The dissolved oxygen requirements of upstream migrant chinook salmon, Oncorhynchus tshawytscha, in the lower Willamette River, Oregon

1988 ◽  
Vol 32 (4) ◽  
pp. 635-636 ◽  
Author(s):  
J. S. Alabaster
Keyword(s):  
Dissolved Oxygen ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Willamette River ◽  
Oxygen Requirements

scholarly journals Juvenile life-history diversity and population stability of spring Chinook salmon in the Willamette River basin, Oregon

2016 ◽  
Vol 73 (6) ◽  
pp. 921-934 ◽  
Author(s):  
R. Kirk Schroeder ◽  
Luke D. Whitman ◽  
Brian Cannon ◽  
Paul Olmsted
Keyword(s):  
Life History ◽  
River Basin ◽  
Chinook Salmon ◽  
Life Histories ◽  
Oncorhynchus Tshawytscha ◽  
Juvenile Salmon ◽  
Population Stability ◽  
Willamette River ◽  
June July ◽  
Willamette River Basin

Migratory and rearing pathways of juvenile spring Chinook salmon (Oncorhynchus tshawytscha) were documented in the Willamette River basin to identify life histories and estimate their contribution to smolt production and population stability. We identified six primary life histories that included two phenotypes for early migratory tactics: fry that migrated up to 140–200 km shortly after emergence (movers) and fish that reared for 8–16 months in natal areas (stayers). Peak emigration of juvenile salmon from the Willamette River was in June–July (subyearling smolts), March–May (yearling smolts), and November–December (considered as “autumn smolts”). Alternative migratory behaviors of juvenile salmon were associated with extensive use of diverse habitats that eventually encompassed up to 400 rkm of the basin, including tributaries in natal areas and large rivers. Juvenile salmon that reared in natal reaches and migrated as yearlings were the most prevalent life history and had the lowest temporal variability. However, the total productivity of the basin was increased by the contribution of fish with dispersive life histories, which represented over 50% of the total smolt production. Life-history diversity reduced the variability in the total smolt population by 35% over the weighted mean of individual life histories, providing evidence of a considerable portfolio effect through the asynchronous contributions of life histories. Protecting and restoring a diverse suite of connected habitats in the Willamette River basin will promote the development and expression of juvenile life histories, thereby providing stability and resilience to native salmon populations.

Evaluating a multi-generational reintroduction program for threatened salmon using genetic parentage analysis

2016 ◽  
Vol 73 (5) ◽  
pp. 844-852 ◽  
Author(s):  
Melissa L. Evans ◽  
Marc A. Johnson ◽  
Dave Jacobson ◽  
Jinliang Wang ◽  
Michael Hogansen ◽  
...  
Keyword(s):  
Chinook Salmon ◽  
Flood Control ◽  
Oncorhynchus Tshawytscha ◽  
Parentage Analysis ◽  
The South ◽  
Mature Adult ◽  
Wild Salmon ◽  
Willamette River ◽  
Old Adult ◽  
Population Demographic

Dams, utilized for hydroelectric or flood control purposes, obstruct organism dispersal and have contributed to the decline of many migratory fish populations. For threatened Chinook salmon (Oncorhynchus tshawytscha) from the Willamette River Basin in Oregon, human-assisted reintroductions are being used to facilitate dispersal to historical habitats located above dams. However, little is known about the reproductive outcomes of reintroduced individuals or the efficacy of reintroductions towards the goal of population demographic viability. Using genetic parentage assignments to 3-, 4-, and 5-year-old adult recruits, we estimated the fitness of hatchery and wild Chinook salmon reintroduced above Foster Dam on the South Santiam River, a tributary of the Willamette River. Our parentage assignments indicated that the fitness of reintroduced salmon was highly variable, with individuals producing a range of 0–40 adult progeny. We also detected a possible trend towards reduced fitness in mate pairs composed of hatchery versus wild salmon. For each of three brood years (2007, 2008, 2009), adult offspring recruitment achieved or exceeded population replacement. We observed the highest cohort replacement rate in 2009, the first year that managers aimed to release wild salmon solely above the dam. Taken together, our results suggest that human-assisted reintroductions of mature adult salmon to historical spawning habitats are a promising method of restoring natural production in populations affected by dams. Moreover, the continued used of wild fish in reintroduction operations may improve population productivity and the prospect of recovery within the South Santiam River.

Hyporheic discharge of river water into fall chinook salmon (Oncorhynchus tshawytscha) spawning areas in the Hanford Reach, Columbia River

2000 ◽  
Vol 57 (8) ◽  
pp. 1647-1656 ◽  
Author(s):  
David R Geist
Keyword(s):  
Dissolved Oxygen ◽  
River Water ◽  
Chinook Salmon ◽  
Hyporheic Zone ◽  
Oncorhynchus Tshawytscha ◽  
Columbia River ◽  
Specific Conductance ◽  
Chemical Gradients ◽  
Spawning Areas ◽  
Hanford Reach

Fall chinook salmon (Oncorhynchus tshawytscha) spawned predominantly in areas of the Hanford Reach of the Columbia River where hyporheic water discharged into the river channel. This upwelling water had a dissolved solids content (i.e., specific conductance) indicative of river water and was presumed to have entered highly permeable riverbed substrate at locations upstream of the spawning areas. Hyporheic discharge zones composed of undiluted ground water or areas with little or no upwelling were not used by spawning salmon. Rates of upwelling into spawning areas averaged 1200 L·m-2·day-1 (95% CI = 784-1665 L·m-2·day-1) as compared with approximately 500 L·m-2·day-1 (95% CI = 303-1159 L·m-2·day-1) in nonspawning areas. Dissolved oxygen content of the hyporheic discharge near salmon spawning areas was about 9 mg·L-1 (±0.4 mg·L-1) whereas in nonspawning areas, dissolved oxygen values were 7 mg·L-1 (±0.9 mg·L-1) or lower. In both cases, dissolved oxygen of the river water was higher (11.3 ± 0.3 mg·L-1). Physical and chemical gradients between the hyporheic zone and the river may provide cues for adult salmon to locate suitable spawning areas. This information will help fisheries managers to describe the suitability of salmon spawning habitat in large rivers.

Systematic hexamitid (Protozoa: Diplomonadida) Infection in seawater pen-reared Chinook salmon Oncorhynchus tshawytscha

1992 ◽  
Vol 14 ◽  
pp. 81-89 ◽  
Author(s):  
ML Kent ◽  
J Ellis ◽  
JW Fournie ◽  
SC Dawe ◽  
JW Bagshaw ◽  
...  
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha

scholarly journals Managed Wetlands Can Benefit Juvenile Chinook Salmon in a Tidal Marsh

2021 ◽  
Author(s):  
Nicole M. Aha ◽  
Peter B. Moyle ◽  
Nann A. Fangue ◽  
Andrew L. Rypel ◽  
John R. Durand
Keyword(s):  
San Francisco ◽  
Growth Rates ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Nursery Habitat ◽  
San Francisco Estuary ◽  
Rice Fields ◽  
Fish Growth ◽  
Juvenile Chinook Salmon ◽  
Juvenile Chinook

AbstractLoss of estuarine and coastal habitats worldwide has reduced nursery habitat and function for diverse fishes, including juvenile Chinook salmon (Oncorhynchus tshawytscha). Underutilized off-channel habitats such as flooded rice fields and managed ponds present opportunities for improving rearing conditions and increasing habitat diversity along migratory corridors. While experiments in rice fields have shown enhanced growth rates of juvenile fishes, managed ponds are less studied. To evaluate the potential of these ponds as a nursery habitat, juvenile Chinook salmon (~ 2.8 g, 63 mm FL) were reared in cages in four contrasting locations within Suisun Marsh, a large wetland in the San Francisco Estuary. The locations included a natural tidal slough, a leveed tidal slough, and the inlet and outlet of a tidally muted managed pond established for waterfowl hunting. Fish growth rates differed significantly among locations, with the fastest growth occurring near the outlet in the managed pond. High zooplankton biomass at the managed pond outlet was the best correlate of salmon growth. Water temperatures in the managed pond were also cooler and less variable compared to sloughs, reducing thermal stress. The stress of low dissolved oxygen concentrations within the managed pond was likely mediated by high concentrations of zooplankton and favorable temperatures. Our findings suggest that muted tidal habitats in the San Francisco Estuary and elsewhere could be managed to promote growth and survival of juvenile salmon and other native fishes.

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