On the Orientation of Young Sockeye Salmon (Oncorhynchus nerka) During Their Seaward Migration Out of Lakes.C. Groot

1966 ◽  
Vol 41 (3) ◽  
pp. 329-329
Author(s):  
George C. Williams
Keyword(s):  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Seaward Migration

Fish age, nematode (Philonema oncorhynchi) infection, and development of sexual dimorphism by the adult male sockeye salmon, Oncorhynchus nerka, in western Alaska

1995 ◽  
Vol 73 (11) ◽  
pp. 1999-2004 ◽  
Author(s):  
Ole Kristian Berg ◽  
Chris J. Foote ◽  
Thomas P. Quinn
Keyword(s):  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Parasite Infection ◽  
Mature Male ◽  
Sexually Dimorphic ◽  
Age Composition ◽  
Body Depth ◽  
Duration Of Residence ◽  
Significant Difference ◽  
Seaward Migration

Of 255 mature male sockeye salmon (Oncorhynchus nerka) from two Alaskan lakes (Aleknagik and Iliamna), 254 (99.6%) were infected with the nematode Philonema oncorhynchi with a mean wet mass of 3.1 g (SD = 3.4 g) of nematodes. Fish that had spent 1 year in the lake prior to seaward migration had significantly lower parasite masses than those that had spent 2 years in the lake (2.7 vs. 4.1 g). However, there was no significant difference in parasite masses between lakes or among spawning populations within the lakes for fish of a given age or of all ages combined, even though the populations differed in age composition. The variation in relative parasite mass (mass of parasite (g)/mass of fish (kg)) was mainly explained by the significant variation in total mass of the parasites and the sea age of the fish. Thus, total parasite mass was correlated with the duration of residence in fresh water, while the relative parasite mass was correlated with fish size, and hence with the duration of residence in the sea. In spite of heavy infections (up to 28 g of nematodes) in many salmon, there were no corresponding reductions in mass/length or in the development of two sexually dimorphic features, body depth and snout length. Thus, parasite infection did not appear to affect traits under sexual selection, as hypothesized by Hamilton and Zuk.

The Relation of Temperature to the Seaward Migration of Young Sockeye Salmon (Oncorhynchus nerka)

1937 ◽  
Vol 3 (5) ◽  
pp. 421-438 ◽  
Author(s):  
R. E. Foerster
Keyword(s):  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Weather Conditions ◽  
First Year ◽  
Temperature Conditions ◽  
Temperature Trends ◽  
Air Temperatures ◽  
Seaward Migration ◽  
Small Growth ◽  
Slight Rise

The period of seaward migration of young sockeye from Cultus lake each spring is inversely correlated with temperature conditions prevailing during the months immediately preceding. Correlating temperature readings of the outflow stream with date when twenty per cent migration occurred, a statistically significant correlation of −0.85 was obtained for February and March and −0.77 for January to March. Using air temperatures, coefficients of −0.91 for January to March and −0.74 for February and March were found. Commencement of migration coincides with vernal rise in lake temperatures. Under normal conditions, with low winter minimum, there appears to be a threshold migration temperature approximating 4.4 °C. (40°F.) but in seasons when lake temperatures are not depressed to this level a slight rise stimulates migration. Progress of migration is largely influenced by prevailing weather conditions and their effect upon temperature trends. Cessation of migration appears to be related to the setting-up of a "temperature blanket" which inhibits migration from the lake of sockeye still resident therein. These latter, showing small growth during their first year, remain in the lake until the following spring and then are among the first to migrate.

Perception of Polarized Light by Yearling Sockeye Salmon (Oncorhynchus nerka)

1971 ◽  
Vol 28 (9) ◽  
pp. 1319-1322 ◽  
Author(s):  
P. A. Dill
Keyword(s):  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Polarized Light ◽  
Seaward Migration ◽  
Linearly Polarized ◽  
Food Conditioning ◽  
Conditioning Experiments

Food-conditioning experiments conducted in the laboratory demonstrated that groups of yearling sockeye salmon (Oncorhynchus nerka) can discriminate between vertical and horizontal planes of linearly polarized light. Removal of the adipose eyelid, a possible analyser of polarized light, did not abolish the response. The findings support the hypothesis that these fish can use polarization patterns for orientation during their seaward migration.

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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