Pacific Salmon at the Crossroads: Stocks at Risk from California, Oregon, Idaho, and Washington

Nehlsen, Willa; Williams, Jack E.; Lichatowich, James A.

doi:10.1577/1548-8446(1991)016<0004:psatcs>2.0.co;2

Cited by 839 publications

(623 citation statements)

References 16 publications

Supporting

Mentioning

618

Contrasting

Unclassified

Order By: Relevance

“…A watershed-based approach encompasses almost all of the critical components of the freshwater ecosystem that supports native salmonid species. It has been widely recognized that restoration and conservation measures developed in a watershed-ecosystem context are more likely to be successful (Nehlsen et al 1991;Reeves et al 1991Reeves et al , 1995Naiman et al 1992Naiman et al , 1995Doppelt et al 1993;FEMAT 1993;Lichatowich et al 1995;Beechie et al 1996Frissell and Bayles 1996;Stouder et al 1997;Williams et al 1997;Beechie and Bolton 1999;Pess et al 1999Pess et al , 2002Pess et al , 2003.…”

Section: Project Approachmentioning

confidence: 99%

Grays River Watershed and Biological Assessment, 2006 Final Report.

May¹,

Geist

2007

View full text Add to dashboard Cite

SummaryThe Grays River Watershed and Biological Assessment was funded to address degradation and loss of spawning habitat for chum salmon (Onchorhynchus keta) and fall Chinook salmon (Onchoryhnchus tshawytscha). In 1999, the National Marine Fisheries Service listed lower Columbia River chum salmon as a threatened Evolutionarily Significant Unit (ESU) under the Endangered Species Act of 1973 (ESA). The Grays River watershed is one of two remaining significant chum salmon spawning locations in this ESU. Runs of Grays River chum and Chinook salmon have declined significantly during the past century, largely because of damage to spawning habitat associated with timber harvest and agriculture in the watershed. In addition, approximately 20-25% of the then-remaining chum salmon spawning habitat was lost during a 1999 channel avulsion that destroyed an important artificial spawning channel operated by the Washington Department of Fish and Wildlife (WDFW). Although the lack of stable, high-quality spawning habitat is considered the primary physical limitation on Grays River chum salmon production today, few data are available to guide watershed management and channel restoration activities. The objectives of the Grays River Watershed and Biological Assessment project were to 1) perform a comprehensive watershed and biological analysis, including hydrologic, geomorphic, and ecological assessments; 2) develop a prioritized list of actions that protect and restore critical chum and Chinook salmon spawning habitat in the Grays River based on comprehensive geomorphic, hydrologic, and stream channel assessments; and 3) gain a better understanding of chum and Chinook salmon habitat requirements and survival within the lower Columbia River and the Grays River.The watershed-based approach to river ecosystem restoration relies on a conceptual framework that describes general relationships between natural landscape characteristics, watershed-scale habitat-forming processes, aquatic habitat conditions, and biological integrity. In addition, human land-use impacts are factored into the conceptual model because they can alter habitat quality and can disrupt natural habitatforming processes. In this model (Figure S.1), aquatic habitat-both instream and riparian-is viewed as the link between watershed conditions and biologic responses. Based on this conceptual model, assessment of habitat loss and the resultant declines in salmonid populations can be conducted by relating current and historical (e.g., natural) habitat conditions to salmonid utilization, diversity, and abundance. In addition, assessing disrupted ecosystem functions and processes within the watershed can aid in identifying the causes of habitat change and the associated decline in biological integrity. In this same way, restoration, enhancement, and conservation projects can be identified and prioritized.A watershed assessment is primarily a landscape-scale evaluation of current watershed conditions and the associated hydrogeomorphic riverine processes. The watershed ass...

show abstract

Section: Project Approachmentioning

confidence: 99%

Grays River Watershed and Biological Assessment, 2006 Final Report.

May¹,

Geist

2007

View full text Add to dashboard Cite

show abstract

“…The abundance of most naturally spawning Pacific salmon species has been substantially below historical levels in recent years (Nehlsen et al 1991, McClure et al 2003. The cause of these low levels has been attributed to a multitude of impacts such as poor forestry and agriculture practices, overgrazing, over-fishing, industrialization, urbanization, dams, hatcheries, variation in ocean conditions, and global climate change (Magnuson 1996).…”

Section: Introductionmentioning

confidence: 99%

Lopsided fish in the Snake River Basin — fluctuating asymmetry as a way of assessing impact of hatchery supplementation in chinook salmon, Oncorhynchus tshawytscha

Johnson

Neely

Waples

2004

Genetics of Subpolar Fish and Invertebrates

View full text Add to dashboard Cite

SynopsisThe use of developmental instability (an individual's failure to produce a consistent phenotype in a given environment) was evaluated to detect the effects of outplanting hatchery fish on wild salmon. Juvenile chinook salmon were collected in 1989, 1990, and 1991 from five drainages in the Snake River Basin. In each drainage we attempted to collect fish from streams with no hatchery supplementation (wild), naturally spawning fish from streams with hatchery supplementation (natural), and fish collected at a hatchery. Forty fish were collected per site and the number of elements in bilateral characters were counted on each side of the fish. Indices of fluctuating asymmetry (FA), a measure of minor, random deviations in perfect symmetry of bilateral counts, were calculated as an estimator of developmental instability. Analysis of character counts from seven paired characters revealed normal distributions. Only one of the characters displayed counts that were statistically larger on one side than the other, indicating that directional asymmetry (DA) or antisymmetry was not a major bias of FA. However, the means of all individual characters revealed a non-statistically significant left side bias. We analyzed our data using two indices of FA (FA1 and FA5) with different levels of sensitivity to DA. Differences in both FA indices were found among years, with collection sites in 1989 having significantly larger FA values than in 1991 (FA p < 0.01). Levels of FA among wild, natural, and hatchery fish were comparatively small (FA1 p = 0.17). This suggests developmental conditions were different in the first year of the study than in the last. The cause of these differences may be linked to either genetic or environmental variation or to gene-environment interactions, but the general population declines of salmon that occurred during this time obscures more specific conclusions.

show abstract

“…Historically, chum salmon (Oncorhynchus keta) had the widest distribution of all Pacific salmon species, comprising up to 50% of annual biomass of the seven species and may have spawned as far up the Columbia River drainage as the Walla Walla River (Nehlsen et al 1991). Although there is no historic run size data for Columbia River chum salmon, the maximum historical commercial fishery landings were approximately 700,000 fish in 1928 (Columbia Basin Fish and Wildlife Authority (CBFWA) 1991).…”

Section: Introductionmentioning

confidence: 99%

Evaluate Factors Limiting Columbia River Gorge Chum Salmon Populations; FY 2002 Annual Report.

Uusitalo¹

2003

View full text Add to dashboard Cite

Pacific Salmon at the Crossroads: Stocks at Risk from California, Oregon, Idaho, and Washington

Cited by 839 publications

References 16 publications

Grays River Watershed and Biological Assessment, 2006 Final Report.

Grays River Watershed and Biological Assessment, 2006 Final Report.

Lopsided fish in the Snake River Basin — fluctuating asymmetry as a way of assessing impact of hatchery supplementation in chinook salmon, Oncorhynchus tshawytscha

Evaluate Factors Limiting Columbia River Gorge Chum Salmon Populations; FY 2002 Annual Report.

Contact Info

Product

Resources

About