Effect of Finclipping on Survival of Sockeye Salmon (Oncorhynchus nerka)

1969 ◽  
Vol 26 (5) ◽  
pp. 1263-1271 ◽  
Author(s):  
Douglas Weber ◽  
Roy J. Wahle

A finclip and a chemical (tetracycline) mark were applied, in similar numbers, to hatchery-reared fingerling sockeye salmon (Oncorhynchus nerka). In mark-sampling of returning adults 3 and 4 years after release from the hatchery, numerical comparison of fish with the two marks showed that fewer finclipped fish returned than expected. It was demonstrated that the tetracycline mark did not affect survival and that the difference between returns of fish with the two marks originated in mortality caused by finclipping. The mortality attributed to finclipping was estimated as 39%.


1973 ◽  
Vol 30 (12) ◽  
pp. 1799-1809 ◽  
Author(s):  
J. R. Brett

Fingerling and adult sockeye salmon (Oncorhynchus nerka) were subjected to long periods of sustained swimming (10–20 days) in air-saturated fresh water. Energy expended was computed from change in body composition and compared with the metabolic equivalent from multiple determinations of oxygen-consumption rate. Caloric loss from body substance exceeded that estimated from total oxygen uptake by an average of 19.8%. The reasons for the difference, and the assumptions involved, are discussed. The difference apparently arises from slight excretion of partially metabolized fuels (anaerobic metabolism) and loss from sloughed body tissues. An oxycalorific equivalent of 4.8 kcal/liter O2 is considered an acceptable value for fish.



1990 ◽  
Vol 47 (11) ◽  
pp. 2250-2260 ◽  
Author(s):  
Chris C. Wood ◽  
Chris J. Foote

Anadromous (sockeye salmon) and nonanadromous (kokanee) Oncorhynchus nerka spawn sympatrically yet appear genetically distinct in a number of rivers in British Columbia. To investigate whether genetic differences are maintained by selection against -hybrid" progeny, we raised pure and reciprocal crosses of Shuswap River sockeye and kokanee under controlled hatchery conditions. Sockeye eggs were larger and survived slightly better than kokanee eggs, regardless of male type, both to the eyed egg stage and as young fry. We observed no differences in survival among cross types during the remainder of the 460 d study. Rate of yolk absorption was similar in pure sockeye and pure kokanee alevins, but significantly faster in alevins sired by sockeye than those sired by kokanee. This indicates a male genetic effect which compensates for the difference in egg size. Hybrid alevins developed differently because egg size is mismatched with the male genotype. Growth rates of fry were significantly more variable within pure kokanee families than within pure sockeye families Hybrid crosses survived as well as pure crosses under the study conditions. However, any progeny resulting from hybrid crosses in nature may sustain higher mortality than those from pure crosses.



1976 ◽  
Vol 33 (2) ◽  
pp. 307-313 ◽  
Author(s):  
J. R. Brett

The extent of metabolic and feeding requirements for fingerling sockeye salmon (Oncorhynchus nerka) are compared over the tolerable range of temperature. Scope for growth, derived from the difference between maximum and maintenance rations, is shown to relate to temperature in a manner similar to that for maximum growth rate. Metabolic scope is compared with scope for growth, supporting the general concept of scope for activity developed by Fry (1947).



Symmetry ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 436
Author(s):  
Ruirui Zhao ◽  
Minxia Luo ◽  
Shenggang Li

Picture fuzzy sets, which are the extension of intuitionistic fuzzy sets, can deal with inconsistent information better in practical applications. A distance measure is an important mathematical tool to calculate the difference degree between picture fuzzy sets. Although some distance measures of picture fuzzy sets have been constructed, there are some unreasonable and counterintuitive cases. The main reason is that the existing distance measures do not or seldom consider the refusal degree of picture fuzzy sets. In order to solve these unreasonable and counterintuitive cases, in this paper, we propose a dynamic distance measure of picture fuzzy sets based on a picture fuzzy point operator. Through a numerical comparison and multi-criteria decision-making problems, we show that the proposed distance measure is reasonable and effective.



Author(s):  
Thomas P. Quinn ◽  
George R. Pess ◽  
Ben J.G. Sutherland ◽  
Samuel J. Brenkman ◽  
Ruth E. Withler ◽  
...  


1987 ◽  
Vol 44 (9) ◽  
pp. 1551-1561 ◽  
Author(s):  
Jeremy S. Collie ◽  
Carl J. Walters

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.



2017 ◽  
Vol 91 (1) ◽  
pp. 41-57 ◽  
Author(s):  
S. C. Godwin ◽  
L. M. Dill ◽  
M. Krkošek ◽  
M. H. H. Price ◽  
J. D. Reynolds


2015 ◽  
Vol 87 (1) ◽  
pp. 169-178 ◽  
Author(s):  
C. Freshwater ◽  
M. Trudel ◽  
T. D. Beacham ◽  
C.-E. Neville ◽  
S. Tucker ◽  
...  


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