Publications

Restoration of salmon populations in the upper Lewis River Basin, Washington, depends on a trap-and-haul program owing to the Lewis River Hydroelectric Project (hereinafter referred to as “Project”) operated by PacifiCorp and Cowlitz Public Utilities District (hereinafter referred to as “Utilities”), which has been a barrier to salmon passage since the 1930s. Thus, sustaining the...

Seismic design criteria for new buildings in the United States have historically focused on life safety performance objectives through minimizing the potential for structural collapse. Development of design criteria to meet this performance objective has evolved over time, leading to the current, risk-targeted maximum considered earthquake (MCER) design basis. Corresponding MCER seismic...

The planning, permitting, and design of stormwater-management projects require estimates of the depths of extreme precipitation for current and future events with specified durations and return periods. In this project, precipitation data from six downscaled climate datasets were used to determine changes in precipitation depth-duration-frequency curves from the period 1966–2005 to the...

Due to the importance of sufficient diets, conservation practices for endangered bats often involve protection and restoration of foraging resources. For insectivorous (or arthropodivorous) bats, detailed knowledge of prey consumption can inform effective management. In this study, we used metabarcoding techniques to investigate the diet of Lasiurus semotus, a primarily insectivorous...

The survival of juvenile Chinook Salmon (Oncorhynchus tshawytscha) depends on the specific migration route they take through the Sacramento–San Joaquin Delta. Factors such as flow magnitude, flow direction, and distribution of fish across the channel significantly affect the likelihood of their entering routes with lower survival probabilities. Management strategies to mitigate the entry...

Green sulfur bacteria biomarkers that indicate euxinia within the photic zone sometimes co-occur with evidence of contradictory depositional redox conditions, such as oxygen-requiring fossils or bioturbation. Intermittent euxinia may explain this apparent contradiction, and recent studies of modern environments show that green sulfur bacteria dwell in transiently euxinic settings. As a...

Chronic wasting disease (CWD) is a fatal neurodegenerative disease caused by infectious prions affecting wild and captive cervids. Transmission occurs directly between hosts or indirectly through contact with prion-contaminated environments. Soils, particularly those rich in clay, are hypothesized to enhance prion stability, retention, and bioavailability. Accurate detection of prions is...

Objective The objective of this study was to evaluate statistical evidence for relationships between flow event characteristics and annelid host distribution, an important and necessary step toward providing and justifying management actions. Declines in Klamath River salmon have been attributed to infection and disease that are caused by the myxozoan parasite Ceratonova shasta. Flow...

This study investigates the influence of soil relative density on strike-slip surface fault rupture manifestations using three-dimensional numerical simulations performed with the discrete element method (DEM). The simulations capture the formation of distinctive fault strands within complex flower structures using tens of millions of grains. The tendency for dense soils to localize...

Managing species in an uncertain future is a reality for natural resource decision makers. Climate change is expected to exacerbate threats such as habitat loss and disease, and cause phenological mismatches, but there is uncertainty in the magnitude of these effects. Amphibians are among the most threatened taxa on earth, and most species in North America are uniquely tied to water...

Parasites can suppress host populations through parasite-induced mortality. However, the negative effects of parasites are difficult to measure in wild populations and we have few tools for quantifying the magnitude of parasite-induced mortality. This is especially true for many ‘misfit’ parasites that do not fit into standard classifications (e.g. fungal-like parasites and myxozoans)...

Distinguishing stream metal loading caused by mine features from that caused by natural background sources remains challenging, yet this distinction is essential for making effective remedial decisions at many legacy mine sites. We combine a stream tracer injection and synoptic sampling study with data from shallow near-stream groundwater wells to estimate left-bank versus right-bank...