Vertical Distribution of Sediment and Organic Debris in Coho Salmon (Oncorhynchus kisutch) Redds in Three Small Oregon Streams

1988 ◽  
Vol 45 (4) ◽  
pp. 742-747 ◽  
Author(s):  
Neil H. Ringler ◽  
James D. Hall
Keyword(s):  
Vertical Distribution ◽  
Coho Salmon ◽  
Particle Diameter ◽  
Oncorhynchus Kisutch ◽  
Organic Content ◽  
Sediment Particle ◽  
Core Samples ◽  
Organic Debris ◽  
Coastal Streams ◽  
Sediment Layers

Vertical distribution of sediment (particle diameter <3.33 mm) and organic debris was studied in coho salmon (Oncorhynchus kisutch) redds in three Oregon coastal streams subjected to different degrees of logging. Gravel composition in frozen cores varied significantly among redds in both logged streams. Sediment content in redds appeared to decrease with depth in the logged streams, but differences in gravel composition among streams obscured differences among depths. Sediment layers of variable thickness were visible in several core samples. In one logged stream, redds contained an average of 25% less sediment than redds used 1 yr earlier. Organic content of the gravel represented <2.8% of the core samples by weight and was directly related to the quantity of sediment in the streambed. The pattern of vertical distribution of organic debris in the clearcut stream (most abundant near the surface) differed significantly from that in the other two streams. Patterns of distribution and variability in gravel composition were consistent with post-logging changes in gravel permeability and survival to emergence of coho salmon.

Variation in Body Morphology Among British Columbia Populations of Coho Salmon, Oncorhynchus kisutch

1985 ◽  
Vol 42 (12) ◽  
pp. 2020-2028 ◽  
Author(s):  
Eric B. Taylor ◽  
J. D. McPhail
Keyword(s):  
British Columbia ◽  
Coho Salmon ◽  
Function Analysis ◽  
Oncorhynchus Kisutch ◽  
Fraser River ◽  
Strait Of Georgia ◽  
Coastal Streams ◽  
Morphological Differences ◽  
Median Fins ◽  
Coastal British Columbia

Ten populations of juvenile coho salmon, Oncorhynchus kisutch, from streams tributary to the upper Fraser River, the lower Fraser River, and the Strait of Georgia region were morphologically compared. Juveniles from coastal streams (Fraser River below Hell's Gate and the Strait of Georgia) were more robust (deeper bodies and caudal peduncles, shorter heads, and larger median fins) than interior Juveniles. Discriminant function analysis indicated that juvenile coho could be identified as to river of origin with 71% accuracy. Juvenile coho from coastal streams were less successfully classified as to stream of origin; however, juveniles could be successfully identified as either coastal or interior with 93% accuracy. Juvenile coho from north coastal British Columbia, Alaska, and the upper Columbia system also fitted this coastal and interior grouping. This suggests that a coastwide coastal–interior dichotomy in juvenile body form exists. Three populations (one interior and two coastal) were studied in more detail. In these populations the coastal versus interior morphology was consistent over successive years, and was also displayed in individuals reared from eggs in the laboratory. Adult coho salmon also showed some of the coastal–interior morphological differences exhibited by juveniles. We concluded that the morphological differences between coastal and interior coho salmon are at least partially inherited.

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.

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.

Fate of Coho Salmon (Oncorhynchus kisutch) Carcasses in Spawning Streams

1989 ◽  
Vol 46 (8) ◽  
pp. 1347-1355 ◽  
Author(s):  
C. J. Cederholm ◽  
D. B. Houston ◽  
D. L. Cole ◽  
W. J. Scarlett
Keyword(s):  
Food Webs ◽  
Human Activities ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Olympic Peninsula ◽  
Streams And Rivers ◽  
Organic Debris ◽  
Spawning Streams

We examined the levels of retention and utilization of 945 coho salmon (Oncorhynchus kisutch) carcasses released experimentally into seven spawning streams on the Olympic Peninsula, Washington. Most carcasses were retained in the streams and in adjacent forests, few were flushed beyond 600 m. Organic debris caught and held many carcasses. Much of the fish mass was consumed by 22 species of mammals and birds. The distances that carcasses drifted appeared to be related directly to the occurrence of freshets and inversely to debris load and carnivore scavenging. The capacity of many streams and rivers to retain carcasses has probably been reduced by human activities. The importance of coho carcasses to populations of carnivores and to the dynamics of lotic food webs merits additional study.

Use of Hatchery Coho Salmon (Oncorhynchus kisutch) Presmolts to Rebuild Wild Populations in Oregon Coastal Streams

1986 ◽  
Vol 43 (12) ◽  
pp. 2443-2449 ◽  
Author(s):  
Thomas E. Nickelson ◽  
Mario F. Solazzi ◽  
Steven L. Johnson
Keyword(s):  
Surface Area ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Early Time ◽  
Wild Populations ◽  
Pool Surface ◽  
Coastal Streams

We evaluated the effectiveness of using hatchery coho salmon (Oncorhynchus kisutch) presmolts to rebuild wild populations in Oregon coastal streams. Juvenile and adult populations were monitored in 15 stocked and 15 unstocked streams from summer 1980 until summer 1985. During the summers following the planting of presmolts, the number of juveniles per square metre of pool surface area was higher in the stocked streams than in the unstocked streams. However, wild juveniles were significantly less abundant in the stocked streams during the 2 yr when density of wild juveniles was estimated separately from hatchery juveniles. Adult returns to the stocked streams were not significantly different from adult returns to the unstocked streams, but returns tended to be earlier in the stocked streams than in the unstocked streams. Despite similar numbers of adults per kilometre in the stocked streams and unstocked streams in the years the presmolts returned to spawn, the resulting densities of juveniles in the stocked streams were significantly lower than the densities of juveniles in the unstocked streams. We concluded that the early time of spawning of the hatchery coho salmon was largely responsible for their failure to rebuild the populations in the streams stocked with presmolts.

The Retention of Coho Salmon (Oncorhynchus kisutch) Carcasses by Organic Debris in Small Streams

1985 ◽  
Vol 42 (6) ◽  
pp. 1222-1225 ◽  
Author(s):  
C J. Cederholm ◽  
N. P. Peterson
Keyword(s):  
Riparian Zone ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Release Site ◽  
Positive Trend ◽  
Stream Channel ◽  
Olympic Peninsula ◽  
Spawning Period ◽  
Organic Debris ◽  
Small Streams

Twenty marked coho salmon (Oncorhynchus kisutch) carcasses were placed in each of nine small streams on the Olympic Peninsula of Washington during the fall–winter spawning period. Distribution of the carcasses in 500 m of stream below each release site was followed for 4 wk. One week after placement, 78 of the 180 carcasses were found in the nine study reaches; 80% were found in the first 200 m downstream of the release sites. A general positive trend was observed between the number of carcasses retained and the amount of debris in the stream channel (r = 0.61). Terrestrial animals rapidly consumed carcasses during the experiment, and removed many of them to the riparian zone.

Vertical and Horizontal Distributions of Coho Salmon (Oncorhynchus kisutch), Yellow Perch (Perca flavescens), and Cisco (Coregonus artedii) in Pallette Lake, Wisconsin

1976 ◽  
Vol 33 (12) ◽  
pp. 2710-2715 ◽  
Author(s):  
Sandy Engel ◽  
John J. Magnuson
Keyword(s):  
Vertical Distribution ◽  
Yellow Perch ◽  
Coho Salmon ◽  
Perca Flavescens ◽  
Oncorhynchus Kisutch ◽  
Vertical Separation ◽  
Sunset Yellow ◽  
Coregonus Artedii ◽  
The Vertical Distribution

Coho salmon (Oncorhynchus kisutch), stocked in Pallette Lake, Wisconsin, remained inshore in April and early May, moved offshore in late May and June, and returned to shore in October. From June to September the vertical distribution of offshore coho salmon overlapped that of yellow perch (Perca flavescens) and cisco (Coregonus artedii). Yellow perch were gillnetted mainly in epilimnetic water of 16–22 C; coho salmon and cisco were mostly caught in metalimnetic water of 12–17 and 8–12 C, respectively. Vertical separation broke down during other months of the year.From June to September diel, horizontal movements were found for yellow perch within the epilimnion and for cisco within the metalimnion. Yellow perch moved offshore around sunrise and onshore around sunset; cisco moved toward shore around sunrise and away from shore around sunset. Yellow perch were mainly active during the day and cisco at night. Perch and Cisco were, therefore, largely temporally and spatially segregated from each other but not from coho salmon.

Variation in Burst and Prolonged Swimming Performance Among British Columbia Populations of Coho Salmon, Oncorhynchus kisutch

1985 ◽  
Vol 42 (12) ◽  
pp. 2029-2033 ◽  
Author(s):  
Eric B. Taylor ◽  
J. D. McPhail
Keyword(s):  
British Columbia ◽  
Coho Salmon ◽  
Swimming Performance ◽  
Oncorhynchus Kisutch ◽  
Body Form ◽  
Coastal Streams ◽  
Fast Start ◽  
Burst Swimming ◽  
Coastal British Columbia ◽  
Different Levels

Burst swimming tests, using both wild and laboratory-reared juvenile coho salmon, Oncorhynchus kisutch, from three streams (two south coastal British Columbia and one interior), indicated that in the first few hundredths of a second of a "fast-start" the coastal juveniles attain greater burst velocities than similar sized interior juveniles. Interior (Coldwater River) juveniles had greater swimming stamina than individuals from the two coastal streams: Wade and Morrison creeks. The differences in stamina performance were demonstrated to be inherited. The differences in swimming performance between coastal and interior are related to differences in body form; coastal coho have deep, robust bodies, while interior juveniles are more fusiform. The differences in swimming performance between coastal and interior coho salmon are probably adaptive and related to differences in the energetic demands of their freshwater migrations and perhaps to different levels of predation in coastal and interior streams.

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