11,306 results match your criteria: "U. S. Geological Survey; MS 926A; National Center; Reston; Virginia 20192. jrepetski@usgs.gov.[Affiliation]"

Produced water (i.e., a mixture of returned injection fluids and geologic formation brines) represents the largest volumetric waste stream associated with petroleum production in the United States.

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Regional- and continental-scale hydrologic models are increasingly important forecasting tools, yet they rely on highly variable channel parameters (e.g. width, depth, hydraulic resistance) that remain unquantified for millions of stream reaches across the country.

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Environmental DNA (eDNA) offers a novel approach to supplement traditional surveys and provide increased spatial and temporal information on species detection, and it can be especially beneficial for detecting at risk or threatened species with minimal impact on the target species. The transport of eDNA in lotic environments is an important component in providing more informed descriptions of where and when a species is present, but eDNA transport phenomena are not well understood. In this study, we used species-specific assays to detect eDNA from two federally endangered mussels in two geographically distinct rivers.

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The animal gut microbiome can have a strong influence on the health, fitness, and behavior of its hosts. The composition of the gut microbial community can be influenced by factors such as diet, environment, and evolutionary history (phylosymbiosis). However, the relative influence of these factors is unknown in most bird species.

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The global prevalence of mercury (Hg) contamination and its complex biogeochemical cycling has resulted in elevated Hg concentrations in biota in remote and pristine environments. However, there is uncertainty in the relative importance of Hg deposition and landscape factors that control Hg cycling and bioaccumulation. To address this, we measured total mercury (THg) concentrations in 1344 fish across 60 subalpine lakes from 12 national parks (NPs).

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Characterizing the Areal Extent of PFAS Contamination in Fish Species Downgradient of AFFF Source Zones.

Environ Sci Technol

October 2024

Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States.

Most monitoring programs next to large per- and polyfluoroalkyl substances (PFAS) sources focus on drinking water contamination near source zones. However, less is understood about how these sources affect downgradient hydrological systems and food webs. Here, we report paired PFAS measurements in water, sediment, and aquatic biota along a hydrological gradient away from source zones contaminated by the use of legacy aqueous film-forming foam (AFFF) manufactured using electrochemical fluorination.

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The state of the bats in North America.

Ann N Y Acad Sci

November 2024

Bat Conservation International, Austin, Texas, USA.

The world's rich diversity of bats supports healthy ecosystems and important ecosystem services. Maintaining healthy biological systems requires prompt identification of threats to biodiversity and immediate action to protect species, which for wide-ranging bat species that span geopolitical boundaries warrants international coordination. Anthropogenic forces drive the threats to bats throughout North America and the world.

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Climate Futures for Lizards and Snakes in Western North America May Result in New Species Management Issues.

Ecol Evol

October 2024

Pacific Northwest Research Station U.S. Department of Agriculture, Forest Service Corvallis Oregon USA.

We assessed changes in fundamental climate-niche space for lizard and snake species in western North America under modeled climate scenarios to inform natural resource managers of possible shifts in species distributions. We generated eight distribution models for each of 130 snake and lizard species in western North America under six time-by-climate scenarios. We combined the highest-performing models per species into a single ensemble model for each scenario.

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Background: Ecological barriers can shape the movement strategies of migratory animals that navigate around or across them, creating migratory divides. Wind plays a large role in facilitating aerial migrations and can temporally or spatially change the challenge posed by an ecological barrier, with beneficial winds potentially converting a barrier into a corridor. Here, we explore the role wind plays in shaping initial southbound migration strategy among individuals breeding at two sites along an ecological barrier.

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Aboveground biomass density (AGBD) estimates from Earth Observation (EO) can be presented with the consistency standards mandated by United Nations Framework Convention on Climate Change (UNFCCC). This article delivers AGBD estimates, in the format of Intergovernmental Panel on Climate Change (IPCC) Tier 1 values for natural forests, sourced from National Aeronautics and Space Administration's (NASA's) Global Ecosystem Dynamics Investigation (GEDI) and Ice, Cloud and land Elevation Satellite (ICESat-2), and European Space Agency's (ESA's) Climate Change Initiative (CCI). It also provides the underlying classification used by the IPCC as geospatial layers, delineating global forests by ecozones, continents and status (primary, young (≤20 years) and old secondary (>20 years)).

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Quantifying nutrient sources in streams, their temporal and spatial variability, and drivers of that variability can support effective water resources management. Yet a lack of data and modeling capabilities has previously prevented comprehensive quantification across both space and time. Here a dynamic SPARROW (Spatially Referenced Regressions on Watershed attributes) model that accounts for a lagged delivery of nutrients to streams was developed and applied to simulate seasonal and source-specific total nitrogen (TN) and total phosphorus (TP) loads in streams across the Illinois River basin (IRB).

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Decision makers are often confronted with inadequate information to predict nutrient loads and yields in freshwater ecosystems at large spatial scales. We evaluate the potential of using data mapped at large spatial scales (regional to global) and often coarse resolution to predict nitrogen yields at varying smaller scales (e.g.

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Onsite wastewater treatment systems (OWTS) are a major source of excess nutrients and co-pollutants in watersheds across the United States. In Barnstable County (Cape Cod), Massachusetts, effluent from septic systems and cesspools contributes approximately 80% of the controllable reactive nitrogen (N) load to numerous impaired estuaries and degrades water quality in the region's sole source aquifer, streams and ponds. In unsewered areas, wastewater N loads could be reduced substantially by Innovative/Alternative (I/A) septic systems designed for enhanced removal.

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The field of microbial ecology, evolution, and biodiversity (EEB) is at the leading edge of understanding how microbes shape our biosphere and influence the well-being of humankind and Earth. To that end, EEB is developing new transdisciplinary tools to analyze these ecologically critical, complex microbial communities. The American Society for Microbiology's Council on Microbial Sciences hosted a virtual retreat in 2023 to discuss the trajectory of EEB both within the Society and microbiology writ large.

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Behavioural analysis has been attracting significant attention as a broad indicator of sub-lethal toxicity and has secured a place as an important subdiscipline in ecotoxicology. Among the most notable characteristics of behavioural research, compared to other established approaches in sub-lethal ecotoxicology (e.g.

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Stream salinization is a global issue, yet few models can provide reliable salinity estimates for unmonitored locations at the time scales required for ecological exposure assessments. Machine learning approaches are presented that use spatially limited high-frequency monitoring and spatially distributed discrete samples to estimate the daily stream-specific conductance across a watershed. We compare the predictive performance of space- and time-unaware Random Forest models and space- and time-aware Recurrent Graph Convolution Neural Network models (KGE: 0.

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The composition of coral-reef sediments is highly variable across space and time, and differences in the life histories of the dominant calcifying organisms on reefs contribute to the heterogeneity of reef sediments. Previous studies have suggested that variations in coral-reef bioerosion can influence spatial and temporal variations of sedimentary assemblages: elevated erosion rates of dead coral skeletons can trigger a pulse of coral-derived sediments and cause a shift in the dominance of sedimentary grains from coralline algae, such as Halimeda, to coral. We assessed the variability of the sedimentary composition and bioerosion rates of reefs at different spatial scales to determine the association between these two variables.

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Accurate estimates of methylmercury (MeHg) exposure are valuable to actionably assess risk and protect wildlife and human health. MeHg trophic transfer is a critical driver of risk: MeHg is generally biomagnified by a factor of 8.3 ± 7.

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Article Synopsis
  • Management decisions in wildlife conservation should consider both habitat selection and demographic performance, as habitat selection alone may not reflect true species viability.
  • This study focuses on the greater sage-grouse to illustrate how mapping habitat selection against survival rates can reveal important mismatches and trade-offs throughout different reproductive life stages.
  • By integrating demographic measures into habitat management, conservation efforts can be more effectively tailored to enhance species survival and resource allocation, particularly during critical life stages.
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Evaluation of flood metrics across the Mississippi-Atchafalaya River Basin and their relation to flood damages.

PLoS One

October 2024

Department of Agriculture, Grassland Soil and Water Research Laboratory, Agricultural Research Service, U.S. Temple, Texas, United States of America.

Societal risks from flooding are evident at a range of spatial scales and climate change will exacerbate these risks in the future. Assessing flood risks across broad geographical regions is a challenge, and often done using streamflow time-series records or hydrologic models. In this study, we used a national-scale hydrological model to identify, assess, and map 16 different streamflow metrics that could be used to describe flood risks across 34,987 HUC12 subwatersheds within the Mississippi-Atchafalaya River Basin (MARB).

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Article Synopsis
  • - San Diego County has a rich bat diversity, with 22 out of 41 U.S. species, but 16 are at risk, highlighting the need for targeted conservation efforts.
  • - Using long-term survey data, researchers developed a scoring system to identify areas needing urgent bat conservation based on species richness and landscape threats, like urbanization and artificial lights.
  • - The study prioritized conservation areas specifically for species of concern, like Townsend's big-eared bat and pallid bat, emphasizing the detrimental impact of urbanization and light pollution on their populations.
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Article Synopsis
  • The island of Sicily is one of the first places in Europe where humans lived a long time ago, especially during the Upper Paleolithic period.
  • A research project called Early Occupation of Sicily (EOS) is studying the southeastern part of the island where not many ancient sites have been explored yet.
  • The team has found caves and collected materials from museum collections, and they even discovered new archaeological sites that still hold secrets about how early humans lived and moved around.
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The National Water Model (NWM) provides critical analyses and projections of streamflow that support water management decisions. However, the NWM performs poorly in lower-elevation rivers of the western United States (US). The accuracy of the NWM depends on the fidelity of the model inputs and the representation and calibration of model processes and water sources.

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Disentangling the influences of climate change from other stressors affecting the population dynamics of aquatic species is particularly pressing for northern latitude ecosystems, where climate-driven warming is occurring faster than the global average. Chinook salmon (Oncorhynchus tshawytscha) in the Yukon-Kuskokwim (YK) region occupy the northern extent of their species' range and are experiencing prolonged declines in abundance resulting in fisheries closures and impacts to the well-being of Indigenous people and local communities. These declines have been associated with physical (e.

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