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.

scholarly journals Current landscapes and legacies of land-use past: understanding the distribution of juvenile coho salmon (Oncorhynchus kisutch) and their habitats along the Oregon Coast, USA

2017 ◽  
Vol 74 (4) ◽  
pp. 546-561 ◽  
Author(s):  
E. Ashley Steel ◽  
Ariel Muldoon ◽  
Rebecca L. Flitcroft ◽  
Julie C. Firman ◽  
Kara J. Anlauf-Dunn ◽  
...  
Keyword(s):  
Land Use ◽  
Surface Area ◽  
Coho Salmon ◽  
Spatial Scales ◽  
Oncorhynchus Kisutch ◽  
River Management ◽  
Land Ownership ◽  
Weak Rock ◽  
Oregon Coast ◽  
Pool Surface

The Oregon Coast landscape displays strong spatial patterns in air temperature, precipitation, and geology, which can confound our ability to detect relationships among land management, instream conditions, and fish at broad spatial scales. Despite this structure, we found that a suite of immutable or intrinsic attributes (e.g., reach gradient, drainage area, elevation, and percent weak rock geology of the catchments draining to each of our 423 study reaches) could explain much of the variation in pool surface area across the landscape and could contribute to an estimate of how many juvenile coho salmon (Oncorhynchus kisutch) one might expect to find in those pools. Further, we found evidence of differences in pool surface area across land ownership categories that reflect differing management histories. Our results also suggest that historical land and river management activities, in particular splash dams that occurred at least 50 years ago, continue to influence the distribution of juvenile coho salmon and their habitats today.

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.

Coho salmon (Oncorhynchus kisutch) ocean migration patterns: insight from marine coded-wire tag recoveries

2002 ◽  
Vol 59 (7) ◽  
pp. 1100-1115 ◽  
Author(s):  
Laurie Weitkamp ◽  
Kathleen Neely
Keyword(s):  
Geographic Variation ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Principal Component ◽  
Distribution Patterns ◽  
Geographic Region ◽  
Small Scale ◽  
Adult Size ◽  
Wild Populations ◽  
Specific Distribution

We investigated geographic variation in the ocean migration of coho salmon (Oncorhynchus kisutch) by examining recovery locations of 1.77 million coded-wire tagged fish from 90 hatcheries and 36 wild populations along the west coast of North America. Principal component, cluster, and similarity analyses were used to reveal both large- and small-scale variation in marine recovery patterns. We identified 12 distinct ocean distribution patterns, each associated with a particular geographic region. Despite these distinct patterns, however, fish from a given population were widely dispersed in the coastal ocean. Recovery patterns for tagged wild populations were consistent with those of hatchery populations from the same region, suggesting that marine distributions based on hatchery populations are reasonable proxies for distributions of wild populations. These region-specific distribution patterns suggest unappreciated life history diversity for coho salmon in the marine environment. When combined with region-specific adult size variation, they suggest migratory differences earlier in the ocean residence period as well. These results provide a novel framework with which to view geographic variation in salmon ocean ecology, conservation, and management.

The influence of hatchery coho salmon (Oncorhynchus kisutch) on the productivity of wild coho salmon populations in Oregon coastal basins

2003 ◽  
Vol 60 (9) ◽  
pp. 1050-1056 ◽  
Author(s):  
Thomas Nickelson
Keyword(s):  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Wild Fish ◽  
Wild Populations ◽  
Large Numbers ◽  
Average Proportion ◽  
Coastal Basins ◽  
High Concentrations ◽  
Coastal River ◽  
Release Strategy

To aid in the recovery of depressed wild salmon populations, the operation of hatcheries must be changed to reduce interactions of juvenile hatchery fish with wild fish. Evidence suggests that productivity of wild populations can be reduced by the presence of large numbers of hatchery smolts in lower rivers and estuaries that attract predators. An index of productivity based on the density-independent rate of reproduction of wild coho salmon (Oncorhynchus kisutch) in 12 Oregon coastal river basins and two lake basins was negatively correlated with the average number of hatchery coho salmon smolts released in each basin. The index of productivity was not significantly correlated with the average proportion of hatchery coho salmon in each naturally spawning population or with habitat quality. Alterations to hatchery programs that could encourage recovery of wild populations include (i) avoiding release of large numbers of smolts in areas with high concentrations of wild fish, (ii) decreasing the number of smolts released, and (iii) using a volitional release strategy or a strategy that employs smaller release groups spread temporally.

Morphological Differences between Hatchery and Wild Populations of Coho Salmon (Oncorhynchus kisutch): Environmental versus Genetic Origin

1991 ◽  
Vol 48 (9) ◽  
pp. 1783-1791 ◽  
Author(s):  
D. P. Swain ◽  
B. E. Riddell ◽  
C. B. Murray
Keyword(s):  
Maternal Effects ◽  
Genetic Divergence ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Principal Component ◽  
Wild Populations ◽  
Genetic Origin ◽  
Environmental Component ◽  
Morphological Differences ◽  
Median Fins

Previous studies have demonstrated morphological differences between hatchery-reared coho salmon (Oncorhynchus kisutch) of hatchery origin and wild-reared coho of wild origin. We tested for a genetic component to this divergence by comparing coho from hatchery and wild populations both reared in the same hatchery environment and for an environmental component by comparing hatchery- and wild-reared coho both of wild origin. As in the previous studies, wild-reared fish from wild populations had greater head dimensions, larger median fins, and deeper bodies than did hatchery-reared fish from hatchery populations. This difference, summarized by the first principal component (PC1) of the size-adjusted data, was related to rearing environment rather than to genetic differences between hatchery and wild populations. Genetic divergence (or maternal effects) did occur between hatchery and wild populations along PC2 and PC3, but this divergence was slight compared with the environmentally induced differences between the two types of fish along PC1.

Variation in Agonistic Behavior between Newly Emerged Juveniles from Hatchery and Wild Populations of Coho Salmon, Oncorhynchus kisutch

1990 ◽  
Vol 47 (3) ◽  
pp. 566-571 ◽  
Author(s):  
D. P. Swain ◽  
B. E. Riddell
Keyword(s):  
Agonistic Behavior ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Its Region ◽  
Population Level ◽  
Mirror Image ◽  
Aggressive Display ◽  
Wild Populations ◽  
Breeding Programs ◽  
Stimulation Tests

We compared agonistic behavior of newly emerged coho salmon (Oncorhynchus kisutch) between hatchery and wild populations using mirror image stimulation tests. We used hatchery populations from two different regions of Vancouver Island B.C., each matched with a wild population from its region. In both comparisons, hatchery juveniles were more aggressive than wild juveniles. Rates of aggressive display increased with time since emergence for both hatchery and wild fish, as did the differences in behavior between the two types. By the sixth day of observation (13 d postemergence), the overall effect of fish type was highly significant for all aggressive behaviours. Since the individuals compared were reared from eggs under identical conditions, these differences are presumably genetic. Comparisons involved relatively few families from each population. However, because heritability was moderate to low within populations, and variance between population types exceeded variance among families within populations, these results indicate real differences at the population level. These results may have important implications for programs to rebuild wild populations using hatchery transplants and for selective breeding programs to develop domestic stocks of coho.

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