Rapid growth in the early marine period improves the marine survival of Chinook salmon (Oncorhynchus tshawytscha) in Puget Sound, Washington

2011 ◽  
Vol 68 (2) ◽  
pp. 232-240 ◽  
Author(s):  
Elisabeth J Duffy ◽  
David A Beauchamp
Keyword(s):  
Body Size ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Puget Sound ◽  
Fork Length ◽  
Adult Survival ◽  
Local Conditions ◽  
Size Dependent ◽  
Marine Survival ◽  
Growing Conditions

We examined the effect of early marine entry timing and body size on the marine (smolt-to-adult) survival of Puget Sound Chinook salmon ( Oncorhynchus tshawytscha ). We used data from coded wire tag release groups of hatchery Chinook salmon to test whether hatchery release date, release size, and size in offshore waters in July and September influenced marine survival. Marine survival was most strongly related to the average body size in July, with larger sizes associated with higher survivals. This relationship was consistent over multiple years (1997–2002), suggesting that mortality after July is strongly size-dependent. Release size and date only slightly improved this relationship, whereas size in September showed little relationship to marine survival. Specifically, fish that experienced the highest marine survivals were released before 25 May and were larger than 17 g (or 120 mm fork length) by July. Our findings highlight the importance of local conditions in Puget Sound (Washington, USA) during the spring and summer, and suggest that declines in marine survival since the 1980s may have been caused by reductions in the quality of feeding and growing conditions during early marine life.

scholarly journals Estimates of Chinook salmon consumption in Washington State inland waters by four marine mammal predators from 1970 to 2015

2017 ◽  
Vol 74 (8) ◽  
pp. 1173-1194 ◽  
Author(s):  
Brandon Chasco ◽  
Isaac C. Kaplan ◽  
Austen Thomas ◽  
Alejandro Acevedo-Gutiérrez ◽  
Dawn Noren ◽  
...  
Keyword(s):  
Chinook Salmon ◽  
Marine Mammal ◽  
Oncorhynchus Tshawytscha ◽  
Interspecific Interactions ◽  
Puget Sound ◽  
The United States ◽  
Washington State ◽  
Killer Whales ◽  
Protected Species ◽  
Annual Biomass

Conflicts can arise when the recovery of one protected species limits the recovery of another through competition or predation. The recovery of many marine mammal populations on the west coast of the United States has been viewed as a success; however, within Puget Sound in Washington State, the increased abundance of three protected pinniped species may be adversely affecting the recovery of threatened Chinook salmon (Oncorhynchus tshawytscha) and endangered killer whales (Orcinus orca) within the region. Between 1970 and 2015, we estimate that the annual biomass of Chinook salmon consumed by pinnipeds has increased from 68 to 625 metric tons. Converting juvenile Chinook salmon into adult equivalents, we found that by 2015, pinnipeds consumed double that of resident killer whales and six times greater than the combined commercial and recreational catches. We demonstrate the importance of interspecific interactions when evaluating species recovery. As more protected species respond positively to recovery efforts, managers should attempt to evaluate tradeoffs between these recovery efforts and the unintended ecosystem consequences of predation and competition on other protected species.

An Evaluation of Rearing Densities to Improve Growth and Survival of Hatchery Spring Chinook Salmon

2013 ◽  
Vol 4 (1) ◽  
pp. 114-123 ◽  
Author(s):  
Douglas E. Olson ◽  
Michael Paiya
Keyword(s):  
Mortality Rate ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Confounding Factor ◽  
Fork Length ◽  
High Density ◽  
Growth And Survival ◽  
Migration Timing ◽  
Rearing Density ◽  
Salmon Stock

Abstract We evaluated growth and survival of spring Chinook salmon Oncorhynchus tshawytscha reared at varying densities at Warm Springs National Fish Hatchery, Oregon. For three consecutive brood years, density treatments consisted of low, medium, and high groups in 57.8-m3 raceways with approximately 16,000, 24,000, and 32,000 fish/raceway, respectively. Fish were volitionally released in both the autumn and spring to mimic the downstream migration timing of the endemic wild spring Chinook salmon stock. Just prior to the autumn release, the rearing density estimate was 4.24 kg/m3 for the low-density group, 6.27 kg/m3 for the medium-density group, and 8.42 kg/m3 for the high-density group. While weight gain did not differ among density treatments (P  =  0.72), significant differences were found in median fork length (P < 0.001) for fish reared at different densities. Fish reared at high density exhibited the highest on-hatchery mortality rate during two brood years; however, differences in mortality rate among densities were not significant (P  =  0.20). In one brood year, adult recovery rates appeared to support the hypothesis that lower initial densities improved postrelease survival (P < 0.01). All rearing densities utilized in this evaluation were relatively low and may partially explain why more differences were not readily apparent among density groups. In addition, the volitional release was a confounding factor in our study because we were unable to quantify the number of fish released in the autumn.

scholarly journals Ecological thresholds in forecast performance for key United States West Coast Chinook salmon stocks

2019 ◽  
Vol 77 (4) ◽  
pp. 1503-1515 ◽  
Author(s):  
William H Satterthwaite ◽  
Kelly S Andrews ◽  
Brian J Burke ◽  
Jennifer L Gosselin ◽  
Correigh M Greene ◽  
...  
Keyword(s):  
Chinook Salmon ◽  
West Coast ◽  
Oncorhynchus Tshawytscha ◽  
Environmental Variability ◽  
Puget Sound ◽  
Threshold Dynamics ◽  
Time Lags ◽  
Environmental Indices ◽  
Forecast Performance ◽  
Salmon Fisheries

Abstract Preseason abundance forecasts drive management of US West Coast salmon fisheries, yet little is known about how environmental variability influences forecast performance. We compared forecasts of Chinook salmon (Oncorhynchus tshawytscha) against returns for (i) key California-Oregon ocean fishery stocks and (ii) high priority prey stocks for endangered Southern Resident Killer Whales (Orcinus orca) in Puget Sound, Washington. We explored how well environmental indices (at multiple locations and time lags) explained performance of forecasts based on different methods (i.e. sibling-based, production-based, environment-based, or recent averages), testing for nonlinear threshold dynamics. For the California stocks, no index tested explained >50% of the variation in forecast performance, but spring Pacific Decadal Oscillation and winter North Pacific Index during the year of return explained >40% of the variation for the sibling-based Sacramento Fall Chinook forecast, with nonlinearity and apparent thresholds. This suggests that oceanic conditions experienced by adults (after younger siblings returned) have the most impact on sibling-based forecasts. For Puget Sound stocks, we detected nonlinear/threshold relationships explaining >50% of the variation with multiple indices and lags. Environmental influences on preseason forecasts may create biases that render salmon fisheries management more or less conservative, and therefore could motivate the development of ecosystem-based risk assessments.

Fry-to-adult survival of natural and hatchery-produced chinook salmon (Oncorhynchus tshawytscha) from a common origin

1997 ◽  
Vol 54 (6) ◽  
pp. 1246-1254 ◽  
Author(s):  
M J Unwin
Keyword(s):  
New Zealand ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Survival Rates ◽  
Adult Survival ◽  
Poor Survival ◽  
Stock Size ◽  
Hatchery Fish ◽  
Stock Recruitment

Fry-to-adult survival rates for chinook salmon (Oncorhynchus tshawytscha) from Glenariffe Stream, a tributary of the Rakaia River, New Zealand, were estimated for fish of both natural and hatchery origin. Survival of naturally produced fry, most of which leave Glenariffe Stream within 24 h of emergence, averaged 0.079% (range 0.013-1.17%). For hatchery fish released at 8-12 months, standardised to a mean weight of 38 g, survival covaried with weight at release consistently across all brood years and averaged 0.34% (range 0.008-3.28%). Survival rates for hatchery fish were four times higher than for naturally produced fry, but were extremely poor relative to their size at release. Survival rates for fish of natural and hatchery origin were positively correlated, suggesting that recruitment of both stocks is primarily controlled by common influences within the marine environment, probably during the first winter at sea. Stock-recruitment analysis for the natural population showed little tendency for recruitment to increase with stock size, suggesting that marine survival rates may be density dependent. Although the reasons for the relatively poor survival of hatchery fish are unclear, the results provide a case study in which hatchery fish appear to have a poorer ``fitness to survive'' than their natural counterparts.

Tidal movements and residency of subyearling Chinook salmon (Oncorhynchus tshawytscha) in an Oregon salt marsh channel

2010 ◽  
Vol 67 (3) ◽  
pp. 524-533 ◽  
Author(s):  
David K. Hering ◽  
Daniel L. Bottom ◽  
Earl F. Prentice ◽  
Kim K. Jones ◽  
Ian A. Fleming
Keyword(s):  
Salt Marsh ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
River Estuary ◽  
Fork Length ◽  
Full Duplex ◽  
Salmon River ◽  
Salt Marsh Habitat ◽  
Tidal Cycles ◽  
Insight Into

A novel application of full-duplex passive integrated transponder (PIT) tag technology was used to investigate movements of individual subyearling Chinook salmon ( Oncorhynchus tshawytscha ; fork length ≥ 60 mm) into and out of tidally flooded salt marsh habitat in the Salmon River estuary, Oregon, USA. PIT interrogation was effective, with mean tag detection ≥ 92%. Salmon movement peaked late during both flood and ebb tide periods, indicating that salmon did not drift passively. Most movements were in the direction of tidal currents, but 20% of individuals entered the channel against the ebbing tide. Individuals occupied the intertidal channel for a median 4.9 h and as long as 8.9 h per tidal cycle, and few were detected moving when water depth was <0.4 m. Some individuals used the channel on multiple successive tidal cycles, and others entered intermittently over periods of up to 109 days. Using an individual-based approach, we characterized diversity of juvenile Chinook salmon behavior within a marsh channel, providing insight into the value of such habitats for conservation and restoration of salmon populations.

Reduced recruitment of Chinook salmon in a leveed bar-built estuary

2021 ◽  
Author(s):  
Emily K Chen ◽  
Mark J. Henderson
Keyword(s):  
Food Availability ◽  
Chinook Salmon ◽  
Stream Flow ◽  
Oncorhynchus Tshawytscha ◽  
Relative Proportion ◽  
Adult Survival ◽  
Growth And Survival ◽  
Estuary Circulation ◽  
Dynamics And Function ◽  
And Function

Estuaries are commonly touted as nurseries for salmonids, providing numerous advantages for smolts prior to ocean entry. In bar-built estuaries, sandbars form at the mouth of rivers during periods of low stream flow, closing access to the ocean and preventing outmigration. We evaluated how summer residency in a leveed bar-built estuary affects the growth, survival, and recruitment of a Chinook salmon (Oncorhynchus tshawytscha) population. We performed a mark-recapture study on outmigrants to determine juvenile estuary abundance, growth, and survival. We used returning adult scales and otoliths to determine the relative proportion of summer estuary residents in spawning adults. Juveniles in the estuary grew less after mouth closure, and ultimately summer estuary residents had lower smolt-to-adult survival and contributed disproportionately less to the spawning population than juveniles that reared in the ocean their first summer. Mouth closure may lower food availability and deteriorate estuary conditions by reducing marine prey influx and estuary circulation. This research demonstrates the complexity of estuary dynamics and function as salmonid nurseries, particularly when considering the extensive modification of estuaries.

Changes in life history parameters in a naturally spawning population of chinook salmon (Oncorhynchus tshawytscha) associated with releases of hatchery-reared fish

1997 ◽  
Vol 54 (6) ◽  
pp. 1235-1245 ◽  
Author(s):  
M J Unwin ◽  
G J Glova
Keyword(s):  
Life History ◽  
New Zealand ◽  
Chinook Salmon ◽  
Life History Traits ◽  
Oncorhynchus Tshawytscha ◽  
Fork Length ◽  
Age At Maturity ◽  
Natural Origin ◽  
Parent Stock ◽  
Stream Type

Chinook salmon (Oncorhynchus tshawytscha) spawning runs in Glenariffe Stream, New Zealand, exhibited significant changes in life history traits following supplementation releases of hatchery-reared juveniles. Total run strength did not change but the proportion of naturally produced fish declined to 34%. Attempts to separate spawners of natural and hatchery origin were unsuccessful, and 31-48% of natural spawners are now of hatchery origin. Hatchery males were smaller at age 2 and 3 than males of natural origin, and more often matured as jacks, producing an 86-mm decrease in mean fork length over 28 years. There was no change in length at age or age at maturity for female spawners. The proportion of jacks entering Glenariffe Stream each year was positively correlated with the proportion of jacks in the ensuing cohort. Most differences between fish of natural and hatchery origin were related to hatchery rearing practices, but the decline in age at maturity among naturally produced males appears to reflect traits inherited from parent stock of hatchery origin. Hatchery releases may also favour the survival of ocean-type fry over stream-type fry, possibly reversing a tendency for stream-type behaviour to evolve in response to the lack of estuaries on most New Zealand chinook salmon rivers.

scholarly journals Decoupling outmigration from marine survival indicates outsized influence of streamflow on cohort success for California’s Chinook salmon populations

2019 ◽  
Vol 76 (8) ◽  
pp. 1398-1410 ◽  
Author(s):  
Cyril J. Michel
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Primary Source ◽  
Environmental Drivers ◽  
Life Stages ◽  
Cohort Size ◽  
Seaward Migration ◽  
Productivity Indices ◽  
Marine Survival ◽  
Marine Productivity

Historically, marine survival estimates for salmon have been confounded with freshwater seaward migration (outmigration) survival. Telemetry studies have revealed low and variable survival during outmigration, suggesting marine mortality may not be the primary source of variability in cohort size as previously believed. Using a novel combination of tagging technologies, survival during these two life stages was decoupled over 5 years for Sacramento River Chinook salmon (Oncorhynchus tshawytscha). Outmigration survival ranged from 2.6% to 17%, and marine survival ranged from 4.2% to 22.8%. Influential environmental drivers in both life stages were also compared with smolt-to-adult ratios (SAR) for three Chinook salmon populations over 20 years. Streamflow during outmigration had higher correlation with SAR (r2 > 0.34) than two marine productivity indices (r2 < 0.08). The few SAR estimates that were poorly predicted by flow occurred during years with the lowest marine productivity, suggesting most interannual SAR fluctuations are explained by outmigration survival, but abnormally poor marine conditions also reduce SAR. The outsized influence of flow on SAR provides managers with a powerful mitigation tool in a watershed where flow is tightly regulated.

Life History of Juvenile Ocean-type Chinook Salmon (Oncorhynchus tshawytscha) in the Situk River, Alaska

1992 ◽  
Vol 49 (12) ◽  
pp. 2621-2629 ◽  
Author(s):  
S. W. Johnson ◽  
J. F. Thedinga ◽  
K. V. Koski
Keyword(s):  
Life History ◽  
Chinook Salmon ◽  
Habitat Preference ◽  
Oncorhynchus Tshawytscha ◽  
Fork Length ◽  
Main Stem ◽  
Seawater Tolerance ◽  
History Of ◽  
Two Phases ◽  
Stream Type

Distribution, abundance, habitat preference, migration and residence timing, seawater tolerance, and size were determined for juvenile ocean-type (age 0) chinook salmon (Oncorhynchus tshawytscha) in the Situk River, Alaska. Chinook primarily occupied main-stem habitats (channel edges in spring, pools and willow edges in summer). Peak chinook densities in the upper and lower main stem were 96 and 76 fish/100 m2, respectively. Chinook migrated downstream in two phases: a spring dispersal of emergent fry and a summer migration. Chinook marked in the upper river in late June and early July were recaptured 20 km downstream in the lower river in late July. Marked chinook resided in the lower river up to 34 d. Mean fork length of chinook in the lower river increased from 40 mm in May to 80 mm in early August. By late August, chinook had emigrated from the lower river at a size of approximately 80 mm. Fish this size were seawater tolerant and had the physical appearance of smolts. Ocean-type chinook in the Situk River are unique because in most Alaskan streams, chinook are stream-type (rear in freshwater at least 1 yr).

Sign in / Sign up

Export Citation Format

Share Document