On the Relation of Adult Sockeye Salmon (Oncorhynchus nerka) Returns to Known Smolt Seaward Migrations

1954 ◽  
Vol 11 (4) ◽  
pp. 339-350 ◽  
Author(s):  
R. E. Foerster
Keyword(s):  
Multiple Regression ◽  
Negative Correlation ◽  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Average Weight ◽  
Actual Number ◽  
Average Percentage ◽  
Residual Variability ◽  
Percentage Survival

Data were obtained from Cultus Lake giving (a) the number of seaward migrating smolts each year from 1927 to 1944, (b) their mean length and weight, and (c) the number of adults from each smolt migration which returned in the spawning escapement to the lake. These indicate a negative correlation –.5;24, (P < 0.05) between number of smolts and percentage return of adults. By multiple regression this is shown to be related almost wholly to the size of the smolts. With an increase in average weight of smolts from 4 to 10 grams, their average percentage survival is tripled.Smolt size and numbers together account for about 60 per cent of the variation in actual number of adult salmon which arrive at the lake. The residual variability could not be definitely related to available qualitative indices of fishing intensity or duration.

Mortality Trend Among Young Sockeye Salmon (Oncorhynchus nerka) During Various Stages of Lake Residence

1938 ◽  
Vol 4a (3) ◽  
pp. 184-191 ◽  
Author(s):  
R. E. Foerster
Keyword(s):  
Linear Relationship ◽  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Mortality Trend ◽  
Percentage Loss ◽  
Percentage Survival

Young sockeye salmon, marked and liberated into Cultus lake, B.C., at intervals during the year were counted as seaward migrants. A linear relationship between time in the lake and percentage survival was found for periods of from 9.5 to 3.5 months, and from this the trend in percentage loss is computed. Mortality is found to be heavy during the first few months—approximately 65.4 per cent in the first 2.5 months—decreasing, however, as the year advances and the young sockeye increase in size.

Enhancement of Sockeye Salmon (Oncorhynchus nerka) by Lake Fertilization in Great Central Lake: Summary Report

1978 ◽  
Vol 35 (12) ◽  
pp. 1580-1596 ◽  
Author(s):  
R. J. LeBrasseur ◽  
C. D. McAllister ◽  
W. E. Barraclough ◽  
O. D. Kennedy ◽  
J. Manzer ◽  
...  
Keyword(s):  
Primary Production ◽  
Food Chain ◽  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Standing Stock ◽  
Ammonium Phosphate ◽  
Trophic Levels ◽  
Percentage Survival ◽  
Initial Hypothesis ◽  
Lake Fertilization

Great Central Lake was treated with ca. 1001 of commercial grade fertilizer (ammonium nitrate and ammonium phosphate) annually from 1970 through 1973. Limnological parameters and sockeye salmon (Oncorhynchus nerka) juveniles and adults were monitored from 1969 through 1976 to test the hypothesis that increasing the supply of inorganic nutrients in an ultraoligotrophic lake would increase production at succeeding trophic levels. Rates of change and linkages between different elements of the food chain leading to juvenile sockeye salmon were identified. During fertilized years mean summer primary production increased fivefold, zooplankton standing stock increased 9 times, the percentage survival from estimated potential egg deposition to juvenile sockeye increased 2.6 times, while mean stock size of adult sockeye increased from < 50 000 to > 360 000. Adult sockeye returning to an adjacent untreated lake also increased in abundance. The data for the 8-yr period support the initial hypothesis, but the dominant processes affecting production and interrelationships between different trophic levels in different years remain masked. Key words: food chain, limnology, sockeye salmon, primary production, zooplankton, eutrophication, lake fertilization, enhancement

Daily Pattern of Nitrogen Excretion and Oxygen Consumption of Sockeye Salmon (Oncorhynchus nerka) under Controlled Conditions

1975 ◽  
Vol 32 (12) ◽  
pp. 2479-2486 ◽  
Author(s):  
J. R. Brett ◽  
C. A. Zala
Keyword(s):  
Oxygen Consumption ◽  
Sockeye Salmon ◽  
Excretion Rate ◽  
Oncorhynchus Nerka ◽  
Ammonia Excretion ◽  
Nitrogen Excretion ◽  
Average Weight ◽  
Urea Excretion ◽  
Maintenance Ration ◽  
Exogenous Nitrogen

Measurements of the rate of ammonia and urea excretion of fingerling sockeye salmon (Oncorhynchus nerka) in fresh water were made at 2–3-hourly intervals throughout the day (average weight = 29 g; temperature = 15 C). One group of fish was fed a maintenance ration while another group was starved for 22 days. Ammonia excretion rose to a sharp peak of 35 mg N/kg per hour, 4–41/2 h after the start of feeding (at 0830) and fell to a baseline level of 8.2 mg N/kg per hour between 0200 and 0800. Urea excretion remained relatively steady at a mean rate of 2.2 mg N/kg per hour throughout the day, showing no diurnal response to feeding. Starved fish showed a nitrogen excretion rate close to that for both the steady state of urea excretion and the baseline rate of ammonia excretion of the fed fish. Oxygen consumption rose to a peak of 370 mg O2/kg per hour just before and during a 1-h feeding period, decreasing thereafter to a low of 170 mg O2/kg per hour at 0300 h. For the starved fish this diurnal metabolic fluctuation continued from the start in a variable and diminishing form whereas nitrogen excretion showed no such response. The results are discussed in relation to hatchery observations. We conclude that for nonstressed salmon at 15 C ammonia is the chief excretory product of exogenous nitrogen metabolism.

scholarly journals 242 Effect of trucking distance on sale price of beef calf and feeder cattle lots sold through video auctions from 2010 through 2018

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 10-11
Author(s):  
Esther D McCabe ◽  
Mike E King ◽  
Karol E Fike ◽  
Maggie J Smith ◽  
Glenn M Rogers ◽  
...  
Keyword(s):  
Multiple Regression ◽  
Regression Models ◽  
Average Weight ◽  
Sale Price ◽  
Feeder Cattle ◽  
A Value ◽  
Multiple Regression Models ◽  
Determine Effect

Abstract The objective was to determine effect of trucking distance on sale price of beef calf and feeder cattle lots sold through Superior Livestock Video Auctions from 2010 through 2018. Data analyzed were collected from 211 livestock video auctions. There were 42,043 beef calf lots and 19,680 feeder cattle lots used in these analyses. Six states (Colorado, Iowa, Kansas, Nebraska, Oklahoma, and Texas) of delivery comprised 70% of calf lots and 83% of feeder cattle lots and were used in these analyses. All lot characteristics that could be accurately quantified or categorized were used to develop multiple regression models that evaluated effects of independent factors using backwards selection. A value of P &lt; 0.05 was used to maintain a factor in the final models. Based upon reported state of origin and state of delivery, lots were categorized into one of the following trucking distance categories: 1) Within-State, 2) Short-Haul, 3) Medium-Haul, and 4) Long-Haul. Average weight and number of calves in lots analyzed was 259.2 ± 38.4 kg BW and 100.6 ± 74.3 head, respectively. Average weight and number of feeder cattle in lots analyzed was 358.4 ± 34.3 kg BW and 110.6 ± 104.1 head, respectively. Beef calf lots hauled Within-State sold for more ($169.24/45.36 kg; P &lt; 0.0001) than other trucking distance categories (Table 1). Long-Haul calf lots sold for the lowest (P &lt; 0.0001) price ($166.70/45.36 kg). Within-State and Short-Haul feeder cattle lots sold for the greatest (P &lt; 0.0001) price ($149.96 and $149.81/45.36 kg, respectively; Table 2). Long-Haul feeder cattle lots sold for the lowest (P &lt; 0.0001) price, $148.43/45.36 kg. These results indicate there is a price advantage for lots expected to be hauled shorter distances, likely because of cost and risk associated with transportation.

Resumption of anadromy or straying? Origins of Sockeye Salmon Oncorhynchus nerka in the Elwha River

2021 ◽  
Author(s):  
Thomas P. Quinn ◽  
George R. Pess ◽  
Ben J.G. Sutherland ◽  
Samuel J. Brenkman ◽  
Ruth E. Withler ◽  
...  
Keyword(s):  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Elwha River

Alternative Recruitment Models of Adams River Sockeye Salmon, Oncorhynchus nerka

1987 ◽  
Vol 44 (9) ◽  
pp. 1551-1561 ◽  
Author(s):  
Jeremy S. Collie ◽  
Carl J. Walters
Keyword(s):  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Status Quo ◽  
Management Policy ◽  
Best Management ◽  
Interaction Terms ◽  
Ricker Model ◽  
The Status ◽  
Stock Recruitment ◽  
High Yields

Despite evidence of depensatory interactions among year-classes of Adams River sockeye salmon (Oncorhynchus nerka), the best management policy is one of equal escapement for all year-classes. We fit alternative models (Ricker model and Larkin model) to 32 yr of stock–recruitment data and checked, using simulation tests, that the significant interaction terms in the Larkin model are not caused by biases in estimating the parameters. We identified a parameter set (Rationalizer model) for which the status quo cyclic escapement policy is optimal, but this set fits the observed data very poorly. Thus it is quite unlikely that the Rationalizer model is correct or that the status quo escapement policy is optimal. Using the fitted stock–recruitment parameters, we simulated the sockeye population under several management policies. The escapement policy optimal under the Ricker model is best overall because of the high yields if it should be correct. If the three stock–recruitment models are equally likely to be correct, the simulations predict that adopting a constant-escapement policy would increase long-term yield 30% over the current policy and that an additional 15% increase in yield could be obtained if the policy were actively adaptive.

Reduced growth in wild juvenile sockeye salmon Oncorhynchus nerka infected with sea lice

2017 ◽  
Vol 91 (1) ◽  
pp. 41-57 ◽  
Author(s):  
S. C. Godwin ◽  
L. M. Dill ◽  
M. Krkošek ◽  
M. H. H. Price ◽  
J. D. Reynolds
Keyword(s):  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Sea Lice

Validation of daily increments and a marine-entry check in the otoliths of sockeye salmon Oncorhynchus nerka post-smolts

2015 ◽  
Vol 87 (1) ◽  
pp. 169-178 ◽  
Author(s):  
C. Freshwater ◽  
M. Trudel ◽  
T. D. Beacham ◽  
C.-E. Neville ◽  
S. Tucker ◽  
...  
Keyword(s):  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Daily Increments
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