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At least 145 records · Page 8Linked to original sources
USGS2026

Water in, no water out—How a rain garden reduced stormwater at City Hall in Gary, Indiana

Introduction Urban stormwater runoff can be an issue in many communities because it may cause flooding, overwhelm sewage treatment plants, and negatively affect water quality in local streams, lakes, and other waterbodies. Stormwater runoff can be controlled by using "green infrastructure," which consists of engineered structures that imitate nature to collect stormwater runoff, reduce the amount of runoff, and improve water quality. In 2014, the city of Gary, Indiana implemented green infrastructure to reduce the negative effects of urban stormwater on Lake Michigan and its tributaries. From November 2016 to June 2017, the mostly impermeable parking lot in front of Gary City Hall was removed and rebuilt with a rain garden. The U.S. Geological Survey studied how the rain garden reduced stormwater runoff and published results in Scientific Investigations Report 2022–5101.

Indiana↗
USGS2026

The further you are, the closer you get: Environmental similarity connects aquatic invertebrate communities across the terrestrial landscape in a large river network

Biodiversity is structured on the landscape through a combination of spatial, environmental, and stochastic factors. In freshwater river networks, the interaction of the linear river network and the three-dimensional terrestrial landscape creates multiple pathways for ecological connectivity that affect aquatic community structure through habitat filtering and dispersal dynamics. Here, we use the high throughput capacity of environmental DNA (eDNA) metabarcoding to explore the influence of spatial relationships and environmental heterogeneity across an expansive and diverse landscape. We collected invertebrate eDNA samples from 70 aquatic habitats in the lower Colorado River Basin (LCRB), ranging from small, free-flowing headwater tributaries to anthropogenically-altered high order rivers, spanning five major drainage regions. Communities displayed high alpha and beta diversity among the drainage regions, structured by a combination of spatial, environmental, and stochastic factors. A novel distance-decay framework adapted from population genetics revealed the influence of terrestrial pathways of ecological connectivity among communities throughout the network. Hierarchical clustering identified patterns of convergent similarity in headwater tributaries despite extreme river network distances separating sites. These results reveal the dual influence of spatial and environmental metacommunity dynamics in aquatic invertebrate communities in the LCRB and the specific influence of interbasin terrestrial connectivity across large spatial scales. Overall, this highlights how terrestrial landscapes can shape convergent patterns of biodiversity in river networks.

Arizona, California, Nevada↗
USGS2026

Historical changes in streamflows important to diadromous fish in United States coastal regions

Diadromous fish species occupy freshwater habitats (rearing, spawning, migration) for a substantial part of their lives. The quality and quantity of these habitats is mainly driven by thermal and streamflow regimes; therefore, understanding trends in streamflow allows better management of diadromous species and their habitats. We investigated seasonal flows for many basins in two U.S. regions on the Pacific coast and two on the Atlantic coast and computed seasonal trends for eight streamflow metrics for each region from 1973 to 2022 and from 1943 to 2022. In the Atlantic regions, February through May maximum streamflows and frequency and duration of high flows mostly decreased from 1973 to 2022. These trends toward drier conditions coincide with migration windows of multiple diadromous species. Summer low-flow frequency and duration in the two Pacific regions increased (toward drier conditions) in many near-natural basins. More low-flow days can affect species directly through decreased river longitudinal connectivity, which can limit habitat access and food availability. Trends in highly regulated systems differed from trends in near-natural systems, especially in the Pacific regions, because large reservoirs often decrease peak flows and increase low flows. For example, in the southwestern U.S. coastal region, low-flow duration and frequency significantly decreased (wetter) in many regulated basins while near-natural basins were not similarly affected. Our results demonstrate how analysis of environmental flows at regional and seasonal scales can inform future habitat management and restoration plans.

Hydrological Processes↗
USGS2026

Landscape controls river continuum dissolved organic carbon in northeastern Alaska

Rivers draining continuous permafrost landscapes on the North Slope of Alaska span from the mountains to the coast, integrating gradients in vegetation, soil organic matter, and hydrologic flow. We investigated how these landscape transitions influence dissolved organic carbon (DOC) concentrations, radiocarbon ages, and export along the river continuum over seasonal timeframes in northeastern Alaska. Water samples were collected from the Canning River and its tributaries from the spring freshet through late summer via multiple campaigns during 2011–2024. A simulation from the Permafrost Water Balance Model (PWBM) estimated terrain-specific contributions to freshwater and DOC export. River DOC concentrations peaked during the spring and declined in summer, with episodic increases linked to summer rainfall. Summer river DOC concentrations from the Brooks Range remained low (0.41–0.64 mg C L −1 ) but increased downstream (0.5–3.0 mg C L −1 ), becoming younger from the mountains (805 yBP) to the river delta (525 yBP) as flow from DOC-enriched streams draining the foothills (6–18 mg C L −1 ; Modern yBP) entered the Canning. The PWBM simulation revealed that while the mountains dominate the Canning's annual (90%) and spring-summer (88%–93%) freshwater export, the foothills disproportionately influence its annual (56%) and spring-summer (44%–58%) DOC export. DOC yields from the coastal plain were also high but had little influence due to its small contributing area. Our findings highlight the outsized role of the foothills in modulating river-integrated DOC export to coastal ecosystems. Considering the impact of these landscapes on carbon source and runoff will aid in anticipating future DOC fluxes from Arctic rivers.

Alaska↗
USGS2026

Dimensionality reduction techniques for analyzing tsunami simulations in hazard assessment and forecasting applications

A wide selection of linear and non-linear dimensionality reduction techniques is evaluated on synthetic tsunami data that is the basis for tsunami hazard assessment and computational forecasting. The data were computed from earthquake rupture forecasts (ERFs) supplying initial generation conditions and a linear long-wave Green's function approach to efficiently calculate tsunami propagation. The dimensionality reduction techniques include various forms of principal component analysis, manifold learning, and neural networks. Both external (e.g., mutual information) and internal (silhouette) metrics are used to evaluate clustering in the reduced dimension, focusing on peak-nearshore tsunami amplitudes (PNTA) along a nearshore isobath and time-series (marigrams) at specific nearshore locations. This evaluation is intentionally scoped to cluster-based downsampling to produce probabilistic inundation maps. For our test case along the Nankai subduction zone, manifold learning methods produced the highest clustering metric scores for PNTA profiles among the examined dimensionality reduction techniques. The marigram results are less consistent, owing primarily to uncertainty in defining appropriate clusters in the original high-dimensional (ambient) space to establish a “ground truth.” A novel application of using the integrative ERF-tsunami approach is that features extracted in the reduced domain, particularly from manifold learning, can be mapped back to rupture zones along the fault. This yields targeted fault information associated with unique PNTA profiles and marigram characteristics, such as late-arriving waves. Further testing would be needed for application-specific workflows and more complex fault systems, but results from this single subduction zone case study support the consideration of non-linear techniques (e.g., manifold learning) as alternatives to linear methods.

Nankai megathrust↗
USGS2026

Evaluation of seismological evidence for decadal changes in Earth’s lowermost mantle and outer core

Recent reports of decadal-scale structural changes in the lowermost mantle and transport of strong heterogeneity in the outer core may offer important insights into core-mantle structure and dynamics. These reports are derived from waveform comparisons of earthquake pairs or repeating earthquakes, particularly using differential travel-time measurements made with cross-correlation techniques. Here we show that the interpretation can contain several overlooked traps, particularly imperfect source repeatability and station-related issues. We systematically examine the earthquake-pair waveforms reported by two recent studies, and provide independent investigations on the source repeatability, along with its associated travel time shifts. We also examine the quality of related stations, using comparisons between co-located sensors. We demonstrate that the reported temporal changes in Earth’s deep interior can be largely explained by artifacts from imperfect source repeatability and station-related issues. Our findings caution that the outer core or lowermost mantle should not be considered as a likely source of detectable temporal variability unless alternative explanations have been exhaustively excluded.

Communications Earth & Environment↗
USGS2026

Effects of temperature on standard metabolic rate, hypoxia tolerance, and critical thermal maxima in invasive cichlids

Objective Jaguar Guapote Parachromis managuensis and Red Devil/Midas cichlids Amphilophus spp. are highly invasive species in the family Cichlidae native to Central America. These cichlids are popular within the aquarium trade, leading to their broad introduction outside of their native range. Information about potential environmental plasticity of a species can improve predictions of invasion potential. In this respect, measures of environmental influences on metabolic rate and hypoxia tolerance are important for understanding limitations in adaptability and subsequently guiding the management of invasive species. Methods Standard metabolic rate (SMR), hypoxia tolerance, and critical thermal maxima (CT max ) were compared between Jaguar Guapote and Amphilophus spp. For SMR and hypoxia tolerance, a range of temperatures spanning subtropical to tropical environments (i.e., 22, 28, and 34°C) was used, followed by stepwise decreases in oxygen saturation until loss of equilibrium. Results Jaguar Guapote and Amphilophus spp. both had lower SMR at 28°C than at 34°C, SMR at 22°C was not different from either temperature. Both Jaguar Guapote and Amphilophus spp. were the most sensitive to hypoxia at the coolest temperature (22°C) relative to warmer temperatures (28°C and 34°C). Upper thermal tolerance (CT max ) was similar between species (∼42°C), although Jaguar Guapote were more resilient based on a higher agitation temperature and recovery following high temperature exposure. Conclusions These results indicate temperatures that are representative of their natural distribution (i.e., near 28°C) offer energetic savings for Jaguar Guapote and Amphilophus spp. relative to warmer temperatures (34°C), with cooler temperatures (22°C) having higher metabolic costs than expected. Both Jaguar Guapote and Amphilophus spp. are sensitive to hypoxia at cooler temperatures (22°C). Therefore, these species are relatively resilient to high temperatures, but low temperatures may restrict their invasiveness.

Transactions of the American Fisheries Society↗
USGS2026

Fine-scale factors affecting the abundance and thermal sensitivity of nonnative Brook Trout in coldwater Rocky Mountain streams

The Brook Trout ( Salvelinus fontinalis ) is a globally distributed nonnative species that threatens native salmonids in coldwater streams. Understanding the factors regulating Brook Trout densities in coldwater refugia is critical to effective management, so we investigated (a) fine-scale drivers of Brook Trout abundance and (b) factors affecting their thermal sensitivity in 49 coldwater streams in Idaho. Among the 14 candidate variables evaluated, Brook Trout density was most closely associated with mean August water temperature (dome-shaped response peaking at 11.0°C–11.1°C), wetted width (negative association), gradient (negative association), run habitat (positive association), and substrate size (negative association). Simulations indicated that densities were most sensitive to climate warming in low-velocity habitats, with the largest increases occurring in areas with baseline temperatures of 8.9°C and largest decreases in areas with temperatures of 12.2°C. We discuss our results in the context of Brook Trout behavior, effects on native salmonids, climate warming, and habitat restoration.

Idaho↗
USGS2026

Abundant ticks but limited Borrelia spp. pathogens in Mojave desert tortoise habitat

Ornithodoros ticks, a genus of soft ticks in the family Argasidae, occur worldwide including throughout deserts in the Southwestern United States. In the Mojave Desert, Ornithodoros parkeri and O. turicata are common ectoparasites of Mojave desert tortoises ( Gopherus agassizii ). These two tick species are vectors of Borrelia spp. that cause tick-borne relapsing fever (TBRF) in people. However, the distribution of O. parkeri and O. turicata and TBRF group Borrelia infection prevalence remain poorly known in the Mojave Desert. These ticks are commonly found in desert tortoise burrows. In this study, 1165 ticks were collected in the Mojave Desert, 1164 of those ticks were identified as belonging to the genus Ornithodoros, while the remaining tick was an Otobius species. We used morphologic characteristics and molecular genetic analysis to identify ticks as O. parkeri and O. turicata . Twenty-two of the 1165 tick samples tested positive for TBRF group Borrelia, five of which could be sequenced and were identified as Borrelia turicatae . This study sheds light on the distributions of tick species and pathogens in an understudied ecosystem, the Mojave Desert, and identifies group Borrelia as a potential risk factor in Mojave desert tortoise habitat.

California, Nevada↗
USGS2026

Nutritional content of phytoplankton communities under ice

The effects of winter environmental conditions on lake ecology can be highly variable. Ice and overlying snow isolate the water below, impeding exchange of materials among water, atmosphere, and the watershed. Even with these limitations, biological communities under the ice can persist, where cold tolerant taxa can be especially abundant. Because many under-ice taxa tend to have a suite of unsaturated lipids that enable them to maintain metabolic function during cold conditions, under-ice biological communities may contain highly nutritious resources for higher level consumers relative to warmer, open-water conditions. To examine the effects of ice presence on under-ice biological productivity and nutritional quality, we aggregated data on under-ice physical, chemical, and biological variables from several existing databases. These data are among the most comprehensive, publicly available environmental and phytoplankton data that can be used to compare under-ice and open-water conditions at the community level. To understand how phytoplankton compositional shifts under ice can precipitate shifts in total algal nutritional content available to consumers relative to open water conditions, we merged characteristic phytoplankton fatty acid profiles with phytoplankton community composition data. Our results suggest that even though photosynthetically active radiation under ice is dramatically reduced by snow cover and opaque ice conditions, algal communities can be highly productive. Furthermore, these under-ice communities tend to be dominated by coldwater taxa, which are associated with elevated essential polyunsaturated fatty acids and reduced saturated fatty acids. Saturated fatty acids tend to be most associated with phytoplankton communities in the summer when cyanobacteria are prevalent, while winter communities tend to be most associated with high polyunsaturated fatty acids. As ice duration and quality continue to shift with increasing temperatures worldwide, phytoplankton assemblages are likely to exhibit altered nutritional profiles that have direct and indirect effects on food webs.

Ecopshere↗
USGS2026

Impacts of transient critical zone evolution on landslide susceptibility and hazard Across the Utuado batholith, Puerto Rico

Landscapes in humid climates often experience rapid chemical and mechanical weathering that can change groundwater fluxes, drainage pathways, and frictional strength via alterations in subsurface mineral composition and matrix porosity. These changes to hillslope critical zone structure and strength should control landslide susceptibility, size, and failure style. Here we test the impact of differential weathering on landslide failure processes by exploiting a natural experiment along the dioritic Utuado batholith in Puerto Rico's Cordillera Central, where a sharp weathering gradient follows an upstream-propagating knickzone into an uplifted shoreline platform that was affected by Hurricane Maria in 2017. Through a combination of landslide mapping, field geophysical and geotechnical surveys, topographic analysis, calibrated stream profile inversion, 3D back-analysis of hillslope strength, and debris-flow inundation assessments, we show that differential weathering induces changes to critical zone structure and consequently landslide susceptibility and hazard. Our mapping reveals that the hurricane-induced landslides preferentially cluster along less weathered hillslopes despite a marked increase in frictional strength. Jointly inverted seismic refraction and electrical resistivity profiles show that the frictionally weak, heavily weathered hillslopes are highly porous and dry, which we posit acts to stabilize slopes through limiting deeper hydrologic connectivity that can produce shallow water tables with destabilizing lateral seepage forces during storms. Debris-flow inundation mapping and analysis reveals that major contributors to debris-flow growth, channel steepness and landslide coalescence, scale linearly with hillslope friction angle. This leads to higher-mobility debris flows along knickzone reaches, which disproportionately affects communities at the base of the plateau.

Puerto Rico↗
USGS2026

Accounting for biases in the analysis of building damage data for the 2023 M7.8 Türkiye/Syria earthquake sequence

In the aftermath of a large earthquake, several practical constraints affect the systematic collection of data for assessing building damage. The available data are therefore typically incomplete, frequently missing key information such as the type of construction, age and geographic location. Moreover, the observations often favour certain locations and damage grades. In the absence of robust methods, using such data directly for characterising the building stock or conducting fragility assessments can introduce systematic bias. Using the 2023 M7.8 Türkiye/Syria earthquake sequence as a case study, we propose a statistical model that enables joint inference over the inventory and fragility of the building stock while explicitly accounting for sources of data error and missing information. The results show higher-than-expected vulnerability amongst several building types, particularly mid- and high-rise reinforced concrete buildings, which performed extremely poorly during the 2023 earthquake sequence. The proposed Bayesian framework provides rigorous uncertainty quantification that can be propagated to future applications.

Earthquake Spectra↗
USGS2026

National-scale remotely sensed lake surface temperature in the contiguous United States

Temperature is a master variable in aquatic ecosystems. Despite its importance for ecosystem function, our capacity to measure temperature is often limited to focal systems with intensive in situ measurements or larger systems with readily accessible data from disparate data streams. These limitations are consequential for holistically understanding aquatic ecosystem status and change, especially considering that most lakes globally do not have consistent in situ data. To empower researchers with macroscale surface temperature observations, we present the first remotely sensed lake temperature dataset that includes measurements from Landsat 8 made every ~ 16 d for 137,394 lakes of at least 4 ha in surface area throughout the contiguous United States from 2013 through 2025. By aggregating data in a cloud computing framework, the dataset is amenable for continual update, thereby allowing end users to track local-to-continental scale changes in lake water temperature over time.

contiguous United States↗
USGS2026

Forecasting marsh resilience in the Plum Island Estuary: Integrating uncertainty to inform coastal management

Salt marshes provide critical ecosystem services yet face increasing threats from accelerated relative sea-level rise (SLR). The long-term persistence of these habitats depends on their ability to vertically accrete and laterally migrate into adjacent uplands. Predicting the location and viability of these future marsh corridors is therefore a primary challenge for coastal managers; one often hindered by uncertainties in future water levels and topographic data accuracy, particularly in vegetated wetlands where light detection and ranging (lidar) data systematically overestimate elevation. This study applies an uncertainty-informed modeling framework to forecast marsh resilience in the Plum Island Estuary, Massachusetts. We integrated the Sea Level Affecting Marshes Model (SLAMM) with a Monte Carlo error analysis, generating an ensemble of bias-corrected digital elevation models (DEMs) alongside three probabilistic SLR scenarios (Intermediate, Intermediate High, High) through 2100. We synthesized these simulations into a “marsh fate” classification map to distinguish between resilient core habitats, vulnerable zones requiring intervention, and likely migration corridors. While the marsh platform exhibits resilience under Intermediate scenarios, a critical tipping point emerges under the High SLR scenario. In this case, accelerating inundation overwhelms accretion capacities, driving a landscape-scale regime shift. By integrating the interacting uncertainties of SLR trajectories and initial marsh elevation, we project 2100 net marsh coverage outcomes ranging from a 10.5% gain to a 23.2% loss. These results demonstrate that incorporating elevation uncertainty is essential for detecting non-linear threshold behaviors that deterministic models often miss. The resulting framework empowers managers with a spatially explicit tool to prioritize land acquisition and restoration efforts in the face of climate uncertainty.

Massachusetts↗
USGS2026

Key considerations for decision makers and stakeholders when identifying source populations for conservation translocations of fishes

Conservation translocations are undertaken to increase the viability of imperiled organisms and/or restore ecosystem functions or processes. A key step in the conservation translocation process is to decide which source or founder population is most likely to lead to translocation success. Existing guidance to inform this decision includes a variety of considerations, but few documents focus solely on this step. Furthermore, despite the importance of stakeholder engagement to long-term conservation success, guidance for selecting source populations rarely describes approaches for stakeholder inclusion. Herein, we undertook a literature review for fish conservation translocations and summarized key considerations (e.g., genetics, habitat, life history, effects on source or recipient populations and ecosystems, logistical) to be used when selecting candidate source populations. We describe the importance of including stakeholders and recommend that decision makers coproduce the source population decision with them. We propose a structured expert judgment approach to assess the probability that specific aspects of these considerations could be achieved for each candidate source population. Finally, we recommend synthesizing results of the expert judgement process to enable decision makers and, ideally, invited stakeholders to choose which source population(s) based on their previously identified fundamental objectives. Although we developed this approach for fishes, it could be used for other conservation translocation efforts where stakeholder involvement and synthesis of support for different source populations are deemed valuable in the planning process.

Global Ecology and Conservation↗
USGS2026

Perceptions of relational organizing as a tool for human–bear coexistence

Conflict between humans and American black bears ( Ursus americanus ) is a growing concern in North America, especially in wildland–urban interfaces. Beyond ecological drivers, conflict reduction relies on changing human behavior. Neighbor-to-neighbor conversations, also known as relational organizing, may drive social diffusion of coexistence actions. However, little research has explored the behavioral conditions enabling (a) residents to initiate conversations and (b) neighbors to listen and adopt bear-safe practices. Using the capability, opportunity, motivations and behavior (COM-B) framework, we analyzed 34 semi-structured interviews with engaged residents in two western U.S. communities with ongoing coexistence efforts. Results highlight that interviewees have heterogeneous knowledge and skills (capability), are committed to leveraging interpersonal relationships but concerned about protecting these relationships (social opportunity), feel more able to engage in relational organizing with enabling programmatic support and regulatory frameworks (physical opportunity), and are motivated by identity, emotion, and beliefs about consequences.

Colorado, Montana↗