Articles
Science Quality and Integrity
The USGS provides unbiased, objective, and impartial scientific information upon which our audiences, including resource managers, planners, and other entities, rely.
The USGS provides unbiased, objective, and impartial scientific information upon which our audiences, including resource managers, planners, and other entities, rely.
Browse more than 65,000 articles authored by our scientists over the past 100+ year history of the USGS and refine search by topic, location, year, and advanced search.
Filter Total Items: 77762
Seasonal and hydrologic variation influences habitat and functional structure of stream fish assemblages Seasonal and hydrologic variation influences habitat and functional structure of stream fish assemblages
Introduction: Hydrologic variability is a key driver of ecological structure in lotic systems, shaping habitat conditions, taxonomic diversity, and the functional traits that mediate species’ persistence and performance (e.g., reproductive success). While many studies examine taxonomic responses to variation in flows, few evaluate how spatiotemporal hydrologic variation influences the...
Authors
Joshua D. Tevin, Daniel D. Magoulick
Estimating discharge from undular hydraulic jumps: Feasibility assessment based on flume experiments Estimating discharge from undular hydraulic jumps: Feasibility assessment based on flume experiments
Rapids are common in steep rivers, often forming where flow transitions from supercritical (Froude number, Fr > 1) to subcritical (Fr
Authors
Daniel C. White, Elowyn Yager, Carl J. Legleiter, Gordon Grant, Laura A. Hempel, Christina M. Leonard, Katherine Adler, Merritt Elizabeth Harlan, Becky Fasth
Development and assessment of fluorescent-dyed, preserved invasive grass carp (Ctenopharyngodon idella) eggs as surrogates for live eggs in transport and dispersal control experiments Development and assessment of fluorescent-dyed, preserved invasive grass carp (Ctenopharyngodon idella) eggs as surrogates for live eggs in transport and dispersal control experiments
Invasive species such as grass carp (Ctenopharyngodon idella) pose substantial ecological threats to North American freshwater ecosystems. Understanding their early life stage behavior is critical for management efforts. From spawning to hatching, invasive carp eggs must remain suspended in the water column while drifting downstream for the best chance of survival. This highly vulnerable...
Authors
Henry F. Doyle, Benjamin H. Stahlschmidt, Anne Marie Herndon, Vindhyawasini Prasad, Amy E. George, Jesse Robert Fischer, P. Ryan Jackson, Cory D. Suski, Rafael O. Tinoco
Satellite time series analysis to quantify changing climax ciénegas using a state and transition model approach Satellite time series analysis to quantify changing climax ciénegas using a state and transition model approach
Ciénegas are rare wetlands in arid landscapes of the North American Southwest, historically providing critical ecological and hydrological functions but increasingly threatened by changing climate and land use pressures. This study quantifies changes in ciénega condition and floodplain dynamics using a state-and-transition model (STM) informed by expert knowledge and remote sensing. Key...
Authors
Laura M. Norman, Roy E. Petrakis, Natalie R. Wilson, Barry R. Middleton, Miguel L. Villarreal, Michael Pollock, Thomas A. Minckley, Dean Hendrickson
A framework for integrating spatiotemporal deep learning methods with landsat for annual land cover and impervious surface mapping A framework for integrating spatiotemporal deep learning methods with landsat for annual land cover and impervious surface mapping
Land cover information is essential for understanding Earth’s surface dynamics and how vegetation, water, soil, climate, and terrain interact. The National Land Cover Database (NLCD) has been the authoritative source for consistent U.S. land cover mapping. To extend NLCD’s temporal resolution and reduce production latency, we developed the Land Cover Artificial Mapping System (LCAMS)—a...
Authors
Rylie Fleckenstein, Danika Fay Wellington, Suming Jin, Heather J. Tollerud, Jesslyn F. Brown, Jon Dewitz, Neal J. Pastick, Christopher P. Barber, Austin O'Brien, Mark Spanier
Stochastic within-host dynamics and climate-sensitive traits generate predictable patterns of variation in disease outcomes Stochastic within-host dynamics and climate-sensitive traits generate predictable patterns of variation in disease outcomes
Understanding how climatic variables impact host-pathogen relationships in temperature-sensitive ectothermic host organisms is crucial under global change. Few studies have explored how temperature gradients generate inter-individual variation in epidemiological traits like host susceptibility or pathogen replication. Here, we develop a mathematical model to explore a novel hypothesis...
Authors
Andrew Carlino, Malina Mariko Loeher, David James Páez, Paul Hershberger, Nathan Wolf, Joseph R. Mihaljevic
Fragmentation as a population rate-changer: A field experiment Fragmentation as a population rate-changer: A field experiment
Experimental and observational studies of effects of fragmentation on biodiversity and population dynamics have produced mixed results, with some reviews concluding strong evidence of negative effects and others concluding small positive effects. In addition, many factors (e.g., interspecific interactions, edge effects, nutrient cycling) have been identified as potential explanations...
Authors
James D. Nichols, James E. Hines, Robert L. Hinz, Janet Hinz
Who needs closure? Estimating abundance with a Markovian availability model for geographically open removal sampling Who needs closure? Estimating abundance with a Markovian availability model for geographically open removal sampling
Removal sampling is an important method for estimating abundance, but nearly all removal models assume closure during sampling. Yet, closure may be difficult to assume, evaluate, or enforce in many settings. To address situations where populations are geographically open between each removal sample, we incorporated a Markovian availability process into an N-mixture model framework. This...
Authors
Russell W. Perry, Adam C. Pope, A. Noble Hendrix, Joseph E. Kirsch, Bryan G. Matthias, Michael J. Dodrill
The impacts of co-circulating pathogens in Pacific herring depend on interactions between viral life-cycle traits and transmission parameters, highlighting interdependencies between pathogen epizootics The impacts of co-circulating pathogens in Pacific herring depend on interactions between viral life-cycle traits and transmission parameters, highlighting interdependencies between pathogen epizootics
The average host susceptibility decreases as the epizootic progresses because easily infected hosts are first removed from the population. While host susceptibility is pathogen-specific, it is likely that host susceptibility is correlated between different pathogens, so that co-circulating pathogens may have reciprocal impacts on their epidemics. However, despite well-documented examples...
Authors
David James Páez, Courtney Ann Grady, Jacob L. Gregg, William N. Batts, Shayla Ferreiro-Luce, V. L. Herron, Malina Mariko Loeher, Sarah Williamson, Paul Hershberger
Comparison of nonlethal techniques as indicators of lipid content in Lake Whitefish Comparison of nonlethal techniques as indicators of lipid content in Lake Whitefish
Objective Energetic reserves are important indicators of the relative health of fish and fish populations. Body condition indices that relate fish weight to length are commonly used as quick, noninvasive methods for approximating lipid content and condition. A microwave meter (i.e., fat meter or energy meter) is a noninvasive method found to be more accurate in some species. The...
Authors
Tyler Reid Funnell, Jenus Shrestha, Rachel R. Leads, Christopher M. Holbrook, Koji Sano, Cheryl A. Murphy
Region-specific understanding of virus transmission to support salmonid health at hatcheries in three regions of the Pacific Northwest, North America Region-specific understanding of virus transmission to support salmonid health at hatcheries in three regions of the Pacific Northwest, North America
Juvenile salmonid mortality due to infectious haematopoietic necrosis virus (IHNV) can be a major burden on fish hatcheries. We consider possible IHNV transmission routes and specialist–generalist patterns across three regions in the Pacific Northwest of North America: Coastal Washington and Oregon (CWO), Lower Columbia River Basin (LCRB) and Snake River Basin (SRB) to obtain multi...
Authors
Jeffrey P. Mattheiss, Rachel B. Breyta, Gael Kurath, Shannon L. LaDeau, David James Páez, Paige F.B. Ferguson
From understanding to action: Integrating new and old methodologies to manage marine infectious disease From understanding to action: Integrating new and old methodologies to manage marine infectious disease
Marine diseases can have far-reaching effects on population, community and ecosystem health; however, our ability to track, predict and manage these diseases has, historically, been poor. As a result, the fields of disease ecology and epidemiology have developed at a slower pace for marine than terrestrial systems [1]. New methodologies, including genomic tools for diagnostics [2,3]
Authors
Maya L. Groner, David James Páez, Alyssa-Lois M. Gehman