Age at Maturity, Fork Length, and Sex Ratio of Upper Willamette River Hatchery Spring Chinook Salmon

2013 ◽  
Vol 33 (2) ◽  
pp. 318-328 ◽  
Author(s):  
Marc A. Johnson ◽  
Thomas A. Friesen
Keyword(s):  
Sex Ratio ◽  
Chinook Salmon ◽  
Fork Length ◽  
Age At Maturity ◽  
Willamette River

Changes in life history parameters in a naturally spawning population of chinook salmon (Oncorhynchus tshawytscha) associated with releases of hatchery-reared fish

1997 ◽  
Vol 54 (6) ◽  
pp. 1235-1245 ◽  
Author(s):  
M J Unwin ◽  
G J Glova
Keyword(s):  
Life History ◽  
New Zealand ◽  
Chinook Salmon ◽  
Life History Traits ◽  
Oncorhynchus Tshawytscha ◽  
Fork Length ◽  
Age At Maturity ◽  
Natural Origin ◽  
Parent Stock ◽  
Stream Type

Chinook salmon (Oncorhynchus tshawytscha) spawning runs in Glenariffe Stream, New Zealand, exhibited significant changes in life history traits following supplementation releases of hatchery-reared juveniles. Total run strength did not change but the proportion of naturally produced fish declined to 34%. Attempts to separate spawners of natural and hatchery origin were unsuccessful, and 31-48% of natural spawners are now of hatchery origin. Hatchery males were smaller at age 2 and 3 than males of natural origin, and more often matured as jacks, producing an 86-mm decrease in mean fork length over 28 years. There was no change in length at age or age at maturity for female spawners. The proportion of jacks entering Glenariffe Stream each year was positively correlated with the proportion of jacks in the ensuing cohort. Most differences between fish of natural and hatchery origin were related to hatchery rearing practices, but the decline in age at maturity among naturally produced males appears to reflect traits inherited from parent stock of hatchery origin. Hatchery releases may also favour the survival of ocean-type fry over stream-type fry, possibly reversing a tendency for stream-type behaviour to evolve in response to the lack of estuaries on most New Zealand chinook salmon rivers.

An Evaluation of Rearing Densities to Improve Growth and Survival of Hatchery Spring Chinook Salmon

2013 ◽  
Vol 4 (1) ◽  
pp. 114-123 ◽  
Author(s):  
Douglas E. Olson ◽  
Michael Paiya
Keyword(s):  
Mortality Rate ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Confounding Factor ◽  
Fork Length ◽  
High Density ◽  
Growth And Survival ◽  
Migration Timing ◽  
Rearing Density ◽  
Salmon Stock

Abstract We evaluated growth and survival of spring Chinook salmon Oncorhynchus tshawytscha reared at varying densities at Warm Springs National Fish Hatchery, Oregon. For three consecutive brood years, density treatments consisted of low, medium, and high groups in 57.8-m3 raceways with approximately 16,000, 24,000, and 32,000 fish/raceway, respectively. Fish were volitionally released in both the autumn and spring to mimic the downstream migration timing of the endemic wild spring Chinook salmon stock. Just prior to the autumn release, the rearing density estimate was 4.24 kg/m3 for the low-density group, 6.27 kg/m3 for the medium-density group, and 8.42 kg/m3 for the high-density group. While weight gain did not differ among density treatments (P  =  0.72), significant differences were found in median fork length (P < 0.001) for fish reared at different densities. Fish reared at high density exhibited the highest on-hatchery mortality rate during two brood years; however, differences in mortality rate among densities were not significant (P  =  0.20). In one brood year, adult recovery rates appeared to support the hypothesis that lower initial densities improved postrelease survival (P < 0.01). All rearing densities utilized in this evaluation were relatively low and may partially explain why more differences were not readily apparent among density groups. In addition, the volitional release was a confounding factor in our study because we were unable to quantify the number of fish released in the autumn.

Tissue toxicants and prespawn mortality in Willamette River Chinook salmon

2020 ◽  
Vol 103 (2) ◽  
pp. 175-183
Author(s):  
Matthew L. Keefer ◽  
George P. Naughton ◽  
Tami S. Clabough ◽  
Matthew J. Knoff ◽  
Timothy J. Blubaugh ◽  
...  
Keyword(s):  
Chinook Salmon ◽  
Willamette River

Growth and Reproduction of the Lake Whitefish, Coregonus clupeaformis, in Lac la Ronge, Saskatchewan

1968 ◽  
Vol 25 (10) ◽  
pp. 2091-2100 ◽  
Author(s):  
S. U. Qadri
Keyword(s):  
North America ◽  
Sex Ratio ◽  
Life Span ◽  
Fork Length ◽  
Growing Season ◽  
Coregonus Clupeaformis ◽  
Lake Whitefish ◽  
Young Fish ◽  
Large Lakes ◽  
Growth And Reproduction

In Lac la Ronge the lake whitefish (Coregonus clupeaformis (Mitchill)) spawned from late October until the middle of November at ages of 8 years and over. The growing season lasted from late May to early October and young fish grew faster than older ones and tended to have a longer growing season. Ages for 1604 fish taken during 4 years showed that they grew to a fork length of about 16 inches in 10 years, the rate being slower than for lake whitefish in other large lakes in North America. The length-weight relationships were linear: for the open lake, log W = 3.48 log L – 3.93, and for Hunter Bay, log W = 3.26 log L – 3.66. The males matured a little earlier than females and their life span was somewhat shorter. The sex ratio was approximately 1:1.

Tidal movements and residency of subyearling Chinook salmon (Oncorhynchus tshawytscha) in an Oregon salt marsh channel

2010 ◽  
Vol 67 (3) ◽  
pp. 524-533 ◽  
Author(s):  
David K. Hering ◽  
Daniel L. Bottom ◽  
Earl F. Prentice ◽  
Kim K. Jones ◽  
Ian A. Fleming
Keyword(s):  
Salt Marsh ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
River Estuary ◽  
Fork Length ◽  
Full Duplex ◽  
Salmon River ◽  
Salt Marsh Habitat ◽  
Tidal Cycles ◽  
Insight Into

A novel application of full-duplex passive integrated transponder (PIT) tag technology was used to investigate movements of individual subyearling Chinook salmon ( Oncorhynchus tshawytscha ; fork length ≥ 60 mm) into and out of tidally flooded salt marsh habitat in the Salmon River estuary, Oregon, USA. PIT interrogation was effective, with mean tag detection ≥ 92%. Salmon movement peaked late during both flood and ebb tide periods, indicating that salmon did not drift passively. Most movements were in the direction of tidal currents, but 20% of individuals entered the channel against the ebbing tide. Individuals occupied the intertidal channel for a median 4.9 h and as long as 8.9 h per tidal cycle, and few were detected moving when water depth was <0.4 m. Some individuals used the channel on multiple successive tidal cycles, and others entered intermittently over periods of up to 109 days. Using an individual-based approach, we characterized diversity of juvenile Chinook salmon behavior within a marsh channel, providing insight into the value of such habitats for conservation and restoration of salmon populations.

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.

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