Declining patterns of Pacific Northwest steelhead trout (<i>Oncorhynchus mykiss</i>) adult abundance and smolt survival in the ocean

Kendall, Neala W.; Marston, Gary Wayne; Klungle, Matthew

doi:10.1139/cjfas-2016-0486

Cited by 51 publications

(56 citation statements)

References 77 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Kendall et al. () reported that ocean entry conditions are important for steelhead smolt‐to‐adult survival. For example, early ocean growth affects the susceptibility of steelhead to ocean predation (Friedland et al.…”

Section: Discussionmentioning

confidence: 99%

A Natural‐Origin Steelhead Population's Response to Exclusion of Hatchery Fish

et al. 2019

View full text Add to dashboard Cite

It is asserted that reduction or elimination of hatchery stocking will increase natural‐origin salmon Oncorhynchus spp. and steelhead O. mykiss production. We conducted an analysis of steelhead population census data (1958–2017) to determine whether elimination of summer steelhead stocking in the upper Clackamas River in 1998 increased the productivity of natural‐origin winter steelhead. A Bayesian state–space stock–recruitment model was fitted to the adult steelhead data set, and productivity was estimated as a function of hatchery‐origin spawner abundance as well as other environmental factors. When used as a predictive variable in our model, the abundance of hatchery summer steelhead spawners (1972–2001) did not have a negative effect on winter steelhead recruitment. However, spill at North Fork Dam (the gateway to the upper Clackamas River basin) and the Pacific Decadal Oscillation (an index of ocean conditions) were both negatively associated with winter steelhead recruitment. Moreover, winter steelhead abundance in the upper Clackamas River basin failed to rebound to abundances observed in years prior to the hatchery program, and fluctuations in winter steelhead abundance were correlated with those of other regional winter steelhead stocks. Our assessment underscores the need for studies that (1) directly quantify the effects of hatchery fish on the production of natural‐origin salmon and steelhead, (2) empirically test published theories about mechanisms of hatchery fish impacts on natural‐origin populations, and (3) document population responses to major changes in hatchery programs.

show abstract

Section: Discussionmentioning

confidence: 99%

A Natural‐Origin Steelhead Population's Response to Exclusion of Hatchery Fish

et al. 2019

View full text Add to dashboard Cite

show abstract

“…Endangered Species Act for Puget Sound populations (Ford et al., ; Ruckelshaus et al., ) and efforts to assess and implement recovery measures for Strait of Georgia populations. Declines in the marine survival of Puget Sound coho salmon (Zimmerman et al., ) and Steelhead trout (Kendall, Marston, & Klungle, In press), Strait of Georgia Chinook and coho salmon (Preikshot et al., ), and concurrent changes in pelagic community structure (Greene, Kuehne, Rice, Fresh, & Penttila, ) raise the possibility that environmental change unique to the Salish Sea ecosystem has contributed to salmon declines. Accordingly, one might expect that marine survival of Salish Sea salmon populations is lower than, and potentially asynchronous with, marine survival of populations outside of the Salish Sea.…”

Section: Introductionmentioning

confidence: 99%

Salish Sea Chinook salmon exhibit weaker coherence in early marine survival trends than coastal populations

Ruff

Kemp

Kendall

et al. 2017

Fisheries Oceanography

Self Cite

View full text Add to dashboard Cite

Identifying factors that influence anadromous Pacific salmon (Oncorhynchus spp.) population dynamics is complicated by their diverse life histories and large geographic range. Over the last several decades, Chinook salmon (O. tshawytscha) populations from coastal areas and the Salish Sea have exhibited substantial variability in abundance. In some cases, populations within the Salish Sea have experienced persistent declines that have not rebounded. We analyzed a time series of early marine survival from 36 hatchery Chinook salmon populations spanning ocean entry years 1980–2008 to quantify spatial and temporal coherence in survival. Overall, we observed higher inter‐population variability in survival for Salish Sea populations than non‐Salish Sea populations. Annual survival patterns of Salish Sea populations covaried over smaller spatial scales and exhibited less synchrony among proximate populations relative to non‐Salish Sea populations. These results were supported by multivariate autoregressive state space (MARSS) models which predominantly identified region‐scale differences in survival trends between northern coastal, southern coastal, Strait of Georgia, and Puget Sound population groupings. Furthermore, Dynamic Factor Analysis (DFA) of regional survival trends showed that survival of southern coastal populations was associated with the North Pacific Gyre Oscillation, a large‐scale ocean circulation pattern, whereas survival of Salish Sea populations was not. In summary, this study demonstrates that survival patterns in Chinook salmon are likely determined by a complex hierarchy of processes operating across a broad range in spatial and temporal scales, presenting challenges to the management of mixed‐stock fisheries.

show abstract

“…While causes of contrasting patterns of salmon body size and abundance are not completely understood, the studies cited above and others discussed possible links to environmental conditions, management practices and density dependence (Claiborne et al, in press; Debertin, Irvine, Holt, Oka, & Trudel, ). Together, these and numerous other studies (Kendall, Marston, & Klungle, ; Kilduff, Botsford, & Teo, ; Ohlberger, Ward, Schindler, & Lewis, ; Zimmerman et al, ) highlight the importance of multidecadal time series documenting basic salmon demographic data across multiple populations for management and conservation purposes.…”

Section: Introductionmentioning

confidence: 60%

“…This is not to say that marine conditions are not important in driving adult abundance and survival or productivity trends for Pacific salmon and steelhead. In fact, Kendall et al () found similar trends for steelhead abundance in the Pacific Northwest and marine survival rates. Freshwater and marine conditions are often impacted by the same large‐scale climate drivers (Di Lorenzo et al, ; Mantua, Hare, Zhang, Wallace, & Francis, ).…”

Section: Discussionmentioning

confidence: 83%

“…The first documentation of declining abundance of Pacific salmonids occurred following European settlement in the Pacific Northwest (Lichatowich, ). Since that time, a variety of factors including overharvest, rapid habitat alteration and, more recently documented, lower marine survival rates (Kendall et al, ; Ruff et al, ; Zimmerman et al, ) have contributed to the dramatic declines of naturally produced Chinook and coho salmon and steelhead in Puget Sound. The combined narrative of the “4‐H's” of human impacts on salmon and steelhead abundance and survival have helped shape recovery plans (e.g.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Changing salmon: An analysis of body mass, abundance, survival, and productivity trends across 45 years in Puget Sound

2019

Self Cite

View full text Add to dashboard Cite

Pacific salmon and trout (Oncorhynchus spp., Salmonidae) of the Puget Sound region of Washington State, USA, have experienced recent and longer‐term (multidecadal) variability in abundance while supporting robust fisheries. As part of the post‐season salmon management process, population‐specific estimates of total adult abundance to Puget Sound (Strait of Juan de Fuca) for pink (O. gorbuscha), chum (O. keta), coho (O. kisutch), sockeye (O. nerka), and Chinook (O. tshawytscha) salmon and steelhead trout (O. mykiss) are calculated annually. We compiled annual estimates of body mass, abundance and survival of hatchery‐ and naturally produced salmon from 1970 to 2015 to compare spatial and temporal patterns across species. Average weights of adult salmon and steelhead returning to Puget Sound, with the exception of coho salmon, have decreased since the 1970s. Temporal trends in abundance, survival and productivity varied by species and origin (hatchery vs. naturally produced). Generally, abundance and survival rates of natural‐origin species decreased whereas those of hatchery‐produced species did not, which is in contrast with other studies' general conclusions of decreasing survival among Puget Sound salmonids. Species diversity has decreased in recent years, with salmonids that rely on a short freshwater rearing phase in the natural environment (hatchery‐produced fish and naturally produced pink and chum) representing >90% of total returns in most years. This new information reveals patterns of body size, abundance, survival and productivity across species, life history and rearing type over the past 45 years and, in doing so, demonstrates the strength in multidecadal, multifactor time series to critically evaluate salmonid species.

show abstract

Declining patterns of Pacific Northwest steelhead trout (Oncorhynchus mykiss) adult abundance and smolt survival in the ocean

Cited by 51 publications

References 77 publications

A Natural‐Origin Steelhead Population's Response to Exclusion of Hatchery Fish

A Natural‐Origin Steelhead Population's Response to Exclusion of Hatchery Fish

Salish Sea Chinook salmon exhibit weaker coherence in early marine survival trends than coastal populations

Changing salmon: An analysis of body mass, abundance, survival, and productivity trends across 45 years in Puget Sound

Contact Info

Product

Resources

About