scholarly journals Identifying the contribution of wild and hatchery Chinook salmon (Oncorhynchus tshawytscha) to the ocean fishery using otolith microstructure as natural tags

2007 ◽  
Vol 64 (12) ◽  
pp. 1683-1692 ◽  
Author(s):  
Rachel Barnett-Johnson ◽  
Churchill B Grimes ◽  
Chantell F Royer ◽  
Christopher J Donohoe
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Wild Fish ◽  
Otolith Microstructure ◽  
Exogenous Feeding ◽  
Daily Growth ◽  
Wild Salmon ◽  
Growth Increments ◽  
In The Wild ◽  
Mixed Stock

Quantifying the contribution of wild (naturally spawned) and hatchery Chinook salmon (Oncorhynchus tshawytscha) to the mixed-stock ocean fishery is critical to understanding their relative importance to the persistence of salmon stocks. The inability to distinguish hatchery and wild salmon has inhibited the detection of declines or recoveries for many wild populations. By using Chinook salmon of known hatchery and wild origin, we established a baseline for separating these two sources using otolith microstructure. Otoliths of wild salmon contained a distinct exogenous feeding check likely reflecting an abrupt transition in food resources from maternal yolk not experienced by fish reared in hatcheries. Daily growth increments in otoliths from hatchery salmon immediately after the onset of exogenous feeding were wider and more uniform in width than those in wild fish. The discriminant function that we used to distinguish individuals reared in hatcheries or in the wild was robust between years (1999 and 2002), life history stages (juveniles and adults), and geographic regions (California, British Columbia, and Alaska) and classified fish with ~91% accuracy. Results from our mixed-stock model estimated that the contribution of wild fish was 10% ± 6%, indicating hatchery supplementation may be playing a larger role in supporting the central California coastal fishery than previously assumed.

Differences in otolith microstructure between hatchery-reared and wild Chinook salmon (Oncorhynchus tshawytscha)

1995 ◽  
Vol 52 (2) ◽  
pp. 344-352 ◽  
Author(s):  
Z. Zhang ◽  
R. J. Beamish ◽  
B. E. Riddell
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Otolith Microstructure ◽  
Exogenous Feeding ◽  
Daily Growth ◽  
Strait Of Georgia ◽  
Growth Increments

Otolith microstructure exhibited some characteristic differences between hatchery-reared and wild chinook salmon (Oncorhynchus tshawytscha) from the Cowichan River. Daily growth increments that formed in the otoliths of the hatchery-reared chinook salmon after exogenous feeding were more regular in width and contrast than those in the otoliths of wild chinook salmon. In addition, otoliths from hatchery-reared individuals frequently produced a check when the fish were released from the hatchery. Eighty-nine percent of a sample of 67 chinook smolts that had been coded-wire tagged in hatcheries and later captured in the Strait of Georgia were correctly identified as originating from hatcheries based on otolith microstructure. These tagged fish originated from at least 17 different hatcheries, indicating that the method could be used to identify chinook salmon originating from other hatcheries.

Effects of pH on the early development and growth and otolith microstructure of chinook salmon, Oncorhynchus tshawytscha

1985 ◽  
Vol 63 (1) ◽  
pp. 22-27 ◽  
Author(s):  
G. H. Geen ◽  
J. D. Neilson ◽  
M. Bradford
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Growth Increment ◽  
Low Ph ◽  
Acidic Water ◽  
Daily Growth ◽  
Stage Of Development ◽  
Growth Increments ◽  
Effects Of Ph ◽  
Daily Growth Increment

Chinook salmon (Oncorhynchus tshawytscha) eggs, alevins, and fry were reared in pH 4.5, 5.0. 5.5, 6.2 (control), and 7.0 water from the eyed stage of development. Survival through hatching was >90% in all instances. Alevin mortality was high at pH 4.5 and 5.0. Fry were more tolerant of low pH than alevins. Growth rates of alevins and fry held at or above pH 5.0 and 4.5, respectively, were not affected by pH, nor did exposure to acidic water retard otolith development or result in their resorption. One otolith daily growth increment was formed every 24 h in alevins and fry irrespective of pH. Widths of otolith daily growth increments decreased when fry were transferred to pH 4.5 water and increased on their return to higher pH indicating changes in growth rate. Transfer of fry from pH 6.2 to pH 5.0 or 5.5 had no effect on increment widths.

Otoliths of Chinook Salmon (Oncorhynchus tshawytscha): Daily Growth Increments and Factors Influencing Their Production

1982 ◽  
Vol 39 (10) ◽  
pp. 1340-1347 ◽  
Author(s):  
John D. Neilson ◽  
Glen H. Geen
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Fish Length ◽  
Feeding Frequency ◽  
Otolith Growth ◽  
Increment Width ◽  
Daily Growth ◽  
Factors Affecting ◽  
Growth Increments ◽  
Otolith Increment

The effects of photoperiod, feeding frequency, and water temperature on formation of otolith daily growth increments in juvenile chinook salmon (Oncorhynchus tshawytscha) were examined. Feeding frequency influenced both increment number and width, whereas photoperiod and temperature affected only increment width. Fish fed once/24 h produced one increment every 24 h on average, while fish fed 4 times/24 h produced more than one increment every 24 h. Wider increments were produced in fish exposed to warmer water (11 °C) or 24 h of darkness. The ratio of otolith size to fish size remained constant throughout and between the photoperiod, temperature, and feeding frequency experiments, regardless of the number or width of increments produced. Although otolith growth is isometric with respect to increase in fish length under these experimental regimes, otolith microstructure will differ in fish of the same size reared under different environmental conditions. An understanding of factors affecting otolith increment production is required before increment number and width can be used to assess growth rates.Key words: otolith, daily, growth increments, chinook salmon

Within-river straying: sex and size influence recovery location of hatchery Chinook salmon (Oncorhynchus tshawytscha)

2020 ◽  
Vol 77 (2) ◽  
pp. 226-235 ◽  
Author(s):  
Amanda M.M. Pollock ◽  
Maryam Kamran ◽  
Andrew H. Dittman ◽  
Marc A. Johnson ◽  
David L.G. Noakes
Keyword(s):  
River Basin ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Classification Tree ◽  
River System ◽  
Classification Tree Analysis ◽  
Spawning Grounds ◽  
Natural Origin ◽  
Elk River ◽  
In The Wild

Salmon straying is often defined as the failure of adults to return to their natal river system. However, straying within a river basin can be problematic if hatchery salmon do not return to their hatchery of origin and subsequently spawn in the wild with natural-origin salmon. We examined within-river straying patterns from 34 years of coded-wire tag data, representing 29 941 hatchery fall Chinook salmon (Oncorhynchus tshawytscha) in the Elk River, Oregon, USA. Using classification tree analysis, we found that females and larger salmon were more likely to be recovered on the spawning grounds than males and smaller fish. Females larger than 980 mm had a 51.6% likelihood of recovery on the spawning grounds rather than at the Elk River Hatchery. Our findings raise questions about the behavior of straying adults and implications for management of these stocks, with a focus on methods to reduce within-river straying. We recommend further studies to determine whether carcass recoveries are fully representative of hatchery salmon that stray within the Elk River basin.

Differences in egg quantity and quality among hatchery- and wild-origin Chinook salmon (Oncorhynchus tshawytscha)

2016 ◽  
Vol 73 (5) ◽  
pp. 737-746 ◽  
Author(s):  
Michaela W. Haring ◽  
Tom A. Johnston ◽  
Murray D. Wiegand ◽  
Aaron T. Fisk ◽  
Trevor E. Pitcher
Keyword(s):  
Stable Isotopes ◽  
Adult Development ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Neutral Lipids ◽  
Fatty Acid Content ◽  
Reproductive Investment ◽  
Gonadal Development ◽  
Gonad Mass ◽  
In The Wild

Each year, millions of hatchery-raised juvenile salmon are released into the wild to help bolster salmon populations all over North America. These fish often differ from their wild-origin conspecifics in terms of survival and reproductive success after release, but our understanding of their reproductive investment is limited. We examined differences in egg number (gonad mass and fecundity) and quality (mass, lipids, fatty acids) between spawning hatchery- and wild-origin Chinook salmon (Oncorhynchus tshawytscha) from Lake Ontario. Hatchery-origin females were found to not differ significantly in body size, age, egg total lipids, and fatty acid content of eggs relative to wild-origin females, but hatchery-origin females allocated significantly less body mass and neutral lipids into egg and gonadal development compared with wild-origin females. We also examined diets of both groups of females using stable isotopes and found that carbon and nitrogen stable isotopes suggested limited differences in the diet between hatchery- and wild-origin adult females. The results from the present study provide evidence that the differing environmental conditions and associated selection pressures of captive environments during early life in hatchery settings can alter certain life-history traits later in adult development, namely gonad mass and egg size, and could contribute to differences in their performance in the wild.

Factors influencing the relative fitness of hatchery and wild spring Chinook salmon (Oncorhynchus tshawytscha) in the Wenatchee River, Washington, USA

2010 ◽  
Vol 67 (11) ◽  
pp. 1840-1851 ◽  
Author(s):  
Kevin S. Williamson ◽  
Andrew R. Murdoch ◽  
Todd N. Pearsons ◽  
Eric J. Ward ◽  
Michael J. Ford
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Parentage Analysis ◽  
Wild Fish ◽  
Relative Fitness ◽  
Male Fitness ◽  
Natural Origin ◽  
Hatchery Fish ◽  
Management And Conservation ◽  
Older Males

Understanding the relative fitness of naturally spawning hatchery fish compared with wild fish has become an important issue in the management and conservation of salmonids. We used a DNA-based parentage analysis to measure the relative reproductive success of hatchery- and natural-origin spring Chinook salmon ( Oncorhynchus tshawytscha ) in the natural environment. Size and age had a large influence on male fitness, with larger and older males producing more offspring than smaller or younger individuals. Size had a significant effect on female fitness, but the effect was smaller than on male fitness. For both sexes, run time had a smaller but still significant effect on fitness, with earlier returning fish favored. Spawning location within the river had a significant effect on fitness for both sexes. Hatchery-origin fish produced about half the juvenile progeny per parent when spawning naturally than did natural-origin fish. Hatchery fish tended to be younger and return to lower areas of the watershed than wild fish, which explained some of their lower fitness.

Fatty Acid Composition of Lipids in the Eggs and Alevins from Wild and Cultured Chinook Salmon (Oncorhynchus tshawytscha)

1993 ◽  
Vol 50 (3) ◽  
pp. 648-655 ◽  
Author(s):  
H. J. Ashton ◽  
D. O. Farkvam ◽  
B. E. March
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Total Lipid ◽  
Polar Lipid ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Wild Fish ◽  
Marine Food Chain ◽  
Neutral And Polar Lipids ◽  
The Mean

The fatty acid profiles of lipids extracted from eggs and alevins of cultured chinook salmon (Oncorhynchus tshawytscha) were significantly different than those from eggs and alevins of wild fish of the same stock. The mean total concentrations of n3 fatty acids in the total lipid of eggs from wild and cultured broodstock were 40.2 and 29.4% and in the polar lipid 45.5 and 38.7% respectively. The mean concentrations of n3 fatty acids in the total lipid of alevins from wild and cultured broodstock were 35.4% and 23.2% and in the polar lipid 43.0 and 38.2%, respectively. The ratios of n3:n6 fatty acids were lower in both the neutral and polar lipids of eggs and of alevins from the cultured fish than in those of wild fish. The higher n3:n6 fatty acid ratios in the eggs and progeny of wild fish reflected the higher ratios in lipids of components of the natural marine food chain.

Dependence of Exploitation Rates for Maximum Yield and Stock Collapse on Age and Sex Structure of Chinook Salmon (Oncorhynchus tshawytscha) Stocks

1986 ◽  
Vol 43 (9) ◽  
pp. 1746-1759 ◽  
Author(s):  
David G. Hankin ◽  
M. C. Healey
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Maximum Yield ◽  
Complex Nature ◽  
Sex Structure ◽  
Early Maturing ◽  
Stock Recruitment ◽  
Mixed Stock ◽  
Age And Sex ◽  
Stock Collapse

In this paper we investigate the equilibrium behavior of an age- and sex-structured version of the Ricker stock–recruitment model specifically tailored to the complex nature of chinook salmon (Oncorhynchus tshawytscha) biology and fisheries. Conclusions from our analysis include the following. (1) Exploitation rates for maximum yield (umsy) and stock collapse (umax) depend strongly on a stock's maturity schedule, being lowest for a late-maturing stock and greatest for an early maturing stock. (2) Values of exploitation rates for umax overlap considerably with those for umsy, emphasizing the probability of stock collapse in fully exploited mixed stock fisheries. (3) Values of umsy and umax are independent of the value of the Ricker β parameter but depend directly on the Ricker α parameter, indicating that management research should focus on obtaining better estimates of α, contrary to recent suggestions in the literature. (4) Because they mature at older ages, female chinook suffer greater cumulative fishery removal rates than males and decline in abundance more rapidly as exploitation increases. Consequently, the use of sex-independent maturity schedules can give misleading estimates for umsy and umax. (5) Maximum changes in mean age of stocks that can be attributed to fishing up effects ranged from 0.32 to 0.81 yr. Many stocks appear already to have declined in mean age by this amount, further emphasizing the probability of impending collapse of some stocks.

Comment on “Gene flow increases temporal stability of Chinook salmon (Oncorhynchus tshawytscha) populations in the Upper Fraser River, British Columbia, Canada”Appears in Can. J. Fish. Aquat. Sci. 66: 167–176.

2010 ◽  
Vol 67 (1) ◽  
pp. 202-205 ◽  
Author(s):  
Terry D. Beacham ◽  
Ruth E. Withler
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Pacific Salmon ◽  
Temporal Stability ◽  
Time Span ◽  
Population Variation ◽  
Stock Identification ◽  
Fraser River ◽  
Mixed Stock ◽  
Conservation And Management

Temporally stable genetic structure among salmonid populations has been reported in many studies, although the time span evaluated in most studies is limited to 10 years or less. This result has important implications in conservation and management of Pacific salmon ( Oncorhynchus spp.) and ramifications for the construction and application of genetic databases for stock identification of fish sampled from mixed-stock fisheries. Walter et al. (2009. Can. J. Fish. Aquat. Sci. 66: 167–176) failed to consider recent studies providing evidence that their conclusion “the overall magnitude of temporal within-population variation exceeding that of among-population variation” for the populations under study may be invalid for Fraser River Chinook salmon ( Oncorhynchus tshawytscha ) populations. Their estimation of rates and patterns of migration among Chinook salmon populations also provided results that are difficult to reconcile with published information. Evaluation of the experimental designed employed by Walter et al. (2009) indicates that their sample sizes were too small to estimate reliably genetic variation among or within populations. Extrapolation of their conclusions relating temporal instability of population structure to other Chinook salmon populations or indeed other salmonid species is unwarranted.

Comparison of Methods for Estimating Mixed Stock Fishery Composition

1990 ◽  
Vol 47 (11) ◽  
pp. 2235-2241 ◽  
Author(s):  
R. B. Millar
Keyword(s):  
Maximum Likelihood ◽  
Maximum Likelihood Estimator ◽  
Random Sample ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Comparison Of Methods ◽  
Likelihood Estimator ◽  
Mixed Stock ◽  
Theoretical Considerations ◽  
Scale Data

Given information on fish of known origin, and a random sample from the mixed stock fishery, the composition of that mixed fishery may be estimated in a number of ways. This study compares the performance of four classification-based estimators and a maximum likelihood estimator. Theoretical considerations show that the maximum likelihood estimator makes better use of the information contained in the mixed fishery sample. However, the classification estimators are shown to be more robust to violations in some of the model assumptions. Scale data from four regional stock groups of chinook salmon (Oncorhynchus tshawytscha) were used in an applied comparison of the five estimators. The results suggest that the maximum likelihood estimator performs best in practice.

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