Performance Assessment of Suture Type, Water Temperature, and Surgeon Skill in Juvenile Chinook Salmon Surgically Implanted with Acoustic Transmitters

2010 ◽  
Vol 139 (3) ◽  
pp. 888-899 ◽  
Author(s):  
Katherine A. Deters ◽  
Richard S. Brown ◽  
Kathleen M. Carter ◽  
James W. Boyd ◽  
M. Brad Eppard ◽  
...  
Keyword(s):  
Water Temperature ◽  
Performance Assessment ◽  
Chinook Salmon ◽  
Juvenile Chinook Salmon ◽  
Juvenile Chinook ◽  
Type Water

scholarly journals Effects of temperature and ration on the otolith-to-somatic size relationship in juvenile Chinook salmon (Oncorhynchus tshawytscha): a test of the direct proportionality assumption

2016 ◽  
Vol 67 (7) ◽  
pp. 913 ◽  
Author(s):  
David G. Stormer ◽  
Francis Juanes
Keyword(s):  
Water Temperature ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Somatic Growth ◽  
Compensatory Response ◽  
Juvenile Chinook Salmon ◽  
Size Relationship ◽  
Juvenile Chinook ◽  
Direct Proportionality ◽  
Somatic Size

Fish otoliths are commonly used to estimate somatic growth rate, but this depends on the assumption that the otolith and body grow in direct proportion. Environmental conditions contribute to variability in somatic growth and can result in deviations from direct proportionality in the otolith-to-somatic size relationship. In the present study we examined the otolith-to-body size relationship for juvenile Chinook salmon (Oncorhynchus tshawytscha) subjected to simulated seasonal (summer, autumn and winter) water temperatures and feeding rations. The otolith-to-somatic size relationship became uncoupled during summer between fish subjected to the cool (15°C) and hot (21°C) water temperatures. A food ration effect was also observed during the summer, such that fish fed an unlimited ration had smaller otoliths than equivalently sized fish fed a limited ration. The effects of water temperature and ration disappeared by the end of autumn, indicating that a seasonal compensatory response occurred in the otolith-to-somatic size relationship after the extreme temperatures and food limitations were alleviated. In winter, this relationship became uncoupled again, but only between fish that were fed throughout the winter and fish that were starved during the 3-month experimental period. The effects of water temperature and rations on the otolith-to-somatic size relationship of juvenile Chinook salmon could have implications for accurately estimating somatic growth from otolith growth in natural populations and should be incorporated into back-calculation techniques.

Fine-scale taxonomic and temporal variability in the energy density of invertebrate prey of juvenile Chinook salmon Oncorhynchus tshawytscha

2020 ◽  
Vol 655 ◽  
pp. 185-198
Author(s):  
J Weil ◽  
WDP Duguid ◽  
F Juanes
Keyword(s):  
Energy Density ◽  
Chinook Salmon ◽  
Temporal Variability ◽  
Energy Content ◽  
Single Point ◽  
Single Species ◽  
Fine Scale ◽  
Temporal Differences ◽  
Juvenile Chinook Salmon ◽  
Juvenile Chinook

Variation in the energy content of prey can drive the diet choice, growth and ultimate survival of consumers. In Pacific salmon species, obtaining sufficient energy for rapid growth during early marine residence is hypothesized to reduce the risk of size-selective mortality. In order to determine the energetic benefit of feeding choices for individuals, accurate estimates of energy density (ED) across prey groups are required. Frequently, a single species is assumed to be representative of a larger taxonomic group or related species. Further, single-point estimates are often assumed to be representative of a group across seasons, despite temporal variability. To test the validity of these practices, we sampled zooplankton prey of juvenile Chinook salmon to investigate fine-scale taxonomic and temporal differences in ED. Using a recently developed model to estimate the ED of organisms using percent ash-free dry weight, we compared energy content of several groups that are typically grouped together in growth studies. Decapod megalopae were more energy rich than zoeae and showed family-level variability in ED. Amphipods showed significant species-level variability in ED. Temporal differences were observed, but patterns were not consistent among groups. Bioenergetic model simulations showed that growth rate of juvenile Chinook salmon was almost identical when prey ED values were calculated on a fine scale or on a taxon-averaged coarse scale. However, single-species representative calculations of prey ED yielded highly variable output in growth depending on the representative species used. These results suggest that the latter approach may yield significantly biased results.

scholarly journals Empirically Estimating Carrying Capacity for Juvenile Chinook Salmon

2021 ◽  
Vol 102 (2) ◽  
Author(s):  
Kevin E. See ◽  
Michael W. Ackerman ◽  
Richard A. Carmichael ◽  
Sarah L. Hoffmann ◽  
Chris Beasley
Keyword(s):  
Chinook Salmon ◽  
Carrying Capacity ◽  
Juvenile Chinook Salmon ◽  
Juvenile Chinook
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