Responses of Coho and Chum Salmon Fry to Current

1953 ◽  
Vol 10 (8) ◽  
pp. 523-538 ◽  
Author(s):  
Dixon MacKinnon ◽  
William S. Hoar
Keyword(s):  
Water Flow ◽  
Chum Salmon ◽  
Coho Salmon ◽  
Initial Response ◽  
Peak Response ◽  
Salmon Fry ◽  
Optimum Response ◽  
Laminar Currents ◽  
Turbulent Water

Chum and coho salmon fry respond positively to changes in water flow by swimming against the current. The magnitude of the response varies with the intensity of the current. Currents eliciting optimum response differ for the two species. Both species respond to the stronger of two parallel laminar currents but, after a time, coho fail to discriminate between small differences while the chums move continuously into the greater flow. No evidence of adaptation is apparent in a two-hour period with rapid complex turbulences. In turbulent water coho fry make a sharper initial response than chum fry but do not seem to maintain the peak response over as wide a range of turbulences.

Influence of the Abundance, Size, and Yolk Reserves of Juvenile Chum Salmon (Oncorhynchus keta) on Predation by Freshwater Fishes in a Small Coastal Stream

1987 ◽  
Vol 44 (2) ◽  
pp. 236-243 ◽  
Author(s):  
Kurt L. Fresh ◽  
Steven L. Schroder
Keyword(s):  
Chum Salmon ◽  
Coho Salmon ◽  
Salmo Gairdneri ◽  
Oncorhynchus Keta ◽  
Predator Prey ◽  
Chum Salmon Oncorhynchus Keta ◽  
Salmon Fry ◽  
Juvenile Chum Salmon ◽  
Controlled Flow ◽  
The Relationship

Predator–prey interactions between juvenile chum salmon (Oncorhynchus keta) and piscivores were studied in a small coastal stream and in sections of a controlled-flow channel. The predators were primarily large [Formula: see text] rainbow trout (Salmo gairdneri) and large [Formula: see text] coho salmon (O. kisutch). The relationship between chum salmon fry abundance and the quantity consumed by predators suggested a type II functional response. Neither prey size nor prey abundance influenced predation, but predators did select fry with relatively high yolk reserves. Our results suggest that the numbers of juvenile chum salmon needed to satiate predators and to enhance fry survival are attainable by enhancement projects located on smaller rivers and streams.

Changes in Body Chloride, Density, and Water Content of Chum (Oncorhynchus keta) and Coho (O. kisutch) Salmon Fry when Transferred from Fresh Water to Sea Water

1951 ◽  
Vol 8b (3) ◽  
pp. 164-177 ◽  
Author(s):  
Virginia Safford Black
Keyword(s):  
Water Content ◽  
Fresh Water ◽  
Chum Salmon ◽  
Coho Salmon ◽  
Sea Water ◽  
The Body ◽  
Oncorhynchus Keta ◽  
Normal Range ◽  
Experimental Conditions ◽  
Salmon Fry

Changes in body chloride, density and water content of chum and coho salmon fry were measured when these fish were transferred from fresh water to sea water, and the reverse. Both species tolerated 50% sea water (8–9‰ Cl). Chum fry survived direct transfer from fresh water to sea water (15–17‰ Cl), but showed a marked increase in body chloride during the first 12 hours, followed by a return to the normal range between 12 and 24 hours. Coho, however, died within the first 36 hours, after a 60% increase in chloride. Coho fry lost more water than chum fry after introduction to sea water. The density of both species approximated that of the water within an hour of transfer to the new medium. When returned to fresh water after 12 hours in sea water the body chloride, density, and water content of both species regained normal levels within 10 hours. Chum salmon go to sea as fry, whereas cohos remain in fresh water a year or more. Although coho fry seem capable of some adjustment to sea water after a preliminary period in 50% sea water, permanent acclimatization could not be demonstrated under the experimental conditions.

EFFECTS OF SOME HORMONES ON THE BEHAVIOR OF SALMON FRY

1952 ◽  
Vol 30 (5) ◽  
pp. 273-286 ◽  
Author(s):  
William S. Hoar ◽  
Dixon MacKinnon ◽  
Aline Redlich
Keyword(s):  
Chum Salmon ◽  
Coho Salmon ◽  
Antithyroid Drug ◽  
Light Gradient ◽  
Salmon Fry ◽  
Patterns Of Behavior ◽  
Quantitative Changes

Chum and coho salmon fry, when immersed in solutions of methyl testosterone, synthetic thyroxine sodium, or the antithyroid drug, thiourea, do not show any new or different patterns of behavior. Chum salmon fry do, however, show quantitative changes in the rate of swimming and in the intensity of schooling. Less marked variations are seen in aggregating behavior of the treated coho. Control chum fry swim in the brightest part of a horizontal light gradient while coho fry, coho smolt, and trout prefer darker areas. Minor changes in this photoresponse, observed in fish treated with drugs, are probably produced by variations in the amount of swimming.

Stream Temperatures and Inter-Annual Variability in the Emigration Timing of Coho Salmon (Oncorhynchus kisutch) Smolts and fry and Chum Salmon (O. Keta) Fry from Carnation Creek, British Columbia

1989 ◽  
Vol 46 (8) ◽  
pp. 1396-1405 ◽  
Author(s):  
L. Blair Holtby ◽  
Thomas E. McMahon ◽  
J. Charles Scrivener
Keyword(s):  
British Columbia ◽  
Chum Salmon ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Oncorhynchus Keta ◽  
Windows Of Opportunity ◽  
Salmon Fry ◽  
Median Date ◽  
Wet Weight ◽  
Laboratory Models

Variability in average stream temperatures between peak spawning and fry emergence accounted for 82 and 77% of the variance in the median emigration date of fry of chum (Oncorhynchus keta) and coho salmon (O. kisutch) respectively over a 9 to 10-yr period. The modeled relationships were indistinguishable from laboratory models that predicted time to maximum alevin wet weight. Variability in stream temperatures during the spring accounted for 60% of the variability in the median date of coho smolt emigration. As stream temperatures increased, the predicted thermal summations required for emigration were nearly constant for coho salmon fry, increased moderately for chum salmon fry and increased strongly for coho salmon smolts The duration of the emigration period also differed between the groups: 50% of the chum salmon fry emigrated over a 1-wk period compared with a 2- to 3-wk period for coho salmon fry and smolts. We speculate that the emigration timing —temperature relationships and timing of adult spawning represent adaptations for synchronizing emigration with "windows of opportunity" in the ocean or stream. The windows are of different widths and levels of predictability for coho and chum salmon fry and coho salmon smolts.

scholarly journals Odor Plumes and Animal Navigation in Turbulent Water Flow: A Field Study

1995 ◽  
Vol 188 (2) ◽  
pp. 111-116 ◽  
Author(s):  
R. K. Zimmer-Faust ◽  
C. M. Finelli ◽  
N. D. Pentcheff ◽  
D. S. Wethey
Keyword(s):  
Field Study ◽  
Water Flow ◽  
Animal Navigation ◽  
Odor Plumes ◽  
Turbulent Water

Density, growth, and change in density of coho salmon and rainbow trout in three Lake Michigan tributaries

1983 ◽  
Vol 61 (5) ◽  
pp. 1120-1127 ◽  
Author(s):  
L. M. Carl
Keyword(s):  
Rainbow Trout ◽  
Growth Rates ◽  
Lake Michigan ◽  
Coho Salmon ◽  
Daily Growth ◽  
Salmon Fry ◽  
Daily Change ◽  
Early Fall ◽  
Growth And Change ◽  
Downstream Movement

Coho salmon spawning peaked in the late fall. Spawning densities ranged from fewer than 5 coho salmon per hectare up to 90 fish per hectare. Subyearling coho salmon densities ranged from 10 to 60 fish per 100 m2 in June and dropped to 5–20 fish by early fall. Coho salmon fry increased in length from 40 mm in early May, to over 120 mm by smolt out-migration in the following April. Coho salmon instantaneous daily change in density coefficients ranged from 0.004 to 0.019 and were dependent on initial coho density. Daily coho salmon growth rates ranged from 0.38 to 0.60 mm per day and were not dependent on initial coho salmon density. Downstream movement of rainbow trout fry began in May, and continued into July. In the spring 10–20 yearlings and one to five 2-year-olds per 100 m2 were present. Most fry emerged in June at a size of 25 mm and grew to 85 mm by fall. Daily growth rates varied from 0.23 to 0.45 mm per day for yearling rainbow trout and were not correlated with rainbow trout density.

scholarly journals Resources and fishery of Pacific salmon in Magadan region in the beginning of the 21st century

Trudy VNIRO ◽  
2020 ◽  
Vol 179 ◽  
pp. 90-102
Author(s):  
M. N. Gorokhov ◽  
V. V. Volobuev ◽  
I. S. Golovanov
Keyword(s):  
Chum Salmon ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Pink Salmon ◽  
Spawning Grounds ◽  
Magadan Region ◽  
Spawning Areas ◽  
Optimal Values ◽  
In The Beginning ◽  
Salmon Fishery

There are two main areas of pacific salmon fishing in the Magadan region: Shelikhova Gulf and Tauiskaya Bay. The main fishing species is pink salmon in the region. Its share of total salmon catch by odd-year returns reaches 85 %. Data on the dynamics of escapement to the spawning grounds of pink salmon of the Shelikhova Gulf and Tauiskaya Bay are presented. The displacement of the level of spawning returns of pink salmon into the Shelihova Gulf with the simultaneous reduction of its returns to the Tauiskaya Bay is shown. Data on the dynamics of the fishing indicators of pink salmon for the two main fishing areas are provided. The Tauiskaya Bay as the main pink salmon fishery area loses its importance is shown. Graphical data on the escapement of producers pink salmon to the spawning grounds are presented and the optimal values of spawning escapements are estimated. Chum salmon is the second largest and most fishing species. Information on the dynamics of the number of returns, catch and escapement to the spawning grounds of chum salmon is given. The indicators of escapement to the spawning areas and their compliance with the optimal passes of salmon producers are analyzed. The issues of the dynamics of returns number, catch and the escapement to the spawning grounds of coho salmon producers are considered. The level of the escapement to the spawning areas is shown and the ratio of actual to optimal values of passes is estimated. The role of coho salmon as an object of industrial fishing and amateur fishing is shown. The extent of fishing press on individual groups of salmon populations is discussed. It is concluded that it is necessary to remove the main salmon fishery from the Tauiskaya Bay to the Shelikhova Gulf.

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