An exploratory study of 48-hour Pacific oyster embryo
bioassays employing spent sulfite liquor (SSL) in test
concentrations ranging from 10 to 45 ppm was made at two
incubation temperatures, 20° and 24° C. Fourteen separate
bioassays, each employing embryos originating from three to
four different parentages, were conducted at the...
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...
Although short-tailed weasels (Mustela erminea) are important predators of small mammals, little is known about their space use, habitat selection, or vulnerability to predation in North America. To evaluate the effects of forest management and social structure on home range size and habitat selection of short-tailed weasels, I conducted a...
A study of the population ecology of Columbia River fall chinook
salmon, Oncorhynchus tshawytscha (Walbaum), was made in an attempt
to determine the cause of a serious decline in this run which occurred
in the early 1950's. Fluctuations in abundance of major salmon runs
the North Pacific were examined to...
The movements of a population of adult sockeye salmon
(Oncorhynchus nerka) were followed in a small tributary of Brooks
Lake, Alaska until spawning was nearly complete in 1963. The objectives
of the study were to describe the movements of sockeye
salmon on the spawning ground of an entire small stream,...
The acute toxicity of Diquat (1:1-ethylene-2:2' dipyridylium
dibromide) and Dichlobenil (2, 6-dichlorobenzonitrile) to six selected
pond invertebrates was determined using the median tolerance limit
estimation method. Diquat was more toxic to the amphipod, Hyalella
azeteca than to the aquatic insects Callibaetis, Limnephilus,
Enallagma, Libellula, and Tendipedidae. The addition of mud...
The fatty acids of coho salmon were identified and then a study
was conducted to determine the effects of exercise on the fatty acids
of salmon forced to swim against water velocities of 52, 54, 56, and
59 cm/sec, The shorter and lighter salmon were less competent at
a given...
The conservation of declining desert fish species requires the identification of relations between fish population dynamics and their environments. Dynamic occupancy modeling, an approach that requires less information than traditional mark-recapture studies, may help identify important factors affecting population processes and aid desert fish conservation and restoration efforts. I used...
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...
Human activities have altered Earth’s ecosystems. Most biomes have experienced a 20-50% conversion to human use. Loss of habitat has obvious effects on the persistence of species. Fragmentation, however, may also negatively affect biodiversity for those species that exhibit behavioral responses to changes in habitat configuration. Such behavioral changes include...
Mule deer (Odocoileus hemionus hemionus) and Rocky Mountain elk (Cervus canadensis nelsoni; hereafter elk) populations in northeast Oregon have declined in the past 10 to 20 years. Concurrent with these declines, cougar (Puma concolor) populations have apparently increased, leading to speculation that predation by cougars may be responsible for declining...
In the last decade, the California Current Large Marine Ecosystem has experienced a trend of increased severity of upwelling-driven coastal hypoxia. This thesis strove to examine the potential upper trophic level impacts of moderate and severe hypoxia in the CCLME. Initially I conducted a literature review of Pacific harbor seal...
The effects of sublethal concentrations of kraft mill effluents
(KME) on the growth, food consumption, and swimming ability of
juvenile chinook salmon, Oncorhynchus tschawytscha (Walbaum),
were studied from February 1966 to May, 1967.
The KME used in these studies was obtained from two pulp and
paper mills producing paper from...
The black crappie was evaluated as a pond fish in four experimental
ponds in the Willamette Valley. Two ponds were stocked with
largemouth bass, bluegill sunfish, and black crappie (1:9:3), and
two ponds with largemouth bass and black crappie (1:3).
Total biomass was greatest in the three-species ponds (80 kg/...
Of 149 wild animals from two western Oregon river drainage
areas and other localities in which "salmon poisoning" disease (SPD)
is enzootic, including ten mammalian and two avian species, 79
harbored Nanophyetus salmincola, the SPD vector. The shorttail
weasel, Mustela erminea; river otter, Lutra canadensis; spotted
skunk, Spilogale putorius; Norway...
The reproductive characteristics of the mountain cottontail
rabbit, Sylvilagus nuttalli (Bachman), were investigated from 269
specimens collected in central Oregon between 28 May 1968 and
28 August 1969.
Male rabbits were in breeding condition between mid-February
and 3 July 1969. Nearly 77% of the females bore four litters between
7...
The individual stocks of sockeye salmon that make up the
annual spawning migration to the Bristol Bay region of Western
Alaska are produced in the lakes and streams of ten major river
systems, which discharge into the bay over a shoreline distance of
120 miles. The hypothesis adopted in this...
The experiment was conducted at the Soap Creek farm ponds
near Corvallis, Oregon. Oregon Moist Pellet and Purina Trout
Chow at three different rates of feeding for each diet were used
to feed fingerling channel catfish stocked at the rate of 1,000 per
acre. A complete random design and Fisher's...
Reproductive characteristics of introduced eastern cottontail
rabbits, Sylvilagus floridanus (J. A. Allen), were determined from
486 rabbits collected between January 1, 1968 and June 30, 1969,
near Corvallis, Oregon.
Sex ratios were 1:1 for all rabbits collected and for all embryos
20 days or more gestation. On the basis of...
This thesis reports the results of a study on the influence of biologically
stabilized kraft mill effluent (SKME) on the food relations and
production of juvenile chinook salmon, Oncorhynchus tschawytscha
(Walbaum), in laboratory streams. Experiments were conducted at
the Oak Creek Fisheries Research Laboratory, Oregon State University,
during 1967 and...
A study of the distribution, relative abundance and diet of
fishes sympatric with juvenile sockeye salmon, Oncorhynchus nerka
(Walbaum), within the freshwater nursery areas of the Naknek River
system was undertaken from 1961 to 1963. The study was part of an
extensive investigation to determine what factors in the freshwater...
Descriptions and distributions are given of 28 species of
Liparidae occurring or possibly occurring below 200 m between San
Francisco and northern Vancouver Island, with keys for their identifications.
Nine genera are included: Careproctus, Elassodiscus,
Lipariscus, Nectoliparis, Rhinoliparis, Acantholiparis, Paraliparis,
and two new genera are described, Odontoliparis and Osteodiscus.
Eight...
Blackside dace, Rhinichthys osculus nubilus (GIRARD), were
collected from ten western Oregon streams and examined for variation
among morphological and meristic characters. Several characters were
observed to vary between populations studied. Number of vertebrae,
number of scales in and above the lateral line, length of snout, and
depth of body...
One means of evaluating the temperature requirements of an
animal is to determine changes temperature causes in the uses and
losses of energy and materials in the food the animal consumes. To
develop energy budgets for cichlids (Cichlasoma bimaculatum) at different
temperatures (20, 24, 28, 32 and 36 C) data...
Plumage development and growth were studied in young whooping
cranes (Grus americana) from hatching until 450 days of age. The
downy stage of the young cranes lasted about six weeks; the development
of the juvenal plumage took until 100 days of age, and the molt
to the adult or all...
The effects of a sublethal concentration of dieldrin (0. 2 ppb)
in the water on the growth and body composition of underyearling rainbow
and cutthroat trout held in aquaria and fed different rations of tubificid
worms or Oregon moist pellets were studied at Oak Creek Fisheries
Research Laboratory, Oregon State...
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...
The production of crop-milk in band-tailed pigeons was investigated
to estimate losses of squabs that occur from hunting
pigeons during September.¹ Living birds held captive were examined
with a cystos cope and pigeons killed by hunters were examined in the
field to determine changes in gross appearance of crops and...
Juvenile Oncorhynchus mykiss migrate extensively in freshwater during fall. We used individual tagging to study the spatial origin, influences, and outcomes of fall migration on fish that emigrated from summer rearing tributaries during fall (early-emigrants) and those that did not (late-emigrants) in the South Fork John Day River, Oregon. Fall...
Deciding which textbook to assign to students is often a very difficult decision. A textbook should offer more than just a synthesis of information, it should inspire curiosity, cause one to reflect, and provide a framework for making decisions. Most reviews reflect a single opinion, sometimes based on personal preferences....
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...
Fidelity to breeding sites in colonial birds is an adaptive trait thought to have evolved to enhance reproductive success by reducing search time for breeding habitat, allowing earlier nest initiation, facilitating mate retention, and reducing uncertainty of predator presence and food availability. Studying a seabird that has evolved relatively low...
The physiological response of juvenile steelhead (Oncorhynchus mykiss) to prolonged heat stress was examined by exposing replicated groups of fish to 25 consecutive days at 15°C, 23°C, and 25°C followed by a 55 day recovery period at 15°C. We found that at temperatures ≥25°C, steelhead consumed significantly less food per...
Mediterranean-climate regions (med-regions) are global hotspots of endemism 40 facing mounting environmental threats associated with human-related activities, including the ecological impacts associated with non-native species introductions. We review freshwater fish introductions across med-regions to evaluate the influences of non-native fishes on the biogeography of taxonomic and functional diversity. Our synthesis...
Despite relatively mild weather, black bears (Ursus americanus)
in southwestern Washington entered dens and remained for an average
of 126 days. Bears entered their dens during a 5-week period which
began on 21 October. A significant difference (P < 0.05) was found
among the average dates of den entrance of...
The effects of discharged sewage on physico-chemical conditions
and the distribution and abundance of marine benthic animals were
studied in Shilshole Bay, a part of Puget Sound, off Seattle,
Washington. For over 50 years prior to 1965, when this study was
initiated, 87,300 pounds (32,400 pounds BOD) per day of...
A group of trout that reside in streams of the desiccating lake
basins of southeastern Oregon differ markedly from other known
Salmo. Known commonly as the red-band trout, this fish was subjected
to chromosome analysis for comparison with other species of
western North American Salmo. The karyotype of the red-banded...
Neuromuscular physiology has been extensively investigated
in several groups of vertebrates excluding fish. To
understand the nature of neuromuscular transmission in this
group, the response of the pectoral fin abductor muscle of
black bass (Micropterus salmoides) to nerve stimulation
under the influence of an anticho1inesterase agent was
studied. Diisopropylfluorophosphate (DFP),...
Light availability strongly influences stream primary production, water temperatures and resource availability at the base of stream food webs. In headwater streams, light is regulated primarily by the riparian forest, but few studies have evaluated the influence of riparian forest stand age and associated structural differences on light availability. In...
A method for predicting the harvest of commercial Dungeness
crab (Cancer magister) one year in advance of the fishing season is
described. The technique is based on the hypothesis that the relative
abundance of sub-legal crabs one year is directly proportional to the
harvest of legal crabs the following year....
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,...
Differences in the chemical composition of calcified skeletal structures (e.g. shells, otoliths) have proven useful for reconstructing the environmental history of many marine species. However, the extent to which ambient environmental conditions can be inferred from the elemental signatures within the vertebrae of elasmobranchs (sharks, skates, rays) has not been...
Identifying drivers of contact rates among individuals is critical to understanding disease dynamics and implementing targeted control measures. We studied the interaction patterns of 149 female elk (Cervus canadensis) distributed across five different regions of
western Wyoming over three years, defining a contact as an approach within one body length...
Juvenile coho salmon (Oncorhynchus kisutch) of three transferrin
genotypes (AA, AC and CC) were experimentally infected with the
causative agent of bacterial kidney disease (BKD) and mortalities
observed. Six experimental and control groups were used:
(1) bacteria-infected + no Fe⁺³ ; (2) bacteria-infected + low Fe⁺³
levels; (3) bacteria-infected +...
Three products derived from shrimp processing waste (Pandalus
jordani) and a protein concentrate extracted from king crab waste
(Paralithodes camschatica) were evaluated as feed supplements for
standard dark and sapphire pelter mink (Mustela vison) replacing
approximately 10 and/or 20 percent of the protein in a standard wet
diet (33 percent...
Temporal changes in gene frequencies and genotype frequencies,
monthly densities, survival rates, growth rates, trap susceptibility
and home ranges were evaluated from 291 Nuttall's cottontails
(Sylvilagus nuttallii) captured 950 times by livetrapping and 53 cottontails
collected by shooting. Electrophoretic analyses of sera revealed
protein polymorphism at the transferrin locus in...
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.
Four streams-Clear Fork, Lost Creek, Camp Creek and Still Creek-in northwestern Oregon's Sandy River Basin were monitored for temperature, dissolved oxygen levels, and fecal bacterial concentrations in a multi-year analysis examining stream health for recreational users and anchor habitat for Pacific Salmon. Temperatures were recorded using micro -T temperature loggers...
The Rusty Blackbird (Euphagus carolinus) has suffered significant population declines across its entire geographic range and the mechanisms associated with this decline are poorly understood. Although much of the Rusty Blackbird breeding habitat in Alaska has remained relatively unaltered by anthropogenic activities, this species continues to decline by an estimated...
I investigated changes in plasma cortisol concentration over time in juvenile salmonids subjected to various stressors that might be encountered in their normal life cycle. This work was directed at finding a general indicator for stress in fish that could be used be used to aid fisheries research and management....
Most parasites and their hosts live in a balance within their environment; however a disease outbreak can occur when either the parasite, host, or environment, are perturbed. Myxozoan parasites are associated with a wide variety of cultured and wild fish populations. Most myxozoans are relatively benign to their vertebrate host;...
The first objective of this study was to quantify the intensity of space use of 70 juvenile (12-26 months old) Steller sea lions (SSLs) from the western Distinct Population Segment (DPS) in the Kenai Fjord(KF)/Prince William Sound (PWS) region of Alaska as derived from externally attached ARGOS satellite transmitter tags....
The endangered Hawaiian Duck (koloa maoli; Anas wyvilliana), a non-migratory and island-endemic species, experienced a significant population decline during the twentieth century due to factors such as habitat loss, overharvest, introduced mammalian predators, and hybridization with introduced feral Mallards (A. platyrhynchos). A key objective for Hawaiian Duck recovery is to...
Wild turkeys (Meleagris gallopavo) were first successfully introduced into Oregon and Washington in the 1960s; the population has grown in size and expanded in distribution to a point where it provides an important recreational hunting opportunity in both states that generates significant funds for habitat conservation and contributes financially to...
A trawling survey was conducted on Nyanza Gulf, Lake
Victoria, East Africa during March-December 1975 to investigate
association and distribution of the major fish species
and to provide information for management of the fishery.
A total of 139 sites was sampled and all fishes caught were
counted, measured, and weighed....
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...
We investigated the movements and selection of settlement sites of translocated pygmy rabbits (Brachylagus idahoensis) in southeastern Oregon from June to December 2008. We captured, radio tagged, and translocated 59 pygmy rabbits across big sagebrush (Artemisia tridentata ssp.) habitat with 3 categories of landscape fragmentation. We used radio telemetry to...
Studies of the effects of forest harvest on streams and fish have a long history in the Pacific Northwest. Results of this work have prompted development of new forest harvest practices that are more protective of these resources, but the effectiveness of these new practices has not been fully evaluated....
The undergradtuate research project was the completion, manipulation and assessment of a population model. The stage based population model assessed the late larval and juveniles stages of the hard shell clam Mercenaria mercenaria. There were seven class sizes input into the model starting with pediveligers and ending with juveniles at...
This research provides information on the distribution of an
unexploited Roosevelt elk population in unaltered habitat in Olympic
National Park. Radio-telemetry was used to document home range and
habitat use by 11 adult cow elk in the Hoh Valley during March 1978,
from 10 June-15 September 1978, and from 1...
In 1976 and 1977 I examined three broad problems associated with the recruitment of young mallards, Anas platyrhynchos, in the Prairie Pothole Region of North Dakota. The three problems studied were: the effects of interspecific nest parasitism on production; the chronology and magnitude of total-brood loss during the brood-rearing period;...
The distribution and trophic ecology of neritic reef fishes was
studied to provide biological information useful in conserving these
stocks. Houk and line fishing was conducted from July 1976 to July
1977 on neritic reefs within 5 km of the Oregon coast adjacent to
Depoe Bay. Sampling was designed to...
The effects of prescribed burning on the abundance, species
composition, and reproduction of small mammals were studied over a
one year period. Two burn areas were studied, one in sagebrush/
bunchgrass and one in cheatgrass. The short-term effects were
studied using monthly mark-recapture trapping on two treatment and
two control...