Evaluation of the Contribution of Fall Chinook Salmon Reared at Columbia River Hatcheries to the Pacific Salmon Fisheries, 1989 Final Report.

Runs of sockeye salmon (Oncorhynchus nerka) and chinook salmon (O. tshawytscha) were established at Frazer Lake, Kodiak Island, Alaska by adult spawner transplants, fry plants, and eyed-egg plants. Falls in the lake outlet formed a barrier to natural ascent of anadromous fish until construction of a fishpass in 1962. Accounts of successful introduction and development of viable and self-sustaining runs of salmon where none previously existed and the lake was inaccessible are scarce in the history of salmon fisheries on the Pacific Coast. The first sockeye returning to Frazer Lake in 1956 were produced from egg plants in 1951. Annual sockeye returns have progressively increased over a 28-yr period reaching record passage of 141 981 in 1978. Sockeye spawning has extended into new areas as returns increased. Spawning area capacity is projected to be sufficient for 365 000 sockeye while rearing area is estimated to be sufficient to support fry production from 400 000 sockeye. Sockeye returns per spawner have averaged 3.2 for six parent years (1966–71) in which returns are complete. A chinook run was created from plants of 160 000 fry over a 4-yr period beginning in 1966. Chinook have returned to spawn in specific sites of fry release above the falls and in the lower river. Key words: salmon introduction, enhancement technique, sockeye, chinook, Frazer Lake, salmon establishment

The Pacific Salmon Fisheries. A Study of Irrational Conservation. James A. Crutchfield and Giulio Pontecorvo. Published for Resources for the Future by the Johns Hopkins Press, Baltimore, 1969. xii + 220 pp., illus. $6

Science ◽

10.1126/science.168.3932.737 ◽

1970 ◽

Vol 168 (3932) ◽

pp. 737-739

Author(s):

J. L. McHugh

Keyword(s):

Pacific Salmon ◽

The Pacific ◽

Salmon Fisheries ◽

The Future

Development of an Effective Transport Media for Juvenile Spring Chinook Salmon to Mitigate Stress and Improve Smolt Survival During Columbia River Fish Hauling Operations, 1985 Final Report.

10.2172/5361394 ◽

1985 ◽

Cited By ~ 1

Author(s):

Gary A. Wedemeyer

Keyword(s):

Chinook Salmon ◽

Columbia River ◽

Final Report ◽

Effective Transport ◽

River Fish

Advances in Fish Tagging and Marking Technology

Advances in Fish Tagging and Marking Technology ◽

10.47886/9781934874271.ch13 ◽

2012 ◽

Keyword(s):

Climate Change ◽

Chinook Salmon ◽

Coho Salmon ◽

Pacific Salmon ◽

Distribution Patterns ◽

Distinct Region ◽

Online Database ◽

Specific Distribution ◽

The Pacific ◽

The Pacific Ocean

Abstract.—The coded wire tag (CWT) database contains detailed information on millions of Pacific salmon Oncorhynchus spp. released from hatcheries or smolt traps and recovered in the Pacific Ocean and its tributaries. I used this information to compare marine distribution patterns of hatchery coho O. kisutch and Chinook O. tshawytscha salmon, based on recoveries of an estimated 1.99 million tagged salmon in coastal areas from southern California to the Bering Sea. Both species show distinct region-specific distribution patterns. Within these release regions, coho and Chinook salmon marine distributions were often similar, with fish distributed largely in local waters. In other regions, Chinook salmon were distributed father north than coho salmon originating from the same region. Only in two regions did the two species have fundamentally different marine distributions, with coho south of, and Chinook salmon north of, the natal stream. The analysis also revealed several “hot spots” of salmon diversity, identified by numerically few recoveries that represented many of the hatcheries used in the analysis. These hotspots may serve as important reservoirs for the continued existence of populations that are particularly vulnerable to climate change due to their restricted marine distributions. Although CWT technology is primitive by modern standards, the enormous amount of data collected in a consistent fashion over decades and contained in an online database provides a unique and underutilized opportunity to address many elusive questions about Pacific salmon.

Characterizing juvenile salmon predation risk during early marine residence

PLoS ONE ◽

10.1371/journal.pone.0247241 ◽

2021 ◽

Vol 16 (2) ◽

pp. e0247241

Author(s):

Elizabeth M. Phillips ◽

John K. Horne ◽

Jeannette E. Zamon

Keyword(s):

Predation Risk ◽

Chinook Salmon ◽

Pacific Salmon ◽

Columbia River ◽

Water Clarity ◽

River Plume ◽

Juvenile Salmon ◽

Physical Factors ◽

Alternative Prey ◽

Plume Area

Predation mortality can influence the distribution and abundance of fish populations. While predation is often assessed using direct observations of prey consumption, potential predation can be predicted from co-occurring predator and prey densities under varying environmental conditions. Juvenile Pacific salmon Oncorhynchus spp. (i.e., smolts) from the Columbia River Basin experience elevated mortality during the transition from estuarine to ocean habitat, but a thorough understanding of the role of predation remains incomplete. We used a Holling type II functional response to estimate smolt predation risk based on observations of piscivorous seabirds (sooty shearwater [Ardenna griseus] and common murre [Uria aalge]) and local densities of alternative prey fish including northern anchovy (Engraulis mordax) in Oregon and Washington coastal waters during May and June 2010–2012. We evaluated predation risk relative to the availability of alternative prey and physical factors including turbidity and Columbia River plume area, and compared risk to returns of adult salmon. Seabirds and smolts consistently co-occurred at sampling stations throughout most of the study area (mean = 0.79 ± 0.41, SD), indicating that juvenile salmon are regularly exposed to avian predators during early marine residence. Predation risk for juvenile coho (Oncorhynchus kisutch), yearling Chinook salmon (O. tshawytscha), and subyearling Chinook salmon was on average 70% lower when alternative prey were present. Predation risk was greater in turbid waters, and decreased as water clarity increased. Juvenile coho and yearling Chinook salmon predation risk was lower when river plume surface areas were greater than 15,000 km2, while the opposite was estimated for subyearling Chinook salmon. These results suggest that plume area, turbidity, and forage fish abundance near the mouth of the Columbia River, all of which are influenced by river discharge, are useful indicators of potential juvenile salmon mortality that could inform salmonid management.