Projected intensification of drought as a result of climate change may reduce the capacity of streams to rear fish, exacerbating the challenge of recovering ESA-listed salmon populations. Without management intervention, some stocks will likely go extinct as stream drying and fragmentation reduce juvenile survival to unsustainable levels. To offset drought-related...
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...
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.
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...
Experiments were carried out in fall and winter, 1990
and spring and summer, 1991 , to determine growth and
mortality of juvenile Pacific oysters {Crassostrea gigas)
in effluent from cultured coho salmon {Oncorhynchus
kisutch) , and effluent from salmon in which the red
macroalga Palmaria mollis was cultured. Ambient sea...
Eight scale characters of known hatchery and wild coho salmon
(Oncorhynchus kisutch) were compared, and a linear discriminant
function was used to determine if hatchery and wild adult coho
salmon could be correctly identified by their scales. Eighty-two
percent of the hatchery and 89% of the wild fish were correctly...
The objective of this research was to study the effects of increased water temperature characteristic of clearcut watersheds of Pacific coastal streams upon the growth rate of juvenile coho salmon. The natural temperature fluctuations of the stream were used in the study of growth of underyearling fish held in aquariums...
Rates of birth, death and population change were calculated for Cyclops sp. and Diaptornus forbesi in Soap Creek Ponds V-VIII near Corvallis, Oregon during the interval April, 1968 to April, 1969. An egg ratio method was used in calculating these rates. Duration of development of the eggs of both species...
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...
Large numbers of coho salmon (Oncorhynehus kisutch) fry move downstream shortly after emergence from the gravel in many spawning tributaries. In three small coastal streams of Oregon about eight times more juveniles leave the tributaries as newly emerged fry than as smolts one year later. Because these early emigrants comprise...
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...
This study examines the ecology and dynamics of coho salmon (Oncorhynchus kisutch) in environments experimentally altered by logging. The objective was to evaluate processes that stabilize or regulate the populations. Two small watersheds in Oregon's Coast Range were logged in
1966, one clear-cut, the other patch-cut. A third adjacent watershed...
Juvenile coho salmon (Oncorhynchus kisutch (Walbaum)) and aquatic invertebrates were subjected to experimentally increased, but naturally fluctuating, temperatures in a model stream channel. Coho of the 1969, 1970, and 1971 year classes were reared in the heated model stream and in an unheated control stream, both located at the Oak...
Phenotypic similarities of coho salmon (Oncorhynchus kisutch)
stocks from Oregon, Washington, and California were compared using
agglomerative and divisive cluster analyses. The phenotypic characters
evaluated included the following: 1) the isozyme gene frequencies
of transferrin and phosphoglucose isomerase; 2) the life history
characters time of peak spawning and proportion of...
Detection of L-serine and D,L-alanine by juvenile coho salmon (Oncorhynchus kisutch) was measured in a two-choice Y-trough. Threshold concentration for olfactory
detection of L-serine was 10-8 M for zero-age parr, 1O-7 M for yearling parr, 10-5 M for smolts in late April-early May, and 10-6 M for smolts in June....
