scholarly journals Spatial and temporal covariability in early ocean survival of Chinook salmon (Oncorhynchus tshawytscha) along the west coast of North America

2014 ◽  
Vol 71 (7) ◽  
pp. 1671-1682 ◽  
Author(s):  
D. Patrick Kilduff ◽  
Louis W. Botsford ◽  
Steven L. H. Teo
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Survival Rates ◽  
Central Valley ◽  
Vancouver Island ◽  
Regional Patterns ◽  
Migration Patterns ◽  
The Pacific ◽  
Spatial Coverage ◽  
Correlation Scale

Abstract Knowledge of the spatial and temporal extent of covariation in survival during the critical ocean entry stage will improve our understanding of how changing ocean conditions influence salmon productivity and management. We used data from the Pacific coastwide coded-wire tagging program to investigate local and regional patterns of ocean survival of Chinook salmon (Oncorhynchus tshawytscha) from the Central Valley of California to southeastern Alaska from 1980–2006. Ocean survival of fish migrating as subyearlings covaried strongly from Vancouver Island to California. Short-term correlations between adjacent regions indicated this covariability increased, beginning in the early 1990s. Chinook salmon survivals exhibited a larger spatial scale of variability (50% correlation scale: 706 km) than those reported for other northeast Pacific Ocean salmon. This scale is similar to that of environmental variables related to ecosystem productivity, such as summer upwelling (50% correlation scale: 746 km) and sea surface temperature (50% correlation scale: 500–600 km). Chinook salmon ocean survival rates from southeastern Alaska and south of Vancouver Island were not inversely correlated, in contrast to earlier observations based on catch data, but note that our data differ in temporal and spatial coverage from those studies. The increased covariability in Chinook salmon ocean survival suggests that the marine phase contributes little to the reduction in risk across populations attributable to the portfolio effect. In addition, survival of fish migrating as yearlings from the Columbia River covaried with Chinook salmon survival from the northernmost regions, consistent with our understanding of their migration patterns.

scholarly journals Survival of a threatened salmon is linked to spatial variability in river conditions

2021 ◽  
Author(s):  
Colby L. Hause ◽  
Gabriel P. Singer ◽  
Rebecca A. Buchanan ◽  
Dennis E. Cocherell ◽  
Nann A. Fangue ◽  
...  
Keyword(s):  
Pacific Northwest ◽  
Chinook Salmon ◽  
Habitat Restoration ◽  
Oncorhynchus Tshawytscha ◽  
Central Valley ◽  
Data Generation ◽  
Habitat Variability ◽  
River Habitat ◽  
San Joaquin River ◽  
The Pacific

AbstractExtirpation of the Central Valley spring-run Chinook Salmon ESU (Oncorhynchus tshawytscha) from the San Joaquin River is emblematic of salmonid declines across the Pacific Northwest. Habitat restoration and fish reintroduction efforts are ongoing, but recent telemetry studies have revealed low outmigration survival of juveniles to the ocean. Previous investigations have focused on modeling survival relative to river discharge and geographic regions, but have largely overlooked the effects of habitat variability. To evaluate the link between environmental conditions and survival of juvenile spring-run Chinook Salmon, we combined high spatial resolution habitat mapping approaches with acoustic telemetry along a 150 km section of the San Joaquin River during the spring of 2019. While overall outmigration survival was low (5%), our habitat-based classification scheme described variation in survival of acoustic-tagged smolts better than other candidate models based on geography or distance. There were two regional mortality sinks evident along the longitudinal profile of the river, revealing poor survival in areas that shared warmer temperatures but that diverged in chlorophyll-α, fDOM, turbidity and dissolved oxygen levels. These findings demonstrate the value of integrating river habitat classification frameworks to improve our understanding of survival dynamics of imperiled fish populations. Importantly, our data generation and modeling methods can be applied to a wide variety of fish species that transit heterogeneous and diverse habitat types.

Estimating spatial–temporal differences in Chinook salmon outmigration survival with habitat- and predation-related covariates

2019 ◽  
Vol 76 (9) ◽  
pp. 1549-1561 ◽  
Author(s):  
Mark J. Henderson ◽  
Ilysa S. Iglesias ◽  
Cyril J. Michel ◽  
Arnold J. Ammann ◽  
David D. Huff
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Survival Rates ◽  
Central Valley ◽  
Physical Factors ◽  
Spatial And Temporal Patterns ◽  
Physical Conditions ◽  
Covariate Model ◽  
Improve Model ◽  
Temporal Model

Low survival rates of Chinook salmon (Oncorhynchus tshawytscha) smolts in California’s Central Valley have been attributed to multiple biological and physical factors, but it is not clear which factors have the largest impact. We used 5 years of acoustic telemetry data for 1709 late-fall Chinook salmon smolts to evaluate the effect of habitat- and predation-related covariates on outmigration survival through the Sacramento River. Using a Cormack–Jolly–Seber mark–recapture model, we estimated survival rates both as a function of covariates (covariate model) and as a function of river location and release year (spatial–temporal model). Our covariate model was overwhelmingly supported as the preferred model based on model selection criteria, suggesting the covariates adequately replicated spatial and temporal patterns in smolt survival. The covariates in the selected model included individual fish covariates, habitat-specific covariates, and temporally variable physical conditions. The most important covariate affecting salmon survival was flow. We describe the importance of these parameters in the context of juvenile salmon predation risk and suggest that additional research on predator distribution and density could improve model estimates.

Energy dynamics and growth of Chinook salmon (Oncorhynchus tshawytscha) from the Central Valley of California during the estuarine phase and first ocean year

2010 ◽  
Vol 67 (10) ◽  
pp. 1549-1565 ◽  
Author(s):  
R. Bruce MacFarlane
Keyword(s):  
San Francisco ◽  
Chinook Salmon ◽  
Climate Models ◽  
Oncorhynchus Tshawytscha ◽  
Energy Content ◽  
Central Valley ◽  
Energy Dynamics ◽  
Period Data ◽  
Energy Gains ◽  
Engraulis Mordax

The greatest rates of energy accumulation and growth in subyearling Chinook salmon ( Oncorhynchus tshawytscha ) occurred during the first month following ocean entry, supporting the importance of this critical period. Data from an 11-year study in the coastal ocean off California and the San Francisco Estuary revealed that juvenile salmon gained 3.2 kJ·day–1 and 0.8 g·day–1, representing 4.3%·day–1 and 5.2% day–1, respectively, relative to estuary exit values. Little gain in energy (0.28 kJ·day–1) or size (0.07 g·day–1) occurred in the estuary, indicating that the nursery function typically ascribed to estuaries can be deferred to initial ocean residence. Calculated northern anchovies ( Engraulis mordax ) equivalents to meet energy gains were one anchovy per day in the estuary (8% body weight·day–1) and about three per day immediately following ocean entry (15% body weight·day–1). Energy content in the estuary was positively related to higher salinity and lower freshwater outflow, whereas in the ocean, cooler temperatures, lower sea level, and greater upwelling resulted in greater gains. These results suggest that greater freshwater flows, warmer sea temperatures, and reduced or delayed upwelling, all of which are indicated by some (but not all) climate models, will likely decrease growth of juvenile Chinook salmon, leading to reduced survival.

Estimating season-wide survival rates of outmigrating salmon smolt in the Snake River, Washington

1998 ◽  
Vol 55 (3) ◽  
pp. 761-769 ◽  
Author(s):  
John R Skalski
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Survival Rates ◽  
Columbia River Basin ◽  
Good Precision ◽  
Sample Size Calculations ◽  
Daily Sampling ◽  
Fish Tagging ◽  
Salmon Smolt ◽  
Careful Management

Standard release-recapture models can provide release-specific estimates of survival probabilities for a group of salmonid smolt released at a particular time and place in the river. However, reliable estimates of season-wide survival for the population of outmigrating smolt are needed in the Snake-Columbia River Basin for careful management of the resource. Alternative estimators are presented to estimate season-wide survival of spring chinook salmon (Oncorhynchus tshawytscha) smolt. Using daily fish tagging, survival for the middle 95% of the migration was estimated to be SS = 0.873 (SE = 0.005) from the tailrace of Lower Granite Dam (RK 695) to the tailrace of Little Goose Dam (RK 635) in 1995. Daily survival estimates were remarkably stable across the migration season with some evidence of decreased survival towards the very end of the migration. Sample size calculations suggest good precision can be attained (i.e., projected SE = 0.01) with tag releases as small as n = 500 fish per day (d = 7) across the outmigration. Less than daily sampling can result in season-wide survival estimates that are too imprecise for many management purposes.

Fry-to-adult survival of natural and hatchery-produced chinook salmon (Oncorhynchus tshawytscha) from a common origin

1997 ◽  
Vol 54 (6) ◽  
pp. 1246-1254 ◽  
Author(s):  
M J Unwin
Keyword(s):  
New Zealand ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Survival Rates ◽  
Adult Survival ◽  
Poor Survival ◽  
Stock Size ◽  
Hatchery Fish ◽  
Stock Recruitment

Fry-to-adult survival rates for chinook salmon (Oncorhynchus tshawytscha) from Glenariffe Stream, a tributary of the Rakaia River, New Zealand, were estimated for fish of both natural and hatchery origin. Survival of naturally produced fry, most of which leave Glenariffe Stream within 24 h of emergence, averaged 0.079% (range 0.013-1.17%). For hatchery fish released at 8-12 months, standardised to a mean weight of 38 g, survival covaried with weight at release consistently across all brood years and averaged 0.34% (range 0.008-3.28%). Survival rates for hatchery fish were four times higher than for naturally produced fry, but were extremely poor relative to their size at release. Survival rates for fish of natural and hatchery origin were positively correlated, suggesting that recruitment of both stocks is primarily controlled by common influences within the marine environment, probably during the first winter at sea. Stock-recruitment analysis for the natural population showed little tendency for recruitment to increase with stock size, suggesting that marine survival rates may be density dependent. Although the reasons for the relatively poor survival of hatchery fish are unclear, the results provide a case study in which hatchery fish appear to have a poorer ``fitness to survive'' than their natural counterparts.

Analysis of microsatellite DNA resolves genetic structure and diversity of chinook salmon (Oncorhynchus tshawytscha) in California’s Central Valley

2000 ◽  
Vol 57 (5) ◽  
pp. 915-927 ◽  
Author(s):  
Michael A Banks ◽  
Vanessa K Rashbrook ◽  
Marco J Calavetta ◽  
Cheryl A Dean ◽  
Dennis Hedgecock
Keyword(s):  
Genetic Structure ◽  
Chinook Salmon ◽  
Microsatellite Dna ◽  
Life Histories ◽  
Oncorhynchus Tshawytscha ◽  
Random Mating ◽  
Central Valley ◽  
Microsatellite Dna Markers ◽  
Maximum Likelihood Methods ◽  
Genetic Structure And Diversity

We use 10 microsatellite DNA markers to assess genetic diversity within and among the four runs (winter, spring, fall, and late fall) of chinook salmon (Oncorhynchus tshawytscha) in California's Central Valley. Forty-one population samples are studied, comprising naturally spawning and hatchery stocks collected from 1991 through 1997. Maximum likelihood methods are used to correct for kinship in juvenile samples and run admixture in adult samples. Through simulation, we determine the relationship between sample size and number of alleles observed at polymorphic microsatellite markers. Most samples have random-mating equilibrium proportions of single and multilocus genotypes. Temporal and spatial genetic heterogeneity is minimal among samples within subpopulations. An FST of 0.082 among subpopulations, however, indicates substantial divergence among runs. Thus, with the exception of our discovery of two distinct lineages of spring run, genetic structure accords with the diverse chinook life histories seen in the Central Valley and provides a means for discrimination of protected populations.

Can behavioral fish-guidance devices protect juvenile Chinook salmon (Oncorhynchus tshawytscha) from entrainment into unscreened water-diversion pipes?

2014 ◽  
Vol 71 (8) ◽  
pp. 1209-1219 ◽  
Author(s):  
Timothy D. Mussen ◽  
Oliver Patton ◽  
Dennis Cocherell ◽  
Ali Ercan ◽  
Hossein Bandeh ◽  
...  
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Central Valley ◽  
Large River ◽  
Water Diversion ◽  
Small Scale ◽  
Fish School ◽  
Juvenile Chinook Salmon ◽  
Juvenile Chinook ◽  
And Behavior

Entrainment through water-diversion structures is a major passage challenge for fishes in watersheds worldwide. Behavioral guidance devices may be effective in passing fish by diversion inlets, thereby decreasing entrainment without reducing water-diversion rates, but data on their effectiveness is limited. In California’s central valley, out-migrating Chinook salmon (Oncorhynchus tshawytscha) are a species at risk for entrainment through unscreened, small-scale water-diversion pipes. Therefore, we tested entrainment susceptibility and behavior of juvenile Chinook salmon in a large-river-simulation flume at a “river” velocity of 0.15 m·s–1 with a 0.46 m diameter pipe diverting water at 0.57 m3·s–1, during the day and night. Compared with control conditions (no fish deterrent devices present), mean fish entrainment increased by 61% (day) and 43% (night) when underwater strobe lights were active, decreased by 30% when using a metal vibrating (12 Hz) ring during the night, and was unaffected by velocity cap attachments. Fish entrainments started at water velocities of 0.8 m·s–1 and decreased by 54% from spring to summer, possibly resulting from decreased pipe-passage frequency and smaller fish-school sizes. Our findings suggest that substantial entrainment can occur if fish repeatedly pass within 1.5 m of active unscreened diversions, with an estimated 50% of fish lost after encountering 18 pipes in spring and 50 pipes in summer.

Separable Virtual Population Analysis of Pacific Salmon with Application to Marked Chinook Salmon, Oncorhynchus tshawytscha, from California's Central Valley

1987 ◽  
Vol 44 (6) ◽  
pp. 1213-1220 ◽  
Author(s):  
Robert G. Kope
Keyword(s):  
Chinook Salmon ◽  
Goodness Of Fit ◽  
Oncorhynchus Tshawytscha ◽  
Pacific Salmon ◽  
Population Analysis ◽  
Central Valley ◽  
Virtual Population Analysis ◽  
Virtual Population ◽  
California's Central Valley ◽  
California’S Central Valley

A separable virtual population analysis model is developed for Pacific salmon which utilizes aged catch and spawning escapement data. This model is applied to marked chinook salmon, Oncorhynchus tshawytscha, from California's Central Valley hatcheries using weighted least squares criteria for goodness of fit. Structural inadequacies of the model apparently produce discrepancies between predicted values and observed data that are of about the same magnitude as the observational errors in estimating the recoveries of marked fish. Some of the inadequacy of the model may be due to environmentally induced variability in population parameters, but for the marked fish used in this analysis, some of the variability is probably due to year-to-year variability in hatchery practices. From this analysis it appears that although nominal fishing effort has been relatively stable or even declining in recent years, fishing mortality has been increasing with the exception of 1983 and 1984.

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