. Documents the number of fish killed. Includes a copy of the blasting permit.
Published December 1908. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
An increase in frequency and severity of hot, dry summers has been associated with a dramatic shift in the coniferous forests of western Oregon’s valleys, especially on the privately-owned properties along the low-elevation edges of these valleys. Various conifer species, including Douglas-fir (Pseudotsuga menziesii), are declining in these forests, leaving...
An experiment was conducted to compare the reproductive
performance and serum concentrations of progesterone and estrogen of
mated first (n=18) and third (n=18) estrous gilts slaughtered in equal
numbers on days 3, 15 and 30 postmating. Fertilization rate did not
differ between mated first and third estrous gilts. Embryonic survival...
"We monitored oyster mortality in Yaquina, Coos, and Tillamook bays from July 1966-March 1972. Pacific oyster (Crassostrea gigas) mortality in Yaquina Bay appears to be lower than in any other reporting area on the Pacific Coast, generally less than 2% per year. Native oyster (Ostrea lurida) mortality ranged from 9.6-28.2%....
"Objectives of Oregon's Oyster Mortality study for the year ending March 1969 were similar to those of the first 2 years of the program: (1) to monitor oyster mortality in Yaquina, Tillamook and Coos bays, (2) to collect hydrographic data in Yaquina Bay and (3) to furnish oysters to the...
"Objectives of Oregon's Oyster Mortality Study from July 1, 1967-March 31, 1968, were: (1) to monitor oyster mortalities to detect a possible increase in mortality rate, (2) to collect hydrographic data for comparison with data from areas where high oyster mortalities occur, and (3) to furnish oysters from a relatively...
"Oyster mortality data collected from suspended trays at three subtidal locations in Yaquina Bay disclosed an unusually high 26.5% Pacific oyster (Crassostrea gigas) mortality during the study year. Almost all of this mortality resulted from culling damage which occurred previous to introduction of the oysters into trays. Native oyster mortality...
Covers: April 1, 1969 - March 30, 1970. "Objectives of Oregon's oyster mortality study for the past year included monitoring oyster mortality in Yaquina, Tillamook, and Coos bays, obtaining hydrographic data in Yaquina Bay; and furnishing oysters to the University of Washington and the Bureau of Commercial Fisheries (BCF) in...
"Although Oregon has been relatively free from any major oyster mortality a monitoring program has been established with the basic objectives being to: (1) monitor mortalities; (2) collect environmental data; and (3) furnish oyster from a disease-free area for histological examination." (Introduction) Includes hydrographic data from test plots in Yaquina,...
This document is a summary of the March 1968 meeting to determine the cause of an oyster mortality incident. It answers several questions about criteria for establishing the causative organism and discusses programs for studying oyster mortalities.
Educational poster of invasive Koi fish. The spread of these fish is often traced to pet owners who release them into wild habitats when they no longer want to care for them. The poster is on display at Hatfield Marine Science Center Visitor Center is Newport, Oregon.
Bluegill sunfish, Lepomia macrochirus, and cutthroat trout,
Salmo clarki, were exposed to a rapidly declining oxygen tension
for a period of time sufficient to just cause loss of equilibrium in
the fish. During recovery from the stress, measurements of
oxygen uptake, blood lactic acid, blood glucose, liver glycogen,
muscle glycogen,...
Aspects of hydromineral balance in the stenohaline fresh-water
catfish, Ictalurus nebulosus (Le Sueur) were studied at 10° and 20°C.
Temperature did not affect water content significantly. Water content
was 78 ml/100 g body weight, 32% of which is in muscle and 49% in
the skeleton and associated connective tissue. The...
Biliary excretion has been of considerable interest in mammals
but has not been extensively studied in fish. To understand the
significance of biliary excretion in rainbow trout (Salmo gairdneri),
two studies were conducted.
The objective of the initial study was to evaluate the ability of
rainbow trout to excrete a...
Methods and utility of age determination of yellowtail rockfish
(Sebastes flavidus), canary rockfish (Sebastes pinniger), and black
rockfish (Sebastes melanops) collected off Oregon during 1972 to
1975 are discussed. Structures compared on the basis of the reproducibility
of counts of annuli (consistency of readings) were the anal fin
pterygiophore, opercle,...
Juvenile coho salmon (Oncorhynchus kisutch) and steelhead trout
(Salmo gairdneri) of different stocks and three transferrin genotypes
(AA, AC, and CC), all reared in identical or similar environments, were
experimentally infected with the causative agent of bacterial kidney
disease (BKD) or Vibrio anguillarum. Mortality due to the pathogens
was compared...
Oregon Department of Fish and Wildlife trout broodstocks from Alsea, Cole Rivers, Klamath, Leaburg, Oak Springs, Roaring River and Willamette Fish Hatcheries were examined for the presence of myxosporidans. Wild fish collected from waters above these hatcheries were also examined. Seven species of myxosporidans were observed in the hatchery broodfish:...
The stages in the life history of the parasitic copepod Nectobrachia
indivisa Fraser, 1920, have been described.
The adult female lives permanently attached to the gills of the
starry flounder, Platichthys stellatus (Pallas, 1811) Girard, 1854.
The adult male is a dwarf, which usually lives attached to the genital
process...
Of 2,122 marine fishes belonging to 36 species collected in the
vicinity of Newport, Oregon, 541 belonging to 8 species were infected
with hemoflagellates. Four species of trypanosomes and three species
of cryptobias were found in offshore fishes, but no hemoflagellates
were observed in fishes from Yaquina Bay.
Trypanosoma pacifica...
Sterile fish muscle homogenate was prepared from the individually
line caught black rockfish (Sebastes melanops) and inoculated
with the pure culture of Pseudomonas putrefaciens strain 17. The
inoculated homogenate was incubated at 5°C and the growth and production
of volatile sulfur compounds determined by a combined gas-liquid
chromatography and mass...
A 50 m² pelagic trawl equipped with a codend opening-closing device was used to sample micronektonic fishes between 500 m and 1000 m. Horizontal tows were made at 500, 650, 800 and 1000 m. Twelve of 15 common species captured showed significant diel differences in abundance at one or more...
The feeding habits of the lanternfishes Tarletonbeania crenularis, Diaphus theta and Stenobrachius leucopsarus were studied by analyzing 1,735 stomachs from 54 collections from the slope waters off Newport, Oregon. Forty-one taxa of food items were identified. Euphausiids
(Euphausia pacifica), copepods (Calanus spp. and Metridia lucens) and amphipods (Parathemisto pacifica) were...
This study was an investigation to determine the distribution, abundance and general food habits of salmonids and non-game fishes residing in several selected coastal streams, Douglas and Coos Counties, Oregon. The physical conditions that characterize the various stream habitat types were monitored and the influence of physical conditions on the...
This is the first report on the susceptibility of salmonid fish to infection with the glochidia of the freshwater mussel Margaritifera. margaritifera using known numbers of parasites under controlled conditions. The relative susceptibility of six species of salmonid fish, 2O to 80 mm in total length, to glochidiosis was determined...
Growth and reproductive patterns of the common lanternfish,
Stenobrachius leucopsarus, are described by length frequency
analysis, otolith analysis and examination of ovaries.
Length frequency analysis, employing the probability paper
method of analysis of polymodal distributions, of three and one-half
years of monthly midwater trawl collections off Oregon showed that
fish...
During 1963 and 1964 collections were made in tributaries of
the lower Columbia River and literature was reviewed to compile a
list of fishes from that area.
Based on available sources and collections in this study, a
total of 28 families and 77 species are known from the lower Columbia...
The garibaldi, Hypsypops rubicundus, is a sexually monochromatic pomacentrid found in rocky subtidal areas of Southern and Baja California. During the spawning season, males attempt to attract females to a nest of red algae located within individually defended territories. Females were observed to enter the nests of several males before...
A varied and complex assemblage of fishes inhabit the coastal waters of Oregon. The variety of habitats, the ocean current patterns, and the geographical placement (42° to 46° N) of this coast allow for visitation and colonization by northern and southern inshore fishes as well as those from the open...
A varied and complex assemblage of fishes inhabit the coastal waters of Oregon. The variety of habitats, the ocean current patterns, and the geographical placement (42° to 46° N) of this coast allow for visitation and colonization by northern and southern inshore fishes as well as those from the open...
This report is a description of the neoplasm disease affecting the native oyster and bay mussel in Yaquina Bay. It lists actions taken to study the disease further, and assures the public that the disease is under control.
All animals that interact with fishing gear are not necessarily captured, and all animals that are captured are not necessarily retained. Fishing practices and gear configuration, management regulations, and markets dictate which animals ultimately are retained or discarded. The impact of a fishery and the efficacy of management regulations can...
The fishes of Upper Klamath Lake appeared to distribute
themselves in three general groups during the summers of 1964
and 1965: (1) the chubs--unrestricted as to distribution with slight
seasonal variations; (2) rainbow trout and yellow perch -- restricted
to certain water conditions that exist only along the northern marsh...
The following projects were completed between July 1, 1965, and June 30, 1966, under the stream clearance segment of the State-wide Stream Improvement Program. The larger segments were initiated by requesting competitive bids with the contract for logjam removal awarded to the lowest acceptable bid. The smaller projects were undertaken...
Of the common adult lanternfishes found off Oregon, two
species have fat-invested swimbladders (Stenobrachius
leucopsarus Eigenmann and Eigenmann 1890 and Stenobrachius
nannochir Gilbert 1891), two species have reduced swimbladders
(Lampanyctus ritteri Gilbert 1915 and Lampanyctus galis
Gilbert 1891), two species have gas-filled swimbladders
((Protomyctophum thomp soni (Chapman 1944)) and (Protomyctophum...