The 1988 status of yellowtail flounder stocks off the U.S. coast
of the Northwest Atlantic is assessed using U.S. and distant water
fleet commercial fishery statistics and Northeast Fisheries Center
bottom trawl survey data. Assessments of Southern New England and
Georges Bank stocks are revised using virtual population analysis of...
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...
Ptychoptera townesi (false crane fly, Diptera) occur in high densities in an experimental stream section that has not been allowed to exceed bankfull flow for more than two decades, but are quite rare in areas both upstream and downstream from this section. By contrast, Paraleptophlebia spp. (mayfly, Epherneroptera) are relatively...
A comparative analysis of structures related to
capture and processing of food, in 624 specimens belonging
to 31 species of Sebastes of Oregon was made. The
structures studied were the following: the tooth-bearing
bones (premaxillary, dentary, vomer, palatine); the
maxillary, angular, articular, parasphenoid and glossohyal
bones; the lower limb of...
Biliary excretion of taurocholate in thermally acclimated rainbow trout was stimulated at higher environmental temperature (18 vs. 14 or 10° C)e Acute 4° C shifts in body temperature produced more pronounced changes in biliary excretion. Thermally modulated biliary excretion was negatively correlated with plasma half live of taurocholate. Absorption of...
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 movements, habitat use, and activity patterns of black-tailed deer in western Oregon, and the influence of suburban housing developments on the behavior of deer in the area, were studied and described. Radio telemetry, spotlight censusing, and a resident questionnaire were used to document the behavior of deer. Radio telemetry...
Crosses were made between a stock of summer steelhead (Salmo
gairdneri) known to be resistant to infection by Ceratomyxa
shasta and stocks of summer steelhead known to be susceptible.
Ceratomyxosis, the disease caused by C. shasta was initiated by
exposure to Willamette River water. I found that the crosses
were...
In higher vertebrates, normal digestion and absorption by the
gastrointestinal tract are dependent on the orderly and controlled
transit of intraluminal contents. A relationship between fluid
passage through the gut and absorption from the gut has yet to be
examined in fish. In marine teleosts, the osmolality and ion concentration...
Samples of weathervane scallops taken on Oregon Department of
Fish and Wildlife cruises off Oregon waters during 1981-1982 were
analyzed for a comparative growth study. No evidence of internal
growth marks were found in the shell structure when analyzed by the
acetate peel technique. Internal growth lines formed in the...
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...
Total copper concentrations of 10 [mu]g/l to 100 [mu]g/l appeared to
alter the predator-prey interactions of fathead minnows (Pimephales
promelas) and Daphnia pulex. The effect of copper concentration on
the total amounts of D. pulex consumed over a 12-h period varied with
the density of prey stocked hourly in the...
The goal of this study was to better understand stream communities through a perspective that might make their structure, organization, and development more understandable. This goal was approached
through the following objectives:
1. To determine the assemblages of stream organisms and define subsystems within a stream community.
2. To explain...
The Oregon chub. Oregonichthys crameri. one of
Oregon's endemic freshwater fishes. is restricted to the
Willamette and Umpqua rivers and their tributaries.
Specimens from the two rivers have traditionally been
considered the same species. The goal of this study was to
re-examine that assumption and determine if the Willamette
Oregon...
Seventeen populations of Gila Baird and Girard are identified from the Alvord Basin of southeastern Oregon and northwestern Nevada. Gila in the Alvord Basin occupy a wide range of habitats, including warm springs, cool springs, creeks, reservoirs, and a thermal lake. These populations became isolated in remnant habitats when waters...
From July 1985 to April 1987 the pelagic zooplankton community of Crater Lake, Oregon was studied to determine taxonomic structure, absolute and relative densities, and spatial and temporal distributional patterns. Samples were collected using vertically-towed zooplankton nets. The community structure consisted of two cladoceran and nine rotifer species, which were...
Regions of similar species composition and groups of demersal fish
species with similar distribution patterns from Cape Flattery,
Washington to Point Hueneme from 50-250 fm (93-460 rn) were defined based
on results of an agglomerative cluster analysis of National Marine
Fisheries Service Rockfish Survey data taken during the summer of...
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...
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...
A study conducted May 1978-December 1980 determined that the present geographic range of Columbian white-tailed deer, Odocoileus virginianus leucurus, (CWTD) in Douglas County, Oregon encompassed 1199km2. The area was predominately a Quercus woodland community, typical of the Interior Valley Zone of western Oregon. The CWTD distribution
was not contiguous throughout...
A herd of California bighorn sheep (Ovis canadensis californiana),
re-introduced to the area of Hell Creek on the Sheldon National
Wildlife Refuge in northwestern Nevada, was studied from 15 June 1978
to 20 August 1980.
Major vegetation and physiographic types were delineated and
described. Habitat preferences were determined from field...
Five sympatric species of desert lizards (leopard lizards (Garnbelia wizlizeni), sagebrush lizards (Sceloporus graciosus), side-blotched. lizards (Uta stansburiana), desert horned lizards
(Phrynosoma platyrhinos), and Western whiptails (Cnemidophorus tigris)) were studied in June and July of 1978 and 1979 in northern Nevada on the Charles Sheldon National Wildlife Refuge. Lizard
distribution,...
The possibility of reduced abundance of western snowy plovers
(Charadrius alexandrinus nivosus) in the face of an altered habitat
prompted a study of snowy plover breeding activities and nesting
habitat on the Oregon coast during 1978 and 1979. At 4 study areas
with varying levels of recreational use, nests were...
Between 1982-1984 I studied site tenacity and mate retention in Black Terns at Sycan Marsh, Lake County, Oregon. I banded 778 adult Black Terns and used this marked population to test the hypotheses that site tenacity and mate retention would be less for Black Terns which nest in variable marsh...
English sole is a major contributor to Oregon and Washington groundfish resources. In accordance with the continued trend of increasing fishing effort, in 1975 Oregon State University Sea Grant
funded an extensive groundfish research program: the Pleuronectid Project. The purpose was to provide information to assist resource management agencies. This...
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...
Selected life history aspects of American shad, Alosa
sapidissima, collected in Lake Umatilla of the Columbia River
during 1980 and 1981 were examined and compared to other shad
populations. Mean fork lengths of adult shad captured in
1981 were 405-, 415- and 423-mm for age III, IV and V males;...
Seasonal habitat availability, utilization, and selection by young
of the year (< 25 mm) and adult (>25 mm) redside shiner, Richardsonius
balteatus, were studied for 1 year in sections of Greasy Creek, Benton
County, Oregon. Intensive stream mapping procedures and snorkling
observations provided most of the quantitative measures for habitat...
The distribution of adult Pacific herring (Clupea harengue
pallasi) near Auke Bay, Lynn Canal, southeastern Alaska, varied by
depth and geographic area over 24 successive months during 1973-75.
From June through September, schools concentrated at 5- to 37-m
depths where zooplankton was abundant, and moderate currents were
present in a...
Daily and seasonal habitat use by Roosevelt elk was investigated
in the Oregon Coast Range on managed, public forestland. Over 3,700
locations of 6 radio-collared cow elk were recorded during 12 consecutive
months. Two elk formed part of a north band and 4 elk were
part of a south band....
The relationships between avian community structure and herbicide
modification of vegetation were analyzed on early-growth clearcuts in
western Oregon that had received phenoxy herbicide treatment 1 or
4 years previously. Only minor effects of herbicide treatment were
evident 1-year after spraying, except for red adler (Alnus rubra),
which still exhibited...
Patterns of resource partitioning among 4 sympatric sturnids: [black-collared starling (Sturnus nigricollis), pied starling (S. contra), common myna (Acridotheres tristis) and crested myna (A. javanicus) were determined based on their food habits, foraging and nesting microhabitat selection, morphology and behavior. The study was
conducted from March 1986 to June 1988...
In a native prairie of Oregon (363 km²) red-tailed (Buteo jamaicensis), ferruginous (Buteo regalis), and Swainson's hawks (Buteo swainsoni) coexist in one of the highest nesting Buteo densities in North America. In 1979 and 1980, the distribution, density, and productivity of the three species was studied in relation to availability...
Whole body accumulation and tissue distribution of dieldrin
(HEOD1) in rainbow trout was studied through oral dose disposition
tests and subchronic exposures via water (0.04 and 0.08 jig dieldrin/l)
and/or diet (0.087 jig dieldrin/g fish/day). Growth and maintenance
rations of 4 and 2% body weight/day were employed. Subchronic testing
produced...
Chum salmon from different stocks were bred together in two experiments. Three stocks contributed gametes to one experiment, two stocks to another. Sibling groups of eggs, alevins, and fry were maintained in a common environment. Variability of development rates, rearing performance, susceptibility to disease, and behavioral traits was partitioned into...
An analysis was conducted to estimate the minimum mesh
size for managing the common Chilean hake (Merluccius gayi)
fishery. Secondary objectives were to establish the
selective relationship between mesh size and fish length,
to examine growth patterns and related parameters, and to
estimate the critical age (or optimum size) at...
The abundance and biomass of cutthroat trout (Salmo clarki) have
been found to be greater in logged than in forested streams of the
Oregon Cascades. Although certain prey taxa increase in abundance
following logging, habitat stability generally decreases and cover
structures are removed. Research was conducted to examine the manner...
Periodic determinations of plasma hormone levels suggested that changes in interrenal activity are unrelated to changes in thyroidal or gonadal activity during development (smoltification) of juvenile coho salmon (Oncorhynchus kisutch). Moreover, in an experiment where fish were reared under various conditions of crowding and water inflow rate, it appeared that...
Hypotheses of phylogenetic and historical zoogeographic relationships of glyptocephalines (Glyptocephalus cynoglossus, G. zachirus, G. stelleri, Microstomus kitt, H. pacificus, H. achne,
Embassichthys bathybius, and Tanakius kitaharae) were constructed based on comparative anatomy and external morphology. The phylogenetic approach was cladistic and character polarity was
determined by using out-group comparison. One...
Organization and the adaptation of aquatic laboratory ecosystems
to resource availability, exploitation, and a toxicant were examined in
a 34-month study. Sixteen 560-liter microcosms including prey,
predator, and competitor populations were employed over a wide range
of energy and habitat resource availability and exploitation of the top
predator. Chronic exposure...
Recreational angling pressure has recently increased in the neritic
reef areas off the central Oregon coast. This study describes
weight-length and age-length relationships as well as ages at sexual
maturity of the black, blue, canary, yelloweye, and yellowtail rockfish
(Sebastes melanops, S. mystinus, S. pinniger, S. ruberrimus, and
S. flavidus,...
A tagging study was conducted from June 1978 through January 1982
to provide information on the movements of adult neritic reef fishes
off the central Oregon coast. To evaluate the cause of low tag
returns of previous tagging studies of reef fish in this area, tag
retention, post-tagging mortality, and...
Descendants of eastern cottontails from Ohio
(Sylvilagns floridanus) introduced in Benton County,
Oregon and cottontails from Ohio were sampled and
analyzed morphometrically and colorimetrically. In
general, Oregon cottontails were smaller and lighter in
color than Ohio rabbits. Introgression and interspecific
competition with the smaller and darker colored native
brush rabbit...
Factors that influenced the uptake, storage, and elimination of dietary quinoline by rainbow trout (Salmo gairdneri) were studied to obtain an understanding of the mechanisms affecting the bioaccumulation of dietary contaminants in teleosts. Rainbow trout readily absorbed ¹⁴C-quinoline from pelleted food (1% ration at 138 ug quinoline/g food) and most...
Questions of assemblage persistence, resiliency arid continuity in time were investigated with data from seasonal bottom trawl surveys conducted by the Northeast Fisheries Center, Woods Hole,
Massachusetts, from 1963-1978. Cluster analysis proved to be a useful statistical method for delineating assemblage boundries and corresponding resident demersal fish components from Georges...
Traditional approaches to research and management of striped
bass have tended to be mechanistic, numerically oriented, and
based on limited life history information. In the study
presented here, comprehensive conceptual perspective was used
in a multivariate study of life history and evolutionary
adaptation of 10 striped bass populations representing the...
Atlantic menhaden, compared to gulf menhaden, exhibit
a life history pattern that appears to be adapted to a more
unpredictable reproductive environment. From experiments
on laboratory-reared eggs and larvae, Atlantic menhaden have
larger eggs with larger yolk volume. They are larger at
hatching, utilize their yolk faster, begin feeding at...
Genetic, ontogenetic, and environmental factors modified characteristic interrenal and glycemic responses to stress in juvenile salmonid fishes. During continuous confinement stress, plasma cortisol rose more quickly in chinook salmon, Oncorhynchus tshawytscha, acclimated to high rather than medium or low temperatures; hyperglycemia following either acute or chronic stress was also highest...
Behavior of grizzly bears (Ursus arctos) toward people was
studied by examining hikers' reports of grizzly bear observations
and by intensively observing grizzlies in an area of Glacier National
Park that was heavily used by day-hikers. Of concern were the apparent
habituation of grizzly bears to people in the study...
Water temperature influenced interactions between redside
shiners and juvenile steelhead trout (≥1+) in the field and the
laboratory. Distribution of the two species within various habitats
was determined in three streams with different water temperature
regimes. The range of habitats occupied by trout in allopatry at
cool temperatures and at...
Reproduction of salmonid fishes in acidic water was studied
using the rainbow trout (Salmo gairdneri). Adult trout were exposed
to various levels of hydrogen ion (pH levels 4.5, 5.0, 5.5, and
control [6.5 to 7.1]) during the final 6 weeks of reproductive
maturation. Reduced survival rates of the progeny of...
Within the tested range of 1000 - 7000 eyed eggs/ft² gravel substrate (1.08 - 7.53 eggs/cm²), the optimum stocking density for chum salmon (Oncorhynchus keta) eggs in shallow matrix substrate incubators occurred at 3000 - 4000 eggs/ft². Premature fry, which predominated early emergence, showed greater variability in lipid content than...
Shallow-water habitats (< 0.5 m depth) of the upper littoral zone of John Day Pool of the Columbia River were heavily used by young fishes in comparison with lower littoral and limnetic waters. Through the season, 96.9% of the 64,700 larvae and juveniles collected (corrected for effort) were from upper...
The hypotheses to be tested in this investigation are: 1) there is a threshold level of liver lipid and glycogen content above which the health condition of hatchery-reared fish is impaired, 2) fatty and high glycogen livers impair liver function and structure, and 3) fatty and high glycogen livers increase...
Kesterson Reservoir (Kesterson) received subsurface agricultural drainwater containing high levels of salts and other minerals from farmland in the San Joaquin Valley of California. Aquatic plants and invertebrates were sampled at Kesterson in May, August, and December of 1984. The reservoir supported a different biota and lower species diversity than...
Complete, identified, developmental series of larval cottids
Artedius fenestralis, A. creaseri, A. meanyi, Oligocottus snyderi,
Clinocottus embryum, and C. globiceps are described for the first
time. In addition, redescriptions of four species, Artedius harringtoni,
A. lateralis, Oligocottus maculosus, and Clinocottus acuticeps
are included that provide new and comparative information on...
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...
Eight adult spotted owls (Strix occidentalis) on the west slope of the Cascade Range in Oregon were fitted with radio transmitters and observed for periods ranging from 271 to 383 days. Mean home range size for the owls was 1,177 ha (range = 920-1,376 ha). There was no significant difference...
Ninety-one species of birds were surveyed in grass/forb, early and late shrub/sapling, pole, and medium sawtimber stages of young-growth Douglas-fir in northwestern California; patterns of bird distribution and abundance were related to habitat conditions and even-age silvicultural treatments. Seven species (band-tailed pigeon, western wood pewee, dusky flycatcher, western bluebird, fox...
The objectives of this study were to determine the
location and extent of populations of pygmy rabbits in Oregon,
and to describe several biotic and physical components within
communities that include pygmy rabbits. Interpretation of
aerial photographs, and information obtained from soil maps
and interviews with biologists and area residents,...
A framework is presented for a more causal explanation and ordering of stream characteristics than traditional means have used. Patterns of stream habitat distribution are related to particular characteristics of the geomorphology of watersheds. Variability in stream characteristics can be explained by the spatial distribution of properties of the watershed...
Diets and foraging strategies of Glaucous-winged Gulls were
studied in areas with and without sea otters in the western Aleutian
Islands, Alaska. Gulls foraged on invertebrates (e.g., sea urchins,
limpets, chitons, mussels, and others) in the rocky intertidal
community and on fish at sea; this study was conducted on gulls...
Seven species of water-dependent birds (northern phalarope,
Phalaropus lobatus; American avocet, Recurvirostra americana; Wilson's
phalarope, P. tricolor; eared grebe, Podiceps nigricollis;
ring-billed gull Larus delawarensis; California gull, L.
californicus; and northern shoveler, Anas clypeata) were studied
during the fall migrations of 1982 and 1983 to determine the diets and
foraging...
Radio-telemetry and scat analysis were used to investigate daily and seasonal movement patterns and food selection of a protected coyote population on Tulelake National Wildlife Refuge (TLNWR) and adjacent Lava Beds National Monument (LABE) in northeastern California. Study emphasis was on evaluation of movements on and off the sanctuary, and...
A population of Nuttall's cottontails (Sylvilagus nuttallii) in Deschutes County, Oregon, decreased fromm 166 individuals in August 1978 to 76 individuals in August 1979. Survival rates of four annual litter groups in 1978 were 0.74, 0.35, 0.72, and 0.93; survival rates for the same litter groups, respectively, in 1979 were...
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...