The influence of family-correlated survival on Nb/N for progeny from integrated multi- and single-generation hatchery stocks of coho salmon (Oncorhynchus kisutch)

2007 ◽  
Vol 64 (9) ◽  
pp. 1258-1265 ◽  
Author(s):  
G R Moyer ◽  
M S Blouin ◽  
M A Banks
Keyword(s):  
Coho Salmon ◽  
Adult Stage ◽  
Oncorhynchus Kisutch ◽  
Parentage Analysis ◽  
Effective Population ◽  
Single Generation ◽  
Marine Life ◽  
A Value ◽  
Significant Difference ◽  
Few Data

There exist surprisingly few data on the final variance and mean of family sizes for hatchery-born fish at the adult stage. Thus, it is difficult to predict, for a conservation hatchery operation that minimizes the variance in progeny number, how much lower the true effective population size (Ne) of a cohort of hatchery-born adults will be than Ne predicted simply by the number of parents that produced them. We used parentage analysis to estimate the survival and Ne for two integrated stocks of hatchery coho salmon (Oncorhynchus kisutch). One hatchery is a multigeneration stock obtained by spawning 70% hatchery with 30% naturally reproducing fish, whereas the second is a single-generation stock derived from naturally reproducing coho. There was no significant difference in average overall survival between stocks, but observed Ne was significantly less than expected for each stock. Family-correlated survival contributed to roughly a 20% reduction in Ne over the freshwater and marine life stages. This reduction is similar to previous estimates and suggests a value that can be used when estimating the effective number of hatchery parents in applications of the Ryman–Laikre formula (at least for programs such as ours that attempt to equalize sex ratios and family sizes).

Genetic structure, migration, and patterns of allelic richness among coho salmon (Oncorhynchus kisutch) populations of the Oregon coast

2008 ◽  
Vol 65 (7) ◽  
pp. 1274-1285 ◽  
Author(s):  
Marc A. Johnson ◽  
Michael A. Banks
Keyword(s):  
Genetic Structure ◽  
Allelic Richness ◽  
Coho Salmon ◽  
Current Source ◽  
Oncorhynchus Kisutch ◽  
Effective Population ◽  
Coastal Lake ◽  
Evolutionarily Significant Unit ◽  
Migration Rates ◽  
Source Sink

Genotypic data from eight microsatellite loci are used to infer population structure, effective population size, migration rates, and patterns of allelic richness among wild and hatchery populations of Oregon coastal coho salmon ( Oncorhynchus kisutch ). Corroborating the results of a previous study, we found relatively weak genetic structure among coho from different river basins, although some geographically and ecologically defined clades are supported. Contemporary migration rates among basins appear to be high and asymmetrical. Hatchery populations tended to resemble the wild populations from which they were founded, but presented significantly lower levels of allelic richness. Allelic richness was also low in Oregon coastal lake populations and peaked in the central region of the evolutionarily significant unit among wild river populations. We suggest that the observed patterns may reflect both current source–sink dynamics and post-Pleistocene colonization events.

Survival, Ocean Growth, and Ocean Distribution of Differentially Timed Releases of Hatchery Coho Salmon (Oncorhynchus kisutch)

1989 ◽  
Vol 46 (7) ◽  
pp. 1216-1226 ◽  
Author(s):  
Stephen B. Mathews ◽  
Yukimasa Ishida
Keyword(s):  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Adult Survivors ◽  
Small Fish ◽  
Large Fish ◽  
Release Date ◽  
Marine Life ◽  
Coos Bay ◽  
The Mean ◽  
Marine Survival

Estimates of growth rates in early ocean life and length frequency distributions at time of release for adult survivors were inferred from scale measurements for lots of coho salmon (Oncorhynchus kisutch) released at several dates from a Columbia River hatchery (Big Creek) and a southern Oregon hatchery (Coos Bay). Analysis of these measurements failed to support either of two literature-suggested hypotheses for the variability of marine survival of hatchery coho by date of release: (1) intraseasonal variability of food supply during early marine life; and (2) intraseasonally improving ability of smaller individuals within release lots to convert to salt water. Marine survival improved substantially with date of release at both hatcheries. However, fish released earliest, which survived relatively poorly, grew as fast in early marine life as fish released later, which survived better. Thus, poor survival of the early released fish did not appear related to lack of food at early ocean life. For the Big Creek hatchery, no significant differences were seen between the mean lengths at date of release and the mean release-date lengths of adult survivors back calculated from their scales, for lots released on May 5, June 3, and July 2. Apparently, small and large fish of each lot survived with equal probability. For the Coos Bay hatchery, the mean release-date lengths of adult survivors were significantly larger than the mean lengths of all fish released, for each of six lots released between early June and late July. Thus, large fish apparently survived better than small ones within each of these six lots. But there was no seasonal trend in survivability of small fish relative to large ones, contrary to hypothesis (2)

Survival, Contribution, and Return of Hatchery Coho Salmon (Oncorhynchus kisutch) Released into Freshwater, Estuarine, and Marine Environments

1991 ◽  
Vol 48 (2) ◽  
pp. 248-253 ◽  
Author(s):  
Mario F. Solazzi ◽  
Thomas E. Nickelson ◽  
Steven L. Johnson
Keyword(s):  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Columbia River ◽  
Fold Increase ◽  
Coast Guard ◽  
Control Group ◽  
Survival Index ◽  
Significant Difference ◽  
Columbia River Plume ◽  
Brood Fish

We released six groups of marked yearling hatchery coho salmon (Oncorhynchus kisutch) in six locations each year for five years beginning with the 1981 brood. Fish were released immediately below Bonneville Dam (control), at the Tongue Point Coast Guard Station (head of saltwater intrusion in the Columbia River), between the jetties at the Columbia River bar, in the Columbia River plume water, in coastal water approximately 19 km north and 19 km offshore of the mouth of the river, and in oceanic water approximately 38 km offshore. We found a 1.6-fold increase in the survival index (ocean catch through September 18 each year) for the fish released at Tongue Point compared with the control group. After adjusting for differences in the survival index between release groups, we found a 2.5-fold increase in the contribution to the Columbia River gillnet fishery from the fish released at Tongue Point compared with the control group. We found no significant difference between survival of the other release groups and survival of the control group. We also found that the percentage of adult fish that returned to locations other than the Columbia basin increased as the distance the fish were transported offshore increased.

Inbreeding and effective population size in a coho salmon (Oncorhynchus kisutch) breeding nucleus in Chile

Aquaculture ◽  
2014 ◽  
Vol 420-421 ◽  
pp. S15-S19 ◽  
Author(s):  
José M. Yáñez ◽  
Liane N. Bassini ◽  
Michael Filp ◽  
Jean P. Lhorente ◽  
Raúl W. Ponzoni ◽  
...  
Keyword(s):  
Population Size ◽  
Effective Population Size ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Effective Population

Effect of Diets Containing Herring Oil Oxidized to Different Degrees on Growth and Immunocompetence of Juvenile Coho Salmon (Oncorhynchus kisutch)

1988 ◽  
Vol 45 (12) ◽  
pp. 2187-2194 ◽  
Author(s):  
Ian Forster ◽  
David A. Higgs ◽  
Gordon R. Bell ◽  
B. S. Dosanjh ◽  
B. E. March
Keyword(s):  
Growth Rate ◽  
Coho Salmon ◽  
Vibrio Anguillarum ◽  
Oncorhynchus Kisutch ◽  
Dietary Treatment ◽  
Feed Conversion ◽  
Oxidized Oil ◽  
Significant Difference ◽  
Antibody Titres ◽  
Dietary Treatments

Growth rate and efficiency of feed conversion were reduced by inclusion of oxidized herring oil in the diet, presumably as a result of reduced digestibility of the oxidized oil and suboptimal dietary concentrations of ω3 fatty acids. There was no evidence of any toxic factors in the oxidized oil. There was no significant difference in growth rate or the efficiency of feed conversion between juvenile coho fed diets supplemented with 30 and 1030 IU vitamin E/kg. Dietary treatment did not affect haematocrit values. Immunocompetence, judged by antibody titres in response to vibrio vaccination, was similar for all treatments. Disease resistance, assessed by the rate of mortality induced by exposure of nonvaccinated fish to challenge with Vibrio anguillarum or V. ordali, was likewise unaffected by the dietary treatments.

Family Size and Effective Population Size in a Hatchery Stock of Coho Salmon (Oncorhynchus kisutch)

1986 ◽  
Vol 43 (12) ◽  
pp. 2434-2442 ◽  
Author(s):  
Raymond C. Simon ◽  
John D. McIntyre ◽  
A. R. Hemmingsen
Keyword(s):  
Population Size ◽  
Family Size ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Effective Size ◽  
Effective Population ◽  
Data Set ◽  
Hatchery Stock ◽  
Study Population ◽  
Related Population

Means and variances of family size measured in five year-classes of wire-tagged coho salmon (Oncorhynchus kisutch) were linearly related. Population effective size was calculated by using estimated means and variances of family size in a 25-yr data set. Although numbers of age 3 adults returning to the hatchery appeared to be large enough to avoid inbreeding problems (the 25-yr mean exceeded 4500), the numbers actually contributing to the hatchery production may be too low. Several strategies are proposed to correct the problem perceived. Argument is given to support the contention that the problem of effective size is fairly general and is not confined to the present study population.

Marine Mortality of Puget Sound Coho Salmon (Oncorhynchus kisutch)

1976 ◽  
Vol 33 (8) ◽  
pp. 1677-1684 ◽  
Author(s):  
Stephen B. Mathews ◽  
Raymond Buckley
Keyword(s):  
Coho Salmon ◽  
Survival Curve ◽  
Puget Sound ◽  
Survival Rates ◽  
Oncorhynchus Kisutch ◽  
High Survival ◽  
Natural Mortality ◽  
Fishing Mortality ◽  
Marine Life ◽  
Mortality Model

A model for natural mortality over the 18 mo of marine life of Puget Sound coho salmon (Oncorhynchus kisutch) is proposed, wherein the natural mortality rate M continuously decreases with increasing weight. Weight closely follows an increasing exponential function of marine age. The model is extended to account for ocean troll and sport fishing mortality and applied to data from marking studies of Puget Sound coho. The survival curve for marine life with only natural mortality declines rapidly for early ocean life and is quite flat over the ages fished. Recent high survival rates for hatchery coho released at a larger than normal size could be partially explained by this mortality model, although additional marking experiments are needed to separate the effects upon survival of size at release and time of release. The model applied to hatchery release-size strategy indicates that 70 g/fish might be optimal.

Effect of egg size on incubation time and alevin and fry size in chum salmon (Oncorhynchus keta) and coho salmon (Oncorhynchus kisutch)

1985 ◽  
Vol 63 (4) ◽  
pp. 847-850 ◽  
Author(s):  
T. D. Beacham ◽  
F. C. Withler ◽  
R. B. Morley
Keyword(s):  
Egg Size ◽  
Chum Salmon ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Oncorhynchus Keta ◽  
Free Swimming ◽  
Chum Salmon Oncorhynchus Keta ◽  
Hatching Time ◽  
Significant Difference ◽  
Yolk Absorption

Variability in hatching time, time of exogenous yolk absorption ("button up") of alevins, alevin size, and fry size was investigated with respect to initial egg size for chum salmon (Oncorhynchus keta) and coho salmon (Oncorhynchus kisutch). There was no significant difference with respect to egg size in hatching time of the alevins (stage between hatching and emergence from the redd) or time of exogenous yolk absorption for either species. For both species, alevins hatching from large eggs were longer and had greater amounts of yolk than those hatching from small eggs. Tissue weights of the alevins were not different. The differences in size between these two groups of alevins were maintained throughout the alevin stage and were greater at exogenous yolk absorption than at hatching. Fry (newly emerged, free-swimming young) derived from large eggs had greater tissue weight at exogenous yolk absorption than those derived from small eggs.

Acute effects of suspended sediment angularity on juvenile coho salmon (Oncorhynchus kisutch)

1999 ◽  
Vol 56 (5) ◽  
pp. 862-867 ◽  
Author(s):  
Randal G Lake ◽  
Scott G Hinch
Keyword(s):  
Suspended Sediment ◽  
Stress Responses ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Suspended Sediments ◽  
Sediment Concentration ◽  
Minimum Concentration ◽  
A Value ◽  
Order Of Magnitude ◽  
Physical Gill

To determine the roles of suspended sediment angularity and concentration as contributors to stress and mortality in salmonids, we exposed juvenile coho salmon (Oncorhynchus kisutch) to anthropogenically derived "extremely angular" and "round" silicate sediments over a range of concentrations in 96-h experiments. Stress responses (e.g., decreased leukocrit) were elicited by exposure to both sediment shapes when concentrations were >40 g·L-1, corresponding to the minimum concentration at which physical gill damage was observed. Extremely angular sediments also caused stress responses (e.g., elevated hematocrit, decreased leukocrit) at concentrations <41 g·L-1. However, we found no difference between sediment shapes in causing mortality at any sediment concentration. Further, mortalities were not observed until concentrations were about 100 g·L-1, a value that is about an order of magnitude greater than high natural concentrations in salmonid rivers. Natural fluvial suspended sediments cause fish stress and mortality at much lower concentrations than we found with our anthropogenically derived suspended sediments.

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