Ryan L. Fosness

Substrate and flow characteristics associated with White Sturgeon recruitment in the Columbia River Basin

A study was conducted to identify habitat characteristics associated with age 0+ White Sturgeon (Acipenser transmontanus Richardson, 1863) recruitment in three reaches of the Columbia River Basin: Skamania reach (consistent recruitment), John Day reach (intermittent/inconsistent recruitment), and Kootenai reach (no recruitment). Our modeling approach involved numerous steps. First, we collected information about substrate, embeddedness, and hydrodynamics in each reach. Second, we developed a set of spatially explicit predictor variables. Third, we built two habitat (probability) models with Skamania reach training data where White Sturgeon recruitment was consistent. Fourth, we created spawning maps of each reach by populating the habitat models with in-reach physical metrics (substrate, embeddedness, and hydrodynamics). Fifth, we examined model accuracy by overlaying spawning locations in Skamania and Kootenai reaches with habitat predictions obtained from probability models. Sixth, we simulated how predicted habitat changed in each reach after manipulating physical conditions to more closely match Skamania reach. Model verification confirmed White Sturgeon generally spawned in locations with higher model probabilities in Skamania and Kootenai reaches, indicating the utility of extrapolating the models. Model simulations revealed significant gains in White Sturgeon habitat in all reaches when spring flow increased, gravel/cobble composition increased, or embeddedness decreased. The habitat models appear well suited to assist managers when identifying reach-specific factors limiting White Sturgeon recruitment in the Columbia River Basin or throughout its range.

Estimating peak-flow frequency statistics for selected gaged and ungaged sites in naturally flowing streams and rivers in Idaho

..........................................................................................................................................................

Sediment Transport in the Lower Snake and Clearwater River Basins, Idaho and Washington, 2008-11

This report documents findings based on sediment data collected by the United States Geological Survey (USGS) in the lower Snake and Clearwater River Basins from 2008 through 2011. The purpose of this report is to provide information that improves the scientific understanding of the processes affecting sediment generation in the lower Snake and Clearwater River Basins and river hydrodynamics controlling sediment transport, deposition, and retention in Lower Granite Reservoir and downstream in the Snake River. The report provides suspended sediment and bedload data to (1) identify the dominant subbasins contributing sediment to Lower Granite Reservoir, (2) evaluate sediment transport in the Clearwater and lower Snake River Basins, and (3) quantify transport of sediment to Lower Granite Reservoir. Additionally, data collected using acoustic Doppler velocity meters (ADVMs) is summarized and compared with conventionally acquired sediment data to evaluate the efficacy of estimating suspended‑sediment concentration (SSC) continuously by means of acoustic surrogates.