Yakima River Species Interactions Studies, Annual Report 2000.

Pearsons, Todd N.

doi:10.2172/789904

Cited by 2 publications

(1 citation statement)

References 21 publications

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“…Offchannel habitats decreased by 38% under low-flow conditions, with the largest losses occurring in connected habitats (decrease in 2.6 ha). Off-channel habitats such as backwater channels, springbrooks and floodplain pools are critical to juvenile salmonids (Pearsons et al, 1994;Morgan and Hinojosa, 1996). The relatively slack water conditions and greater abundance of bank habitat in these areas provide protection from predators and serve as important rearing habitat for salmonids (Snyder and Stanford, 2000).…”

Section: See Text For Explanations Of Depth and Velocity Abbreviationsmentioning

confidence: 99%

Application of airborne multispectral digital imagery to quantify riverine habitats at different base flows

Whited

Stanford

Kimball

2002

River Research & Apps

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We employed an integrated system of airborne remote sensing and ground surveys for regional mapping of instream habitats under variable flows over a 70 km section of the Lower Yakima River in southern Washington, USA. Airborne multispectral digital imagery was obtained in conjunction with field survey measurements and used to quantify the spatial extent, condition and temporal changes of selected river habitat characteristics under two different flows (14 and 28 m 3 s −1 ). Under each flow, geomorphic measures were quantified (e.g. channel complexity, number and size of habitats). Water depth and velocity were also classified for instream habitats, and temperature and turbidity were recorded. Remote sensing classification accuracies for islands, exposed rocks and water surfaces were greater than 99%, while more detailed depth/flow classifications were less accurate (68% and 72%, for the high and low flows, respectively). While high turbidity (>4 Nephelometric Turbidity Units (NTU)), shadows and bidirectional reflectance factor reduced classification accuracies, the overall effect of these factors was minimal. Under the low-flow situation, off-channel habitats were less abundant, more isolated and had shallower depths and warmer temperatures. Our analysis suggests that airborne multispectral imagery, coupled with appropriate ground truth data, can be a viable method for regional mapping of diverse riverine habitats under variable flows. We concluded from this analysis that the higher flow situation provided substantially better habitat than currently exists in the Lower Yakima River.

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Section: See Text For Explanations Of Depth and Velocity Abbreviationsmentioning

confidence: 99%

Application of airborne multispectral digital imagery to quantify riverine habitats at different base flows

Whited

Stanford

Kimball

2002

River Research & Apps

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Impacts of Early Stages of Salmon Supplementation and Reintroduction Programs on Three Trout Species

Pearsons

Temple

2007

N American J Fish Manag

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Salmon supplementation and reintroduction programs have the potential to negatively impact other valued fish taxa that are not the targets of enhancement (nontarget taxa [NTT]). Impacts of the supplementation of spring Chinook salmon Oncorhynchus tshawytscha and the reintroduction of coho salmon O. kisutch (hereafter supplementation) on populations of rainbow trout O. mykiss, steelhead (anadromous rainbow trout), cutthroat trout O. clarkii, and bull trout Salvelinus confluentus were evaluated after 5 years of stocking approximately 1 million yearling smolts in the upper Yakima River basin between 1999 and 2003. Field methods included backpack electrofishing and snorkeling in tributaries and drift-boat electrofishing in the main stem. We used three sequential steps in our evaluation: (1) we determined whether spatial overlap occurred between supplemented fish and NTT; (2) if overlap occurred, we determined whether a change in abundance, size, or biomass occurred during supplementation; and (3) if a change occurred, we determined whether the change could be reasonably attributed to supplementation. Salmon rarely overlapped cutthroat trout or bull trout in tributaries, but some overlap with cutthroat trout occurred in relatively high elevations of the main stem and considerable overlap with rainbow trout occurred in tributaries and the main stem. Except in steelhead, the lower 90% confidence limit (CL) of abundance, size, and biomass was above the containment objective for NTT that overlapped significantly with salmon. We used rainbow trout as an analog for steelhead. The lower 90% CL of rainbow trout abundance and size in tributaries and the main stem and biomass in the main stem was below the containment objective for steelhead. However, comparisons of rainbow trout abundance, size, and biomass between tributaries and main-stem sections with relatively high and low salmon abundances revealed that the change was probably not the result of supplementation (before-after controlimpact paired site analysis: P . 0.05). Our data indicate that early stages of salmon supplementation have not impacted trout species in the upper Yakima River basin beyond predetermined containment objectives.

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Yakima River Species Interactions Studies, Annual Report 2000.

Abstract: Mean lengths of hatchery fall chinook released and minimum length of chinook in gut considered hatchery origin (>99% of releases were equal to or greater than this length) in

Cited by 2 publications

References 21 publications

Application of airborne multispectral digital imagery to quantify riverine habitats at different base flows

Application of airborne multispectral digital imagery to quantify riverine habitats at different base flows

Impacts of Early Stages of Salmon Supplementation and Reintroduction Programs on Three Trout Species

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