Physiological Changes during Seaward Migration of Wild Juvenile Coho Salmon (Oncorhynchus kisutch)

1987 ◽  
Vol 44 (2) ◽  
pp. 452-457 ◽  
Author(s):  
Jeffrey D. Rodgers ◽  
Richard D. Ewing ◽  
James D. Hall
Keyword(s):  
Atpase Activity ◽  
Coho Salmon ◽  
Condition Factor ◽  
Specific Activity ◽  
Oncorhynchus Kisutch ◽  
Physiological Changes ◽  
Fish Gill ◽  
Seaward Migration ◽  
Cyclic Changes

Peaks in migration of wild juvenile coho salmon (Oncorhynchus kisutch) from Knowles Creek (Siuslaw River, Oregon) occurred in November and May. Condition factor of nonmigrant fish was higher than migrants or captives throughout the study. Skin guanine levels of migrant fish rose sharply during the first 2 wk of April and continued to rise through June. Gill (Na + K)-ATPase specific activity of migrants rose gradually from a low in January to a maximum in June. Gill (Na + K)-ATPase activity of migrants and nonmigrants was low and not significantly different during November to mid-March. During April, however, gill ATPase activity of migrants rose to become significantly higher than that of nonmigrants until the first 2 wk of May. Cyclic changes in gill (Na + K)-ATPase activity was not observed in these fish. Gill (Na + K)-ATPase activity of fish reared in a laboratory was similar to that of wild nonmigrants until it peaked during the last 2 wk of April, after which the specific activity was lower than either migrants or nonmigrants.

scholarly journals Evidence for Freshwater Residualism in Coho Salmon, Oncorhynchus kisutch, From a Watershed on the North Coast of British Columbia

2017 ◽  
Vol 130 (4) ◽  
pp. 336 ◽  
Author(s):  
Eric A Parkinson ◽  
Chris J Perrin ◽  
Daniel Ramos-Espinoza ◽  
Eric B Taylor
Keyword(s):  
British Columbia ◽  
Fresh Water ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Oncorhynchus Kisutch ◽  
Water Levels ◽  
North Coast ◽  
The North ◽  
Seaward Migration ◽  
Mature Fish

The Coho Salmon, Oncorhynchus kisutch, is one of seven species of Pacific salmon and trout native to northeastern Pacific Ocean watersheds. The species is typically anadromous; adults reproduce in fresh water where juveniles reside for 1–2 years before seaward migration after which the majority of growth occurs in the ocean before maturation at 2–4 years old when adults return to fresh water to spawn. Here, we report maturation of Coho Salmon in two freshwater lakes on the north coast of British Columbia apparently without their being to sea. A total of 15 mature fish (11 males and four females) were collected in two lakes across two years. The mature fish were all at least 29 cm in total length and ranged in age from three to five years old. The occurrence of Coho Salmon that have matured in fresh water without first going to sea is exceedingly rare in their natural range, especially for females. Such mature Coho Salmon may represent residual and distinct breeding populations from those in adjacent streams. Alternatively, they may result from the ephemeral restriction in the opportunity to migrate seaward owing to low water levels in the spring when Coho Salmon typically migrate to sea after 1–2 years in fresh water. Regardless of their origin, the ability to mature in fresh water without seaward migration may represent important adaptive life history plasticity in response to variable environments.

Effects of Logging on Size and Age Composition of Juvenile Coho Salmon (Oncorhynchus kisutch) and Density of Presmolts in Southeast Alaska Streams

1989 ◽  
Vol 46 (8) ◽  
pp. 1383-1391 ◽  
Author(s):  
John F. Thedinga ◽  
Michael L. Murphy ◽  
Jonathan Heifetz ◽  
K V. Koski ◽  
Scott W. Johnson
Keyword(s):  
Coho Salmon ◽  
Condition Factor ◽  
Oncorhynchus Kisutch ◽  
Buffer Strips ◽  
Short Term ◽  
Old Growth ◽  
Age Composition ◽  
Southeast Alaska ◽  
Clear Cut ◽  
Northern Regions

Short-term effects of logging on age composition and size of juvenile coho salmon (Oncorhynchus kisutch) were studied in 18 streams in Southeast Alaska in 1982 and 1983; studies were in old-growth and clear-cut reaches with or without buffer strips. The number of fry (age 0) in summer and winter was proportionately higher in buffered and clear-cut reaches than in old-growth reaches, and all treatments averaged a 20% decrease in fry from summer to winter. Fry length and condition factor were greater for buffered and clear-cut reaches than for old-growth reaches, whereas parr (age 1 and older) size did not differ among treatments. Fry and parr were larger in the southern than in the northern regions and their length and weight were directly related to peripbyton biomass and benthos density. A higher percentage of large [Formula: see text] fry remained in buffered reaches than in clear-cut and old-growth reaches; therefore, the density of fry that were potentially large enough to become smolts the next spring (presmolts) was greater in buffered reaches. The larger fry in buffered and clear-cut reaches compared with old-growth reaches was probably due to earlier fry emergence that resulted from increased water temperature.

Bias in hatchery-origin coho salmon survival estimates due to underestimated prerelease mortality

2021 ◽  
pp. 1-4
Author(s):  
James R. Irvine
Keyword(s):  
British Columbia ◽  
Experimental Evidence ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Data Sets ◽  
Wild Salmon ◽  
Natural Origin ◽  
Additional Work ◽  
Seaward Migration ◽  
Over Time

The widely accepted belief that hatchery-origin salmon survive less well than natural-origin or wild salmon can be, at least in part, an artifact of the way hatchery salmon survival is estimated. Hatchery salmon are often marked several months before release, while natural salmon are marked during their seaward migration. Underestimated prerelease mortalities result in biased low survival estimates. In British Columbia, although hatchery rearing practices have been modified to reduce unrecorded mortalities, experimental evidence indicates that coho salmon (Oncorhynchus kisutch) smolt survivals continue to be underestimated by ∼13%. Better reporting and incorporation of survival bias in data sets and analyses as well as additional work to evaluate bias for other regions and species over time is needed.

Riverine and Estuarine Migratory Behavior of Coho Salmon (Oncorhynchus kisutch) Smolts

1991 ◽  
Vol 48 (9) ◽  
pp. 1670-1678 ◽  
Author(s):  
Mary L. Moser ◽  
Alan F. Olson ◽  
Thomas P. Quinn
Keyword(s):  
Current Velocity ◽  
Return Migration ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Metabolic Cost ◽  
Tidal Currents ◽  
Migratory Behavior ◽  
Caloric Expenditure ◽  
Low Velocity ◽  
Seaward Migration

Using radio and ultrasonic transmitters, we tracked coho salmon (Oncorhynchus kisutch) smolts in the Chehalis River and Grays Harbor estuary, Washington, to document patterns of seaward migration. In spite of dramatic differences in the two habitats, the fish behaved similarly in both systems. Migratory progress was saltatory, characterized by movement in the direction of the current and extended periods of holding in areas of low current velocity. Consequently, smolts were displaced rapidly downstream by swift, unidirectional river currents but were retained in the estuary by relatively low-velocity, reversing tidal currents. Smolts did not use tidal currents to move seaward and appeared to swim most rapidly against strong ebbing currents. Estimated mean total metabolic cost incurred by migrating smolts was 0.027 cal∙s−1∙smolt−1 (1 cal = 4.184 J). Estimated daily caloric expenditure by smolts in 1988 was twice that of smolts tracked in 1989, apparently due to faster water velocities in 1988. The observation that coho salmon migration through estuaries is slower than riverine migration suggests that a period of estuarine residence may be necessary for them to adjust their osmoregulatory capability, orient for their return migration, feed, or reduce their vulnerability to predators.

Influence of orally administered L-thyroxine or 3,5,3′-triiodo-L-thyronine on growth, food consumption, and food conversion of underyearling coho salmon (Oncorhynchus kisutch)

1979 ◽  
Vol 57 (10) ◽  
pp. 1974-1979 ◽  
Author(s):  
David A. Higgs ◽  
U. H. M. Fagerlund ◽  
J. R. McBride ◽  
J. G. Eales
Keyword(s):  
Food Consumption ◽  
Coho Salmon ◽  
Condition Factor ◽  
Oncorhynchus Kisutch ◽  
Food Conversion ◽  
Thyroid Follicle ◽  
Natural Photoperiod

Between August and November, groups of underyearling coho salmon, held at 10 °C and on a natural photoperiod, were fed twice daily to satiation with Oregon moist pellets supplemented with 0, 20, 100. or 500 ppm of L-thyroxine (T4) or 3,5,3′-triiodo-L-thyronine (T3).The T3 significantly increased weight (20 and 100 ppm) and length (all doses), depressed condition factor (100 and 500 ppm), stimulated food consumption (20 ppm), improved food conversion (all doses), decreased thyroid follicle epithelial height (500 ppm), and influenced pituitary basophil and somatotrop number, size, and granulation.The T4 influenced neither growth nor food conversion, but did increase food consumption (20 ppm) and condition factor (500 ppm). and decreased thyroid follicle epithelial height (500 ppm).No breakdown of either added T4 or T3 was observed during prolonged food storage.It is concluded that T3 unlike T4, can be administered in the diet of coho held at 10 °C to enhance growth and improve food conversion.

Changes in physiological indices of smolting during seaward migration of wild coho salmon, Oncorhynchus kisutch

Aquaculture ◽  
1998 ◽  
Vol 168 (1-4) ◽  
pp. 69-83 ◽  
Author(s):  
R.D Ewing ◽  
J.D Rodgers
Keyword(s):  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Physiological Indices ◽  
Seaward Migration

Effects of Logging on Stream Temperatures in Carnation Creek British Columbia, and Associated Impacts on the Coho Salmon (Oncorhynchus kisutch)

1988 ◽  
Vol 45 (3) ◽  
pp. 502-515 ◽  
Author(s):  
L. Blair Holtby
Keyword(s):  
British Columbia ◽  
Life History ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Growing Season ◽  
Temperature Changes ◽  
Clear Cut ◽  
Seaward Migration ◽  
Logging Effects ◽  
Spring Temperatures

Clear-cut logging of 41% of the basin of Carnation Creek, British Columbia, resulted in increased stream temperatures in all months of the year, increases above prelogging temperatures ranged from 0.7 °C in December to 3.2 °C in August. Earlier emergence of coho salmon (Oncorhynchus kisutch) fry associated with the temperature increases lengthened their summer growing season by up to 6 wk. Fingerlings were significantly larger by the fall in the years after logging compared with the years before logging. The increased size of fingerlings was associated with improved overwinter survival. Following logging, yearling smolt numbers doubled, although 2-yr-old smolt numbers decreased. Warmer spring temperatures were also associated with earlier seaward migration of smolts, probably resulting in decreased smolt-to-aduit survivals. A linked series of models that first predict logging effects on stream temperatures and then the effects of those temperatures on critical coho life history events are developed. The life history model is used to quantify the effects of stream temperature changes related to logging on the population size of adult coho salmon. The predicted effect of those temperature changes was a 9% increase in adult coho numbers prior to the fishery, an increase considerably less than the observed 47% increase in smolt numbers.

Temperature and Photoperiod Effects on Gill (Na + K)–ATPase Activity in Chinook Salmon (Oncorhynchus tshawytscha)

1979 ◽  
Vol 36 (11) ◽  
pp. 1347-1353 ◽  
Author(s):  
R. D. Ewing ◽  
S. L. Johnson ◽  
H. J. Pribble ◽  
J. A. Lichatowich
Keyword(s):  
Atpase Activity ◽  
Growth Rates ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Specific Activity ◽  
First Year ◽  
Two Temperatures ◽  
Cyclic Changes ◽  
Two Peaks ◽  
Response To Water

Juvenile Rogue River spring Chinook salmon (Oncorhynchus tshawytscha) reared at two temperatures and photoperiods for a 2-yr period were examined for cyclic changes in gill (Na + K)–ATPase specific activity. Three peaks in activity were observed: a peak in October of the first year, a second higher peak the following May, and a peak in October of the second year. Exposure to photoperiods artificially advanced 3 mo (July–October) suppressed the October peak during the first year, but did not greatly alter the subsequent two peaks in activity. The temperature at which the fish were reared did not directly affect the changes in enzyme activity. However, growth rates varied in response to water temperature. Altered growth rates resulted in differences in the cyclic changes in gill (Na + K)-activated ATPase activity in the two temperature groups. A threshold of 8 cm was suggested as the minimal size at which the fish could respond to the appropriate photoperiod by altering the gill (Na + K)–ATPase activity. Key words: (Na + K)–ATPase, chinook salmon, temperature, photoperiod, Oncorhynchus tshawytscha.

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