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.

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.

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.

Large Woody Debris and Salmonid Habitat in a Small Coastal British Columbia Stream

1992 ◽  
Vol 49 (4) ◽  
pp. 682-693 ◽  
Author(s):  
Kurt D. Fausch ◽  
Thomas G. Northcote
Keyword(s):  
British Columbia ◽  
Standing Crop ◽  
Coho Salmon ◽  
Woody Debris ◽  
Cutthroat Trout ◽  
Large Woody Debris ◽  
Habitat Conditions ◽  
Debris Removal ◽  
Coastal British Columbia ◽  
Complex Habitat

Sections of a small coastal British Columbia stream that had previously been cleaned of large woody debris (LWD) were compared with sections where most debris was left and with others where debris had been relatively undisturbed for at least 40 yr. Three sections where debris had been removed had simple habitat that was less sinuous, wider, and shallower and had less pool volume and overhead cover than four sections with more complex habitat where debris was retained. Habitat in four relatively undisturbed sections was generally similar to complex sections. Most pools in all sections were scour or plunge pools formed by LWD or large roots oriented perpendicular to the flow or angled downstream. Standing crop (kolograms per hectare) and individual weights of age 1 + and older coho salmon (Oncorhynchus kisutch) and cutthroat trout (O. clarki) were significantly greater (P < 0.02) in complex than in simple sections. Biomass of age 1 + and older salmonids was closely related to section pool volume (r2 = 0.92, P = 0.0006). Projections based on this model and average habitat conditions suggest that during 1990 a total of 8.0 kg of salmonid biomass, 5 times the current standing crop, was forgone in the 332-m simple reach due to prior debris removal.

Advances in Fisheries Bioengineering

2008 ◽  
Keyword(s):  
Habitat Use ◽  
Coho Salmon ◽  
Woody Debris ◽  
Natural Habitat ◽  
Oncorhynchus Kisutch ◽  
Invertebrate Drift ◽  
Return Rates ◽  
Side Channels ◽  
Long Channel ◽  
Important Habitat

Abstract<em>.</em>—Side channels are recognized as an important habitat component for stream resident species such as coho salmon <em>Oncorhynchus kisutch</em>. The objectives of this study were to (1) design, construct, and monitor a natural-like channel for rearing coho salmon, and (2) demonstrate an alternative rearing technique that could be incorporated into hatchery operations. Data on migration, growth, habitat use, and ultimately return rates were collected. A 286-m-long channel containing riffles, pools, ponds, alcoves, and abundant large woody debris was constructed. Discharge was set at 0.1 m3/s and was adjustable from 0 to 0.3 m<sup>3</sup>/s. Channel width averaged 1.2 m and had a surface area of 971 m<sup>2</sup>. Invertebrate drift was supplemented with a prepared diet. Fifty thousand eyed coho eggs were incubated in the channel. The resulting fry were enumerated at the tail works and allowed to emigrate so that fish residence in the channel was volitional. Out-migration was high initially, dropped in the summer, and spiked over a 3-d period in the fall before slowing during winter followed by a distinct spring out-migration. Habitat use was quantified through visual counts, snorkeling, and underwater video. Densities of fish were approximately seven times higher than comparable natural habitat. Smolts leaving the channel in the spring equated to 1.5 fish/m<sup>2</sup>, which is higher than most comparable natural habitat. We concluded that engineered channels could volitionally support numbers of fish at densities higher than in natural habitat, that fish behavior in them was comparable to wild fish, and that engineered channels could be used by hatchery programs thus contributing to hatchery reform.

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.

Discriminating coho salmon (Oncorhynchus kisutch) populations within the Fraser River, British Columbia, using microsatellite DNA markers

1998 ◽  
Vol 7 (2) ◽  
pp. 141-155 ◽  
Author(s):  
M. P. SMALL ◽  
T. D. BEACHAM ◽  
R. E. WITHLER ◽  
R. J. NELSON
Keyword(s):  
British Columbia ◽  
Dna Markers ◽  
Microsatellite Dna ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Fraser River ◽  
Microsatellite Dna Markers

Kudoa thyrsitis (Gilchrist) (Myxosporea: Multivalvulida) in coho salmon, Oncorhynchus kisutch (Walbaum)

1986 ◽  
Vol 64 (4) ◽  
pp. 1038-1040 ◽  
Author(s):  
Z. Kabata ◽  
D. J. Whitaker ◽  
J. W. Bagshaw
Keyword(s):  
British Columbia ◽  
Cardiac Muscle ◽  
Unusual Case ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Unusual Site ◽  
First Report

An unusual case of infection of coho salmon, Oncorhynchus kisutch (Walbaum), in British Columbia, Canada, with a myxosporean Kudoa thyrsitis (Gilchrist) is described. This first report of Kudoa parasitizing a member of the genus Oncorhynchus is interesting also because of the unusual site of Kudoa in the fish, the cardiac muscle.

Effects of large woody debris on surface structure and aquatic habitat in forested streams, southern interior British Columbia, Canada

2008 ◽  
Vol 24 (6) ◽  
pp. 862-875 ◽  
Author(s):  
Xiaoyong Chen ◽  
Xiaohua Wei ◽  
Rob Scherer ◽  
Dan Hogan
Keyword(s):  
British Columbia ◽  
Surface Structure ◽  
Woody Debris ◽  
Aquatic Habitat ◽  
Large Woody Debris
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