The red-band trout is native to many small, isolated streams in southeastern Oregon. A study of the red-band population of Three-
mile Creek and Reservoir was conducted from August 1973 to June 1975. Data were collected concerning population size, age composition,
growth, biomass, recruitment, fecundity, and habitat. During the spring...
Ninety-six hour acute toxicity bioassays were employed to
determine the tolerance of juvenile coho salmon to chlorinated
stabilized kraft mill effluent (SKME). In addition the effect of
chlorinated SKME on the growth of juvenile coho salmon in six and
ten day experiments was studied.
Results of the acute toxicity tests...
Predator-prey interactions, as measured by the consumption
and growth rates of a predator (Micropterus salmoides) and by the
observed activities of both predator and prey (Gambusia affinis),
were found to be sensitive to sublethal levels of ammonium chloride
(reported as unionized ammonia NH₃).
One bass and 15, 30, 60 or...
There is evidence that recent ecological changes in lakes and their watersheds can be detected from analysis of lake sediments. This study was initiated to correlate
changes in some sediment characteristics of four Oregon lakes with past cultural developments of the lakes and their watersheds. The lakes chosen for this...
Great Basin Canada goose (Branta canadensis moffitti) productivity and nesting habitat utilization were studied on the Columbia River within the boundaries of the Umatilla National Wildlife Refuge during the springs of 1974 and 1975.
Five islands, BL-1, BL-2, SD-1, SD-2, and Telegraph Island (TI), contained 88 percent of the nesting...
Long-term oceanographic and meteorological data were used to develop models that describe the observed variation in the recruitment of Pacific mackerel (Scomber japonicus) in the California
Current region. The models that were found to best describe recruitment included both density-dependent factors and environmental factors. Models incorporating only density-dependent factors
accounted...
Clinical methods to diagnose specific organ dysfunction have not been evaluated in fishes. To determine if an accepted clinical test of mammalian liver function could be applied to fishes, the
hepatic disposition of the organic anion sulfobromophthalein (BSP) was studied in rainbow trout (Salmo gairdneri) treated with a model hepatotoxicant....
Six standard coyote scent station index lines and one scentless control line were repeatedly sampled from May through October, 1974, on a 400 square mile study area in Central Oregon. The scent station index remained relatively constant at a mean value of 0.025 from May through mid-August; increased to a...
Relative growth and survival of offspring from matings of hatchery and wild Deschutes River (Oregon) summer steelhead trout, Salmo gairdneri, were monitored to determine if hatchery fish differ genetically from wild fish in traits which can affect the stock-recruitment relationship of wild populations. Four natural streams and a hatchery pond...
A study of population trends, nest site selection, and food habits of ospreys (Pandion haliaetus carolinensis) nesting on the Bend District of the Deschutes National Forest, Oregon, was conducted
during 1970 and 1971. Intensive observations were made of 95 nesting attempts of ospreys. Energy demands of the population were estimated...
The genotype frequencies of one-year-old oyster spat
(Crassostrea gigas) from parents of known genotype, are compared
to the frequencies expected with Mendelian inheritance. The genotypes
are characterized at three enzyme loci, Aspartate amino-transferase
(AAT), Phosphohexose isomerase (PHI) and Leucine
aminopeptidase (LAP), and a general protein locus. In this study
expression...