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At least 577 records · Page 32Linked to original sources

USGS2016

Potential utility of environmental DNA for early detection of Eurasian watermilfoil ( Myriophyllum spicatum )

Considering the harmful and irreversible consequences of many biological invasions, early detection of an invasive species is an important step toward protecting ecosystems (Sepulveda et al. 2012). Early detection increases the probability that suppression or eradication efforts will be successful because invasive populations are small and localized (Vander Zanden et al. 2010). However, most invasive species are not detected early because current tools have low detection probabilities when target species are rare and the sampling effort required to achieve acceptable detection capabilities with current tools is seldom tractable (Jerde et al. 2011). As a result, many invasive species go undetected until they are abundant and suppression efforts become costly. Novel DNA-based surveillance tools have recently revolutionized early detection abilities using environmental DNA (eDNA) present in the water (Darling and Mahon 2011, Bohmann et al. 2014). In brief, eDNA monitoring enables the identification of organisms from DNA present and collected in water samples. Aquatic and semiaquatic organisms release DNA contained in sloughed, damaged, or partially decomposed tissue and waste products into the water and molecular techniques allow this eDNA in the water column to be identified from simple and easy-tocollect water samples (Darling and Mahon 2011). Despite limited understanding of the production, persistence, and spread of DNA in water (Barnes et al. 2014), eDNA monitoring has been applied not only to invasive species (Jerde et al. 2011), but also to species that are rare, endangered, or highly elusive (Spear et al. 2014). However, most eDNA research and monitoring has focused on detection of invertebrates and vertebrates and less attentionhas been given to developing eDNA techniques for detecting aquatic invasive plants. Eurasian watermilfoil (EWM; Myriophyllum spicatum L.) is an invasive species for which improved early detection would be particularly helpful. Advanced EWM invasions have negative impacts on native biodiversity, recreational boating, fishing, and other types of aquatic tourism (e.g., Eiswerth et al. 2000). On a broader scale, EWM can also be harmful to man-made aquatic infrastructure, such as hydroelectric dams. If an EWM invasion can be detected in an early stage where eradication is still a possibility, many of these negative consequences can be limited or prevented altogether (e.g., Madsen et al. 2002). The purpose of this research was to develop and validate a traditional polymerase chain reaction (PCR) assay for the detection of pure and hybridized EWM DNA using both laboratory and field experiments. We performed a pilot experiment in outdoor tanks to determine the basic functionality and sensitivity of the assay. Following this initial test, we collected field samples from Michigan and Montana lakes with and without known EWM populations. Taken together, our findings suggest that eDNA techniques have potential to be a useful strategy for the early detection of EWM.

Journal of Aquatic Plant Management↗

USGS2009

Holocene core logs and site statistics for modern patch-reef cores: Biscayne National Park, Florida

The bedrock in Biscayne National Park (BNP), a 1,730-square kilometer (km2) region off southeast Florida, consists of Pleistocene (1.8 million years ago (Ma) to 10,000 years ago (ka)) and Holocene (10 ka to present) carbonate rocks (Enos and Perkins, 1977; Halley and others, 1997; Multer and others, 2002). Most of the surficial limestone in BNP, including the islands of the Florida Keys, was formed at ~125 ka during the highstand of marine oxygen-isotope substage 5e, when sea level was approximately 6 meters (m) higher than today (Chappell and Shackleton, 1986; Multer and others, 2002; Lidz and others, 2003; Siddall and others, 2003; Balsillie and Donoghue, 2004). During the substage-5e regression, the entire Florida Platform became exposed. Subaerial exposure lasted for approximately 115,000 years (kyr), which resulted in erosion and enhancement of karst-like features (Lidz and others, 2006). As the Holocene transgression began to flood the Florida shelf ~7 to 6 ka, the bedrock depression under Biscayne Bay began to flood, and Holocene coral and reef debris laid the foundation for the present reef system (Enos and Perkins, 1977; Lighty and others, 1982; Toscano and Macintyre, 2003; Lidz and others, 2006). More than 3,000 patch reefs exist within the BNP boundary. Most contain hermatypic corals of various species such as those belonging to Montastrea, Diploria, Siderastrea, Porites, Acropora, and Agaricia. Patch reefs within BNP have two morphologies: pinnacle and flat top. Experimental Advanced Airborne Research Lidar (EAARL) data collected along the offshore BNP coral reef tract show that these two morphologies are clearly defined both in the high-resolution bathymetry maps produced by the Lidar data and by statistical analyses of the Lidar dataset (Brock and others, 2008). Brock and others (2008) also show that the pinnacle patch reefs are deeper than the more shallow, broad, and flat patch reefs. The control for these two patch-reef morphologies is unclear; however, their shapes may be due to a slightly lowered sea level or a stillstand in the middle-Holocene around 4 ka that caused erosion of the shallower reefs and allowed the deeper reefs to remain unaffected. Lidz and others (2006) have suggested a stillstand around 4 ka that carved a 2.5-kilometer (km)-wide nearshore rock ledge into the seaward side of every island in the Florida Keys. The objectives of this study were to sample living corals to understand the more recent (<200 years) changes in climate and environmental conditions of the area and to investigate the Holocene (in this case, <8,000 years in the Florida Keys) depositional history at progressively deeper patch-reef sites. This report provides statistics for the cores and core sites and a basic lithologic description of these Holocene cores.

Florida↗

USGS2021

Estimating age and growth of invasive sea lamprey: A review of approaches and investigation of a new method

We review recent advances in age and growth estimation of invasive sea lamprey ( Petromyzon marinus ) in the Great Lakes and present a more accurate method for growth estimation. To forecast growth and prioritize streams for control actions, sea lamprey managers currently use an average daily growth model. Here, a new linear model that included stream and lake as contributing variables was investigated and found to outperform the currently used growth model (roughly a 10 mm difference at age 1). Length-at-age of larvae between ages 1 and 4 were also best forecasted by a linear model with the predictor variables including growing degree days, stream, lake, and larval lamprey density. The model predicts that larval sea lamprey grow faster in warm streams with low densities of lamprey larvae. More accurate growth models could allow sea lamprey control managers to improve decisions concerning how sea lamprey control effort is allocated among streams, and could help inform broader modeling efforts evaluating the population demographics of a lake-wide populations exposed to varying control and environmental scenarios. Priority areas for research include investigating if temperatures have increased in sea lamprey-producing streams in response to climate change, using close-kin mark-recapture to mark family groups at age 1 to age large larvae and transformers years later, and determining if sex determination is environmentally mediated by larval growth and density.

Great Lakes↗

USGS2022

The MODFLOW Application Programming Interface for simulationcontrol and software interoperability

The MODFLOW API allows other programs to control MODFLOW and interactively change variables without having to modify the source code. The MODFLOW API is based on the Basic Model Interface (BMI), which is a set of conventions that define how to initialize a simulation, update the model state by advancing in time, and finalize the run. For many existing MODFLOW coupling applications, the information provided to MODFLOW must be updated multiple times in a time step. As this capability to modify variables within a time step is not defined by the BMI, an extension to BMI was developed. This eXtended Model Interface is part of the MODFLOW API and allows such a tight coupling to other models. Examples are included for a variety of use cases, including new flexibility for users to develop custom packages without modifying the MODFLOW source code and coupling MODFLOW with other models and optimization libraries.

Environmental Modelling & Software↗

USGS2005

Microbial biogeochemistry of uranium mill tailings

Uranium mill tailings (UMT) are the crushed ore residues from the extraction of uranium (U) from ores. Among the radioactive wastes associated with the nuclear fuel cycle, UMT are unique in terms of their volume and their limited isolation from the surficial environment. For this latter reason, their management and long-term fate has many interfaces with environmental microbial communities and processes. The interactions of microorganisms with UMT have been shown to be diverse and with significant consequences for radionuclide mobility and bioremediation. These radionuclides are associated with the U-decay series. The addition of organic carbon and phosphate is required to initiate the reduction of the U present in the groundwater down gradient of the mills. Investigations on sediment and water from the U-contaminated aquifer, indicates that the addition of a carbon source stimulates the rate of U removal by microbial reduction. Moreover, most attention with respect to passive or engineered removal of U from groundwaters focuses on iron-reducing and sulfate-reducing bacteria.

Advances in Applied Microbiology↗

USGS2024

The potential for species distribution models to distinguish source populations from sinks

1. While species distribution models (SDM) are frequently used to predict species occurrences to help inform conservation management, there is limited evidence evaluating whether habitat suitability can reliably predict intrinsic growth rates or distinguish source from sink populations. Filling this knowledge gap is critical for conservation science, as applications of SDMs for management purposes ultimately depend on these typically unobserved population or metapopulation dynamics. 2. Using regression, we associate previously published population level estimates of intrinsic growth and abundance derived from a Bayesian analysis of mark-recapture data for 17 bird species found in the contiguous United States with SDM habitat suitability estimates fitted here to opportunistic data for these same species. We then use AUC to measure how well SDMs can distinguish populations categorized as sources and sinks, depending on their intrinsic growth rates estimated from the mark-recapture data. We built SDMs using two different approaches, boosted regression trees (BRT) and Generalized Linear Models (GLM), and compared their predictive performance. Each SDM was built with presence points obtained from eBird and 10 environmental variables previously selected to model intrinsic growth rates and abundance for these species. 3. We show that SDMs built with opportunistic data are poor predictors of species demography in general; both BRT and GLM explained very little spatial variation of intrinsic growth rate and population abundance (median R2 across 17 species was close to 0.1 for both SDM methods). SDMs do, however, estimate higher suitability for source populations as compared to sinks. Out of 13 species which had both source and sink populations, both BRT and GLM had AUC values greater than 0.7 for 7 species when discriminating between sources and sinks. 4. Habitat suitability have the potential to be a useful measure to indicate a population’s ability to sustain itself as a source population, however more research on a diverse set of taxa is essential to fully explore this potential. This interpretation of habitat suitability can be particularly useful for conservation practice, and identification of explicit cases of when and how SDMs fail to match population demography can be informative for advancing ecological theory.

Journal of Animal Ecology↗

USGS2014

Long Term Resource Monitoring Program procedures: fish monitoring

This manual constitutes the second revision of the U.S. Army Corps of Engineers’ Upper Mississippi River Restoration-Environmental Management Program (UMRR-EMP) Long Term Resource Monitoring Program (LTRMP) element Fish Procedures Manual. The original (1988) manual merged and expanded on ideas and recommendations related to Upper Mississippi River fish sampling presented in several early documents. The first revision to the manual was made in 1995 reflecting important protocol changes, such as the adoption of a stratified random sampling design. The 1995 procedures manual has been an important document through the years and has been cited in many reports and scientific manuscripts. The resulting data collected by the LTRMP fish component represent the largest dataset on fish within the Upper Mississippi River System (UMRS) with more than 44,000 collections of approximately 5.7 million fish. The goal of this revision of the procedures manual is to document changes in LTRMP fish sampling procedures since 1995. Refinements to sampling methods become necessary as monitoring programs mature. Possible refinements are identified through field experiences (e.g., sampling techniques and safety protocols), data analysis (e.g., planned and studied gear efficiencies and reallocations of effort), and technological advances (e.g., electronic data entry). Other changes may be required because of financial necessity (i.e., unplanned effort reductions). This version of the LTRMP fish monitoring manual describes the most current (2014) procedures of the LTRMP fish component.

Illinois;Iowa;Minnesota;Montana;Wisconsin↗

USGS2022

Local diversity in phenological responses of migratory lake sturgeon to warm winters

Rich intraspecific diversity in traits that shape responses to environmental conditions implies that effects of climate change will differ within species or even populations. Nevertheless, few studies investigate how different groups within species respond to climatic fluctuations, and most risk assessments rely upon species-wide generalizations. We studied effects of among-year variation in air temperature on the spring migratory phenology of a metapopulation of lake sturgeon Acipenser fulvescens within waters connecting Lake Huron and Lake Erie of the Laurentian Great Lakes. Sturgeon here express multiple migratory phenotypes that all spawn in either the St. Clair River or Detroit River but differ in their use after spawning of more than 86 000 km 2 of accessible lake and river habitat. Acoustic tracking over nine years (2012–2020) revealed mixed phenological responses to late-winter air temperatures, with three migratory groups arriving at rivers earlier during warm years and one whose arrival was consistent across years regardless of temperature. Notably, two groups that spawn in the same river but overwinter in different lakes entered the river with greater synchrony during warm years because one advanced its phenology while the other did not. The results indicated warm weather could alter the dynamics of the metapopulation and broader community, and exemplify the complexity hidden beneath broadscale generalizations of species' response to climate change.

Michigan, Ontario↗

USGS2016

Forecasting climate change impacts on plant populations over large spatial extents

Plant population models are powerful tools for predicting climate change impacts in one location, but are difficult to apply at landscape scales. We overcome this limitation by taking advantage of two recent advances: remotely sensed, species-specific estimates of plant cover and statistical models developed for spatiotemporal dynamics of animal populations. Using computationally efficient model reparameterizations, we fit a spatiotemporal population model to a 28-year time series of sagebrush ( Artemisia spp.) percent cover over a 2.5 × 5 km landscape in southwestern Wyoming while formally accounting for spatial autocorrelation. We include interannual variation in precipitation and temperature as covariates in the model to investigate how climate affects the cover of sagebrush. We then use the model to forecast the future abundance of sagebrush at the landscape scale under projected climate change, generating spatially explicit estimates of sagebrush population trajectories that have, until now, been impossible to produce at this scale. Our broadscale and long-term predictions are rooted in small-scale and short-term population dynamics and provide an alternative to predictions offered by species distribution models that do not include population dynamics. Our approach, which combines several existing techniques in a novel way, demonstrates the use of remote sensing data to model population responses to environmental change that play out at spatial scales far greater than the traditional field study plot.

Wyoming↗

USGS2023

Hydrogeology of sand and gravel aquifers in the Owasco Inlet watershed, Cayuga and Tompkins Counties, New York

This study is a continuation of a series of hydrogeologic appraisals that have been conducted since 1980, as part of a cooperative, long-term, detailed aquifer mapping program by the U.S. Geological Survey and the New York State Department of Environmental Conservation. These appraisals provide a foundation for wellhead protection programs, water-resource management and planning decisions, and groundwater remediation in upstate New York. The Owasco Inlet watershed drains north directly to Owasco Lake, one of New York’s Finger Lakes. The watershed is similar in form to other watersheds of the Finger Lakes region of New York State and is characterized by broad, smooth uplands punctuated by the 18-mile-long Owasco Inlet valley and the secondary valleys of Decker, Dresserville, and Hemlock Creeks. All these streams occupy “through valleys”—the valleys are continuous into adjacent watersheds such that watershed divides are high points within the valley bottoms, rather than in uplands. Most glacial deposits in the watershed were deposited during the Valley Heads Readvance and subsequent retreat (with at least one minor readvance). Estimates are that the Valley Heads Readvance likely peaked in the Cayuga basin about 17,000 (calendar) years ago based on dates from western New York and the Mohawk Valley in east-central New York. It was the last major ice advance of the Pleistocene Epoch in this region. This readvance covered the entire Owasco watershed. Valley Heads ice in the Owasco watershed was part of the Cayuga ice lobe, which flowed parallel to the Owasco Inlet valley as far south as Moravia, but which became progressively more eastward south of Locke, effectively raking across the valley from the west. The Owasco Inlet watershed drains north, like other Finger Lakes watersheds, and during deglaciation, northward meltwater drainage was largely blocked by the ice, which resulted in development of a series of regional proglacial lakes in which fine lacustrine sediments predominated. Lacustrine sediments constitute much of the Owasco Inlet valley fill, but it has been pointed out that there are no obvious outlet channels exiting the Owasco Inlet watershed, and it has been proposed that there was northward drainage of meltwater into the ice within the larger, neighboring Cayuga Trough. The lacustrine deposits in the Owasco Inlet valley are commonly underlain by thinner coarse-grained stratified deposits (subaqueous fans and eskers) of variable sorting and permeability. An exception occurs at Groton, N.Y., where retreating ice paused long enough for coarse-grained sediments to fill much of the valley. Smaller, higher elevation valleys have a wider variety of glacial valley-fill deposits, ranging from fine lacustrine sediments to sand and gravel to till. Groundwater is the sole source of water supply in the area; glacial sand and gravel aquifers are the primary water source in the Owasco Inlet and Decker Creek valleys, and fractured bedrock aquifers typically supply domestic wells in the remaining valleys and upland areas. Municipal supplies tap a variety of aquifer types in the Owasco Inlet valley and nearby uplands. The hamlet of Locke taps the extensive confined aquifer beneath fine-grained lacustrine deposits in the valley. The Village of Moravia taps a semiconfined aquifer that overlies proglacial lake deposits and is partly confined by overlying recent lake deposits and alluvium. Withdrawals from this aquifer may also induce water from the Owasco Inlet into the aquifer. The Village of Groton draws from two aquifers: (1) a thin upland unconfined sand and gravel aquifer tapped by an infiltration gallery and (2) the local unconfined or semiconfined aquifer in the Owasco Inlet valley. Another aquifer with potential for municipal supply is the unconfined aquifer in the Decker Creek valley near Wilson Corners. The confined aquifer in the lower Dresserville Creek valley may have some water-resource potential, but it is largely untested. Unconfined aquifers are the most susceptible to contamination from activities at land surface directly above the aquifer because precipitation and subsequent recharge can transport contaminants directly to the water table. Adjacent upland areas can also contribute contaminants. Confined aquifers are less susceptible to contamination from overlying land surface areas because confining units largely prevent downward movement of water. Recharge occurs elsewhere at unconfined upvalley locations and along valley walls where alluvial fans, ice-contact deposits, or stream incision into the valley wall may provide pathways for downward movement of groundwater.

New York↗

USGS2024

Vaccination of endangered wildlife as a conservation tool: Hindsights and new horizons in the pandemic era

Vaccines are an established conservation tool that can reduce the threat of infectious disease in endangered wildlife populations. Vaccines exist for many infectious pathogens, and at a time of rapid technological advances in vaccinology, developing vaccines and vaccination programs for free-living endangered wildlife could help efforts to prevent extinctions from disease threats. Vaccination efforts could focus on protecting members of the target species or could be directed at reservoir populations to prevent pathogen spillover. Vaccination strategies need to be substantiated by research on safety and effectiveness, include risk and feasibility assessments, account for differences in host biology and disease epidemiology, and align with relevant regulatory frameworks. Engagement with stakeholders and the public is important to ensure the success of endangered species vaccination programs. Challenges such as funding, regulation, and societal acceptance are barriers to progress in vaccination programs for some species and geographic regions. We recommend the development of scientifically based international guidelines and a transdisciplinary forum with a specific emphasis on endangered wildlife vaccination. New technologies could be used collaboratively to prevent transmission of diseases for which vaccines are not currently available. Careful approaches and enhanced collaborations could help ensure the successful development of wildlife vaccination programs and promote resilience of endangered wildlife populations to increasing anthropogenic and environmental stressors on biodiversity.

Biological Conservation↗

USGS2023

Characterization of fish assemblages in eleven multi-use reservoirs from North Carolina, USA

Managing impounded river systems is a recurring challenge for aquatic resource professionals because reservoirs serve multiple functions with different ecological and socioeconomic outcomes. However, research on fishes in reservoirs has disproportionally focused on recreationally and economically important species, with less attention directed toward fish assemblages despite the potential for management at the assemblage level. As such, evaluation of relationships between reservoir fish assemblages and biotic and abiotic factors and testing whether assemblage structure is affected by changing environmental conditions may deepen ecological understanding and provide insights for reservoir fisheries management. Our overall objective was to assess these relationships in 11 reservoirs from North Carolina, USA. We sampled fish assemblages in the reservoirs, which spanned five river basins representing a range of habitat conditions, using experimental gillnets and pulsed DC nighttime electrofishing. Multivariate statistical analyses indicated that taxonomic differences in fish assemblage composition among river basins followed a gradient of productivity. The top contributing species to reservoir dissimilarity were bluegill ( Lepomis macrochirus ), gizzard shad ( Dorosoma cepedianum ), black crappie ( Pomoxis nigromaculatus ), and white perch ( Morone americana ). These four species were positively associated with factors that reflect increasing eutrophic conditions in the 11 reservoirs and could, therefore, serve as indicators of reservoir productivity, anthropogenic influence, and fish assemblage structure, in addition to their key role in reservoir fisheries management. Whereas fisheries research has historically focused on assessing fish populations, our results illustrate the ecological and management insights derived from simultaneously collecting assemblage- and population-level data. Research on reservoir fish assemblages in relation to biotic and abiotic conditions may help advance fish ecology and management alike.

North Carolina↗

USGS2017

Integrating future scenario‐based crop expansion and crop conditions to map switchgrass biofuel potential in eastern Nebraska, USA

Switchgrass ( Panicum virgatum ) has been evaluated as one potential source for cellulosic biofuel feedstocks. Planting switchgrass in marginal croplands and waterway buffers can reduce soil erosion, improve water quality, and improve regional ecosystem services (i.e. it serves as a potential carbon sink). In previous studies, we mapped high risk marginal croplands and highly erodible cropland buffers that are potentially suitable for switchgrass development, which would improve ecosystem services and minimally impact food production. In this study, we advance our previous study results and integrate future crop expansion information to develop a switchgrass biofuel potential ensemble map for current and future croplands in eastern Nebraska. The switchgrass biomass productivity and carbon benefits (i.e. NEP: net ecosystem production) for the identified biofuel potential ensemble areas were quantified. The future scenario‐based (‘A1B’) land use and land cover map for 2050, the US Geological Survey crop type and Compound Topographic Index (CTI) maps, and long‐term (1981–2010) averaged annual precipitation data were used to identify future crop expansion regions that are suitable for switchgrass development. Results show that 2528 km 2 of future crop expansion regions (~3.6% of the study area) are potentially suitable for switchgrass development. The total estimated biofuel potential ensemble area (including cropland buffers, marginal croplands, and future crop expansion regions) is 4232 km 2 (~6% of the study area), potentially producing 3.52 million metric tons of switchgrass biomass per year. Converting biofuel ensemble regions to switchgrass leads to potential carbon sinks (the total NEP for biofuel potential areas is 0.45 million metric tons C) and is environmentally sustainable. Results from this study improve our understanding of environmental conditions and ecosystem services of current and future cropland systems in eastern Nebraska and provide useful information to land managers to make land use decisions regarding switchgrass development.

Nebraska↗

USGS2020

Compounds of emerging concern detected in water samples from potable water and wastewater treatment plants and detected in water and bed-sediment samples from sites on the Trinity River, Dallas, Texas, 2009–13

The population in the Dallas-Fort Worth metropolitan area in northern Texas is rapidly growing, resulting in a rapid increase in the demand for potable water and an increase in the discharge of wastewater treatment plant effluent. An assessment of compounds of emerging concern (CECs) in samples collected at potable water and wastewater treatment plants in Dallas and downstream from Dallas in the Trinity River was completed by the U.S. Geological Survey in cooperation with the City of Dallas, Dallas Water Utilities. CECs are synthetic or naturally occurring chemicals that are not commonly monitored in the environment but can enter the environment and cause known or suspected adverse ecological or human health effects. CECs can enter the environment through nonpoint sources (for example, runoff) and point sources (for example, concentrated animal feeding operations and treated-effluent discharge from wastewater treatment plants), which can increase concentrations of CECs especially in highly populated areas. CECs include pharmaceuticals (prescription and nonprescription), steroidal hormones, stanols, sterols, detergents and detergent metabolites (hereinafter referred to as “detergents”), personal-use products, pesticides, polycyclic aromatic hydrocarbons (PAHs), flame retardants, plasticizers, and other organic compounds used in everyday domestic, agricultural, and industrial applications. The release of CECs to the environment went largely unrecognized until relatively recently. Increased loading of certain CECs to the environment, combined with advancements in laboratory analysis methods that resulted in appreciably lower detection levels, brought greater attention to the release of CECs. In addition, synthesis of new chemicals or changes in use and disposal of existing chemicals can create new sources of CECs. Some CECs are endocrine disrupting compounds (EDCs), which can elicit adverse effects on development, behavior, and reproduction of wildlife and can cause dysfunction of human and wildlife endocrine (hormone) systems. Results of studies in the United States and Europe indicate that CECs, their metabolites, and industrial, agricultural, and household wastewater products are present in the aquatic environment, water treatment plants, and septic systems. CECs, especially pharmaceuticals, are of interest because of their persistence, widespread use, and potential to cause adverse effects in humans and nontargeted organisms. There is also concern that some CECs and EDCs resist degradation of water treatment processes at potable water treatment plants (PWTPs) and wastewater treatment plants (WWTPs) and that treated-effluent discharge could contain compounds that negatively affect biota living in receiving waters. Therefore, CECs and EDCs are more likely to be detected in environmental samples collected near areas of high population density where treated effluent from WWTPs can contribute substantially to receiving waters. The U.S. Geological Survey, in cooperation with the City of Dallas, Dallas Water Utilities, evaluated the occurrence and concentrations of selected CECs in samples collected at PWTPs and WWTPs in Dallas and downstream from the Dallas-Fort Worth metropolitan area in the Trinity River, Texas, from August 2009 to December 2013. Water samples were collected at three PWTP sites, two WWTP sites, and five study sites on the Trinity River; all sites where samples were collected were in or downstream from Dallas. These water samples were analyzed for 120 CECs, including human-health pharmaceuticals (prescription and nonprescription), antibiotics, steroidal hormones, stanols, sterols, detergents, personal-use products (flavors and fragrances), pesticides and repellents, industrial wastewater compounds, disinfection compounds, PAHs, flame retardants, and plasticizers. Additionally, bed-sediment samples were collected at each of the five Trinity River sites. The bed-sediment samples were analyzed for 57 CECs. In general, the water treatment processes at PWTPs and WWTPs were effective at reducing detections and concentrations of CECs to undetectable levels or transforming the compounds into degradates that were not analyzed. There were 14 and 73 CECs detected in raw water and in untreated-influent water at PWTPs and WWTPs, respectively. Of these, 11 of the 14 CECs detected in raw-water samples and 44 of the 73 CECs detected in untreated-influent samples were not detected in finished water or in treated-effluent water samples, respectively, indicating that these compounds were removed or degraded to compounds that were not analyzed. Some CECs, however, are resistant to degradation and were detected in untreated and treated water at PWTPs and at WWTPs. The three CECs detected at PWTPs in raw-water and finished-water samples were tris(dichloroisopropyl)phosphate, benzophenone, and methyl salicylate. At WWTPs, 29 CECs were detected, including carbamazepine, sulfamethoxazole, 4-androstene-3,17- dione , 3-beta-coprostanol, acetyl-hexamethyl-tetrahydronaphthalene (AHTN), hexahydro-hexamethyl-cyclopenta-benzopyran (HHCB), 1,4-dichlorobenzene, tribromomethane, benzophenone, and tris(dichloroisopropyl)phosphate, in untreated and treated water, indicating that treatment processes likely did not remove or degrade these compounds. Of the 23 CECs detected in stream-water samples collected at 5 sites on the Trinity River in or near Dallas, 10 CECs (carbamazepine, sulfamethoxazole, caffeine, 3-beta-coprostanol, cholesterol, HHCB, benzophenone, triethyl citrate, tributyl phosphate, and tris(dichloroisopropyl)phosphate) were detected at all 5 sites. The 10 CECs detected in water samples collected at all 5 sites on the Trinity River were also detected in treated-effluent water at WWTPs. Eleven of the 57 targeted CECs were detected in bed-sediment samples collected at study sites on the Trinity River. Of these 11 CECs, only 2 (beta-sitosterol and cholesterol) were detected in bed-sediment samples at all 5 sites on the Trinity River. Nine of these 11 CECs were not detected in any water-column sample, likely because of the strong hydrophobic characteristics of these compounds. Results from water treatment plants indicate that the water treatment process is less effective for removing or degrading compounds that are engineered to be resistant to degradation. These results also indicate the presence of CECs and EDCs at locations upstream from PWTPs in Dallas. Results from Trinity River main-stem sites indicate that some compounds are naturally attenuated during transport, but a few are persistent throughout the study reach. Many CECs and EDCs are hydrophobic and were only detected in bed sediment, indicating multiple pathways through which CECs can persist in the environment. In general, concentrations of CECs in the Dallas-Fort Worth metropolitan area were similar to those found in metropolitan areas nationwide.

Texas↗

USGS2011

Vulnerability of riparian ecosystems to elevated CO 2 and climate change in arid and semiarid western North America

Riparian ecosystems, already greatly altered by water management, land development, and biological invasion, are being further altered by increasing atmospheric CO 2 concentrations ([CO 2 ]) and climate change, particularly in arid and semiarid (dryland) regions. In this literature review, we (1) summarize expected changes in [CO 2 ], climate, hydrology, and water management in dryland western North America, (2) consider likely effects of those changes on riparian ecosystems, and (3) identify critical knowledge gaps. Temperatures in the region are rising and droughts are becoming more frequent and intense. Warmer temperatures in turn are altering river hydrology: advancing the timing of spring snow melt floods, altering flood magnitudes, and reducing summer and base flows. Direct effects of increased [CO 2 ] and climate change on riparian ecosystems may be similar to effects in uplands, including increased heat and water stress, altered phenology and species geographic distributions, and disrupted trophic and symbiotic interactions. Indirect effects due to climate-driven changes in streamflow, however, may exacerbate the direct effects of warming and increase the relative importance of moisture and fluvial disturbance as drivers of riparian ecosystem response to global change. Together, climate change and climate-driven changes in streamflow are likely to reduce abundance of dominant, native, early-successional tree species, favor herbaceous species and both drought-tolerant and late-successional woody species (including many introduced species), reduce habitat quality for many riparian animals, and slow litter decomposition and nutrient cycling. Climate-driven changes in human water demand and associated water management may intensify these effects. On some regulated rivers, however, reservoir releases could be managed to protect riparian ecosystem. Immediate research priorities include determining riparian species' environmental requirements and monitoring riparian ecosystems to allow rapid detection and response to undesirable ecological change.

Global Change Biology↗

USGS1999

Use of generalized linear models and digital data in a forest inventory of northern Utah

Forest inventories, like those conducted by the Forest Service's Forest Inventory and Analysis Program (FIA) in the Rocky Mountain Region, are under increased pressure to produce better information at reduced costs. Here we describe our efforts in Utah to merge satellite-based information with forest inventory data for the purposes of reducing the costs of estimates of forest population totals and providing spatial depiction of forest resources. We illustrate how generalized linear models can be used to construct approximately unbiased and efficient estimates of population totals while providing a mechanism for prediction in space for mapping of forest structure. We model forest type and timber volume of five tree species groups as functions of a variety of predictor variables in the northern Utah mountains. Predictor variables include elevation, aspect, slope, geographic coordinates, as well as vegetation cover types based on satellite data from both the Advanced Very High Resolution Radiometer (AVHRR) and Thematic Mapper (TM) platforms. We examine the relative precision of estimates of area by forest type and mean cubic-foot volumes under six different models, including the traditional double sampling for stratification strategy. Only very small gains in precision were realized through the use of expensive photointerpreted or TM-based data for stratification, while models based on topography and spatial coordinates alone were competitive. We also compare the predictive capability of the models through various map accuracy measures. The models including the TM-based vegetation performed best overall, while topography and spatial coordinates alone provided substantial information at very low cost.

Utah↗

USGS2020

An overview of bioaerosol load and health impacts associated with dust storms: A focus on the Middle East

Dust storms are an important environmental problem worldwide. The main sources of dust storms include the Sahara, the Middle East, and central and northeastern Asia. Dust storms originating from these regions can be dispersed across oceans and in some cases globally. They occur throughout the year and vary in frequency and intensity. The biological agents (e.g., fungi, bacteria and viruses) and the mineral and chemical compositions of dust may have adverse effects on human health and quality of life. Desert dusts may cause respiratory diseases, cardiovascular diseases, cardiopulmonary diseases, mental health issues, injuries and death from transport accidents caused by poor visibility. This paper presents dust storm human health research conducted in the Middle East in both indoor and outdoor environments. Results illustrate that particle concentration and bioaerosol types in the atmosphere are affected by climate change and meteorological factors. Recent data trends indicate that annual dust aerosol concentrations have increased worldwide. According to studies conducted in the Middle East, the incidence of respiratory and cardiovascular mortality and hospital visits have increased dramatically following dust storm exposures but very few have demonstrated a regional causation. National and international collaborative efforts are needed to advance our understanding of the global implications of dust storms and what may be the most effective means of mitigation.

Middle East↗

USGS2017

Fluorine

Fluorine compounds are essential in numerous chemical and manufacturing processes. Fluorspar is the commercial name for fluorite (isometric CaF 2 ), which is the only fluorine mineral that is mined on a large scale. Fluorspar is used directly as a fluxing material and as an additive in different manufacturing processes. It is the source of fluorine in the production of hydrogen fluoride or hydrofluoric acid, which is used as the feedstock for numerous organic and inorganic chemical compounds. The United States was the world’s leading producer of fluorspar until the mid-1950s. In the mid-1970s, the U.S. fluorspar mining industry began to decline because of foreign competition. By 1982, there was essentially only a single U.S. producer left, and that company ceased mining in 1996. Consumption of fluorspar in the United States peaked in the early 1970s, which was also the peak period of U.S. steel production. Since then, U.S. fluorspar consumption has decreased substantially; the United States has nonetheless increased its imports of downstream fluorine compounds, such as, in order of tonnage imported, hydrofluoric acid, aluminum fluoride, and cryolite. This combination of no U.S. production (until recently) and high levels of consumption has made the United States the world’s leading fluorspar-importing country, in all its various forms. The number of fluorspar-exporting countries has decreased substantially in recent decades, and, as a result, the United States has become dependent on just a few countries to supply its needs. In 2013, the United States imported the majority of its fluorspar from three countries, which were, in descending order of the amount imported, Mexico, China, and South Africa. Geologically, in igneous systems, fluorine is one of a number of elements that are “incompatible.” These incompatible elements become concentrated in the residual magma while the common silicates crystallize upon magma ascent and cooling, leading to relatively high fluorine concentrations in the more evolved or differentiated igneous rocks and in hydrothermal deposits associated with those evolved igneous rocks. In sedimentary rocks, fluorine’s highest concentrations are found in phosphorites because fluorine substitutes for hydroxyl ions in apatite, which leads to fluorine concentrations of, typically, from 2 to 4 weight percent in phosphorites. Because of the presence of fluorine, phosphate fertilizer manufacturers can produce a fluorosilicic acid byproduct. Most deposits mined for fluorine are hydrothermal, however, and consist of fluorine minerals that precipitated from hot water. Magmatic brines and brines from deep within sedimentary basins that have high concentrations of dissolved fluoride are the mineralizing fluids for various types of hydrothermal fluorspar deposits. Relatively dilute hydrothermal fluids that formed in some volcanic rocks can also transport sufficient fluoride to form a high-grade fluorspar deposit. Fluorite has low solubility in a common range of hydrothermal temperatures, particularly from about 160 degrees Celsius (°C) down to 60 °C. The increasing fluorite solubility below 60 °C partly explains why some water with exceptionally high levels of dissolved fluorine are found even at ambient temperatures in evaporitic lake basins in some East African Rift valleys in Kenya and Tanzania. The geologic conditions that led to the high concentrations there are known to exist in a number of other places in the world as well, including, perhaps, places in the Basin and Range province of the United States. Eight minerals or mineral groups have sufficient fluorine in their structures to be considered as possible ores of the element; they are bastnaesite (also spelled bastnäsite; and other fluorocarbonates), cryolite, sellaite, villiaumite, fluorite, fluorapatite (in phosphorites), various phyllosilicates, and topaz. Fluorite is currently the only mineral that is mined for fluorine, and nomineral except fluorite is likely to become a source of commercially produced fluorine as a primary product as long as supplies from relatively thick and high-grade fluorite deposits continue to be available. At least seven classes (which include one subclass) of hydrothermal fluorite deposits are recognized; they are classified according to their tectonic and (or) magmatic settings, as follows: (1) carbonatite-related fluorspar deposits; (2) alkaline-intrusion-related fluorspar deposits; (3) alkaline-volcanic-related epithermal fluorspar deposits; (4) Mississippi Valley-type fluorspar deposits (and a subclass of salt-related carbonate-hosted fluorspar deposits); (5) fluorspar deposits related to strongly differentiated granites; (6) subalkaline-volcanic-related epithermal fluospar deposits; and (7) fluorspar deposits that appear to be conformable within tuffaceous limy lacustrine sediments. An eighth class (not hydrothermal) is that of fluorspar deposits concentrated in soils and weathered zones; that is, residual fluorspar deposits. Generally, fluorspar deposits related to strongly differentiated granites have larger tonnages and lower grades than carbonatite-related fluorspar deposits, which, in turn, have larger tonnages and lower grades than fluorspar vein deposits from various other classes. The United States has a few identified resources of fluorspar, most notably the Klondike II property in the Illinois- Kentucky fluorspar district located about 8 kilometers southwest of Salem, Kentucky, which has a large vein that contains at least 1.6 million metric tons at a grade of 60 percent CaF 2 (Feytis, 2009). Additional fluorspar resources of lower grade but larger tonnage have been identified at Hicks Dome in the Illinois-Kentucky fluorspar district and at Lost River near the western tip of the Seward Peninsula in Alaska, along with a couple of dozen smaller, higher grade resources. Internationally, new mines that either opened before the beginning of 2013 or were scheduled to open soon after that time include the Nui Phao tungsten-fluorspar-bismuth-copper-gold deposit in northern Vietnam; the St. Lawrence project in Newfoundland, Canada, which is located in a well-known fluorspar district; the Bamianshan deposit, which is related to a strongly differentiated granite in northwestern Zhejiang Province, China, near some of that Province’s large, subalkaline-volcanic-related epithermal veins; and the Nokeng project in South Africa, which is also related to a strongly differentiated granite. Other deposits in northwestern Australia, Nevada (United States), Norway, South Africa, and Sweden have been identified and could be put into production within just a few years. Among undiscovered resources, an interesting possibility might be to produce a fluorine product from evaporitic, high-fluorine, high-pH sodium-carbonate brines like Lake Magadi (Kenya) and Lake Natron (Tanzania) in Africa’s Eastern Rift Valley. In addition, apparently conformable fluorspar deposits in tuffaceous limy lacustrine sediments, such as those in Italy, are likely to occur in similar young alkalic volcanic settings elsewhere in the world. Modern geophysical and geochemical exploration techniques have typically not been brought to bear in exploration for new fluorspar deposits, although such techniques are likely to be used in future exploration. The tendency for fluorine to dissolve in significant concentrations in water at low temperature allows both surface water and groundwater to be used as sampling media in geochemical exploration. Evolved granite-related fluorspar deposits may be particularly susceptible to geophysical exploration methods because crystalline rocks that form a basement to sedimentary sections can be approximately defined with gravity and magnetic methods, and magnetite-bearing skarns can be directly detected with magnetic surveys. Environmental considerations of fluorine mining focus especially on drinking water, where high fluorine concentrations can lead to tooth decay; dental and skeletal fluorosis; and bone and cartilage conditions, including genu valgum, which is the crippling bone deformity more commonly known as knock knee. Trace amounts of other elements in fluorspar ores are a concern at some deposits; for example, high beryllium concentrations in alkaline-volcanic-related epithermal deposits or high cadmium concentrations associated with Mississippi Valley-type and salt-related carbonate-hosted fluorspar deposits. Future research might include testing whether fluorine can be extracted economically from high-pH, sodium-carbonate brines and exploring for new occurrences of apparently conformable fluorspar deposits in tuffaceous limy lacustrine sediments outside of the Latium Region of Italy. Other promising new areas of research could be studies of fluorspar deposit fluid inclusion compositions by quadrupole mass spectrometry, by noble gas mass spectrometry on irradiated fluid inclusions, or by chlorine isotopes, while also measuring the chemistry of the same fluid inclusions either by bulk crush-and-leach methods or by laser ablation-inductively coupled plasma mass spectrometry. Advanced studies of fluid inclusion chemistry could be applied beneficially to some of the enigmatic large epithermal fluorspar veins at various places in the world, where they might determine those deposits’ possible relationships to igneous intrusions, or to dissolved salt, or to heated meteoric water in volcanic sections, or perhaps to all three. This knowledge could help focus new exploration.

Professional Paper↗