Flesh pH, Color, Thaw Drip, and Mineral Concentration of Pacific Halibut (Hippoglossus stenolepis) and Chinook Salmon (Oncorhynchus tshawytscha) Frozen at Sea

1973 ◽  
Vol 30 (1) ◽  
pp. 71-77 ◽  
Author(s):  
J. R. Botta ◽  
J. F. Richards ◽  
N. Tomlinson
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Potassium Concentration ◽  
Chloride Concentration ◽  
Mineral Concentration ◽  
Pacific Halibut ◽  
Hippoglossus Stenolepis ◽  
Subsequent Storage

The effects of brine-freezing and plate-freezing at sea on flesh pH, color (Hunter a/b ratio), thaw drip, and mineral concentration were determined at intervals during subsequent storage of the glazed, polyethylene covered fish at − 30 C.The difference in flesh pH between the brine- and plate-frozen samples was not significant for either halibut or salmon and the pH generally declined during storage.The changes in the Hunter a/b ratio of salmon were similar for both methods of freezing and the ratio generally increased slightly during storage.The thaw drip of halibut and salmon was less for the brine- than the plate-frozen samples after storage for 9–31 weeks whereas subsequently the brine-frozen samples had approximately equal or greater thaw drip than the plate-frozen. Except for plate-frozen halibut, thaw drip tended to increase with length of storage.Method of freezing did not significantly affect the potassium concentration of either halibut or salmon. For both species the sodium and chloride concentration of brine-frozen outside muscle was at least two to three times greater than brine-frozen inside or plate-frozen muscle.

Flesh Concentration of Various Long-Chain Free Fatty Acids of Pacific Halibut (Hippoglossus stenolepis) and Chinook Salmon (Oncorhynchus tshawytscha) Frozen at Sea

1973 ◽  
Vol 30 (1) ◽  
pp. 79-82
Author(s):  
J. R. Botta ◽  
J. F. Richards ◽  
N. Tomlinson
Keyword(s):  
Fatty Acids ◽  
Free Fatty Acids ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Frozen Storage ◽  
Pacific Halibut ◽  
Hippoglossus Stenolepis ◽  
Long Chain

Changes in the concentration of long-chain free fatty acids were determined gas chromatographically from inside and outside muscle samples of brine- or plate-frozen Pacific halibut and chinook salmon stored for 9–81 weeks.With both species the concentration of individual free fatty acids was greater in outside muscle than in inside muscle. Few differences in concentration of free fatty acids were noted between plate- and brine-frozen samples. Numerous free fatty acids increased significantly in concentration during frozen storage. For both species the increase was most rapid during the first 26–45 weeks of storage. The detection of flavor differences was unrelated to the concentration of individual free fatty acids.

Thiobarbituric Acid Value, Total Long-Chain Free Fatty Acids, and Flavor of Pacific Halibut (Hippoglossus stenolepis) and Chinook Salmon (Oncorhynchus tshawytscha) Frozen at Sea

1973 ◽  
Vol 30 (1) ◽  
pp. 63-69 ◽  
Author(s):  
J. R. Botta ◽  
J. F. Richards ◽  
N. Tomlinson
Keyword(s):  
Fatty Acids ◽  
Free Fatty Acids ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Frozen Storage ◽  
Thiobarbituric Acid ◽  
Pacific Halibut ◽  
Intermediate Storage ◽  
Storage Times ◽  
Long Chain

The effects of brine-freezing and plate-freezing at sea upon 2-thiobarbituric acid (TBA) values, concentration of long-chain free fatty acids (FFA), and flavor of Pacific halibut and chinook salmon were determined at intervals during subsequent storage of the glazed, polyethylene covered fish at − 30 C. Evaluations were conducted on both outside and inside muscle.Brine-frozen samples of outside muscle generally had higher TBA values than plate-frozen samples and the differences were most pronounced at intermediate storage times (26–45 weeks).Method of freezing significantly (P ≤ 0.05) affected the concentration of total FFA in Pacific halibut, and the total FFA concentration of both Pacific halibut and chinook salmon significantly increased with length of frozen storage. For both species the concentration of total FFA was significantly greater in outside than in inside muscle.Significant flavor differences between brine- and plate-frozen samples of outside muscle were evident at intermediate storage times for both species. For inside muscle of halibut, the significance of flavor differences generally increased with storage time whereas flavor differences for inside muscle of salmon were consistently nonsignificant.Taste panel results and TBA values indicated that, in comparison to plate-freezing, brine-freezing impaired the quality of outside muscle of Pacific halibut and chinook salmon during the early stages of frozen storage.

Systematic hexamitid (Protozoa: Diplomonadida) Infection in seawater pen-reared Chinook salmon Oncorhynchus tshawytscha

1992 ◽  
Vol 14 ◽  
pp. 81-89 ◽  
Author(s):  
ML Kent ◽  
J Ellis ◽  
JW Fournie ◽  
SC Dawe ◽  
JW Bagshaw ◽  
...  
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha

scholarly journals Managed Wetlands Can Benefit Juvenile Chinook Salmon in a Tidal Marsh

2021 ◽  
Author(s):  
Nicole M. Aha ◽  
Peter B. Moyle ◽  
Nann A. Fangue ◽  
Andrew L. Rypel ◽  
John R. Durand
Keyword(s):  
San Francisco ◽  
Growth Rates ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Nursery Habitat ◽  
San Francisco Estuary ◽  
Rice Fields ◽  
Fish Growth ◽  
Juvenile Chinook Salmon ◽  
Juvenile Chinook

AbstractLoss of estuarine and coastal habitats worldwide has reduced nursery habitat and function for diverse fishes, including juvenile Chinook salmon (Oncorhynchus tshawytscha). Underutilized off-channel habitats such as flooded rice fields and managed ponds present opportunities for improving rearing conditions and increasing habitat diversity along migratory corridors. While experiments in rice fields have shown enhanced growth rates of juvenile fishes, managed ponds are less studied. To evaluate the potential of these ponds as a nursery habitat, juvenile Chinook salmon (~ 2.8 g, 63 mm FL) were reared in cages in four contrasting locations within Suisun Marsh, a large wetland in the San Francisco Estuary. The locations included a natural tidal slough, a leveed tidal slough, and the inlet and outlet of a tidally muted managed pond established for waterfowl hunting. Fish growth rates differed significantly among locations, with the fastest growth occurring near the outlet in the managed pond. High zooplankton biomass at the managed pond outlet was the best correlate of salmon growth. Water temperatures in the managed pond were also cooler and less variable compared to sloughs, reducing thermal stress. The stress of low dissolved oxygen concentrations within the managed pond was likely mediated by high concentrations of zooplankton and favorable temperatures. Our findings suggest that muted tidal habitats in the San Francisco Estuary and elsewhere could be managed to promote growth and survival of juvenile salmon and other native fishes.

Analysis of straying variation in Alaskan hatchery chinook salmon (Oncorhynchus tshawytscha) following transplantation

1999 ◽  
Vol 56 (4) ◽  
pp. 578-589 ◽  
Author(s):  
Jeffrey J Hard ◽  
William R Heard
Keyword(s):  
British Columbia ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Release Site ◽  
Substantial Variation

In 1976 chinook salmon (Oncorhynchus tshawytscha) gametes from the Chickamin and Unuk rivers in southeastern Alaska were transplanted 250 km to establish hatchery runs at Little Port Walter (LPW), Baranof Island. From 1977 to 1989, 1 862 058 marked smolts from 12 broods were released from LPW. Homing and straying were estimated from adult recoveries at 25 locations in Alaska and British Columbia between 1981 and 1989. Of 22 198 LPW fish recovered over this period, 21 934 (98.8%) were collected at LPW. Of 264 fish recovered elsewhere, 38.3% were within 7 km of LPW; 64.4% were within 25 km of LPW. No LPW fish were recovered from the ancestral rivers, but nine fish were recovered from rivers supporting wild chinook salmon. Straying declined with distance from the release site but varied between hatcheries and streams. Straying declined with increasing age and run size. Straying was similar between the populations but varied among broods, and analysis of straying in experimental groups provided evidence for a heritable component. Males strayed more often than females. Population, gender, run size, and recovery age interacted to produce substantial variation in straying, indicating that run composition can produce complex straying responses.

scholarly journals Evidence for rapid avoidance of rockfish habitat under reduced quota and comprehensive at-sea monitoring in the British Columbia Pacific halibut fishery

2020 ◽  
Vol 77 (8) ◽  
pp. 1409-1420
Author(s):  
Robyn E. Forrest ◽  
Ian J. Stewart ◽  
Cole C. Monnahan ◽  
Katherine H. Bannar-Martin ◽  
Lisa C. Lacko
Keyword(s):  
British Columbia ◽  
Spatial Clustering ◽  
Clustering Methods ◽  
Quota System ◽  
Encounter Rates ◽  
System A ◽  
Pacific Halibut ◽  
Hippoglossus Stenolepis ◽  
Footprint Area ◽  
Management Changes

The British Columbia longline fishery for Pacific halibut (Hippoglossus stenolepis) has experienced important recent management changes, including the introduction of comprehensive electronic catch monitoring on all vessels; an integrated transferable quota system; a reduction in Pacific halibut quotas; and, beginning in 2016, sharp decreases in quota for yelloweye rockfish (Sebastes ruberrimus, an incidentally caught species). We describe this fishery before integration, after integration, and after the yelloweye rockfish quota reduction using spatial clustering methods to define discrete fishing opportunities. We calculate the relative utilization of these fishing opportunities and their overlap with areas with high encounter rates of yelloweye rockfish during each of the three periods. The spatial footprint (area fished) increased before integration, then decreased after integration. Each period showed shifts in utilization among four large fishing areas. Immediately after the reductions in yelloweye rockfish quota, fishing opportunities with high encounter rates of yelloweye rockfish had significantly lower utilization than areas with low encounter rates, implying rapid avoidance behaviour.

Route selection in a large river during the homing migration of Chinook salmon (Oncorhynchus tshawytscha)

2006 ◽  
Vol 63 (8) ◽  
pp. 1752-1762 ◽  
Author(s):  
Matthew L Keefer ◽  
Christopher C Caudill ◽  
Christopher A Peery ◽  
Theodore C Bjornn
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Columbia River ◽  
Large River ◽  
Migration Route ◽  
Route Selection ◽  
Behavioral Differences ◽  
Long Distance ◽  
Selection Decisions ◽  
Efficient Route

Upstream-migrating adult salmon must make a series of correct navigation and route-selection decisions to successfully locate natal streams. In this field study, we examined factors influencing migration route selections early in the migration of 4361 radio-tagged adult Chinook salmon (Oncorhynchus tshawytscha) as they moved upstream past dams in the large (~1 km wide) Columbia River. Substantial behavioral differences were observed among 11 conspecific populations, despite largely concurrent migrations. At dams, Chinook salmon generally preferred ladder passage routes adjacent to the shoreline where their natal tributaries entered, and the degree of preference increased as salmon proximity to natal tributaries increased. Columbia River discharge also influenced route choices, explaining some route selection variability. We suggest that salmon detect lateral gradients in orientation cues across the Columbia River channel that are entrained within tributary plumes and that these gradients in cues can persist downstream for tens to hundreds of kilometres. Detection of tributary plumes in large river systems, using olfactory or other navigation cues, may facilitate efficient route selection and optimize energy conservation by long-distance migrants.

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