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Publications

Filter Total Items: 1991

Comparison of mercury mass loading in streams to atmospheric deposition in watersheds of Western North America: Evidence for non-atmospheric mercury sources

Annual stream loads of mercury (Hg) and inputs of wet and dry atmospheric Hg deposition to the landscape were investigated in watersheds of the Western United States and the Canadian-Alaskan Arctic. Mercury concentration and discharge data from flow gauging stations were used to compute annual mass loads with regression models. Measured wet and modeled dry deposition were compared to annual stream
Authors
Joseph L. Domagalski, Michael S. Majewski, Charles N. Alpers, Chris S. Eckley, Collin A. Eagles-Smith, Liam N. Schenk, Susan Wherry

Thermal regimes, nonnative trout, and their influences on native Bull Trout in the Upper Klamath River Basin, Oregon

The occurrence of fish species may be strongly influenced by a stream’s thermal regime (magnitude, frequency, variation, and timing). For instance, magnitude and frequency provide information about sublethal temperatures, variability in temperature can affect behavioral thermoregulation and bioenergetics, and timing of thermal events may cue life history events, such as spawning and migration. We
Authors
Joseph R. Benjamin, Jeannie Heltzel, Jason B. Dunham, Michael Heck, Nolan P. Banish

Mercury and methylmercury in aquatic sediment across western North America

Large-scale assessments are valuable in identifying primary factors controlling total mercury (THg) and monomethyl mercury (MeHg) concentrations, and distribution in aquatic ecosystems. Bed sediment THg and MeHg concentrations were compiled for > 16,000 samples collected from aquatic habitats throughout the West between 1965 and 2013. The influence of aquatic feature type (canals, estuaries, lakes
Authors
Jacob Fleck, Mark C. Marvin-DiPasquale, Collin A. Eagles-Smith, Joshua T. Ackerman, Michelle A. Lutz, Michael T. Tate, Charles N. Alpers, Britt D. Hall, David P. Krabbenhoft, Chris S. Eckley

Channel-planform evolution in four rivers of Olympic National Park, Washington, U.S.A.: The roles of physical drivers and trophic cascades

Identifying the relative contributions of physical and ecological processes to channel evolution remains a substantial challenge in fluvial geomorphology. We use a 74-year aerial photographic record of the Hoh, Queets, Quinault, and Elwha Rivers, Olympic National Park, Washington, U.S.A., to investigate whether physical or trophic-cascade-driven ecological factors—excessive elk impacts after wolve
Authors
Amy E. East, Kurt J. Jenkins, Patricia J. Happe, Jennifer A. Bountry, Timothy J. Beechie, Mark C. Mastin, Joel B. Sankey, Timothy J. Randle

Factors influencing movement of two migratory fishes within the tailrace of a large neotropical dam and their implications for hydropower impacts

Fish attempting to move upstream through hydroelectric dams can be trapped and killed in turbines. Understanding fish movement patterns can provide useful insights for how to manage dam operations to minimize fish kill in turbines. We evaluated the movements of two migratory fish (Curimba-Prochilodus argenteus and Mandi-Pimelodus maculatus) using acoustic telemetry in the tailrace of Três Marias D
Authors
F. M. Suzuki, Jason B. Dunham, L. G. M. Silva, C. B. M. Alves, P.S. Pompeu

Golden Eagle fatalities and the continental-scale consequences of local wind-energy generation

Renewable energy production is expanding rapidly despite mostly unknown environmental effects on wildlife and habitats. We used genetic and stable isotope data collected from Golden Eagles (Aquila chrysaetos) killed at the Altamont Pass Wind Resource Area (APWRA) in California in demographic models to test hypotheses about the geographic extent and demographic consequences of fatalities caused by
Authors
Todd E. Katzner, David M. Nelson, Melissa A. Braham, Jacqueline M. Doyle, Nadia B. Fernandez, Adam E. Duerr, Peter H. Bloom, Matthew C. Fitzpatrick, Tricia A. Miller, Renee C. E. Culver, Loan Braswell, J. Andrew DeWoody

Ancient DNA reveals substantial genetic diversity in the California Condor (Gymnogyps californianus) prior to a population bottleneck

Critically endangered species that have undergone severe population bottlenecks often have little remaining genetic variation, making it difficult to reconstruct population histories to apply in reintroduction and recovery strategies. By using ancient DNA techniques, it is possible to combine genetic evidence from the historical population with contemporary samples to provide a more complete pictu
Authors
Jesse D'Elia, Susan M. Haig, Thomas D. Mullins, Mark P. Miller

Genetic diversity and population structure in the threatened Oregon silverspot butterfly (Speyeria zerene hippolyta) in western Oregon and northwestern California— Implications for future translocations and the establishment of new populations

Executive SummaryWe present results of population genetic analyses performed on Oregon silverspot butterflies (OSB; Speyeria zerene hippolyta) in western Oregon and northwestern California. We used DNA sequences from a 561-base pair region of the mitochondrial cytochrome oxidase subunit I (COI) gene for a dataset comprised of 112 S. z. hippolyta and 32 S. z. gloriosa individuals collected at 9 loc
Authors
Mark P. Miller, Thomas D. Mullins, Susan M. Haig

Moving from awareness to action: Advancing climate change vulnerability assessments and adaptation planning for Idaho and Montana National Forests

The rugged landscapes of northern Idaho and western Montana support biodiverse ecosystems, and provide a variety of natural resources and services for human communities. However, the benefits provided by these ecosystems may be at risk as changing climate magnifies existing stressors and allows new stressors to emerge. Preparation for and response to these potential changes can be most effectively
Authors
Jessi Kershner, Andrea Woodward, Alicia Torregrosa

Reservoirs and water management influence fish mercury concentrations in the western United States and Canada

Anthropogenic manipulation of aquatic habitats can profoundly alter mercury (Hg) cycling and bioaccumulation. The impoundment of fluvial systems is among the most common habitat manipulations and is known to increase fish Hg concentrations immediately following impoundment. However, it is not well understood how Hg concentrations differ between reservoirs and lakes at large spatial and temporal sc
Authors
James J. Willacker, Collin A. Eagles-Smith, Michelle A. Lutz, Michael T. Tate, Jesse M. Lepak, Joshua T. Ackerman

Decomposition drives convergence of forest litter nutrient stoichiometry following phosphorus addition

Background and aims Nutrient levels in decomposing detritus and soil can influence decomposition rates and detrital nutrient dynamics in differing ways among various detrital components of forests. We assessed whether increased phosphorus (P) levels in litter and soil influenced decomposition rates and litter nutrient dynamics of foliage, fine roots, and twigs in nitrogen (N)-rich Douglas-fir (Ps
Authors
Tiff L. van Huysen, Steven Perakis, Mark E. Harmon