Geology topics

Research about United States

Source-linked reports with geographic coverage including United States.

At least 955 records · Page 53Linked to original sources

USGS2025

Hydrogeologic characterization of the Cahuilla Valley and Terwilliger Valley Groundwater Basins, Riverside County, California

The relation between the groundwater and the amount of natural recharge to the Cahuilla Valley and Terwilliger Valley groundwater basins is not well understood. During the 20th century, the reliance on groundwater near Anza, California, used for agricultural, domestic, and municipal reasons has increased, and there is the potential for changes in groundwater availability related to climate change. Several types of existing data were evaluated, and new data were collected for this study, with the goal of characterizing the region’s hydrogeology. The study’s scope included constructing a geologic framework model to show where the groundwater-bearing units are present and their relation to each other, estimating the major components of the groundwater budget, and understanding local short-term and regional long-term groundwater flow and how that has changed since the early 1900s. Two electrical resistivity tomography surveys were done in the Durasno Valley about 2,150 feet apart to identify the thickness of the alluvium, its horizontal extent, and the depth-to-basement along two profiles perpendicular to Cahuilla Creek. The subsurface sediments were mostly horizontally layered and the transitional boundary between the alluvium and basement was thinner and shallower along the upgradient profile where the depth-to-basement was about 70 feet below land surface; the depth-to-basement at the downgradient profile was more than about 140 feet below land surface. The results from the surveys were used to place four monitoring wells at two sites along the survey profiles. Artesian flow from the deepest well at the downgradient site indicated that the decomposed and competent basement likely contributed some groundwater to the overlying alluvium, laterally, from below, or both. A digital three-dimensional geologic framework model was constructed using EarthVision software to represent the subsurface geometry of the alluvium, decomposed basement, and competent basement. Maps and cross sections of the modeled thicknesses of the alluvium and decomposed basement, and the modeled elevation of the top of the competent basement, were made to show the subsurface geometry of vertical faults, selected wells, and the groundwater-bearing units. Because natural recharge is related to the variable cycles of precipitation, estimates are difficult to quantify. Recharge and runoff have extreme interannual variability in the study area; recharge and runoff can be sporadic, and a substantive amount may not occur in some years. Estimates of recharge from a previous study and the regional-scale Basin Characterization Model for California for four different periods ranged from 3,800 acre-feet/year for 1897–1947 to 5,900 acre-feet/year for 1971–2000. Potential recharge from the disposal of domestic septic systems may have been as much as 500 acre-feet in 2020. It was estimated that between about 400 and 2,400 acre-feet/year of groundwater is lost through evapotranspiration by vegetation and evaporation from open water bodies, but the main source of discharge is through pumpage, mainly used for agriculture from the alluvium in the Cahuilla Valley and Terwilliger Valley groundwater basins. The estimated total pumpage for 1991–2021 ranged from about 1,140 acre-feet in 2019 to about 3,450 acre-feet in 1994. When summed, the cumulative amount of estimated pumpage between 1991 and 2021 was about 81,400 acre-feet. The general direction of groundwater flow is from the northeast along the San Jacinto fault zone at the headwaters of Cahuilla and Hamilton Creeks, to the surface-water outlets at the west and southeast parts of the study area. Groundwater-level data from the 1950s and earlier indicate that there was a natural groundwater divide between the Cahuilla Valley and Terwilliger Valley groundwater basins, but the changing magnitude and extent of the groundwater depressions caused by pumping since about 1950 indicate that the location of the natural groundwater boundary between the Cahuilla Valley and Terwilliger Valley groundwater basins has migrated over time. Flow from the upper to the lower parts of the Cahuilla Valley groundwater basin roughly follows the course of Cahuilla Creek through the narrow Durasno Valley where an estimated volume of flow in April 2019 was about 10–150 acre-feet/year. Short-term trends in groundwater levels, particularly in wells where groundwater is shallow and in the basement unit, show how some areas respond quickly to recharge and discharge. Wells located further to the east within the Cahuilla Valley groundwater basin in the alluvium show much less of a response to recharge events; areas of sustained pumpage from the alluvium, primarily for agriculture, show long-term declines in groundwater levels and generally do not show the effects of storm events or recent runoff. Groundwater levels in wells that are farthest from where most of the recharge occurs and where pumping has been the greatest, had some of the largest long-term groundwater-level declines at a rate of about 0.8 foot/year between 1971 and 2021.

California↗

USGS2025

A probabilistic assessment methodology for the evaluation of geologic energy storage capacity—Natural gas storage in depleted hydrocarbon reservoirs

The need for energy storage, particularly underground, where capacity and duration may far exceed battery storage technologies, is especially relevant given the increasing demands for reliable power alongside the development of intermittent renewable electricity sources. Geologic energy storage facilities already exist, and expanded use would enable storing gases such as methane and hydrogen. In 2018, a National Academies of Sciences, Engineering, and Medicine report, “Future Directions for the U.S. Geological Survey's Energy Resources Program,” recommended that the U.S. Geological Survey (USGS) prioritize assessing underground energy storage in geologic formations in the United States. The U.S. Geological Survey has since developed a methodology for assessing natural gas storage capacities in depleted hydrocarbon reservoirs on a national scale. The methodology introduced in this report prescribes three approaches for calculating gas storage capacity. This methodology relies on the availability of input data, including cumulative hydrocarbon production records, reservoir petrophysical properties, and reservoir pressure data. Assessment inputs can be obtained from public, State-level databases and propriety national-scale databases, although the use of analogs could be warranted for estimating input parameters. Probabilistic assessment results are aggregated to play, petroleum province, regional, and national scales. The steps defined in this report are demonstrated on the Michigan Basin Province, which includes the Mississippian Sandstone Gas Play and the Clinton Structural Play. This methodology could be used to systematically and consistently assess hydrocarbon plays and provinces for natural gas storage capacity across the United States.

Michigan↗

USGS2025

Diurnal patterns of nitrous oxide fluxes from a seasonal prairie wetland

Wetlands have spatially and temporally dynamic nitrous oxide (N 2 O) fluxes. Understanding diurnal patterns in N 2 O fluxes in wetlands can reveal short-term drivers and improve process-based models. An automated chamber system was used to determine N 2 O flux rates every 2.5 to 4 h in a prairie pothole wetland in North Dakota during the 2013 to 2014 growing seasons under ponded, moist, and dry soil conditions. The wetland generally emitted N 2 O under all conditions, although median fluxes during ponded conditions were low over the two-year study. A significant diurnal N 2 O pattern was observed under dry soil conditions, but not in moist soil or ponded conditions. When soils were dry, daytime (~ 10:00–14:00; 2.43 ± 0.31 ng m -2 hr -1 ) and late-day (~ 14:00–18:00; 2.20 ± 0.16 ng m -2 hr -1 ) average N 2 O fluxes were 77% and 61% greater, respectively, than other times during the 24-hr diel cycle (< 1.37 ng m -2 hr -1 ). N 2 O flux was positively correlated to air ( r = 0.58) and soil ( r = 0.49) temperatures under dry conditions, while no significant correlations to environmental factors were observed under ponded and moist conditions. Incorporating diurnal patterns in N 2 O fluxes in wetlands and other ecosystems can improve extrapolations from daily to annual flux calculations and constrain global N 2 O inventories.

North Dakota↗

USGS2025

Landscape associations and population genetics of a generalist carnivore at a range limit

American black bear ( Ursus americanus ) sightings have increased in the Oklahoma Panhandle, an area outside of the species’ historical range, prompting an assessment of bears in the region. We used camera traps and an occupancy modeling framework to identify factors influencing bear detection and space-use patterns. We used noninvasive genetic sampling techniques to evaluate genetic diversity, population structure, and bear abundance in the region. During the summers of 2022–2023, we deployed cameras at 160 sites across western Oklahoma (USA) and detected ≥1 bear at 20 sites. The most-supported model from our single-season single-species analysis indicated that bear detection was positively associated with temperature and precipitation, negatively associated with day of year, and differed between years. The most-supported model indicated that bear space use was negatively associated with elevation (β = −0.013, 85% CI = −0.025, 0.000), and positively associated with slope (β = 0.645, 85% CI = 0.305, 0.984) and coarse woody debris counts (β = 1.539, 85% CI = 0.314, 2.765). We deployed 41 hair snares in Oklahoma resulting in the collection of 153 hair samples and received 69 tissue samples from black bears harvested in northeastern New Mexico. Using 11 microsatellite markers, we identified 21 (12M:9F) bears in western Oklahoma, and 69 (40M:29F) in New Mexico. We found evidence that bears occurring in Oklahoma were an extension of a previously documented population that occurred in northcentral New Mexico. We detected significant population-level heterozygote deficiency ( P = 0.013) compared to expectations under Hardy-Weinberg equilibrium. Using capture with replacement models, we estimated 26 (95% CI = 19–43) bears in western Oklahoma during 2022–2023. Our results provide baseline data on population distribution, abundance, and genetic health of bears in the region and identify factors that may drive human-bear conflicts as the bear population increases in western Oklahoma.

New Mexico, Oklahoma↗

USGS2025

A comprehensive geologic framework of the National Crustal Model for seismic hazard studies in the conterminous United States

A three-dimensional (3D) geologic framework has been developed for the conterminous United States (U.S.) as part of the U.S. Geological Survey National Crustal Model to enhance seismic hazard modeling. The geologic framework is created from geologic maps and multiple subsurface geologic unit boundaries including the base of the Miocene, Cenozoic, Phanerozoic, and the Mohorovičić discontinuity. Modifications are made to surficial geologic maps to remove discontinuities across state and country borders. The subsurface distribution of rock type and age is extrapolated from the surface, seeded with subsurface geologic information, and constrained by a map of basement geology. The framework provides the basis for estimates of subsurface seismic velocity and density that is needed to improve estimates of earthquake ground shaking and seismic hazard. The present framework greatly expands and updates a previously published 3D geologic framework of the western part of the U.S. that was itself a first-of-its-kind digital 3D portrayal of the nation.

conterminous United States↗

USGS2025

Shallow geologic framework of the Mississippi Sound and the potential for sediment resources

The Mississippi Sound, an estuarine environment located between the mainland and barrier islands bordering the northern Gulf of America (formerly the Gulf of Mexico), serves as a vital ecosystem for the States of Mississippi and Alabama. Spanning approximately 100 kilometers from east to west and covering 1,400 square kilometers, the sound is home to marine industry and ports, and its shallow and brackish waters sustain a diverse array of marine life. Barrier islands along the southern edge of the sound separate the microtidal estuary from the Gulf of America. This protection from gulf wave action mediates current flow within the sound, resulting in predominantly fine-grained sediment deposition along the seafloor. This study, conducted by the U.S. Geological Survey in cooperation with the U.S. Army Corps of Engineers, provides insight on fluvial and tidal processes spanning the past 5,000 years. The report synthesizes existing research to provide a comprehensive overview of the sound geology, from Pleistocene origins to present-day morphology, and utilizes high-resolution single channel seismic profiles and sediment data to identify and map sedimentary deposits and morphologic features at and below the seafloor. Despite its ecological significance, the Mississippi Sound faces environmental challenges, including water-quality issues, habitat degradation, storm-induced erosion, and the ongoing threats of sea-level rise and environmental changes. This study uses the present-day understanding of the sound's geology to inform coastal management decisions, hazard assessment, and potential mineral resources.

Louisiana, Mississippi↗

USGS2025

Dynamic risk from Mexican wolves and mountain lions influences elk foraging behavior

Foraging time is a major component of ungulate activity budgets but can be limited by anti-predator behaviors (e.g., vigilance). Multitasking can reduce the nutritional costs of vigilance under heightened predation risk, but this may depend on the response of prey to risk from multiple predators across a complex spatiotemporal landscape. Mexican gray wolves ( Canis lupus baileyi ) and mountain lions ( Puma concolor ) are primary predators for elk ( Cervus canadensis ) in the Mexican wolf experimental population area in east-central Arizona and west-central New Mexico. We observed elk foraging across varying levels of wolf risk throughout all seasons and diel periods to quantify proportions of foraging, intense vigilance, and multitasking at the individual and herd levels. We quantified encounter and kill risk from Mexican wolves and mountain lions using habitat selection functions and utilization distributions. We modeled elk behaviors as functions of predicted risk for both predators in addition to temporal and environmental covariates and accounted for human presence. Our results indicate that individual elk reduced foraging in areas with higher predicted risk from Mexican wolves or mountain lions and increased intense vigilance and multitasking in areas with higher wolf risk. A reduction in the proportion of bedded elk in the herd during all diel periods under increased wolf risk supports previous findings. These results also suggest that elk compensate for higher intense vigilance and reduced foraging during foraging bouts by increasing cumulative foraging bouts per day at the cost of resting. Additionally, the probability of multitasking for individuals depended on an interaction between short- and long-term wolf risk, and the likelihood of intense vigilance was highest under the greatest combined spatial and temporal risk from wolves. This research provides insight into the fine-scale and complex behavioral responses of elk to their primary predators and implies a need for researchers to consider these non-consumptive effects in future studies of predator–prey dynamics.

Arizona, New Mexico↗

USGS2025

Changing dynamic phosphorus forms from field to stream during surface runoff events

The risk of water quality impairment from agricultural runoff depends on nutrient source, transport, and bioavailability. Phosphorus (P) spirals between dissolved and particulate forms as it is transported with suspended sediment (SS) from agricultural fields, through the stream network, to receiving water bodies. This dynamic sorption-desorption influences bioavailability. We quantified P form and abundance in samples collected during surface-runoff events from a farm field in the East River Basin, Wisconsin and compared them to those in stream water collected from the East River. We sampled five events between late March 2022 and June 2023. During most events, P in surface runoff was mainly in dissolved form, with particulate P sorbed to fine clay, the most abundant particle fraction transported from the field, whereas P in stream water was mainly in particulate form and sorbed to silt, even though fine clay was the most abundant particle fraction in the stream during events. Overall capacity for P sorption to SS in the stream varied among events. Total P and SS concentrations were lower during summer baseflow conditions and smaller surface runoff events; however, what SS was present was more P enriched. This shift in P form from field to stream indicates a potential for sorbing dissolved P to SS during transport through the stream network, which changes the bioavailability of P exported downstream with less bioavailable P as dissolved P binds to SS.

Wisconsin↗

USGS2025

Quantifying leachable phosphorus from the leaves of common midwest urban street trees and implications for stormwater management

Urban runoff containing high amounts of nutrients like phosphorus (P) is a well-established driver of surface water eutrophication. In residential areas, a primary source of nutrients is derived from leaf litter. P contained in leaves is leached and transported by stormwater from source to stream. The majority of P leached from leaf litter is in the dissolved phase, which can be difficult to remove using conventional treatment practices, leaving source control as the most viable option. Additional tools are needed to help forecast how different tree species may improve or hinder contributions of nutrients to runoff. For this reason, ten street tree species that are common throughout the contiguous U.S. were chosen to evaluate the effect of species on leachable P from tree leaves using laboratory experiments. After 48 h of exposure to water, the amount of P released ranged from 2.16 mg P g −1 leaf for Silver Maple to 0.03 mg P g −1 leaf for Hackberry. More than half of the P was lost in the first 12 h for eight of the ten tree species, making guided source control important to reduce inputs to surface water from key locations. Results were used to identify ‘hotspots’ of P leaching in Madison, WI and can be used to assess current street tree inventories that can then guide management to areas with the highest nutrient reduction potential and inform urban foresters who may wish to tailor future planting scenarios that minimize nutrients in runoff.

Wisconsin↗

USGS2025

Phytoplankton biomass dynamics in wet (2019) and dry (2023) years in Lake Pontchartrain estuary, Louisiana from Sentinel 2-MSI and PACE-OCI observations

This study provides a comprehensive assessment of phytoplankton biomass dynamics in Lake Pontchartrain, Louisiana, by combining monthly water quality data with multispectral and hyperspectral satellite observations using a machine learning algorithm. A machine learning model based on Variational Autoencoder (VAE), globally applicable, was used to estimate phytoplankton biomass via chlorophyll- a (Chl- a ) from Sentinel 2-MSI and NASA's new hyperspectral mission, PACE-OCI, enabling the first direct comparison between the two sensors. The model performed well in this complex estuarine system, with higher accuracy from PACE-OCI (MAE: 1.48, RMSE: 10.40, slope: 0.87) than Sentinel 2-MSI (MAE: 1.57, RMSE: 11.08, slope: 0.83). This approach enabled continuous high-resolution monitoring of phytoplankton biomass across space and time. Comparative analysis of 2019, a wet year with Bonnet Carré Spillway (BCS) openings, and 2023, a dry year with extremely low riverine inputs, revealed distinct biomass dynamics. In 2019, BCS discharge initially suppressed Chl- a within turbid waters (<5 mg Chl- a m −3 ) but later acted as a nutrient and hydrodynamic driver, transporting nutrients toward the lake outlet and Mississippi coast, promoting high biomass (25–45 mg Chl- a m −3 ) near the entrance. In contrast, dry conditions in 2023 led to more frequent-than-expected high biomass (>35 mg Chl- a m −3 ), persisting in the lake center. Similar spatial patterns were observed again in 2024, revealed for the first time by PACE-OCI. This study demonstrates the value of satellite-derived observations for capturing transient phytoplankton biomass events and highlights the potential of PACE-OCI's hyperspectral capabilities to better distinguish phytoplankton communities and improve understanding of their responses to freshwater inflows and associated processes driving pulses into estuaries.

Louisiana↗

USGS2025

From models to management: Implementing the climate-change refugia conservation cycle in national parks of the northeastern United States

Managing climate-change refugia is a commonly recommended strategy for conserving biodiversity. However, few efforts have moved beyond the modeling phase of refugia science to management. Here, we present two case studies that move beyond modeling to testing models and management. In the first case study, we model refugia for two plant species (three-toothed cinquefoil [ Sibbaldia tridentata ] and black crowberry [ Empetrum nigrum ]) in Acadia National Park, Maine, United States, and use greenhouse experiments, common-garden experiments, and participatory science to evaluate the output of those models. Our results suggest that three-toothed cinquefoil growth and survival are reduced under increased temperatures as models predict. However, other variables (e.g., soil moisture and salinity) might also be important to modeling and managing refugia for both species. National Park Service staff and partners have been directing restoration for both species to refugia, but are also exploring other adaptation strategies. In the second case study, we demonstrate that existing prioritization processes for habitat restoration in national parks of the northeastern United States rarely incorporate refugia for two indicator species: Jefferson salamander ( Ambystoma jeffersonianum ) and grasshopper sparrow ( Ammodramus savannarum ). Our work demonstrates that moving beyond modeling can improve models and lead to new management insights.

Northeast United States↗

USGS2025

Integrating refugia modeling and decision science to support climate-adaptive conservation in the Sierra Nevada

To reduce detrimental impacts of anthropogenic change, natural resource managers often look for place-based solutions to minimize biodiversity loss. Climate-change refugia, areas buffered from contemporary climate change, can enable the persistence of valued natural resources and prolong the benefits of conservation action. Here we combine climate-change refugia modeling with structured decision-making to inform conservation decisions for the endangered foothill yellow-legged frog ( Rana boylii ) in the Sierra Nevada region of California, USA. We used an ensemble of species distribution models to identify areas projected to remain suitable into the 2040s and the 2080s under an RCP 8.5 emissions scenario, as well as areas projected to transition to suitable habitat during this time. We integrated these projections with a structured decision-making process to align management strategies with refugia model outcomes for R. boylii in a subset of the study area. Habitat suitability for R. boylii is projected to decline in the study area by over 90% by the 2040s and by a subsequent 15% by the 2080s. Climate-change refugia are projected to occupy ~7% of present-day suitable habitat, with high agreement between GCMs and model timesteps. Areas projected to transition to suitable habitat within the existing R. boylii clade boundaries are negligible. Collectively, climate-change refugia modeling and structured decision-making provide opportunities to improve resource allocation and empower conservation practitioners in climate change adaptation for at-risk species.

California↗

USGS2025

Novel adomaviruses associated with blotchy bass syndrome in black basses ( Micropterus spp. )

Black bass ( Micropterus spp. ) are the most important warmwater game fishes in the United States. They have high socioeconomic and recreational value and support an important aquaculture industry. Since 2008, fisheries managers have been reporting the observation of hyperpigmented melanistic lesions (HPMLs) on smallmouth bass ( M. dolomieu ) in different ecoregions of the United States. Similar HPMLs have been observed in largemouth bass ( M. nigricans ) since the 1980’s. Here, we report the association between novel adomaviruses and the hallmark blotchy clinical presentation of hyperpigmented lesions on the skin of smallmouth and largemouth black bass. The two adomaviruses are structurally and phylogenetically similar but share only 68.0% identity at aligned nucleotide sites and each has been found in only one host species to date. The manifestation of this skin disease appears to be seasonal (observed between the fall and spring) in both species, primarily affects adults and is of unknown health consequence. Although the significance of infection to fish health remains unclear, understanding the disease ecology of these viruses can inform biosecurity and the interjurisdictional movement of individuals. Moreover, as hyperpigmentation in other fish species is often idiopathic, our findings reframe perspectives for future investigations into this clinical presentation in other species.

Michigan, Pennsylvania, Texas, Vermont, Virginia↗

USGS2025

Assessment of undiscovered oil and gas resources in the Haynesville Formation within the onshore United States and State waters of the Gulf Coast Basin, 2024

Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean resources of 152 million barrels of oil and 47.9 trillion cubic feet of gas in reservoirs of the Haynesville Formation within the onshore United States and State waters of the Gulf Coast Basin.

Alabama, Arkansas, Florida, Louisiana, Mississippi↗

USGS2025

Environmental characterization of Blue Mesa Reservoir and potential causes of and management strategies for harmful algal blooms, 1970 through 2023, Curecanti National Recreation Area, Colorado

Blue Mesa Reservoir, in the Curecanti National Recreation Area, is the largest storage reservoir in Colorado and consists of three distinct basins: Iola (the shallowest), Cebolla, and Sapinero. After algal toxins were first documented in Iola basin in 2018, the U.S. Geological Survey began a study in cooperation with the National Park Service, Colorado River Water Conservation District, Upper Gunnison River Water Conservancy District, Gunnison County, Project 7 Water Authority, and Uncompahgre Valley Water Users Association to better understand occurrence of toxic cyanobacteria harmful algal blooms (cyanoHABs) and identify possible causal mechanisms to potentially inform management strategies. Toxic cyanoHABS occurred when the algal toxin microcystin exceeded a concentration of 8 micrograms per liter primarily in Iola basin in 2018 and 2020–22, years having some of the lowest reservoir water-level elevations (reservoir levels) since 1984. The toxic cyanoHABs started in mid-September and continued through the fall months. Algal abundance was greatest in Iola basin compared to Cebolla and Sapinero basins, with Aphanizomenon , a toxin-producing cyanobacterium, being the most abundant. During blooms, enhanced algal photosynthesis caused elevated pH and dissolved oxygen concentrations especially in Iola basin. Continuous monitor data in Iola basin indicated peaks in phycocyanin fluorescence, pH, and dissolved oxygen concentration that preceded the onset of toxic cyanoHABs by about 2 weeks potentially indicating a useful early warning monitoring strategy for future response to toxic cyanoHABs. Long-term trends showed increases in mean air and surface-water temperatures and chlorophyll- a concentrations in the reservoir but no change in nutrient inputs from major tributaries. In Iola basin, reservoir level was positively correlated with Secchi disk depth and inversely correlated with total phosphorus concentration. Because of its shallow depth, the effect of low reservoir levels may disproportionately affect Iola basin compared to other basins, resulting in algal blooms and toxin production especially at reservoir levels below about 7,470 feet above North American Vertical Datum of 1988. Elevated phosphorus at low reservoir level likely was primarily phosphorus contained in algal tissue. This report indicates that the main driver for recent toxic cyanoHABs in Iola basin is low reservoir level that likely causes favorable conditions (shallow and warm) for algal growth and increased recruitment of algae from bottom sediments such as during wind-driven turbulence. Control of external nutrients to the reservoir is unlikely to help control algal blooms because Aphanizomenon fixes nitrogen from the atmosphere, and there is an abundant geogenic source of phosphorus. Maintenance of reservoir levels greater than about 7,470 feet might help minimize the occurrence of toxic cyanoHABs. Additional data could help better understand how the timing and duration of reservoir levels below 7,470 feet contribute to toxic cyanoHABs.

Colorado↗

USGS2025

U.S. Geological Survey—Department of the Interior, Region 11, Alaska—2023–24 biennial science report

Introduction U.S. Geological Survey (USGS) Mission—The USGS national mission is to monitor, analyze, and predict the current and evolving dynamics of complex human and natural Earth-system interactions and to deliver actionable information at scales and timeframes relevant to decision makers. Consistent with the national mission, the USGS in Alaska provides timely and objective scientific information to help address issues and inform management decisions across five interconnected focus areas: Energy and Minerals; Geospatial Mapping; Natural Hazards; Water Quality, Streamflow, and Ice Dynamics; and Ecosystems. The USGS in Alaska consists of approximately 350 scientists and support staff working in 3 Alaska-based science centers. USGS science activities are also initiated by the Cooperative Research Unit and USGS centers outside Alaska. In the last 5 years, USGS research in Alaska has produced many scientific benefits resulting from more than 900 publications. Publications relevant to Alaska can be conveniently searched by keyword through the USGS Publications Warehouse at https://pubs.usgs.gov/.

Alaska↗

USGS2025

Assessing streams in the Chesapeake Bay Watershed to guide conservation and restoration activities

Freshwater streams in the Chesapeake Bay watershed are home to numerous aquatic organisms (like fish, amphibians, mussels, and insects) and provide drinking water and recreational opportunities to people living in or visiting the watershed. Land-use changes, such as urban development and increased activities in certain agricultural sectors, have degraded water quality and altered conditions in these streams, thereby affecting their health and function. The U.S. Geological Survey (USGS) is working with Federal, State, and local partners to develop modeled assessments of stream health in freshwater streams and rivers within the Chesapeake Bay watershed. The USGS compiled large datasets for multiple stream health indicators, including instream stressors (salinity, water temperature, physical habitat, and streambank erosion) and living resources (macroinvertebrates and fish communities; fig. 1). These datasets were used by USGS scientists to develop models to predict stream health conditions across the entire region, including areas with little or no monitoring data. Collectively, these stream health assessments provide critical information to natural resource managers who implement restoration and conservation activities in the region.

Chesapeake Bay Watershed↗

USGS2025

Responding to ecological transformation in Capitol Reef National Park, Utah—Employee perspectives from pilot interviews from the Cross-Park Resist-Assist-Direct Project

Executive Summary Climate change is causing a range of changes that can affect the natural, cultural, and built resources of the Nation’s protected areas and affect opportunities to visit and recreate in these spaces. Changes in temperature and precipitation patterns also affect species and habitats, leading to ecological transformation. This report describes findings from pilot research conducted in Capitol Reef National Park, Utah (hereinafter referred to as “Capitol Reef” or “the Park”) as part of a larger interagency study of how National Park Service (NPS) staff are considering management of transforming ecosystems. Semi-structured interviews were used to assess how Capitol Reef employees (n=9) understand the challenge of ecological transformation, including their perceptions of how climate change is affecting the Park’s natural and cultural resources, the multiple timeframes over which employees respond to climate change impacts, and their awareness and understanding of ecological transformation and the Resist-Accept-Direct (RAD) framework, which was developed to address ecological transformation, that is, ecosystems changing in response to changes in climate conditions (Schuurman and others, 2020, 2022). The interviews also solicited employee perceptions about constraints and enabling factors that allow Capitol Reef to effectively respond to ecological transformation. The report uses a conceptual framework that has been used by the National Park Service Climate Change Response Program (Clifford and others, 2022) to structure the reporting of the data about constraints and enabling factors, with sections describing the role of factors internal to an individual employee (culture, worldviews, and understanding of an ecological system) and contextual factors external to an individual (institutional context, social feasibility and scientific uncertainty as influenced by available scientific information). Participating Capitol Reef staff perceived the most pressing climate impacts in the Park as increasing air temperatures, aridity, and flash floods, which are impacting natural and cultural resources, public safety, and infrastructure. Staff mostly agreed on what the future landscape (approximately 50 years into the future) may look like at Capitol Reef in terms of changes in vegetation and future temperature and precipitation conditions. However, staff had more divergent views or were uncertain about how specific species will adapt to future conditions (for example, how endemic plants might shift their ranges) and are grappling with which management strategies to take at which times. Staff also had differing opinions about how much data is needed to prompt action. Interviewees agreed that leadership in the Park had made climate change a priority and created a climate-attuned culture among staff. Participating employees described the park culture at Capitol Reef as collaborative, with frequent communication and work across divisions, which, as an example, shapes responses to flash floods and other events (for example, working across divisions on search and rescue, or repairing fencing that is washed out by storms). This collaborative, climate-attuned culture may help Capitol Reef in future problem-solving as it grapples with how to respond to climate change and ecological transformation in the Park.

Utah↗