Geology topics

Research about United States

Source-linked reports with geographic coverage including United States.

At least 1,333 records · Page 74Linked to original sources

USGS2025

Estimating the hypothetical endowment of critical minerals and other commodities in porphyry copper mine waste in the Four Corners states, USA

Society is fundamentally dependent upon commodities that are used in end-use products for the aerospace, defense, energy, telecommunication, and transportation sectors, resulting in centuries of mining to supply these commodities and materials. Waste from these mining operations can remain on the landscape indefinitely, but there is a lack of national understanding of the distribution and scale of such waste features. The renewable energy transition will continue to increase demand for critical minerals and will result in increasing volumes of mine waste on the Earth’s surface. Reprocessing mine waste can reduce environmental risks and recover needed commodities to match growing demand for societal growth. Therefore, understanding the approximate abundance of commodities that may be available for recovery within mine waste features can be an important piece of domestic critical mineral supply.

Arizona, Colorado, New Mexico, Utah↗

USGS2025

Regional differentiation in somatic growth and maturation attributes for loggerhead sea turtles (Caretta caretta) in the Northwest Atlantic

The ages and sizes at which organisms mature have significant implications for lifetime reproductive success. For species at risk of extinction, such as sea turtles, these attributes can ultimately impact probability of population persistence. Within the Northwest Atlantic Ocean, the broader loggerhead sea turtle ( Caretta caretta ) population comprises management units both along the US Gulf of America (formerly Gulf of Mexico) and Atlantic coasts. Although age, growth, and maturation have been more intensively studied along the US Atlantic, data specific to the Gulf of America have remained sparse. To address this data gap, we conducted skeletal growth mark analysis (skeletochronology) for 123 humerus bones collected from loggerheads found dead in the US Gulf of America from 1998 to 2021. We compared resulting age, growth, and maturation data with information from studies of US Atlantic coast loggerheads for similar size and year ranges, using the exact same skeletochronology methods, as well as with Gulf of America mark-recapture growth data. Results indicate that Gulf of America loggerheads exhibit significantly faster juvenile somatic growth. In addition, sizes at maturation were substantially smaller, corresponding with mean estimates of age at maturation 7.5 to 15 years earlier than US Atlantic counterparts. Finally, the maximum observed Gulf of America adult age estimate was 42.5 years, considerably less than the highest US Atlantic estimate of 77.0 years. These detailed data offer insights into regional variability in somatic growth dynamics and characteristics associated with maturation, which in turn can impact relative reproductive contributions and, ultimately, population trajectories.

Marine Biology↗

USGS2025

Tracking status and trends in seven key indicators of river and stream condition in the Chesapeake Bay watershed

Freshwater streams and rivers are recognized as vital habitats within the Chesapeake Bay watershed, which has been undergoing extensive restoration efforts for more than 30 years. Resource managers need to understand stream and river condition and how these conditions are changing over time to determine whether regional long-term restoration and conservation goals are being met. The objective of this report was to document the spatial and temporal variability of conditions for seven indicators of river and stream health across the nontidal Chesapeake Bay watershed. The framework for the U.S. Geological Survey’s Nontidal Network (NTN), a network of more than 100 nutrient and suspended sediment monitoring locations, was extended to assess conditions for six additional indicators of stream health: temperature, salinity, toxic contaminants, streamflow, hydromorphology, and biological aquatic communities. For each indicator, the latest available data from multiple sources were compiled and harmonized, and key metrics were identified to describe indicator conditions across space and time. A status condition was defined for each indicator to describe overall spatial variability in recent condition, and trend analyses were used to describe changes in each indicator metric over time. The analysis revealed clear differences in spatial and temporal data coverage across the seven indicators, so individual indicator trend analyses were not constrained to a common time interval. However, a status snapshot was conducted across all indicators for the 2015–17 period to simultaneously explore spatial variability across all indicators. The status snapshot highlighted general degraded conditions across multiple indicators in large metropolitan regions, such as the Baltimore–Washington, D.C., metropolitan area. Regression analysis between indicator status metrics and major land cover for the sites suggest urbanization as a potential driver of degraded conditions for many of the indicator metrics, including total phosphorus, salinity, temperature, high-flow frequency, and metrics of habitat and biological assemblage quality. A final analysis exploring the spatial representation of each indicator network showed that some indicator monitoring networks did not cover certain settings, such as small watersheds. These results provided an initial assessment of stream health status and trends and will continue to be leveraged to describe conditions across the Chesapeake Bay watershed to help inform local and regional management decisions. These results also highlighted the need for improved coordination among monitoring organizations to support long-term multi-indicator monitoring and assessment.

Chesapeake Bay watershed↗

USGS2025

Economic costs of invasive carps in the United States: Case study and management implications

Biological invasions can have far-reaching impacts and incur enormous monetary costs. Economic considerations play an important role in management decision-making. We used the invasion of U.S. waterways by silver ( Hypophthalmichthys molitrix ) and bighead ( H. nobilis ) carp as a case study of the costs of aquatic invasive species. Although these carps are well-known invaders, published reports on their economic costs are lacking. Our study included market values for commercial fisheries, non-market values for recreational fisheries, and management costs. Our results showed that by 2020, U.S. federal and state agencies had spent nearly $592 million in cumulative management costs. A difference-in-difference model testing for the effect of invasive carp on commercial harvest in invaded versus uninvaded reaches of the Mississippi and Illinois Rivers showed no statistical significance. A benefit transfer analysis of invasion effects on total economic value of recreational fishing, an important ecosystem service, in a heavily invaded section of the Illinois River estimated a total loss of more than $10 million over 10 years. While there are other known impacts on ecosystem services, including alteration of aquatic food webs, plankton communities, and native fish communities, these could not be quantified in economic terms in our analysis.

conterminous United States↗

USGS2025

Low genetic diversity in populations of a clonal invasive plant limits sexual reproduction

Premise Clonality, a form of asexual reproduction and spread, is common among invasive plants, though sexual reproduction via seeds is often still important for their long-range dispersal. In small populations, clonality has been hypothesized to interfere with sexual reproduction by limiting outcrossing opportunities of a plant. Methods We developed a structural equation model based on estimates of genetic diversity and seed production of Lepidium draba , a problematic invasive clonal plant, at 26 sites in Colorado to test whether site characteristics relating to small founder populations resulted in low genetic diversity and sexual reproduction. The next year, in pollen supplementation experiments at six sites (three with high genetic diversity, three with low), we tested whether populations with low genetic diversity were limited by non-self pollen. Results Large populations and populations associated with rivers tended to have higher genetic diversity. Percentage seed fill and total seed production were considerably higher at sites with higher genetic diversity. At populations with low genetic diversity, supplementation with pollen from outside of the site, but not from within the site, increased seed production. At populations with high genetic diversity, pollen supplementation from off-site did not increase seed production. Conclusions Our study shows that, in low-diversity populations that are dominated by a few large clones, L. draba produces few seeds compared to high-diversity populations and that this appears to be due to limited availability of non-self pollen. The data indicate that low genetic diversity decreases sexual reproduction, which may greatly reduce long-distance dispersal from these populations.

Colorado↗

USGS2025

Intrinsic and extrinsic factors simultaneously modulated the use of roadways by golden eagles during winter.

Animals often face trade-offs wherein foraging opportunities may coincide spatiotemporally with higher risk of mortality, especially within landscapes altered by humans. Resolving such trade-offs can depend on intrinsic factors such as age and sex, and extrinsic factors (e.g., resource availability) within the surrounding environment. Yet both are rarely assessed simultaneously. Roads constitute a widespread form of human-induced habitat alteration that concurrently offer potential food rewards, in the form of carrion from roadkill, and risk in the form of death by vehicle collision. We evaluated the extent to which suites of intrinsic and extrinsic factors modulated the selection for areas near roads by a large opportunistic scavenger, the golden eagle ( Aquila chrysaetos ). We used a collaborative, multi-agency telemetry dataset of 51 golden eagles overwintering in Wyoming, USA during 2014 to 2023 representing 175 unique eagle-years. Both intrinsic and extrinsic factors influenced road use. Males were 14.2 times more likely than females to select areas closer to roads. Adults, compared with their subadult counterparts (Subadult I, Subadult II, and Subadult III) were 16.3, 16, and 15.3 times more likely to select areas near roads, respectively. Moreover, individuals were more likely to select areas near roads during periods with higher snow depth on the landscape. Specifically, during periods of high snow depth (> 17.9 cm) golden eagles were 17 times more likely to select areas near roads than during periods with no snow. Our results suggest that both intrinsic and extrinsic factors influenced proximate habitat decisions and the use of areas near risky landscape elements. Our work has important implications for the contexts under which efforts to reduce golden eagle mortality, such as the removal of carcasses from roads, would be most effective.

Wyoming↗

USGS2025

Some of these are not like the others: Relative thermal sensitivity among anuran species of the Southeast United States

Estimating how close a species is to its upper thermal limits (i.e., warming tolerance, a thermal sensitivity index) and how that proximity changes across space enables spatially explicit identification of species with increased extinction risk as temperatures increase. Yet, thermal sensitivity is often difficult to calculate because it is the result of many traits. We aimed to synthesize multiple traits into a single estimate of relative terrestrial thermal sensitivity for 13 anuran species in the southeastern United States. We employed models that incorporate traits and microclimate variation to (1) estimate species warming tolerance (the difference between species critical thermal maximum and modeled operative temperature, an estimate of body temperature) and (2) investigate how warming tolerance varied with latitude (whereby latitude represents different temperature regimes and external drivers of thermal sensitivity). We ran mechanistic niche models across a 12° latitudinal gradient and 10 years to estimate individual operative temperature. We calculated the minimum, 25th percentile (hottest quarter), and median daily minimum warming tolerance. Estimates of minimum warming tolerance spanned −5 to 10°C ( Lithobates palustris and Gastrophryne carolinensis respectively) and differed among species. For most species, modeled operative temperatures exceeded species' critical thermal maximum during extreme warm temperatures (i.e., heat waves) in part of their range, and warming tolerance increased with latitude. During heat waves, five species had lower warming tolerance at higher latitudes, and three species' warming tolerance did not change with latitude. We identified species that are approaching their thermal limits in the Southeast and characterized spatial patterns of warming tolerance. Increased temperatures could increase anuran extinction risk, posing an additional challenge for threatened anuran species. Spatial patterns of warming tolerance were not consistent among species in our study, highlighting that patterns identified at higher taxonomic categories could be inconsistent at lower taxonomic categories.

southeastern United States↗

USGS2025

Assessing American eel (Anguilla rostrata) distribution in a heavily dammed watershed using eDNA : The Penobscot River watershed, Maine, USA

Catadromous American eel ( Anguilla rostrata ) are native to Maine's Penobscot River watershed and historically have migrated through many of its tributaries prior to extensive damming. Recent restoration efforts, including dam removals, have improved connectivity in the lower reaches of the Penobscot River. Characterizing the extent of the American eel's distribution is important to inform restoration and identify extant barriers to migrations within the watershed. In the summer of 2023, we conducted eDNA surveys throughout the Penobscot River watershed to estimate the current distribution of the American eel and identify barriers to inland waters. Water samples were collected from 70 sites representing 37 rivers and streams; the presence or absence of American eel genetic markers within those samples was assessed using qPCR. We have shown that American eel are present in virtually the full extent of the area surveyed (68/70 sites). The results suggest that the majority of the main-stem dams may be passed by American eels at some level, with eel DNA being confirmed upstream of six dams. We confirmed the presence of American eels throughout the lower watershed with just 1 week of eDNA sampling and have highlighted this method for determining the species' access to habitat upstream of dams. The use of eDNA to sample locally (or regionally) for American eel may provide cost-effective information in data deficient areas and help assess the permeability of dam structures to diadromous species.

Maine↗

USGS2025

Bridging theory and practice to inform seed selection for restoration

Introduction Land managers often face the critical decision of what plant materials to select for ecological restoration. Selection depends on factors that span ecological conditions and human interventions in the restoration process, which can strongly influence the recovery of a degraded ecosystem. Objectives To improve the seed selection process, we compared scientific literature and guidance from five federal agencies to bridge seed selection “theory” and “practice” in the interior western and central United States. Methods We extracted recurring themes and keywords associated with abiotic, biotic, land management, and producer practices that influence seed selection and analyzed their proportional use between agency guidance and scientific literature. Results We identified significant overlap between key concepts in guidance and literature, highlighting the interconnectedness between science and management. However, nuanced patterns emerged across seed selection themes, including more focus in the literature on local adaptation and genetic structure, ramifications of introducing gene flow and artificial selection during plant production, and provenancing strategies to address changing climatic conditions. In contrast, agency guidance focused on genetically appropriate and environmentally suitable seed selection and practical concerns, including seed cost, availability, and diversity. Seed selection studies in the literature were concentrated in the Great Basin and Colorado Plateau, scattered in the Great Plains, and were largely experimental. Conclusions Our review suggests new opportunities for co-production of science and decision-making frameworks among researchers, land managers, and seed producers to inform seed selection guidance for restoration.

Restoration Ecology↗

USGS2025

Magnitude, depth and methodological variations of spectral stress drop within the SCEC/USGS Community Stress Drop Validation Study using the 2019 Ridgecrest Earthquake Sequence

We present the first ensemble analysis of the 56 different sets of results submitted to the ongoing Community Stress Drop Validation Study using the 2019 Ridgecrest, California, earthquake sequence. Different assumptions and methods result in different estimation of the source contribution to recorded seismograms, and hence to the source parameters (principally corner frequency, f c ⁠ , spectral stress drop, Δσ, and seismic moment, M 0 ⁠ ) obtained from modeling calculated source spectra. For earthquakes smaller than magnitude (M) 2.5 there is negligible correlation between the f c values obtained by different studies, implying that no present method is reliable using available data. For larger magnitude events, correlation between f c measurements of different studies, within even a small M range is always higher than spectral ⁠Δσ , because the f c measurements simply reflect the underlying physical decrease in f c with increasing M. We model the observed trends of submitted f c with both magnitude and depth. Most methods report an increase in spectral Δσ with M, although a magnitude‐invariant spectral Δσ is within the confidence limits. The depth dependence is smaller and depends on whether a study allows attenuation to vary with source depth; a combination of depth‐dependent attenuation correction, and depth‐dependent shear‐wave velocity can compensate for reported depth trends. We model the submitted values to remove differing M and depth variation to investigate the relative interevent variability. We find consistent relative variation between individual events, and also lower relative spectral Δσ in the northwest of the aftershock sequence, and higher on the cross fault and in the region of main fault intersection. This large‐scale comparison implies that absolute spectral Δσ estimates are dependent on the methods used; studies of different regions or using different methods should not be directly compared and improved constraints on path and site corrections are needed to resolve these absolute spectral Δσ differences.

California↗

USGS2025

Decision analysis in support of the National Elk Refuge bison and elk management plan

Preface This report was developed to evaluate the performance of a set of proposed alternatives for Cervus elaphus canadensis (elk) and Bison bison (bison) management at the National Elk Refuge (NER) in Wyoming, U.S.A., and to inform a National Environmental Policy Act Environmental Impact Statement focused on developing the next “Bison and Elk Management Plan” (BEMP). The U.S. Geological Survey facilitated a structured decision-making process for the U.S. Fish and Wildlife Service to develop the alternatives and the criteria (performance metrics) for evaluating the alternatives. Chapter A provides scoping details of the report, a summary of the 19 metrics that are used to evaluate the performance of each of 6 alternatives, and methodological details of 2 performance metrics that were not covered in other technical chapters. Chapter B analyzes elk population and chronic wasting disease dynamics under the five initial alternatives. Chapter C evaluates elk space-use based on data collected from global positioning system collars on elk and expert elicitation for scenarios with limited data. Chapter D evaluates bison population dynamics, conflict, and harvest patterns under the five initial alternatives. Chapter E assesses social and economic consequences. Chapter F is newly added to this superseding report and details the analysis and results of a new alternative that was developed after discussion among the lead and cooperating agencies working on the BEMP. The full set of six alternatives are anticipated to have varying affects on bison and elk population abundance and private land use, wildlife-related recreation and tourism, and hunters and outfitters in the region. Each chapter was developed under advisement of a technical team, made up science experts from U.S. Fish and Wildlife Service, National Park Service, U.S. Forest Service, and Wyoming Game and Fish Department.

Wyoming↗

USGS2025

Decision framing overview and performance of management alternatives for bison and elk feedground management at the National Elk Refuge in Jackson, Wyoming

This report was developed to evaluate the performance of a set of proposed alternatives for Cervus elaphus canadensis (elk) and Bison bison (bison) management at the National Elk Refuge in Wyoming, U.S.A., and to inform a National Environmental Policy Act Environmental Impact Statement focused on developing the next “Bison and Elk Management Plan” (BEMP). The U.S. Geological Survey facilitated a structured decision-making process for the U.S. Fish and Wildlife Service to develop the alternatives and the criteria (performance metrics) for evaluating the alternatives. Chapter A (this chapter) provides scoping details of the “BEMP,” a summary of the 19 metrics used to evaluate the performance of each of the 6 alternatives, and methodological details of 2 performance metrics that were not covered in other technical chapters. Additional technical details, results, and interpretations are briefly covered in this chapter but are mostly contained in chapters B–F.

Wyoming↗

USGS2025

Predictions of elk and chronic wasting disease dynamics at the National Elk Refuge in Jackson, Wyoming, and surrounding areas

The U.S. Fish and Wildlife Service National Elk Refuge (NER) in Jackson, Wyoming, supplementally feeds Cervus elaphus canadensis (elk) and Bison bison (American bison) during winter months, but the costs and benefits of this management strategy are being reevaluated considering the potential effects of chronic wasting disease (CWD) on elk. U.S. Geological Survey scientists worked with the U.S. Fish and Wildlife Service on a structured decision-making process that considered five alternative feeding strategies and their effects on bison, elk, and humans. This chapter focuses on elk population dynamics and CWD using computer models. Our modeling results highlight a short-versus long-term tradeoff between the continue feeding and no feeding alternatives. Management alternatives associated with a cessation of supplemental feeding were assumed to make elk more susceptible to severe winters, resulting in initially lower population sizes and less CWD transmission. The increased CWD prevalence and transmission associated with the continue feeding alternative resulted in lower elk population sizes by year 20 (mean=6,700, standard deviation=1,600 in the analysis area) in 70 percent of simulations compared to no feeding (mean=8,400, standard deviation=1,500). No feeding alternatives resulted in higher elk populations than the continue feeding alternative between years 7 and 13 when CWD prevalence exceeded 20 percent in the Jackson elk herd. The increased harvest alternative minimized CWD and natural mortality in 83 out of 100 simulations compared to the continue feeding alternative.

Wyoming↗

USGS2025

Evaluating elk distribution and conflict under proposed management alternatives at the National Elk Refuge in Jackson, Wyoming

We evaluated measurable attributes describing the current and future distribution of Cervus elaphus canadensis (elk) across a region surrounding Jackson, Wyoming, for five feedground management alternatives proposed by the U.S. Fish and Wildlife Service as a revision to the 2007 “Bison and Elk Management Plan” of the National Elk Refuge. A resource selection function evaluated measurable attributes of interest to managers, including elk use of private property and sensitive habitat types at monthly timesteps and varying winter conditions. The study area boundaries were created through an expert elicitation process and consist of the Jackson Elk Herd Unit, Grand Teton National Park, the National Elk Refuge, and the northern third of the Fall Creek Elk Herd Unit. For each of the five alternatives, we distributed monthly elk numbers calculated in a concurrent analysis that simulated chronic wasting disease dynamics in this system for 20 years. Measurable attributes representing potential elk use of (1) private property, (2) cattle properties as an index of Brucella abortus risk, and sensitive habitats consisting of (3) Populus tremuloides Michx. (quaking aspen), (4) Populus angustifolia E. James (narrowleaf cottonwood), and (5) Salix L. (willow) in core winter use areas all closely followed the declines of elk abundance projected by the elk chronic wasting disease model. After 20 years, the continue feeding alternative ranked most favorably in terms of limiting elk days on private property and reducing brucellosis risk from elk to cattle because this alternative concentrated elk on the National Elk Refuge and resulted in the lowest elk population sizes. However, other management alternatives, including increase harvest and reduce feeding, tended to limit elk use of sensitive quaking aspen, narrowleaf cottonwood, and willow habitats during winter (December–April).

Wyoming↗

USGS2025

Bison population dynamics, harvest, and human conflict potential under feedground management alternatives at the National Elk Refuge in Jackson, Wyoming

Bison bison were once abundant across North America but declined due to overharvesting in the late 1800s. The reintroduced population in and around Jackson, Wyoming has averaged 485 individuals between 2018–2023 and is the subject of a planning process to inform management strategies that will guide the U.S. Fish and Wildlife’s next “Bison and Elk Management Plan” for the National Elk Refuge. This small population may benefit from historical winter-feeding operations on the National Elk Refuge because those operations may increase overwinter survival and limit human-bison conflicts, which are the number of individual bison that engage in nuisance, damaging, or otherwise aggressive behaviors with humans and livestock, that may lead to culling and other sources of mortality (for example, vehicle collisions). To inform the next “Bison and Elk Management Plan,” the U.S. Geological Survey used a population model to evaluate five management alternatives for bison and Cervus elaphus canadensis feedground operations that included continuing the elk and bison feeding program, immediately stopping the feeding program, and three other alternatives that would phase out the feeding program after a period of time. The results indicate that the bison population would be expected to decline over the next 20 years under all alternatives that stop feeding bison on the refuge. Further, this decline would lead to an associated reduction in bison harvest opportunities for resident, nonresident, and Tribal hunters. Finally, human-bison conflicts would also be expected to increase under the no feeding alternatives because bison may venture onto private lands in greater numbers if feed is not provisioned during winter months. In combination, these results suggest that feeding may lead to better outcomes for bison over the next 20 years; however, these effects may be traded off against other downsides of the feedground program, such as increased rates of animal-to-animal contact on feedgrounds that can lead to disease transmission.

Wyoming↗

USGS2025

Estimating the social and economic consequences of proposed management alternatives at the National Elk Refuge in Jackson, Wyoming

The National Elk Refuge (Refuge) is managed by the U.S. Fish and Wildlife Service and includes habitats for bison and elk. Bison and elk provide opportunities for wildlife-related recreation and contribute to the tourism industry in and around Jackson, Wyoming. Over the last century, the Refuge has provisioned supplemental feed to elk and, more recently, bison during winter months to ensure adequate forage and prevent starvation and conflict with private landowners. However, supplemental feeding artificially aggregates animals and can increase rates of disease transmission and localized damage to sensitive habitats near the feeding areas. This report presents analyses and results to support two of the nine management objectives in the next “Bison and Elk Management Plan,” with a particular focus on the social and economic consequences of five management alternatives considered in this study. The alternatives are to continue feeding bison and elk during winter months on the Refuge, stop feeding after CWD is measured at 3 percent prevalence or above in the Jackson elk herd, stop feeding immediately, reduce feeding for five years and then stop feeding, and increase elk harvest for five years and then stop feeding. These alternatives are anticipated to alter bison and elk population and space-use dynamics, with corresponding effects on wildlife-related recreation and tourism, including the number of visitors and sleigh-ride participants on the Refuge, and hunters and outfitters within the Jackson Elk Herd Unit. The performance of each of this study’s alternatives was variable, resulting in overlap in the performance of alternatives on the select objectives over the next 20 years. Generally, visitation-related objectives performed better under the continue feeding alternative, whereas hunting-related objectives performed better under the increase harvest alternative. The results presented here may assist U.S. Fish and Wildlife Service decision makers in balancing social and economic benefits identified in the decision-making process for the “Bison and Elk Management Plan” with other objectives evaluated in this report.

Wyoming↗

USGS2025

Turning trash into treasure: Leveraging discarded filters for national-scale aquatic eDNA biomonitoring

Monitoring biodiversity changes over large spatiotemporal scales is critical for effective ecosystem conservation and management. This study investigates the potential of environmental DNA (eDNA) metabarcoding to enhance national-scale biomonitoring of freshwater diversity by leveraging discarded filters associated with routine water quality sampling from the U.S. Geological Survey's (USGS) National Water Quality Network (NWQN). We tested 375 samples from 103 NWQN sites for eDNA of native and non-native fish and found that 52% of the filters yielded fish eDNA for a total of 70 fish species detections. Of the filters that had fish eDNA present, an average of 3.7 species were detected. Benchmarking these results to USGS's Aquatic Gap Analysis Project (AGAP)—which includes both field-verified observations along with predictive models derived from fish capture and landscape predictor datasets—we found that eDNA from these filters detected only a fraction of the observed and expected fish diversity for these sites. Our results indicate that these discarded filters may not be sufficient for eDNA sampling of fish communities and posit that alternative filter types more appropriate for eDNA sampling may yield more valuable biomonitoring data. Nevertheless, we tested the efficacy of two novel approaches to facilitate large-scale biomonitoring. Though these filters did not yield adequate fish eDNA, the AGAP database provides a useful method for ground truthing fish species presence. The potential of integrating eDNA sampling into existing monitoring frameworks, which, when paired with more optimal eDNA methods, could be a cost-effective strategy to enhance biodiversity monitoring at large scales.

Aquaculture, Fish and Fisheries↗

USGS2025

Characterizing projected future droughts for south Florida (2056–2095)

Balance anomalies, defined as the deviation of monthly precipitation minus reference evapotranspiration from their long-term monthly historical means (1950–2005), were computed for regions in south Florida and temporally averaged over 6- and 12-month timescales to identify meteorological drought events during a historical (1950–2005) and future (2056–2095) period of interest for 40 CMIP5 general circulation models (GCM) and scenario combinations downscaled by the Multivariate Adaptive Constructed Analogs method. Under the assumption of stomatal resistance ( r s ) remaining constant at the historical standard value (70 s/m), 81% of models project declines in monthly balance anomalies in the future compared to historical, with multimodel ensemble mean declines of 3.7 in/year under RCP4.5 and 8.7 in/year under RCP8.5. Drought events were identified from the downscaled model projections, their characteristics (duration and intensity) extracted, and their historical joint distributions validated against those derived from historical observational datasets. The future joint distributions of drought characteristics were compared across models using hierarchical clustering. A climate model summary plot and table were developed based on these methods to guide climate model selection for hydrologic modeling in support of water-supply planning at the South Florida Water Management District (SFWMD). The model summary plot for the entire SFWMD shows that 35% of GCM/training-dataset combinations have historical joint distributions of drought characteristics that are significantly different at the 10% level from those derived from observational gridded data, whereas 39% of GCM/scenario/training-dataset combinations have future joint distributions that are significantly different from historical. A sensitivity analysis was performed assuming r s increasing with increasing CO 2 .

Florida↗