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 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 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 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/...
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...
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...
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...
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...
A study was conducted at Yaquina Bay, Oregon, to determine
the age-fecundity relationships in the striped seaperch Embiotoca
lateralis. A questionnaire was sent to California, Oregon, and
Washington to ascertain what regulations were in effect, and the value
of the family Embiotocidae with regard to the sport and commercial
harvest....
Five species of aquatic organisms were exposed to TCDD. Lethal effects of initial exposure to coho salmon of 23.4 nanogram TCDD/gram fish wet weight (23.4 ng/g), or equivalent to 100 nanogram
per liter (100 ng/l) TCDD in water, for 24 hours were irreversible; 95% mortality occurred in 60 days. Exposure...
Precocious male coho are of limited economic value and control of their numbers returning to the hatchery or the increased survival of full-sized adults would be beneficial. Factors influencing
early sexual maturation and attempts to suppress this maturation of males through the incorporation of a hormone in the diet, treatment...
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...
Aspects of the limnology and benthic ecology of Upper Klamath Lake, Oregon, are described emphasizing those features that identify its uniqueness. The lake is large, shallow, and characterized by nuisance abundances of Aphanizomenon flos-aquae and midge flies. Results of this study indicate that it does not stratify and dissolved oxygen...
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...
