Influence of Cover Complexity and Current Velocity on Winter Habitat Use by Juvenile Coho Salmon (Oncorhynchus kisutch)

1989 ◽  
Vol 46 (9) ◽  
pp. 1551-1557 ◽  
Author(s):  
Thomas E. McMahon ◽  
Gordon F. Hartman
Keyword(s):  
Habitat Use ◽  
Management Practices ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Structural Complexity ◽  
Rapid Decline ◽  
Stream Channels ◽  
Low Velocity ◽  
Winter Habitat ◽  
Wood Debris

Winter habitat use by juvenile coho salmon (Oncorhynchus kisutch) varied with cover type and flow level in outdoor stream channels. Cover utilization and the number of fish remaining in stream channels increased significantly as cover complexity increased. Most fish emigrated during a simulated freshet unless the most complex cover (low velocity, shade, and wood debris combined) was available. At both high and low flows, emigration occurred primarily during the rapid decline in light levels at twilight. Most coho formed aggregations beneath cover, exhibiting feeding and aggression at temperatures as low as 2.5 °C. We conclude that (1) social interactions, in concert with habitat features, influence the abundance of coho salmon within specific stream habitats in winter, and (2) structural complexity of wood debris is an important consideration for management practices designed to protect or enhance winter habitat for this species.

Winter Distribution of Juvenile Coho Salmon (Oncorhynchus kisutch) Before and After Logging in Carnation Creek, British Columbia, and Some Implications for Overwinter Survival

1983 ◽  
Vol 40 (4) ◽  
pp. 452-461 ◽  
Author(s):  
P. J. Tschaplinski ◽  
G. F. Hartman
Keyword(s):  
Survival Rate ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Habitat Characteristics ◽  
Main Stream ◽  
Low Velocity ◽  
Tree Roots ◽  
Apparent Survival ◽  
Winter Habitat ◽  
Clear Cut

Numbers of juvenile coho salmon (Oncorhynchus kisutch) in streams are reduced substantially in winter compared to those that occur in summer. Most of this reduction occurs early in autumn with the onset of the first seasonal freshets. Stream sections containing adequate winter habitat in the form of deep pools, log jams, and undercut banks with tree roots and debris lost fewer fish during freshets and maintained higher numbers of coho in winter than sections without these habitat characteristics. These features provide shelter and reduce stream velocities. Microhabitats occupied by coho juveniles in winter after logging were unchanged from those described before logging — all microhabitats were characterized by low water velocities (≤ 0.3 m/s). Up to 48% of the coho population inhabiting stream sections with adequate shelter remained there by midwinter (Jan. 3). This percentage was typical of stream sections where at least some trees remained after logging. Streamside trees stabilized the banks and prevented their collapse. In contrast, two of three study sections that had been clear-cut logged had unstable banks which collapsed during winter freshets. Almost no coho remained in these sections in winter. Many coho emigrate from the main stream to seek the shelter of low-velocity tributaries and valley sloughs concurrent with the decline of coho populations in Carnation Creek during autumn and early winter. This seasonal shift in distribution reverses in the spring when large numbers of coho reenter the main stream. Fish overwintering in these sites have a high apparent survival rate. Before logging a 4-yr mean of 169 ± 44 coho entered one tributary (a slough called 750-m site) in autumn. Of these numbers entering, 72.2% came out in spring. During and after logging, an annual mean of 288 coho entered the same site. The apparent survival rate during and after logging was 67.4%, essentially unchanged from the prelogging value. Logging has neither reduced the numbers of coho juveniles that enter such sites in autumn to overwinter, nor reduced the numbers leaving these sites to reenter Carnation Creek in spring.

Seasonal Changes in Habitat Use by Juvenile Coho Salmon (Oncorhynchus kisutch) in Oregon Coastal Streams

1992 ◽  
Vol 49 (4) ◽  
pp. 783-789 ◽  
Author(s):  
Thomas E. Nickelson ◽  
Jeffrey D. Rodgers ◽  
Steven L. Johnson ◽  
Mario F. Solazzi
Keyword(s):  
Habitat Use ◽  
Seasonal Changes ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Beaver Pond ◽  
Winter Habitat ◽  
Oregon Coast ◽  
Beaver Ponds ◽  
Salmon Fry ◽  
Coastal Streams

Habitat use by juvenile coho salmon (Oncorhynchus kisutch) during spring, summer, and winter was examined in Oregon coastal streams. Coho salmon fry were most abundant in backwater pools during spring. During summer, juvenile coho salmon were more abundant in pools of all types than they were in glides or riffles. During winter, juvenile coho salmon were most abundant in alcoves and beaver ponds. Because of the apparent strong preference for alcove and beaver pond habitat during winter and the rarity of that habitat in coastal streams, we concluded that if spawning escapement is adequate, the production of wild coho salmon smolts in most coho salmon spawning streams on the Oregon Coast is probably limited by the availability of adequate winter habitat.

Stress and Chronic Effects of Untreated and Treated Bleached Kraft Pulpmill Effluent on the Biochemistry and Stamina of Juvenile Coho Salmon (Oncorhynchus kisutch)

1979 ◽  
Vol 36 (9) ◽  
pp. 1049-1059 ◽  
Author(s):  
Donald J. McLeay ◽  
David A. Brown
Keyword(s):  
Prolonged Exposure ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Effluent Treatment ◽  
Control Fish ◽  
Continuous Exposure ◽  
Stream Channels ◽  
Body Protein ◽  
Glucose Levels ◽  
Treated Effluent

Growth of juvenile coho salmon (Oncorhynchus kisutch) fed a limiting ration (70% of satiation) in experimental stream channels was not altered significantly by prolonged exposure to untreated or laboratory-treated (fermented) bleached kraft pulpmill effluent (BKME), although mean weights for control fish were consistently lower than those for all effluent-exposed groups from 100 to 200 d. Body protein, fat, and moisture content were unaffected by treatment at 30, 90, and 200 d. Fish exposed to all strengths of untreated or treated BKME (i.e. untreated concentrations equivalent by volume to 0.05, 0.1, 0.2, 0.3, and 0.5 of the untreated effluent's 96-h LC50 value; and treated concentrations equivalent by volume to 0.2 and 1.0 LC50) showed significant decreases in serum albumin levels at 30 d, whereas these recovered to control values at 90 and 200 d. The serum electrolytes Na+, K+, and Ca++ were unaffected by treatment at 200 d and not measured for other exposures. Liver and muscle glycogen reserves were decreased significantly by continuous exposure of fish to untreated or treated BKME concentrations for 30 d. These values recovered to control levels at 90 d and were unaffected or depressed at 200 d. Plasma glucose levels at 30 d were elevated significantly in all BKME-exposed groups except those held in the lowest concentration of untreated or treated effluent. Blood sugar values at 90 d were increased only by the highest strength of untreated or treated BKME; whereas at 200 d these values were elevated from control levels in all effluent-exposed groups. Levels of plasma lactic acid were unmeasured at 30 d, increased at 90 d in all BKME-exposed groups except the lowest strength of untreated effluent, and elevated at 200 d in all effluent-exposed groups. The stamina of these fish as determined by critical swimming speeds in freshwater was unaffected by exposure to pulpmill effluent for 90 d and unmeasured for other exposures. Based on the changes in intermediary metabolism for BKME-exposed fish at 30, 90, and 200 d, it was concluded that these fish remained in a state of chronic stress and did not acclimate to prolonged exposure to pulpmill effluent. Treatment of this waste reduced or removed its acute (lethal) toxicity but did not alter the biochemical effects caused by chronic exposure. Key words: stress, growth, proximate analyses, albumin, electrolyte, glycogen, glucose, lactate, critical swimming speed, acclimation

Effectiveness of Selected Stream Improvement Techniques to Create Suitable Summer and Winter Rearing Habitat for Juvenile Coho Salmon (Oncorhynchus kisutch) in Oregon Coastal Streams

1992 ◽  
Vol 49 (4) ◽  
pp. 790-794 ◽  
Author(s):  
Thomas E. Nickelson ◽  
Mario F. Solazzi ◽  
Steven L. Johnson ◽  
Jeffrey D. Rodgers
Keyword(s):  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Natural Habitats ◽  
Winter Habitat ◽  
Stream Width ◽  
Coastal Streams

We examined the use of constructed pools by juvenile coho salmon (Oncorhynchus kisutch) during summer and winter. Log, gabion, and rock structures placed across the full stream width provided good summer habitat but poor winter habitat for juvenile coho salmon. Rearing densities in constructed habitats during summer and winter were generally similar to those in natural habitats of the same type, except that constructed dammed pools supported lower densities during winter than natural dammed pools. The addition of brush bundles to pools created by full-stream-width structures increased the density of juvenile coho salmon in dammed pools during winter, but not in plunge pools. We concluded that the development of off-channel habitat has the greatest potential to increase production of wild coho salmon smolts in Oregon coastal streams.

Habitat use by woodland caribou near Takla Lake in central British Columbia

2000 ◽  
Vol 78 (9) ◽  
pp. 1552-1561 ◽  
Author(s):  
Kim G Poole ◽  
Douglas C Heard ◽  
Garth Mowat
Keyword(s):  
British Columbia ◽  
Forest Management ◽  
Habitat Use ◽  
Management Practices ◽  
Satellite Image ◽  
High Elevation ◽  
Life History Strategies ◽  
Home Ranges ◽  
Winter Habitat ◽  
Risk Of Predation

Caribou (Rangifer tarandus) living in the mountainous areas of British Columbia are usually classified as either northern caribou, which spend much of the winter in low-elevation relatively young forests foraging primarily on terrestrial lichens, or mountain caribou, which winter in high-elevation old subalpine forests foraging exclusively on arboreal lichens. The forest-management practices necessary to conserve caribou differ substantially between these two categories of animals with different life-history strategies. Because of this variability in winter-habitat use, information relating specifically to Takla Lake caribou was required for forest management. To provide this information, we radio-collared 15 female caribou in two subherds in the vicinity of Takla Lake and determined their distribution and movements between January 1996 and May 1998 in relation to topography and vegetation cover. Habitat selection was examined using a classified satellite image. At the landscape scale, Takla Lake caribou avoided low-elevation forests (presumably because of the associated high risk of predation from wolves (Canis lupus)), occupying small seasonally overlapping home ranges (mean 151 km2) at intermediate and high elevations. Within home ranges in all seasons, caribou were most often found in the forest but, relative to availability, they selected forests only during calving. When in the forest, caribou selected open hybrid white-Engelmann spruce (Picea glauca × Picea engelmannii) - subalpine fir (Abies lasiocarpa) forests over lodgepole pine (Pinus contorta) and deciduous forests in all seasons except spring. Caribou selected open spruce-fir stands over dry and closed spruce-fir stands in all seasons except calving. We conclude that caribou feed primarily on arboreal lichens in winter, because the open spruce-fir forests that they use have moderate to high arboreal lichen abundance, deep snow, and few terrestrial lichens. Takla Lake caribou were not typical of either mountain or northern caribou, but as is typical of insular populations of any species, have adapted to the food, topography, and cover types available to them on their mountain islands in a sea of moose (Alces alces) and wolves.

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.

Microhabitat Partitioning among Stream-Dwelling juvenile Coho Salmon, Oncorhynchus kisutch, and Dolly Varden, Salvelinus malma

1990 ◽  
Vol 47 (12) ◽  
pp. 2297-2306 ◽  
Author(s):  
C. Andrew Dolloff ◽  
Cordon H. Reeves
Keyword(s):  
Habitat Use ◽  
Coho Salmon ◽  
Focal Point ◽  
Oncorhynchus Kisutch ◽  
The Other ◽  
Dolly Varden ◽  
Salvelinus Malma ◽  
Fish Size ◽  
Dolly Varden Salvelinus Malma ◽  
Natural Streams

Microhabitat use and partitioning among age 0+ and 1+ coho salmon, Oncorhynchus kisutch, and age 0+, 1+ and 2+ Dolly Varden, Salvelinus malma, was studied in small (<2 m wide), natural streams on Prince of Wales Island, Alaska, and in laboratory stream channels. Coho salmon occupied midwater positions that they defended from other fish. Dolly Varden were more closely associated with the stream bottom and were seldom territorial. For each species, the depth of water, depth of focal point, and distance to nearest fish increased with fish size, whereas the distance to nearest cover decreased as fish size increased. Most fish selected focal point velocities between 0.0–9.0 cm∙s−1.Woody debris was the most frequently used cover type and most fish occurred over gravel substrates ranging from 2–100 mm particle diameter. Habitat use by each species in the laboratory was similar to the pattern observed in the field. Each species occupied similar habitats both when alone and when the other species was present. Although habitat use by juveniles of coho salmon and Dolly Varden overlapped among several key parameters, each species primarily exploited resources not readily available to or selected by the other in the natural streams we studied.

Food abundance and fish density alters habitat selection, growth, and habitat suitability curves for juvenile coho salmon (Oncorhynchus kisutch)

2005 ◽  
Vol 62 (8) ◽  
pp. 1691-1701 ◽  
Author(s):  
Jordan S Rosenfeld ◽  
Thomas Leiter ◽  
Gerhard Lindner ◽  
Lorne Rothman
Keyword(s):  
Habitat Selection ◽  
Food Availability ◽  
Habitat Suitability ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Food Abundance ◽  
Fish Density ◽  
Invertebrate Drift ◽  
Stream Channels ◽  
Lower Growth

To understand how fish density and food availability affect habitat selection and growth of juvenile coho salmon (Oncorhynchus kisutch), we manipulated fish density (2–12 fish·m–2) and natural invertebrate drift (0.047–0.99 mg·m–3) in 12 experimental stream channels constructed in a side-channel of Chapman Creek, British Columbia. Increased food resulted in increased growth of both dominant and subdominant fish and a shift to higher average focal velocities (from 6.5 to 8.4 cm·s–1) with maximum growth in the range of 10–12 cm·s–1. Increased food appears to permit juvenile coho to exploit higher velocity microhabitats that might otherwise be bioenergetically unsuitable at lower food levels. Increased fish density resulted in lower growth of subdominant but not of dominant fish and a general displacement of fish to both higher and lower focal velocities. The shapes of habitat suitability curves were sensitive to food abundance, implying that differences in food availability may affect transferability of habitat suitability curves between streams of different productivity. While habitat suitability curves captured the change in extent of available habitat following prey enrichment, actual increases in growth rate with enrichment (i.e., changes in habitat quality) were poorly represented by habitat suitability values and better represented by bioenergetic model predictions.

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.

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