Babine Lake Sockeye Salmon (Oncorhynchus nerka) Enhancement Program: Testing some Major Assumptions

1984 ◽  
Vol 41 (1) ◽  
pp. 70-92 ◽  
Author(s):  
J. McDonald ◽  
J. M. Hume
Keyword(s):  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Effective Means ◽  
Growth And Survival ◽  
Program Testing ◽  
Basic Assumptions ◽  
Before And After ◽  
Average Size ◽  
Before And After Study ◽  
Future Management

The objective of the Babine Lake sockeye salmon (Oncorhynchus nerka) enhancement project was to increase fry outputs (and thus, smolt outputs and adult returns) by expanding and improving available spawning beds through the use of artificial spawning channels and related water flow control facilities. The project proceeded on four basic assumptions: (1) the artificial spawning channels would prove an effective means of producing sockeye fry, (2) the fry produced would be as viable as those produced from natural spawning beds, (3) the lake nursery area had the capacity to support larger juvenile populations, and (4) increased smolt outputs would result in increased adult returns. A before and after study has allowed these assumptions to be tested. Egg-to-fry survival in the channels was close to 40%, as expected. Comparisons of wild and channel-produced fry did not reveal any substantial difference in their distribution, growth, and survival in the lake. Increases in the abundance of fry were followed by corresponding increases in the abundance of underyearlings in the lake and seaward migrating smolts. No significant change in the average size of the juveniles or their survival in the lake could be detected when population size increased. While the assumptions regarding juvenile production were found to be generally valid, adult returns did not meet expectations. This was due largely to the lack of response to increased smolt outputs from even-numbered brood years. Some options for future management are offered.

An Acoustic Estimate of the Escapement of Sockeye Salmon (Oncorhynchus nerka) into Lake Washington in 1971

1974 ◽  
Vol 31 (2) ◽  
pp. 222-225 ◽  
Author(s):  
Richard E. Thorne ◽  
James J. Dawson
Keyword(s):  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Spawning Migration ◽  
Spawning Ground ◽  
Large Fish ◽  
Before And After ◽  
Lake Washington

The feasibility of estimating the escapement of sockeye salmon (Oncorhynchus nerka) into Lake Washington by hydroacoustics was explored during 1971. Surveys were made of large fish targets within the lake just before and after the spawning migration of sockeye salmon up the Cedar River. A decrease was observed after the spawning migration comparable to the estimated escapement as determined by weir counts and spawning ground surveys.

scholarly journals Host-pathogen-environment interactions determine survival outcomes of adult sockeye salmon (Oncorhynchus nerka) released from fisheries

2021 ◽  
Author(s):  
Amy Teffer ◽  
Scott Hinch ◽  
Kristina Miller ◽  
David Patterson ◽  
Arthur Bass ◽  
...  
Keyword(s):  
Gene Expression ◽  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
High Water ◽  
Host Responses ◽  
Physiological Status ◽  
Immune Gene ◽  
Animal Populations ◽  
Host Pathogen ◽  
Before And After

Incorporating host-pathogen(s)-environment axes into management and conservation planning is critical to preserving species in a warming climate. However, the role pathogens play in host stress resilience remains largely unexplored in wild animal populations. We experimentally characterized how independent and cumulative stressors (fisheries handling, high water temperature) and natural infections affected the health and longevity of released wild adult sockeye salmon (Oncorhynchus nerka) in British Columbia, Canada. Returning adults were collected before and after entering the Fraser River, yielding marine- and river-collected groups, respectively. Fish were exposed to a mild (seine) or severe (gill net) fishery treatment at collection, and then held in circulating freshwater tanks for up to four weeks at historical (14°C) or projected migration temperatures (18°C). Using weekly nonlethal gill biopsies and high-throughput qPCR, we quantified loads of up to 46 pathogens with host stress and immune gene expression. Marine-captured fish had less severe infections than river-captured fish, a short migration distance (100 km, 5-7 d) that produced profound infection differences. At 14°C, river-collected fish survived 1-2 weeks less than marine-collected fish. All fish held at 18°C died within 4 weeks unless they experienced minimal handling. Gene expression correlated with infections in river-collected fish, while marine-collected fish were more stressor-responsive. Cumulative stressors were detrimental regardless of infections or collection location, likely due to extreme physiological disturbance. Because river-derived infections correlated with single stressor responses, river entry likely decreases stressor resilience of adult salmon by altering both physiological status and pathogen burdens, which redirect host responses toward disease resistance.

Population Estimates of Sockeye Salmon (Oncorhynchus nerka) in a Fertilized Oligotrophic Lake

1978 ◽  
Vol 35 (6) ◽  
pp. 851-860 ◽  
Author(s):  
D. G. Robinson ◽  
W. E. Barraclough
Keyword(s):  
Survival Data ◽  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Age Groups ◽  
Close Correlation ◽  
Oligotrophic Lake ◽  
Population Estimates ◽  
Good Resolution ◽  
Growth And Survival ◽  
Carry Over

Pelagic juvenile sockeye salmon (Oncorhynchus nerka) populations were studied in Great Central Lake, British Columbia, during 1969–76 to determine the effect of nutrient enrichment upon their growth and survival. Data for population estimates were collected concurrently by a high-frequency echosounder, and a midwater trawl whose efficiency was inversely related to ambient light above about 1.9 × 10−5 lx. Echogram counts supplemented by trawl catches yielded estimates with low variance, good resolution between age-groups, and indicated close correlation between numbers of spawners and resultant progeny within respective treatments. Survival to the fall for the treated 1969–72 brood years averaged 11.65% (range 11.11–12.81%) of potential egg deposition compared to 3.5% for the pretreatment 1968 brood year fish; 2.73 and 6.29% for the posttreatment 1974 and 1975 brood year fish. A carry-over of fertilization effects on the immediate posttreatment 1973 brood year may have induced a cyclic pattern on the survival of the two succeeding year-classes. The relatively consistent annual production of age 0+ sockeye may be due to the inherent stability of inlake spawning and incubation coupled with the low predation rates. The conservative estimate of a 2.5 increase in survival relative to the natural level indicates a positive response to enhanced feeding conditions caused by the fertilization of this oligotrophic lake. Key words: sockeye, survival, Great Central Lake, fertilization, enhancement, acoustic estimates, townet efficiency

Impact of fertilization and stocking on trophic interactions and growth of juvenile sockeye salmon (Oncorhynchus nerka)

2002 ◽  
Vol 59 (8) ◽  
pp. 1361-1373 ◽  
Author(s):  
Asit Mazumder ◽  
Jim A Edmundson
Keyword(s):  
Food Web ◽  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Trophic Levels ◽  
Food Web Structure ◽  
Web Structure ◽  
Mean Size ◽  
Average Size ◽  
The Impact

Using 16 years of data on nutrients, plankton, and sockeye fry and smolts from Packers Lake, Alaska, we test the impact of nutrients and fry stocking on the growth and productivity of juvenile sockeye salmon (Oncorhynchus nerka). To enhance sockeye production, this lake was fertilized (1983–1996) and stocked annually (1987–1996) with sockeye fry. Before fertilization, the density of sockeye fry was low (<0.20 fry·m–2), the size and biomass of Daphnia were low, and sockeye smolts were relatively small. Before stocking, all trophic levels responded positively to fertilization. The biomass and mean size of Daphnia increased significantly. The average size of age-1 and age-2 smolts increased three- to four-fold. Fry stocking produced dramatic declines in both biomass and mean length of Daphnia and in size of smolts. When large-sized (>1 mm) Daphnia were significantly reduced in density under heavy predation by sockeye fry, the growth of juvenile sockeye declined, even under continued fertilization. We show that fry density and associated food web structure are major determinants of juvenile sockeye responses to fertilization and stocking. This study probably provides the first long-term experimental results linking limnological and nutrient – food web concepts to trophodynamics and productivity of juvenile sockeye salmon.

Only problem gamblers spend less money when loot boxes are removed from a game: A before and after study of Heroes of the Storm

2019 ◽  
Author(s):  
David Zendle
Keyword(s):  
Video Games ◽  
Problem Gambling ◽  
Video Game ◽  
Real World ◽  
Complex Pattern ◽  
Problem Gamblers ◽  
Before And After ◽  
Gambling Severity ◽  
Reliable Correlation ◽  
Before And After Study

Loot boxes are items in video games that may be paid for with real-world money, but which contain randomised contents. There is a reliable correlation between loot box spending and problem gambling severity: The more money gamers spend on loot boxes, the more severe their problem gambling tends to be. However, it is unclear whether this link represents a case in which loot box spending causes problem gambling; a case in which the gambling-like nature of loot boxes cause problem gamblers to spend more money; or whether it simply represents a case in which there is a general dysregulation in in-game spending amongst problem gamblers, nonspecific to loot boxes.The multiplayer video game Heroes of the Storm recently removed loot boxes. In order to better understand links between loot boxes and problem gambling, we conducted an analysis of players of Heroes of the Storm (n=112) both before and after the removal of loot boxes.There were a complex pattern of results. In general, when loot boxes were removed from Heroes of the Storm, problem gamblers appeared to spend significantly less money in-game in contrast to other groups. These results suggest that the presence of loot boxes in a game may lead to problem gamblers spending more money in-game. It therefore seems possible that links between loot box spending and problem gambling are not due to a general dysregulation in in-game spending amongst problem gamblers, but rather are to do with specific features of loot boxes themselves.

A pilot study on the effect of ulipristal acetate on myoma angiogenesis, measured by 2D ultrasound and VEGF serum levels

2020 ◽  
pp. 19-29
Author(s):  
Patricia Diaz Ortega ◽  
Manuel García Manero
Keyword(s):  
Pilot Study ◽  
Power Doppler ◽  
Uterine Fibroids ◽  
Premenopausal Women ◽  
Serum Levels ◽  
Ulipristal Acetate ◽  
Before And After ◽  
Angiogenesis Process ◽  
2D Ultrasound ◽  
Average Size

Introduction: Symptomatic uterine fibroids can cause symptoms that can be disabling. There are many treatments, including ulipristal acetate, whose role in reducing symptoms and decreasing the size of the fibroid is well known. With this preliminary study, we also try to evaluate the correlation between myoma vascularization measured by ultrasound (Power Doppler 2D) and serum VEGF levels, before and after treatment with ulipristal acetate; in patients diagnosed with symptomatic uterine fibroids. Materials and Methods: A preliminary, prospective observational pilot study was designed. Twenty-four premenopausal women, diagnosed with symptomatic uterine fibroids, were included and all of them completed the study. Four cycles of ulipristal acetate were administered according to the dose and indications specified in the data sheet. In order to assess the influence of this treatment on the angiogenesis process of the fibroids, measurements of VEGF serum levels were made and their vascularization was assessed by means of 2D power doppler ultrasound; at the beginning and the end of treatment. In addition, several determinations of the same parameters were made throughout the successive visits. Endpoints were defined as the decrease in VEGF levels from previous levels, the decrease in myoma vascularization on ultrasound, and the reduction in myoma size. Result: 24 patients who met the inclusion criteria were enrolled (n=24). The average size of myomas was reduced from 45,08 ? 24,02mm to 29?16,96mm after treatment. The average VEGF serum level significantly decreased after the first treatment cycle (from 147,17 ? 153,51 pg/ml to 102,04 ? 186,08pg/ml). Vascularization of myomas after treatment with ulipristal acetate was analyzed, and a significantly decrease was achieved in 83,3% of cases. Conclusion: There is a correlation between myoma vascularization and treatment with Ulipristal acetate. SPRMs may provide effective treatment for women with symptomatic fibroids by two ways: supports selective progesterone receptor modulators and reduced angiogenesis. Keywords: Angiogenesis; Ulipristal Acetate; Uterine fibroids; VEGF

INTERVENSI PELATIHAN PENILAIAN KINERJA PADA ATASAN UNTUK MENINGKATKAN PERCEIVED ORGANIZATIONAL SUPPORT & EMPLOYEE ENGAGEMENT

2017 ◽  
Vol 2 (2) ◽  
pp. 1-8
Author(s):  
Holy Greata
Keyword(s):  
Performance Appraisal ◽  
Employee Engagement ◽  
Study Design ◽  
Work Engagement ◽  
Organizational Support ◽  
Perceived Organizational Support ◽  
Paired Sample ◽  
Utrecht Work Engagement Scale ◽  
Before And After ◽  
Before And After Study

This study aims to look at the effectiveness of performance appraisal training programs to improve perceived organizational support and employee engagement among employees at YPTK educational institutions. This research uses a quantitative approach, with the before-and-after study design research design. The strength of this program is the ability to measure the impact of an intervention. Measuring devices perceived organizational support is an adaptation of the survey of perceived organizational support, while measuring instruments employee engagement is an adaptation of the Utrecht work engagement scale. The results of this study indicate the influence of perceived organizational support on employee engagement of 0.168 (p = 0.016 significant at l.o.s 0.05). Paired sample t-test results showed significant differences in perceived organizational support and employee engagement scores before and after the training and outreach of performance appraisal. Keywords: Perceived Organizational Suppor; Employee Engagement, Performance assessment   Penelitian ini bertujuan melihat efektifitas program pelatihan penilaian kinerja untuk meningkatkan perceived organizational support dan employee engagement pada karyawan di lembaga pendidikan YPTK. Penelitian ini menggunakan pendekatan kuantitatif, dengan design penelitian the before-and-after study design. Kelebihan dari program ini adalah kemampuan untuk mengukur dampak dari sebuah intervensi. Alat ukur perceived organizational support merupakan adaptasi dari survey of perceived organizational support, sedangkan alat ukur employee engagement merupakan adaptasi dari Utrecht work engagement scale. Hasil penelitian ini menunjukkan adanya pengaruh perceived organizational support terhadap employee engagement sebesar 0.168 (p=0.016 signifikan pada l.o.s 0.05). Hasil uji paired sample t-test menunjukkan adanya perbedaan skor perceived organizational support dan employee engagement yang signifikan sebelum dan sesudah dilakukan pelatihan dan sosialisasi penilaian kinerja.   Kata Kunci: Perceived Organizational Suppor; Employee Engagement, Penilaian Kinerja.

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