Marine survival difference between wild and hatchery-reared steelhead trout determined during early downstream migration

2014 ◽  
Vol 71 (6) ◽  
pp. 831-846 ◽  
Author(s):  
Michael C. Melnychuk ◽  
Josh Korman ◽  
Stephen Hausch ◽  
David W. Welch ◽  
Don J.F. McCubbing ◽  
...  
Keyword(s):  
Adult Life ◽  
Downstream Migration ◽  
Wild Fish ◽  
Steelhead Trout ◽  
Short Term ◽  
Strait Of Georgia ◽  
Return Rates ◽  
Hatchery Fish ◽  
Survival Difference ◽  
Survival Differences

We observed large survival differences between wild and hatchery-reared steelhead trout (Oncorhynchus mykiss) during the juvenile downstream migration immediately after release, which persisted through adult life. Following a railway spill of sodium hydroxide into the Cheakamus River, British Columbia, a short-term conservation hatchery rearing program was implemented for steelhead. We used acoustic telemetry and mark–recapture models to estimate survival of wild and (or) hatchery-reared steelhead during 4 years of the smolt migration, with both groups released in 2008. After adjusting for estimated freshwater residualization, 7%–13% of wild smolts and 30%–40% of hatchery smolts died in the first 3 km of the migration. Estimated survival from release to ocean entry was 71%–84% for wild fish and 26%–40% for hatchery fish and to exit from the Strait of Georgia system was 22%–33% for wild fish and 3.5%–6.7% for hatchery fish. A calculated 2.3-fold survival difference established during the downstream migration was similar to that after the return of adult spawners, as return rates were 8.0% for wild fish and 4.1% for hatchery fish. Contrary to current understanding, a large proportion of salmon mortality in the smolt-to-adult period, commonly termed “marine mortality”, may actually occur prior to ocean entry.

Comparisons between hatchery and wild steelhead trout (Oncorhynchus mykiss) smolts: physiology and habitat use

2006 ◽  
Vol 63 (7) ◽  
pp. 1627-1638 ◽  
Author(s):  
Megan S Hill ◽  
Gayle Barbin Zydlewski ◽  
William L Gale
Keyword(s):  
Habitat Use ◽  
Atpase Activity ◽  
Oncorhynchus Mykiss ◽  
Plasma Osmolality ◽  
Wild Fish ◽  
Microhabitat Use ◽  
Steelhead Trout ◽  
Hatchery Fish ◽  
Before And After ◽  
Seawater Challenge

Hatchery steelhead trout (Oncorhynchus mykiss) smolts, progeny of a newly founded native origin broodstock, were released into Abernathy Creek, Washington, in 2003 and 2004. After release, saltwater tolerance, gill Na+,K+-ATPase activity, and habitat use were compared. A subsample of hatchery and wild steelhead trout were implanted with 23 mm passive integrated transponder (PIT) tags each year. PIT-tagged migrants were used for physiological comparisons. Hatchery fish were significantly larger than wild fish. Hatchery migrants expressed significantly lower levels of gill Na+,K+-ATPase activity than wild migrants. After a 24 h seawater challenge, hatchery migrants had significantly higher plasma osmolality and [Na+] than wild migrants. Microhabitat use of PIT-tagged hatchery and wild individuals in a control (wild fish only) and effect (hatchery and wild fish) site were compared before and after the introduction of hatchery fish. No difference was detected in hatchery and wild smolt habitat use. Wild fish did not change their habitat use after the introduction of hatchery fish. Although hatchery and wild fish differed in smolt physiology, differences in short-term use of freshwater habitat were not detected, and hatchery fish did not appear to displace wild fish.

Genetic Differences in Growth and Survival of Juvenile Hatchery and Wild Steelhead Trout, Salmo gairdneri

1977 ◽  
Vol 34 (1) ◽  
pp. 123-128 ◽  
Author(s):  
R. R. Reisenbichler ◽  
J. D. McIntyre
Keyword(s):  
Growth Rates ◽  
Genetic Differences ◽  
Wild Fish ◽  
Salmo Gairdneri ◽  
Steelhead Trout ◽  
Growth And Survival ◽  
Hatchery Fish ◽  
Natural Streams ◽  
Stock Recruitment ◽  
Relationship Of

Relative growth and survival of offspring from matings of hatchery and wild Deschutes River (Oregon) summer steelhead trout, Salmo gairdneri, were measured to determine if hatchery fish differ genetically from wild fish in traits that can affect the stock–recruitment relationship of wild populations. Sections of four natural streams and a hatchery pond were each stocked with genetically marked (lactate dehydrogenase genotypes) eyed eggs or unfed swim-up fry from each of three matings: hatchery × hatchery (HH), hatchery × wild (HW), and wild × wild (WW). In streams, WW fish had the highest survival and HW fish the highest growth rates when significant differences were found; in the hatchery pond, HH fish had the highest survival and growth rates. The hatchery fish were genetically different from wild fish and when they interbreed with wild fish may reduce the number of smolts produced. Hatchery procedures can be modified to reduce the genetic differences between hatchery and wild fish.

Bias and significance of relative reproductive success estimates based on steelhead trout (Oncorhynchus mykiss) data: a Bayesian meta-analysis

2011 ◽  
Vol 68 (10) ◽  
pp. 1827-1835 ◽  
Author(s):  
Shuichi Kitada ◽  
Hirohisa Kishino ◽  
Katsuyuki Hamasaki
Keyword(s):  
Reproductive Success ◽  
Oncorhynchus Mykiss ◽  
Meta Analysis ◽  
Wild Fish ◽  
Steelhead Trout ◽  
Bayesian Hierarchical ◽  
Hatchery Fish ◽  
In The Wild ◽  
The Mean ◽  
Log Normal

The evaluation of the reproductive success (RS) of hatchery fish in the wild is one of the most important issues in hatchery supplementation, aquaculture, and conservation. Estimates of the relative reproductive success (RRS) have been used to evaluate RS. Because RRS may vary greatly depending on cross, years of release, and environmental conditions, we introduced a log-normal distribution to quantify the variation. The classical estimator of RRS based on multiple measurements is contrasted with the mean of this distribution. We derived the mean, variance, and relative bias and applied our Bayesian hierarchical model to 42 empirical RRS estimates of steelhead trout ( Oncorhynchus mykiss ) in the Hood River, Oregon, USA. The RRS estimate generally had an upward bias. Although the average level of RRS implied the reproductive decline of hatchery fish and wild-born hatchery descendants, we could not reject the null hypothesis that hatchery fish and their descendants have the same chance of having smaller RS than wild fish as they do of having larger RS than wild fish.

Extranodal Extension as an Indicator for Sinonasal Squamous Cell Carcinoma Prognosis

2021 ◽  
pp. 019459982098746
Author(s):  
Christopher C. Tseng ◽  
Jeff Gao ◽  
Gregory L. Barinsky ◽  
Christina H. Fang ◽  
Jordon G. Grube ◽  
...  
Keyword(s):  
Squamous Cell Carcinoma ◽  
Cell Carcinoma ◽  
Squamous Cell ◽  
Multivariate Regression ◽  
Multivariate Analyses ◽  
National Cancer Database ◽  
Extranodal Extension ◽  
Survival Difference ◽  
Survival Differences ◽  
Retrospective Database

Objective Although extranodal extension (ENE) is a known indicator of poor prognosis for head and neck malignancies, its value as an indicator for sinonasal squamous cell carcinoma (SCC) has not been well characterized. This study seeks to assess the usefulness of ENE as a prognostic marker for sinonasal SCC. Study Design Retrospective database review. Setting National Cancer Database from 2010 to 2015. Methods The National Cancer Database was queried from 2010 to 2015 for all patients with sinonasal SCC with available ENE status (n = 355). These cases were divided into those with pathologically confirmed ENE (n = 146) and those without ENE (n = 209). Univariate and multivariate analyses were used to examine survival differences and predictors of ENE status. Results Most patients with ENE were ≥60 years old (61.7%), male (61.6%), and white (83.6%). Patients aged 60 to 69 and 80+ years were more likely to have ENE than those under 60 years ( P < .05). Patients with ENE had worse 1-year overall survival than those without ENE (58.2% vs 70.8%, log-rank P = .008). After multivariate regression, however, there was no survival difference detected between ENE-positive and ENE-negative cases (hazard ratio, 1.14 [0.775-1.672], P = .508). Conclusion ENE status did not have a significant effect on survival in patients with sinonasal SCC. Thus, ENE alone may not necessarily be a helpful indicator for sinonasal SCC prognosis.

Effects of Early Rearing Environment on Stress Response, Immune Function, and Disease Resistance in Juvenile Coho (Oncorhynchus kisutch) and Chinook Salmon (O.tshawytscha)

1993 ◽  
Vol 50 (4) ◽  
pp. 759-766 ◽  
Author(s):  
Kira Salonius ◽  
George K. Iwama
Keyword(s):  
Disease Resistance ◽  
Chinook Salmon ◽  
Coho Salmon ◽  
Vibrio Anguillarum ◽  
Oncorhynchus Kisutch ◽  
Significant Rise ◽  
Wild Fish ◽  
Handling Stress ◽  
Hatchery Fish ◽  
Natural Water Body

Coho (Oncorhynchus kisutch) and chinook salmon (0. tshawytscha) from aquaculture and wild environments were subjected to handling (30–60 s of netting and aerial emersion) and disease challenges. Plasma cortisol concentrations ([cortisol]pl) in both coho and chinook salmon from wild environments were significantly elevated 4 h after handling. Colonized coho salmon (hatchery-reared fish, transported into a natural water body as fry) responded in a similar fashion to wild fish, while those reared entirely in the hatchery showed no significant rise in [cortisol]pl. The responses to handling stress were retained in wild and colonized coho salmon after 7 mo of hatchery rearing. A transient increase in the leukocyte to red blood cell ratio in both wild and hatchery-reared chinook salmon occurred 4 h after handling. Handling signficantly decreased the antibody-producing cell (APC) number in wild fish and elevated their [cortisol]plrelative to hatchery fish. Wild fish had the highest APC number among the three groups before the handling. No difference in resistance to Vibrio anguillarum was apparent in coho and chinook salmon among the different rearing environments, although chinook salmon were generally more susceptible; disease resistance was reduced in wild coho salmon after 7 mo of rearing in a hatchery.

Evaluation of anchor tags for marking the commercial sand crab, Portunus pelagicus (L.) (Portunidae : Decapoda)

1986 ◽  
Vol 37 (6) ◽  
pp. 707 ◽  
Author(s):  
MJ Williams
Keyword(s):  
Population Studies ◽  
Field Trials ◽  
Short Term ◽  
Portunus Pelagicus ◽  
Term Survival ◽  
Return Rates ◽  
Moreton Bay ◽  
Short Term Survival

Laboratory and field trials of a modified Floy FD67 anchor tag were conducted on P. pelagicus in Moreton Bay, Queensland. The tags did not affect short-term survival of the crabs in the laboratory. Only 470 of 1754 crabs tagged and released in the field were returned. Return rates of crabs by size, sex, and area of tagging class were markedly heterogeneous. Poor visibility of the tags on recapture, regardless of their colour, makes this tag unsuitable for any quantitative population studies. Poor return rates were exacerbated by fishermen not examining categories of crabs that are unmarketable.

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.

Effect of Stocking Density on the Survival, Growth, and Dispersal of Steelhead Trout Fry (Salmo gairdneri)

1987 ◽  
Vol 44 (2) ◽  
pp. 271-281 ◽  
Author(s):  
Jeremy M. B. Hume ◽  
Eric A. Parkinson
Keyword(s):  
British Columbia ◽  
Overall Survival ◽  
Stocking Density ◽  
Mortality Rates ◽  
Wild Fish ◽  
Density Effect ◽  
Salmo Gairdneri ◽  
Steelhead Trout ◽  
Density Dependent ◽  
Coastal British Columbia

In a coastal British Columbia stream a stocking density of between 0.3 and 0.7 fry/m2 maximized the production of steelhead trout (Salmo gairdneri) parr and smolts. A severe autumn flood doubled the mortality rates of fry stocked at densities of 0.7 fry/m2 or higher but had little effect on fry stocked at lower densities (<0.15 fry/m2). Overall survival to smolts appeared to be lower than measured elsewhere for wild fish (2 vs. 4.5 – 18%). The proportion (<10%) of surviving fry found below the stocked sections was considered to be an indicator of potential displacement mortality in streams with no vacant downstream areas. This downstream dispersal was not density dependent and was small in comparison with the mortality of nondispersing fish. Although initial fry and parr sizes were density dependent, there was no detectable density effect on older parr or smolt sizes.

scholarly journals Fish hatchering and its effects on the morphology of Prochilodus lineatus (Actinopterygii: Prochilodontidae)

2016 ◽  
Vol 76 (1) ◽  
pp. 209-217
Author(s):  
S. O. Saraiva ◽  
P. S. Pompeu
Keyword(s):  
Environmental Enrichment ◽  
Morphological Variability ◽  
Survival Rates ◽  
Fish Farming ◽  
Wild Fish ◽  
Prochilodus Lineatus ◽  
Phenotypic Differences ◽  
Hatchery Fish ◽  
In Captivity ◽  
Natural Water Bodies

Abstract The fish stocking in captivity for later release into natural water bodies has historically been applied in Brazil, as a measure to mitigate impacts caused by dams. However, the released fish are adapted to the hatchery environment, which is totally different from the natural, which results in low post-release survival rates and ineffectiveness of stocking as a management measure. Worldwide, several studies have demonstrated the existence of large phenotypic differences between farmed and wild fish, but in Brazil, there is a great need for this kind of study. Based on this, our objective here was to verify if hatchery fish differ morphologically from its wild counterparties, at the same size class. Hence, a population of young Prochilodus lineatus raised in a fish farming station was compared with another from marginal lagoons of the Grande river. The results indicated that the fish farming resulted in morphologically different individuals of P. lineatus and a less diverse population, compared with wild fish. Measures such as environmental enrichment of hatchery tanks should be studied as a way to increase environmental heterogeneity and increase the morphological variability of the fingerlings produced.

scholarly journals ADHD Medication in the Longer Term

2019 ◽  
Vol 47 (6) ◽  
pp. 542-546 ◽  
Author(s):  
Eric Taylor
Keyword(s):  
Adult Life ◽  
Initial Therapy ◽  
The Other ◽  
Continuing Care ◽  
Adhd Medication ◽  
Short Term ◽  
The Core ◽  
Core Symptoms ◽  
Further Development

Abstract. This review starts from the finding that there is strong persistence of ADHD problems into adult life, despite the availability of effective treatment with stimulants and other drugs. Short-term trials in adults reveal that those drugs can still be efficacious in adults. Pharmacoepidemiology studies, on the other hand, clearly show that most young people discontinue medication during adolescence. Neuropharmacology research suggests a waning of stimulant effects after a few years. Longitudinal studies are scarce but provide some evidence that prognosis is often determined by factors other than the core symptoms of inattentiveness and impulsive overactivity. The implications for clinical practice are discussed. Continuing care, especially during the follow-up after initial therapy, needs further development.

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