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...
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 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 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 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 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...