Effects of Streamflow and Upwelling on Yield of Wild Coho Salmon (Oncorhynchus kisutch) in Oregon

1981 ◽  
Vol 38 (4) ◽  
pp. 471-475 ◽  
Author(s):  
Dennis L. Scarnecchia
Keyword(s):  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Positive Relation ◽  
Significant Relation ◽  
Oregon Coast ◽  
Growth And Survival ◽  
Coastal Rivers ◽  
High Flows ◽  
Oceanic Upwelling

To investigate the dependence of coho salmon (Oncorhynchus kisutch) yield on streamflow and oceanic upwelling, I regressed catch by the Oregon commercial troll fishery from 1942 to 1962 against indices of offshore upwelling the previous spring and measurements of streamflow from five Oregon coastal rivers during the freshwater rearing phase. A highly significant positive relation was found between total streamflows during the freshwater residency of the fish for the five rivers combined and the weight of the annual catch of coho salmon from 1942 to 1962. There was also a significant positive relation between total combined annual (January–December) flows for these rivers and the catch 2 yr later. Conversely, I found no significant relation between the 60 consecutive days of lowest flow during summer and catch 2 yr later. High flows during freshwater rearing probably provide more habitat and better conditions for growth and survival. I also found a significant positive relation between April through June upwelling at two stations and catch of coho salmon the following year from 1947 to 1962. Fifty-six percent of the variation in catch from 1947 to 1962 was explained by the total flows during freshwater residency, 60 consecutive days of lowest flow, plus combined April through June upwelling at both stations. It is suggested that some stocks of coho salmon smolts may move southward or remain in local offshore waters after they enter the ocean to take advantage of the production of invertebrates resulting from upwelling.Key words: streamflow, upwelling, coho salmon, Oregon coast

Effect of forecast skill on management of the Oregon coast coho salmon (Oncorhynchus kisutch) fishery

2012 ◽  
Vol 69 (6) ◽  
pp. 1016-1032 ◽  
Author(s):  
David E. Rupp ◽  
Thomas C. Wainwright ◽  
Peter W. Lawson
Keyword(s):  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Status Quo ◽  
Forecast Skill ◽  
Oregon Coast ◽  
Performance Metric ◽  
Specific Performance ◽  
The Status ◽  
Target Performance ◽  
Fish Survival

Better fisheries management is often given as one justification for research on improving forecasts of fish survival. However, the value gained from expected improvements in forecast skill in terms of achieving management goals is rarely quantified as part of research objectives. Using Monte Carlo simulations of population dynamics, we assessed the effect of forecast skill under two strategies for managing Oregon coast natural (OCN) coho salmon ( Oncorhynchus kisutch ). The first, or status quo, strategy is currently being used to rebuild threatened OCN coho populations. This strategy determines harvest based on both a forecasted marine survival rate and parental spawner abundance. The second strategy relies on a forecast of preharvest adult abundance to achieve a constant spawner escapement target. Performance of the status quo strategy was largely insensitive to forecast skill, while the second strategy showed sensitivity that varied with escapement target and specific performance metric. The results imply that effort towards improving forecasts is not justifiable solely on the basis of improved management under the status quo strategy, though it may be were the management strategy altered.

Potential benefits of a conservation hatchery program for supplementing Oregon coast coho salmon (Oncorhynchus kisutch) populations: a stochastic model investigation

2005 ◽  
Vol 62 (8) ◽  
pp. 1920-1935 ◽  
Author(s):  
Gretchen R Oosterhout ◽  
Charles W Huntington ◽  
Thomas E Nickelson ◽  
Peter W Lawson
Keyword(s):  
Habitat Restoration ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Solution Space ◽  
Oregon Coast ◽  
Hatchery Fish ◽  
Natural Production ◽  
Management Actions ◽  
Genetic Risks ◽  
Hatchery Program

This study developed a stochastic life cycle model to simulate idealized supplementation strategies to investigate the following question: under what circumstances could hatchery fish stocking contribute to the recovery of Oregon coast coho salmon (Oncorhynchus kisutch)? Simulations were used to find a solution space, defined by the attributes of wild and hatchery-bred salmon, their offspring, and their environments, where hatchery fish could supplement natural production without further depressing it until natural or human factors restricting production were relieved. These simulations suggest that short-duration, tightly controlled, low-intensity conservation hatchery programs designed to minimize genetic and ecological risks may yield minor short-term increases in adult coho salmon abundance while posing significant ecological and genetic risks. No solution space was found that indicated clear long-term benefits from such a supplementation program. Of all the management actions modeled, habitat restoration offered by far the largest and only permanent gains in coho salmon abundance while posing no genetic or ecological risk to the fish. The modeled benefits of habitat restoration were significant regardless of assumptions made about the fitness of hatchery fish and their offspring.

Social interactions of coho salmon (Oncorhynchus kisutch) smolts in seawater

1985 ◽  
Vol 63 (10) ◽  
pp. 2401-2407 ◽  
Author(s):  
Cynthia A. Paszkowski ◽  
Bori L. Olla
Keyword(s):  
Social Behavior ◽  
Social Interactions ◽  
Social System ◽  
Agonistic Behavior ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Distribution Patterns ◽  
Oregon Coast ◽  
Fish Hatchery ◽  
Free Ranging

The behavior of coho salmon (Oncorhynchus kisutch) smolts was examined under laboratory conditions to determine if the hierarchical–territorial social system characteristic of this species in freshwater persisted in seawater. When held in groups of two to eight fish, hatchery-reared, accelerated underyearling smolts formed hierarchies controlled by a single dominant who was responsible for most of the observed movement, chases, and feeding. Agonistic behavior also occurred within pairs of recently smolted fingerlings from two hatchery stocks with different rearing histories and in groups containing free-ranging fish captured off the Oregon coast. Possible relationships between the observed social behavior and marine distribution patterns of juvenile coho salmon are discussed.

Effect of triploidy on growth and survival of pre-smolt and post-smolt coho salmon (Oncorhynchus kisutch)

Aquaculture ◽  
1998 ◽  
Vol 168 (1-4) ◽  
pp. 413-422 ◽  
Author(s):  
Ruth E Withler ◽  
W.Craig Clarke ◽  
John Blackburn ◽  
Ian Baker
Keyword(s):  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Growth And Survival

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.

Genetic population structure of central Oregon Coast coho salmon (Oncorhynchus kisutch)

2004 ◽  
Vol 5 (6) ◽  
pp. 797-812 ◽  
Author(s):  
Michael J. Ford ◽  
David Teel ◽  
Donald M. Van Doornik ◽  
David Kuligowski ◽  
Peter W. Lawson
Keyword(s):  
Population Structure ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Genetic Population Structure ◽  
Genetic Population ◽  
Oregon Coast

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.

scholarly journals Oversummer growth and survival of juvenile coho salmon (Oncorhynchus kisutch) across a natural gradient of stream water temperature and prey availability: an in situ enclosure experiment

2020 ◽  
Vol 77 (2) ◽  
pp. 413-424 ◽  
Author(s):  
Robert A. Lusardi ◽  
Bruce G. Hammock ◽  
Carson A. Jeffres ◽  
Randy A. Dahlgren ◽  
Joseph D. Kiernan
Keyword(s):  
Water Temperature ◽  
Growth Rates ◽  
Coho Salmon ◽  
Prey Availability ◽  
Stream Water ◽  
Oncorhynchus Kisutch ◽  
Thermal Conditions ◽  
Maximum Temperature ◽  
Growth And Survival

Conservation efforts for Pacific salmon (Oncorhynchus spp.) increasingly prioritize maintenance of cool water temperatures that protect all freshwater life stages. However, development of appropriate temperature standards requires a robust understanding of the interactions among water temperature, ecosystem productivity, and fish performance. We used a series of in situ enclosures to examine how natural spatiotemporal gradients in thermal conditions and prey availability affected the summer growth and survival of age-0+ coho salmon (Oncorhynchus kisutch). Coho salmon absolute growth rates peaked at a mean daily average water temperature (mean T) of 16.6 °C and an associated maximum weekly maximum temperature (MWMT) of 21.1 °C. Juvenile growth under these thermal conditions was sixfold greater than the growth rates observed for conspecifics rearing in the coolest study reach (mean T = 13.0 °C; MWMT = 16.0 °C). Even at the highest rearing temperature (mean T = 18.1 °C; MWMT = 24.0 °C), growth rates remained positive and above the study-wide average, although overall survival was reduced. Among the predictor variables examined, invertebrate prey abundance was the predominant factor influencing age-0+ coho salmon growth. These results suggest that abundant prey resources may mitigate the negative effects of elevated water temperature on fish growth in riverine environments. Given the likelihood of increasing stream temperatures with climate change, productive ecosystems may provide critical refuges for juvenile salmonids.

Growth and survival of newly emerged and juvenile coho salmon (Oncorhynchus kisutch) reared at different salinities

1993 ◽  
Vol 71 (6) ◽  
pp. 1230-1237 ◽  
Author(s):  
C. B. Murray ◽  
T. D. Beacham ◽  
L. W. Barner
Keyword(s):  
Fresh Water ◽  
Growth Rates ◽  
Variance Component ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Subsequent Growth ◽  
Saline Environment ◽  
Rearing Environment ◽  
Growth And Survival ◽  
Coastal Population

Newly emerged coho salmon (Oncorhynchus kisutch) from 40 families of a coastal-spawning population were reared in fresh water and seawater for 144 d after ponding. Growth and survival were, on average, higher in fresh water than in seawater, but juveniles from some families had higher or equivalent survival in seawater compared with fresh water. Heritability (sire variance component) of survival and length ranged between 0.30 and 0.35. The transfer of juveniles from fresh water to 15‰ seawater after 70 d of rearing in fresh water had little effect on their subsequent growth and survival. In a second experiment, newly emerged fry from a coastal- and an interior-spawning population had the same survival in fresh water, but survival was higher for the coastal population than for the interior population in 15 or 25‰ seawater. Rearing environment had no effect on survival for the coastal population, but as rearing salinities increased, survival for the interior population decreased. Within a population, length, weight, and instantaneous growth rates for length and weight decreased with increased rearing salinity. The growth and survival of some juveniles in a saline environment were comparable to those observed for juveniles reared in fresh water, indicating that the marine environment provides a suitable rearing environment for some coho salmon.

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