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.

The Behaviour of Chum, Pink and Coho Salmon in Relation to their Seaward Migration

1951 ◽  
Vol 8b (4) ◽  
pp. 241-263 ◽  
Author(s):  
William S. Hoar
Keyword(s):  
Fresh Water ◽  
Coho Salmon ◽  
Pink Salmon ◽  
Water Levels ◽  
Salmon Fry ◽  
Seaward Migration ◽  
Active Swimming ◽  
Increased Activity ◽  
Downstream Movement ◽  
Marked Tendency

In fresh water, chum and pink salmon fry form schools or mills, are constantly active both day and night, show positive rheotaxis and move into fast water. This activity takes them into the swiftest currents. At night loss of visual and contact stimuli reduces the intensity of the rheotactic response and results in downstream movement. An active swimming downstream occurs only with unusually high temperatures. Coho salmon fry occupy and defend territory, maintain definite positions in relation to particular objects in their environment, show a less marked tendency to move into fast water and are quiet at night. They are thus displaced downstream to a much lesser degree. Coho smolts, in contrast to the fry, demonstrate a lowered threshold for stimulation both day and night, a tendency to aggregate and a lessening in territory behaviour. During the day smolts group in deeper water or under cover. At night they rise to the surface and manifest increased activity which, in swift water, will result in displacement seaward. Pronounced changes in temperature modify these reactions. Sudden elevation of water levels hastens the downstream displacement.

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.

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.

VARIATIONS IN THE SODIUM AND POTASSIUM CONTENT OF THE MUSCLE TISSUE OF PACIFIC SALMON WITH PARTICULAR REFERENCE TO MIGRATION

1958 ◽  
Vol 36 (1) ◽  
pp. 1257-1268 ◽  
Author(s):  
Robert A. MacLeod ◽  
R. E. E. Jonas ◽  
J. R. McBride
Keyword(s):  
Fresh Water ◽  
Muscle Tissue ◽  
Sockeye Salmon ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Salt Water ◽  
Small Fish ◽  
Spawning Ground ◽  
Marked Rise ◽  
Mature Fish

Further confirmation was obtained of the observation made previously that the Na+ and K+ levels of the muscle tissue of spring salmon (Oncorhynchus tschawytscha) on the Pacific coast appear to vary with the size of the fish and, in the case of small fish, with the season of the year. Small fish (3 to 5 lb) caught in regions of relatively constant salinity had higher Na+ and lower K+ concentrations in the spring and summer than in fall and winter. Under the same conditions the levels of Na+ and K+ in the flesh of larger fish (9 to 10 lb) did not vary.When spring salmon were sampled along the route of their spawning migration up the Fraser River it was found that at the mouth of the river the Na+ level was less than in fish at sea. Further up the river, Na+ had dropped to less than one-half of the value at sea. At the spawning grounds in three groups out of four examined, Na+ rose again to levels the same as or above those prevailing at sea. In general, a drop in Na+ was accompanied by a rise in K+ and vice versa, though at the spawning ground the drop in K+ considerably exceeded the rise in Na+.In the case of sockeye salmon (Oncorhynchus nerka) heading up river, a lowered Na+ and elevated K+ occurred in the muscle tissue of the fish while they were still in salt water. After the fish had entered fresh water the ion levels were restored and maintained at levels similar to those normally prevailing at sea. At or near the spawning ground a marked rise in Na+ as well as a drop in K+ occurred. Evidence was obtained that this change occurred first in the male of the species.The flesh of juvenile coho salmon (Oncorhynchus kisutch) migrating to the sea was found to contain less Na+ and more K+ than mature fish of the same species caught at sea. Young sockeye in fresh water, however, contained about the same levels of Na+ and K+ as the mature fish at sea.

Behaviour, Habitat Use, and Movements of Coho Salmon (Oncorhynchus kisutch) Smolte during Seaward Migration

1992 ◽  
Vol 49 (7) ◽  
pp. 1478-1485 ◽  
Author(s):  
Thomas E. McMahon ◽  
L. Blair Holtby
Keyword(s):  
British Columbia ◽  
Habitat Use ◽  
Coho Salmon ◽  
Saline Water ◽  
Woody Debris ◽  
Oncorhynchus Kisutch ◽  
Large Woody Debris ◽  
Seaward Migration

Coho salmon (Oncorhynchus kisutch) smolts formed aggregations in pools with large woody debris during their migration downstream and into the Carnation Creek estuary, British Columbia. Smolts utilized the estuary throughout the smolt run, with periods of high outmigration coinciding with spring tides which brought warmer, more saline water into the estuary. Smolt abundance in the stream and estuary was positively related to debris volume, and 82% of the 1260 smolts observed during underwater counts occurred within 1 m of debris. Debris volume and smolt density were significantly lower in clearcut than in buffered stream sections. Our observations support the need to retain and manage large woody debris for smolt habitat in streams and estuaries.

VARIATIONS IN THE SODIUM AND POTASSIUM CONTENT OF THE MUSCLE TISSUE OF PACIFIC SALMON WITH PARTICULAR REFERENCE TO MIGRATION

1958 ◽  
Vol 36 (12) ◽  
pp. 1257-1268 ◽  
Author(s):  
Robert A. MacLeod ◽  
R. E. E. Jonas ◽  
J. R. McBride
Keyword(s):  
Fresh Water ◽  
Muscle Tissue ◽  
Sockeye Salmon ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Salt Water ◽  
Small Fish ◽  
Spawning Ground ◽  
Marked Rise ◽  
Mature Fish

Further confirmation was obtained of the observation made previously that the Na+ and K+ levels of the muscle tissue of spring salmon (Oncorhynchus tschawytscha) on the Pacific coast appear to vary with the size of the fish and, in the case of small fish, with the season of the year. Small fish (3 to 5 lb) caught in regions of relatively constant salinity had higher Na+ and lower K+ concentrations in the spring and summer than in fall and winter. Under the same conditions the levels of Na+ and K+ in the flesh of larger fish (9 to 10 lb) did not vary.When spring salmon were sampled along the route of their spawning migration up the Fraser River it was found that at the mouth of the river the Na+ level was less than in fish at sea. Further up the river, Na+ had dropped to less than one-half of the value at sea. At the spawning grounds in three groups out of four examined, Na+ rose again to levels the same as or above those prevailing at sea. In general, a drop in Na+ was accompanied by a rise in K+ and vice versa, though at the spawning ground the drop in K+ considerably exceeded the rise in Na+.In the case of sockeye salmon (Oncorhynchus nerka) heading up river, a lowered Na+ and elevated K+ occurred in the muscle tissue of the fish while they were still in salt water. After the fish had entered fresh water the ion levels were restored and maintained at levels similar to those normally prevailing at sea. At or near the spawning ground a marked rise in Na+ as well as a drop in K+ occurred. Evidence was obtained that this change occurred first in the male of the species.The flesh of juvenile coho salmon (Oncorhynchus kisutch) migrating to the sea was found to contain less Na+ and more K+ than mature fish of the same species caught at sea. Young sockeye in fresh water, however, contained about the same levels of Na+ and K+ as the mature fish at sea.

scholarly journals Physiological resilience of pink salmon to naturally occurring ocean acidification

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Andrea Y Frommel ◽  
Justin Carless ◽  
Brian P V Hunt ◽  
Colin J Brauner
Keyword(s):  
British Columbia ◽  
Elevated Co2 ◽  
Condition Factor ◽  
Pacific Salmon ◽  
Pink Salmon ◽  
Hypoxia Tolerance ◽  
High Co2 ◽  
The North ◽  
Naturally Occurring ◽  
Co2 Levels

Abstract Pacific salmon stocks are in decline with climate change named as a contributing factor. The North Pacific coast of British Columbia is characterized by strong temporal and spatial heterogeneity in ocean conditions with upwelling events elevating CO2 levels up to 10-fold those of pre-industrial global averages. Early life stages of pink salmon have been shown to be affected by these CO2 levels, and juveniles naturally migrate through regions of high CO2 during the energetically costly phase of smoltification. To investigate the physiological response of out-migrating wild juvenile pink salmon to these naturally occurring elevated CO2 levels, we captured fish in Georgia Strait, British Columbia and transported them to a marine lab (Hakai Institute, Quadra Island) where fish were exposed to one of three CO2 levels (850, 1500 and 2000 μatm CO2) for 2 weeks. At ½, 1 and 2 weeks of exposure, we measured their weight and length to calculate condition factor (Fulton’s K), as well as haematocrit and plasma [Cl−]. At each of these times, two additional stressors were imposed (hypoxia and temperature) to provide further insight into their physiological condition. Juvenile pink salmon were largely robust to elevated CO2 concentrations up to 2000 μatm CO2, with no mortality or change in condition factor over the 2-week exposure duration. After 1 week of exposure, temperature and hypoxia tolerance were significantly reduced in high CO2, an effect that did not persist to 2 weeks of exposure. Haematocrit was increased by 20% after 2 weeks in the CO2 treatments relative to the initial measurements, while plasma [Cl−] was not significantly different. Taken together, these data indicate that juvenile pink salmon are quite resilient to naturally occurring high CO2 levels during their ocean outmigration.

Evidence of chemically mediated population recognition in coho salmon (Oncorhynchus kisutch)

1986 ◽  
Vol 64 (1) ◽  
pp. 84-87 ◽  
Author(s):  
Thomas P. Quinn ◽  
Graeme M. Tolson
Keyword(s):  
British Columbia ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
The Other ◽  
Potential Source ◽  
Source Of Information

To test the hypothesis that population-specific pheromones guide adult salmonids to their natal streams, juvenile and adult coho salmon (Oncorhynchus kisutch) were tested for chemosensory responses in two-choice tanks. Coho salmon from Quinsam and Big Qualicum rivers, British Columbia, Canada, distinguished their own population from the other. Tagging evidence indicates that straying between these two rivers and a third, geographically intermediate river seldom occurs. Thus, population-specific chemicals constitute a potential source of information for homing coho salmon, though their role vis-à-vis imprinted odors from other sources could not be evaluated.

scholarly journals Pacific salmon abundance trends and climate change

2011 ◽  
Vol 68 (6) ◽  
pp. 1122-1130 ◽  
Author(s):  
James R. Irvine ◽  
Masa-aki Fukuwaka
Keyword(s):  
Climate Change ◽  
Pacific Ocean ◽  
North Pacific ◽  
Sockeye Salmon ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
North Pacific Ocean ◽  
Pink Salmon ◽  
The North ◽  
Abundance Trends

Abstract Irvine, J. R., and Fukuwaka, M. 2011. Pacific salmon abundance trends and climate change. – ICES Journal of Marine Science, 68: 1122–1130. Understanding reasons for historical patterns in salmon abundance could help anticipate future climate-related changes. Recent salmon abundance in the northern North Pacific Ocean, as indexed by commercial catches, has been among the highest on record, with no indication of decline; the 2009 catch was the highest to date. Although the North Pacific Ocean continues to produce large quantities of Pacific salmon, temporal abundance patterns vary among species and areas. Currently, pink and chum salmon are very abundant overall and Chinook and coho salmon are less abundant than they were previously, whereas sockeye salmon abundance varies among areas. Analyses confirm climate-related shifts in abundance, associated with reported ecosystem regime shifts in approximately 1947, 1977, and 1989. We found little evidence to support a major shift after 1989. From 1990, generally favourable climate-related marine conditions in the western North Pacific Ocean, as well as expanding hatchery operations and improving hatchery technologies, are increasing abundances of chum and pink salmon. In the eastern North Pacific Ocean, climate-related changes are apparently playing a role in increasing chum and pink salmon abundances and declining numbers of coho and Chinook salmon.

A preliminary study of insulin participation in the growth regulation of coho salmon (Oncorhynchus kisutch)

1977 ◽  
Vol 55 (10) ◽  
pp. 1756-1758 ◽  
Author(s):  
Bryan Ludwig ◽  
David A. Higgs ◽  
Ulf H. M. Fagerlund ◽  
Jack R. McBride
Keyword(s):  
Body Weight ◽  
Growth Regulation ◽  
Specific Growth ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Oncorhynchus Kisutch ◽  
Growth Promoter ◽  
Pancreatic B Cells ◽  
Preliminary Study ◽  
Specific Growth Rates

As part of an ongoing survey to identify hormones capable of stimulating growth in Pacific salmon, groups of underyearling coho salmon were injected with bovine (Ultralente) insulin (0.32, 1.0, 3.2, or 10 IU/kg body weight) into the peritoneal cavity either once or twice weekly for 70 days.All doses of insulin, when injected twice weekly, increased the values for specific growth rates and decreased those for food–gain ratios relative to solvent-injected controls, but the differences were not statistically significant. All doses of insulin caused a marked increase in the granulation of the pancreatic B cells. Plasma glucose concentrations in starved coho injected with 10 IU insulin/kg body weight were significantly lower than in solvent-injected controls 4 h after injection.It is concluded that proper evaluation of the effectiveness of insulin as a growth promoter for salmon requires further studies preferably using insulin preparations specific to teleosts.

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