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At least 343 records · Page 19Linked to original sources
USGS2026

Spatio-temporal modeling for assessing geoenergy resources: A workflow applied to gas in place variation in coal beds

The ability to estimate spatio-temporal changes in hydrocarbon reservoir properties and energy resources within pore volumes is essential for optimizing production, reservoir management, geologic energy storage, and safety in underground mining operations. In coal seams, predicting remaining methane gas-in-place (GIP) is critical for quantifying producible gas and improving mine safety and productivity through effective ventilation planning. Although such changes are commonly evaluated using physics-based numerical simulation models, these approaches often require extensive data, calibration effort, and time. This study presents a spatio-temporal geostatistical modeling approach that bridges the gap between purely spatial models and full numerical simulations. The method is applied to a case study of coal seam degasification in the Mary Lee coal group, Black Warrior Basin, Alabama, USA, to estimate GIP evolution over time within a selected mining district. The analysis uses published data from prior natural gas production history-matching of degasification using vertical wells. Empirical spatial and temporal statistics were calculated for reservoir pressure and water saturation, and spatio-temporal variogram models were fitted to experimental variograms. These models provided the structural basis for spatio-temporal kriging, integrated with spatial estimates of time-invariant parameters (porosity, density, and thickness) to estimate GIP. This approach enabled estimation of GIP changes over time, including periods without data. Boxplots of GIP estimates indicated systematic depletion and decreasing spatial variability, reflecting the impacts of degasification. Comparison with cumulative gas production from empirical well records showed approximately 85% agreement based on a relative similarity metric. Spatio-temporal GIP estimates were also used to estimate methane emissions to longwall ventilation systems and compared with reported emissions from the U.S. EPA Greenhouse Gas Reporting Program, showing similar distributions (≈80%) given data limitations. Overall, this integrated modeling approach provides time-dependent GIP estimates with broader implications for resource assessment applications.

Alabama↗
USGS2013

Sustainably connecting children with nature: an exploratory study of nature play area visitor impacts and their management

Parks are developing nature play areas to improve children's health and “connect” them with nature. However, these play areas are often located in protected natural areas where managers must balance recreation with associated environmental impacts. In this exploratory study, we sought to describe these impacts. We also investigated which ages, gender, and play group sizes most frequently caused impact and where impacts most frequently occur. We measured the lineal and aerial extent and severity of impacts at three play areas in the eastern United States. Methods included soil and vegetation loss calculations, qualitative searches and tree and shrub damage classifications. Additionally, we observed 12 h of play at five play areas. Results showed that measurable negative impacts were caused during 33% of the time children play. On average, 76% of groundcover vegetation was lost at recreation sites and 100% was lost at informal trails. In addition, approximately half of all trees and shrubs at sites were damaged. Meanwhile, soil exposure was 25% greater on sites and trails than at controls. Boys and small group sizes more frequently caused impact, and informal recreation sites were most commonly used for play. No statistically significant correlations were found between age or location and impact frequency. Managers interested in developing nature play areas should be aware of, but not deterred by these impacts. The societal benefits of unstructured play in nature may outweigh the environmental costs. Recommended management strategies include selecting impact-resistant sites, improving site resistance, promoting low impact practices, and managing adaptively.

Landscape and Urban Planning↗
USGS2019

Physical controls on salmon redd site selection in restored reaches of a regulated, gravel-bed river

Large‐scale river restoration programs have emerged recently as a tool for improving spawning habitat for native salmonids in highly altered river ecosystems. Few studies have quantified the extent to which restored habitat is utilized by salmonids, which habitat features influence redd site selection, or the persistence of restored habitat over time. We investigated fall‐run Chinook salmon spawning site utilization and measured and modeled corresponding habitat characteristics in two restored reaches: a reach of channel and floodplain enhancement completed in 2013 and a reconfigured channel and floodplain constructed in 2002. Redd surveys demonstrated that both restoration projects supported a high density of salmon redds, 3 and 14 years following restoration. Salmon redds were constructed in coarse gravel substrates located in areas of high sediment mobility, as determined by measurements of gravel friction angles and a grain entrainment model. Salmon redds were located near transitions between pool‐riffle bedforms in regions of high predicted hyporheic flows. Habitat quality (quantified as a function of stream hydraulics) and hyporheic flow were both strong predictors of redd occurrence, though the relative roles of these variables differed between sites. Our findings indicate that physical controls on redd site selection in restored channels were similar to those reported for natural channels elsewhere. Our results further highlight that in addition to traditional habitat criteria (e.g., water depth, velocity, and substrate size), quantifying sediment texture and mobility, as well as intragravel flow, provides a more complete understanding of the ecological benefits provided by river restoration projects.

Water Resources Research↗
USGS2018

Artelle et al. (2018) miss the science underlying North American wildlife management

Artelle et al . (2018) conclude that “hallmarks of science” are largely missing from North American wildlife management based on a desk review of selected hunting management plans and related documents found through Internet searches and email requests to state and provincial wildlife agencies. We highlight three fundamental problems that compromise the validity of the conclusions posited: missing information to support selection of “hallmarks of science,” confusion about the roles and nature of science and management, and failure to engage effectively with the scientists and managers actively managing wildlife populations in North America.

Science Advances↗
USGS2006

Microbial transformations of arsenic in the environment: From soda lakes to aquifers

Arsenic is a highly toxic element that supports a surprising range of biogeochemical transformations. The biochemical basis of these microbial interactions is described, with an emphasis on energy-yielding redox biotransformations that cycle between the As5+ and As3+ oxidation states. The subsequent impact of As3+-oxidising and As 5+-reducing prokaryotes on the chemistry of selected environments is also described, focusing on soda lakes with naturally high concentrations of the metalloid and on Southeast Asian aquifer sediments, where the microbial reduction of sorbed As5+ and subsequent mobilisation of As 3+ into water abstracted for drinking and irrigation threaten the lives of millions.

Elements↗
USGS2011

Development of industrial minerals in Colorado

Technology and engineering have helped make mining safer and cleaner for both humans and the environment. Inevitably, mineral development entails costs as well as benefits. Developing a mine is an environmental, engineering, and planning challenge that must conform to many Federal, State, and local regulations. Community collaboration, creative design, and best management practices of sustainability and biodiversity can be positive indicators for the mining industry. A better understanding of aesthetics, culture, economics, geology, climate, vegetation and wildlife, topography, historical significance, and regional land planning is important in resolving land-use issues and managing mineral resources wisely. Ultimately, the consuming public makes choices about product use (including water, food, highways, housing, and thousands of other items) that influence operations of the mineral industry. Land planners, resource managers, earth scientists, designers, and public groups have a responsibility to consider sound scientific information, society's needs, and community appeals in making smart decisions concerning resource use and how complex landscapes should change. An effort to provide comprehensive geosciences data for land management agencies in central Colorado was undertaken in 2003 by scientists of the U.S. Geological Survey and the Colorado Geological Survey. This effort, the Central Colorado Assessment Project, addressed a variety of land-use issues: an understanding of the availability of industrial and metallic rocks and minerals, the geochemical and environmental effects of historic mining activity on surface water and groundwater, and the geologic controls on the availability and quality of groundwater. The USDA Forest Service and other land management agencies have the opportunity to contribute to the sustainable management of natural aggregate and other mineral resources through the identification and selective development of mineral resources and the reclamation of mines on lands that they administer. The information in this Circular will help them carry out that task.

Colorado↗
USGS1982

Preliminary geotechnical and geophysical logs from drill hole 2C-80 in the Capps coal field, Cook Inlet region, Alaska

The drilling and logging information provided in this report was collected during September 1980 as part of the Energy Lands program of the U.S. Geological Survey. Drill hole 2C-80 is located in the Capps Coal Field, approximately 100 km (62 mi) west of Anchorage, Alaska (fig. 1). The drilling was undertaken to obtain information on the geotechnical characteristics of a part of the coal-bearing Tyonek Formation and overlying surficial deposits. The preliminary results of a previous drill hole (1C-79), located 1.3 km (0.8 mi) northeast of drill hole 2C-80, were reported by Chleborad and others (1980). The Tyonek Formation is early Oligocene to middle Miocene in age (Wolfe and Tanai, 1980). At the drill site it is overlain by a thin colluvial deposit of Quaternary age. The drilling and continuous core sampling penetrated 19.5 m (63.9 ft) of overburden, a major coal bed (Waterfall bed), and approximately 29 m (95.1 ft) of underlying material, to a total depth of 61 m (200 ft). Drill hole 2C-80 stratigraphically overlaps drill hole 1C-79 and continues down section approximately 33 m (108 ft). A proposed open pit coal-mining plan (Placer Amex, Inc., 1977, status report of December 1977) outlines a sequential mining and reclamation scheme for five areas in the Capps Coal Field. Figure 2 shows the location of drill holes 2C-80 and 1C-79 with respect to the proposed mining areas as well as selected surface features. A general description of the geology and natural hazards of the region are given by Schmoll and others (1981). The generalized lithology interpreted from core obtained from drilling and supplemented by outcrop mapping accomplished during the 1979 and 1980 field seasons is presented in figure 3. A more detailed lithologic log is presented as part of the geotechnical log. The geotechnical and geophysical logs presented herein (pls. 1 and 2) provide basic physical-property and engineering data useful in predicting the response of geologic materials to proposed large-scale coal mining and related development, and in identifying and assessing potential geologic hazards.

Alaska↗
USGS2007

Use of chemical analysis and assays of semipermeable membrane devices extracts to assess the response of bioavailable organic pollutants in streams to urbanization in six metropolitan areas of the United States

Studies to assess the effects of urbanization on stream ecosystems are being conducted as part of the U.S. Geological Survey’s National Water-Quality Assessment (NAWQA) Program. The overall objectives of these studies are to (1) determine how hydrologic, geomorphic, water quality, habitat, and biological characteristics respond to land-use changes associated with urbanization in specific environmental settings, and (2) compare these responses across environmental settings. As part of an integrated assessment, semipermeable membrane devices (SPMDs) were deployed in streams along a gradient of urban land-use intensity in and around Atlanta, Georgia; Raleigh-Durham, North Carolina; and Denver-Fort Collins, Colorado, in 2003; and Dallas-Fort Worth, Texas; Milwaukee-Green Bay, Wisconsin; and Portland, Oregon, in 2004. Sites were selected to avoid point-source discharge and to minimize natural variability within each of the six metropolitan areas. In addition to standard chemical analysis for hydrophobic organic contaminants, three assays were used to address mixtures and potential toxicity: (1) Fluoroscan provides an estimate of the total concentration of polycyclic aromatic hydrocarbons (PAHs); (2) the P450RGS assay indicates the presence and levels of aryl hydrocarbon receptor agonists; and (3) Microtox® measures toxicological effects on photo-luminescent bacteria. Of the 140 compounds targeted or identified by gas chromatography/mass spectrometry analysis in this study, 67 were not detected. In terms of numbers and types of compounds, the following were detected: 2 wood preservatives, 6 insecticides (parent compounds), 5 herbicides, 22 polycyclic aromatic hydrocarbons, 2 dibenzofurans, 4 polychlorinated biphenyls, 7 compounds associated with fragrances or personal care products, 4 steroids associated with wastewater, 5 polydibromated diphenyl ethers (flame retardants), 3 plasticizers, 3 antimicrobials/disinfectants, and 3 detergent metabolites. Of the 73 compounds detected and three assays utilized, 29 were detected in 25 percent or more of the streams and were strongly related to increases in urban intensity (defined as having a Spearman’s rho > 0.5 with percent urban land cover) in at least one of the six metropolitan areas investigated. These 29 endpoints included 16 PAHs, a wood preservative (pentachloroanisole), 2 insecticides (chlorpyrifos and chlordane), 3 herbicides (benfluralin, trifluralin, and dacthal), a synthetic musk (hexahydrohexamethylcyclopentabenzopyran, HHCB), 2 furans (methyldibenzofuran and benzo[b]naphtho[2,3-d]furan), and a flame retardant (BDE 47). In addition, the number of compounds detected and results of the Fluoroscan and P450RGS assays were strongly related to urban intensity. Average water concentrations estimated from SPMDs were compared to screening benchmarks for the protection of human health and aquatic life; of the 14 compounds with available benchmarks, 3 compounds (anthracene, dieldrin, and diazinon) exceeded those levels in one or more streams. Both dieldrin and anthracene exceeded their respective benchmarks in seven streams, and diazinon in only one stream. There were more exceedances in Milwaukee-Green Bay and Raleigh-Durham than in the other metropolitan areas, and there were no exceedances in Dallas-Fort Worth. The six metropolitan areas studied differed in the number and types of endpoints related to urban intensity, probably from a combination of factors governing source strength, transport, and fate of hydrophobic compounds. The number of endpoints strongly related to urban intensity ranged from 3 in Dallas-Fort Worth and Portland to 21 in Raleigh-Durham. High frequencies of detection and strong correlations with urban land cover for pyrogenic PAHs (such as unsubstituted 4-ringed PAHs) in all six metropolitan areas indicate that these compounds are an important component of urbanization, regardless of location. Pentachloroanisole, dibenzofurans, and petrogenic PAHs (alkylated PAHs and heterocyclic dibenzothiophenes) were frequently detected and strongly related to urban intensity in Atlanta, Raleigh-Durham, Milwaukee-Green Bay, and Denver-Fort Collins. Two insecticides were related to urban intensity: chlorpyrifos in Atlanta, Raleigh-Durham, and Dallas-Fort Worth; and chlordane in Raleigh-Durham. Three herbicides were strongly related to urban intensity: trifluralin in Atlanta and Raleigh-Durham; benfluralin in Atlanta, and dacthal in Denver-Fort Collins. The detection frequencies for most wastewater indicator compounds were too low to establish relations with urban intensity. Of the wastewater compounds analyzed, HHCB in Raleigh-Durham and Denver-Fort Collins, and BDE 47 in Denver-Fort Collins and Dallas-Forth Worth, had the strongest relations with urban intensity. In addition to pyrogenic PAHs, levels of aryl hydrocarbon receptor agonists (as measured by the P450RGS assay) were strongly related to increasing urban intensity in all six metropolitan areas. PAHs were the only group of aryl hydrocarbon agonists consistently detected and related with urban intensity in all six metropolitan areas. It is unknown which compounds in the SPMDs caused the increased response in the P450RGS assay because the SPMDs likely contained many aryl hydrocarbon receptor agonists not quantified by chemical analysis. It is clear that bioavailable, aryl hydrocarbon receptor agonists increase in streams with increasing urban intensity in the basin. Potential toxicity mediated by this metabolic pathway should be considered in integrated assessments of the response of aquatic biota to urbanization.

Scientific Investigations Report↗
USGS2012

Biodegradation of chloroethene compounds in groundwater at Operable Unit 1, Naval Undersea Warfare Center, Division Keyport, Washington, 1999-2010

The U.S. Geological Survey evaluated the biodegradation of chloroethene compounds in groundwater beneath the former landfill at Operable Unit 1 (OU 1) of the U.S. Naval Undersea Warfare Center (NUWC), Division Keyport. The predominant contaminants in groundwater are the chloroethene compounds trichloroethene, cis -1,2-dichloroethene, and vinyl chloride. The remedy selected for groundwater contamination at OU 1 includes phytoremediation and natural attenuation. In 1999, the U.S. Navy planted two hybrid poplar plantations, referred to as the northern and southern plantations, over the most contaminated parts of the landfill. The U.S. Navy monitors tree health, groundwater levels, and contaminant concentrations to assess the effectiveness of phytoremediation. The U.S. Geological Survey began a cooperative effort with the U.S. Navy in 1995 to monitor the effectiveness of natural attenuation processes for removing and controlling the migration of chloroethenes and chloroethanes. Field and laboratory studies from 1996 through 2000 demonstrated that biodegradation of chloroethenes and chloroethanes in shallow groundwater at OU 1 was substantial. The U.S. Geological Survey monitored geochemical and contaminant concentrations in groundwater annually from 2001 through 2010. This report presents groundwater geochemical and contaminant data collected by the U.S. Geological Survey during June 2010 and evaluates evidence for continued biodegradation of chloroethenes in groundwater. Geochemical and contaminant concentration data through 2010 indicate that biodegradation of chloroethenes in groundwater continued beneath the landfill at OU 1. Contaminant concentrations in groundwater decreased beneath most of the 9-acre landfill between 1999 and 2010. The evidence indicating that biodegradation was a primary cause for the decreased concentrations included decreasing ratios of more highly chlorinated compounds to less chlorinated compounds over time, and widespread detections of non-chlorinated biodegradation end-products ethane and ethene. No widespread changes in groundwater reduction-oxidation (redox) conditions were observed that could result in either more or less efficient biodegradation. Even with continued biodegradation, dissolved-phase contaminant concentrations in the tens of milligrams per liter have persisted beneath part of the 0.7-acre southern plantation. The magnitude and persistence of those concentrations indicate that non-aqueous phase liquid chloroethenes likely are present beneath the southern plantation and are not substantially affected by biodegradation. During 2010, chloroethenes continued to be measured in shallow groundwater samples from the southern part of the adjacent marsh, although at the lowest concentrations ever measured. Flux calculations based on 2010 data indicate that 95 percent of dissolved-phase chloroethenes in the upper aquifer beneath the southern landfill were degraded before discharging to surface water. Overall, biodegradation of chloroethenes in groundwater throughout OU 1 continued through 2010, and it prevented most of the mass of dissolved-phase chloroethenes in the upper aquifer beneath the landfill from discharging to surface water.

Washington↗
USGS1956

Water requirements of the carbon-black industry

Carbon blacks include an important group of industrial carbons used chiefly as a reinforcing agent in rubber tires. In 1953 more than 1,610 million pounds of carbon black was produced, of which approximately 1,134 million pounds was consumed by the rubber industry. The carbon-black industry uses small quantities of water as compared to some industries; however, the water requirements of the industry are important because of the dependence of the rubber-tire industry on carbon black. Two methods are used in the manufacture of carbon black - contact and furnace. The only process use of water in the contact method is that used in pelleting. Water is used also in the plant washhouse and for cleaning, and sometimes the company camp may be supplied by the plant. A survey made during the last quarter of 1953 showed that the average values of unit water use at contact plants for process use, all plant uses, and all uses including company camps are 0.08, 0.14, and 0.98 gallon of water per pound of carbon black respectively. In addition to use in wet pelleting, large quantities of water are required in continuous and cyclic furnace methods to reduce the temperature of the gases of decomposition in order to separate and collect the entrained carbon black. The 22 furnace plants in operation in 1953 used a total of 12.4 million gallons per day for process use. Four furnace plants generate electric power for plant use; condenser-cooling water for one such plant may nearly equal the requirements of the entire industry for process use. The average values of unit water use at furnace plants for process use, all plant uses and all uses including company camps but excluding power generation are 3.26, 3.34, and 3.45 gallons of water per pound of carbon black respectively. Carbon-black plants in remote, sparsely settled areas often must maintain company camps for employees. Twenty-one of twenty-seven contact plants surveyed in 1953 had company camps. These camps used large quantities of water: 0.84 gallon per pound of carbon black as compared to 0.14 gallon per pound used in the plants. Furnace plants can generally be located near a labor supply and, therefore, do not require company camps. Ten of the twenty-two furnace plants surveyed in 1953 had company camps. Because water used for pelleting and gas quenching is evaporated, leaving the dissolved minerals in the product as objectionable impurities, particular attention was paid to the quality of water available for use at the plants visited during the 1953 survey. Reports of chemical analyses of water samples were obtained at 23 plants. A study of these reports does not develop a pattern of the limits of tolerance of dissolved solids in water used in process or of the need for water treatment based on geographical location of the plant. However these analyses show that water used for quenching contains less dissolved solids than water used by the industry for any other purpose. Based on trends in the industry it is expected that the quantity of water used by the carbon-black industry will increase more rapidly than will the quantity of carbon black produced because of the increasing percentage produced in furnace plants, and that selection of sites for modern furnace plants will be influenced more by quantity and quality of the available water supply than was the case in selecting sites for contact plants for which low-cost natural gas was the primary consideration.

Water Supply Paper↗
USGS2001

Role of environmental variability in evaluating stressor effects

In this chapter, we discuss how environmental variability affects the exposure of organisms and ecological systems to stressors, and give guidance on how to understand influences of stressors. We consider the characteristics of environmental variability and issues relating to the measurement of environmental variation. We discuss how to select the optimal indicators of ecological response in a variable natural environment. Finally, we suggest some approaches to incorporate environmental variability into resource management. In all cases we employ examples and case studies throughout to illustrate principles.

Book chapter↗
USGS2001

A field and statistical modeling study to estimate irrigation water use at Benchmark Farms study sites in southwestern Georgia, 1995-96

A benchmark irrigation monitoring network of farms located in a 32-county area in southwestern Georgia was established in 1995 to improve estimates of irrigation water use. A stratified random sample of 500 permitted irrigators was selected from a data base--maintained by the Georgia Department of Natural Resources, Georgia Environmental Protection Division, Water Resources Management Branch--to obtain 180 voluntary participants in the study area. Site-specific irrigation data were collected at each farm using running-time totalizers and noninvasive flowmeters. Data were collected and compiled for 50 farms for 1995 and 130 additional farms for the 1996 growing season--a total of 180 farms. Irrigation data collected during the 1996 growing season were compiled for 180 benchmark farms and used to develop a statistical model to estimate irrigation water use in 32 counties in southwestern Georgia. The estimates derived were developed from using a statistical approach know as "bootstrap analysis" that allows for the estimation of precision. Five model components--whether-to-irrigate, acres irrigated, crop selected, seasonal-irrigation scheduling, and the amount of irrigation applied--compose the irrigation model and were developed to reflect patterns in the data collected at Benchmark Farms Study area sites. The model estimated that peak irrigation for all counties in the study area occurred during July with significant irrigation also occurring during May, June, and August. Irwin and Tift were the most irrigated and Schley and Houston were the least irrigated counties in the study area. High irrigation intensity primarily was located along the eastern border of the study area; whereas, low irrigation intensity was located in the southwestern quadrant where ground water was the dominant irrigation source. Crop-level estimates showed sizable variations across crops and considerable uncertainty for all crops other than peanuts and pecans. Counties having the most irrigated acres showed higher variations in annual irrigation than counties having the least irrigated acres. The Benchmark Farms Study model estimates were higher than previous irrigation estimates, with 20 percent of the bias a result of underestimating irrigation acreage in earlier studies. Model estimates showed evidence of an upward bias of about 15 percent with the likely cause being a misrepresented inches-applied model. A better understanding of the causes of bias in the model could be determined with a larger irrigation sample size and increased substantially by automating the reporting of monthly totalizer amounts.

Georgia↗
USGS2018

Maps showing predicted probabilities for selected dissolved oxygen and dissolved manganese threshold events in depth zones used by the domestic and public drinking water supply wells, Central Valley, California

The purpose of the prediction grids for selected redox constituents—dissolved oxygen and dissolved manganese—are intended to provide an understanding of groundwater-quality conditions at the domestic and public-supply drinking water depths. The chemical quality of groundwater and the fate of many contaminants is influenced by redox processes in all aquifers, and understanding the redox conditions horizontally and vertically is critical in evaluating groundwater quality. The redox condition of groundwater—whether oxic (oxygen present) or anoxic (oxygen absent)—strongly influences the oxidation state of a chemical in groundwater. The anoxic dissolved oxygen thresholds of <0.5 milligram per liter (mg/L), <1.0 mg/L, and <2.0 mg/L were selected to apply broadly to regional groundwater-quality investigations. Although the presence of dissolved manganese in groundwater indicates strongly reducing (anoxic) groundwater conditions, it is also considered a “nuisance” constituent in drinking water, making drinking water undesirable with respect to taste, staining, or scaling. Three dissolved manganese thresholds, <50 micrograms per liter (µg/L), <150 µg/L, and <300 µg/L, were selected to create predicted probabilities of exceedances in depth zones used by domestic and public-supply water wells. The 50 µg/L event threshold represents the secondary maximum contaminant level (SMCL) benchmark for manganese (U.S. Environmental Protection Agency, 2017; California Division of Drinking Water, 2014), whereas the 300 µg/L event threshold represents the U.S. Geological Survey (USGS) health-based screening level (HBSL) benchmark, used to put measured concentrations of drinking-water contaminants into a human-health context (Toccalino and others, 2014). The 150 µg/L event threshold represents one-half the USGS HBSL. The resultant dissolved oxygen and dissolved manganese prediction grids may be of interest to water-resource managers, water-quality researchers, and groundwater modelers concerned with the occurrence of natural and anthropogenic contaminants related to anoxic conditions. Prediction grids for selected redox constituents and thresholds were created by the USGS National Water-Quality Assessment (NAWQA) modeling and mapping team.

California↗
USGS2022

The researcher's lament: Why do they ignore my science?

The researcher's lament is shared by many environmental and conservation scientists who complain about the little support they receive for their research proposals during the review and selection process. Understandably, any hopes of having their anticipated scientific findings applied toward the formulation of environmental management decisions or natural resource policy action are shattered. They attribute this lack of endorsement to shortcomings and limitations among decision makers and proposal selection officials when, in many cases, the rejection of project proposals is often a function of a handful of self-inflicted failures by applied scientists who anchor themselves stubbornly to doomed approaches. Familiar deficiencies in their research proposals perpetuate the disconnect between the enterprise of science and real-world resource management challenges. Researchers themselves can affect conditions that turn up the appetite for their scientific endeavors as a more meaningful component of the decision-making process, namely, to stage and deliver science that is more readily "actionable." Perhaps it is time for them to consider a course correction to improve the viability of their actionable science proposals. A few basic steps may help rejigger the science planning process in this direction and, consequently, help avoid the researcher's lament. The likelihood of gaining support during the proposal review and award adjudication process, and securing practical application of scientific products, increases when the products are (1) the result of active engagement of researchers with decision makers; (2) better connected to social and political priorities; (3) clearly designed to inform specific management decisions; and (4) tailored to fit the needs of targeted end users. These considerations and activities exist beyond the comfort zone of many environmental or conservation scientists. Yet, those who adopt them will spend less time lamenting rejection and become more influential in the production of actionable knowledge.

Ecosphere↗
USGS1998

Thermally induced chronic developmental stress in coho salmon: Integrating measures of mortality, early growth and fluctuating asymmetry

Developmental stability, or homeostasis, facilitates the production of consistent phenotypes by buffering against stress. Fluctuating asymmetry is produced by developmental instability and is manifested as small random departures from bilateral symmetry. Increased fluctuating asymmetry is thought to parallel compromised fitness, in part, because stress promotes energy dissipation. Compensatory energy expenditures within the organism are required to complete development, thus promoting instability through reductions in homeostasis. Increased heterozygosity may enhance developmental stability by reducing energy dissipation from stress through increased metabolic efficiency, possibly by providing greater flexibility in metabolic pathways. Traditionally, fluctuating asymmetry has been used as a bioindicator of chronic stress, provided that selective mortality of less fit individuals did not reduce stress-mediated increases in fluctuating asymmetry to background levels produced by natural developmental error, or create data inconsistencies such as higher asymmetry in groups exposed to lower stress. Unfortunately, absence of selective mortality and its effects, while often assumed, can be difficult to substantiate. We integrated measures of early growth, mortality, fluctuating asymmetry (mandibular pores, pectoral finrays, pelvic finrays, and gillrakers on the upper and lower arms of the first branchial arch) and directional asymmetry (branchiostegal rays) to assess chronic thermal stress (fluctuating temperatures as opposed to ambient temperatures) in developing eggs from two different coho salmon (Oncorhynchus kisutch) stocks and their reciprocal hybrids. Hybridization provided insight on the capacity of heterozygosity to reduce stress during development. Although egg losses were consistently higher in crosses exposed to fluctuating temperatures, egg mortality was predominantly a function of maternal stock of origin. Post-hatch losses were higher in crosses exposed to ambient temperatures than in crosses exposed to fluctuating temperatures during embryogenesis. Observed patterns of early growth revealed no heterosis, but instead reflected maternal effects, with some crosses slowing growth and yolk utilization when exposed to fluctuating temperatures. Analyses of fluctuating asymmetry also showed no effects from heterosis. While analyses of composite asymmetry scores and branchiostegal rays were inconclusive, analyses of individual characters showed significantly higher fluctuating asymmetry in pelvic finray counts and a marginal change in the numbers of fish asymmetric for this character in crosses exposed to chronic thermal stress. In contrast, the fluctuating asymmetry in lower gillraker counts was significantly higher in crosses exposed to ambient temperatures and there were significantly more fish asymmetric for this character. Data on mortalities and fluctuating asymmetry indicate pelvic finray development was thermally stressed, while the heightened fluctuating asymmetry in lower gillraker counts under ambient temperatures was due to a greater frequency of less fit fish that had not been culled by thermal stress. Changes in early growth patterns in response to developmental stress yielded no parallel responses in meristic characters. We conclude that chronic thermal stress produced both selectively lethal and sublethal effects that directly shaped fluctuating asymmetry and fitness profiles in these crosses. Implicit in this conclusion is that developmental instability analyses can detect more than just chronic sublethal stress, thus providing substantial credence for using instability studies as proactive bioassessment methodologies.

Oikos↗
USGS2007

Development and evaluation of a gas chromatographic method for the determination of triazine herbicides in natural water samples

A multi-residue method is described for the determination o triazine herbicides in natural water samples. The technique uses solvent extraction followed by gas chromatographic separation and detection employing nitrogen-selective devices. Seven compounds can be determined simultaneously at a nominal detection limit of 0.1 μg/L in a 1-litre sample. Three different natural water samples were used for error analysis via evaluation of recovery efficiencies and estimation of overall method precision. As an alternative to liquid-liquid partition (solvent extraction) for removal of compounds of interest from water, solid-phase extraction (SPE) techniques employing chromatographic grade silicas with chemically modified surfaces have been examined. SPE is found to provide rapid and efficient concentration with quantitative recovery of some triazine herbicides from natural water samples. Concentration factors of 500 to 1000 times are obtained readily by the SPE technique.

International Journal of Environmental Analytical ↗
USGS1995

Water-quality assessment of the Rio Grande Valley study unit, Colorado, New Mexico, and Texas -- Analysis of selected nutrient, suspended-sediment, and pesticide data

This report contains a summary of data compiled from sources throughout the Rio Grande Valley study unit of the National Water-Quality Assessment program. Information presented includes the sources and types of water-quality data available, the utility of water-quality data for statistical analysis, and a description of recent water-quality conditions and trends and their relation to natural and human factors. Water-quality data are limited to concentrations of selected nutrient species in surface water and ground water, concentrations of suspended sediment and suspended solids in surface water, and pesticides in surface water, ground water, and biota. The Rio Grande Valley study unit includes about 45,900 square miles in Colorado, New Mexico, and Texas upstream from the streamflow-monitoring station Rio Grande at El Paso, Texas. The area also includes the San Luis Closed Basin and the surface-water closed basins east of the Continental Divide and north of the United States-Mexico international border. The Rio Grande drains about 29,300 square miles in these States; the remainder of the study unit area is in closed basins. Concentrations of all nutrients found in surface-water samples collected from the Rio Grande, with the exception of phosphorus, generally remained nearly constant from the northernmost station in the study unit to Rio Grande near Isleta, where concentrations were larger by an order of magnitude. Total nitrogen and total phosphorus loads increased downstream between Lobatos, Colorado, and Albuquerque, New Mexico. Nutrient concentrations remained elevated with slight variations until downstream from Elephant Butte Reservoir, where nutrient concentrations were lower. Nutrient concentrations then increased downstream from the reservoir, as evidenced by elevated concentrations at Rio Grande at El Paso, Texas. Suspended-sediment concentrations were similar at stations upstream from Otowi Bridge near San Ildefonso, New Mexico. The concentration and estimated load were nearly two orders of magnitude larger at this station relative to upstream stations. Cochiti Lake allows suspended sediment to settle, thus the resulting concentration is substantially lower downstream from the reservoir. Downstream from Cochiti Lake, concentrations again increased due to inflow from tributaries, other ephemeral streams and arroyos, and agricultural and urban areas. Two ephemeral tributaries (Rio Puerco and Rio Salado, which are south of Albuquerque) contribute substantial amounts of suspended sediment to the Rio Grande. Suspended-sediment concentrations in the Rio Grande just downstream from Elephant Butte Dam decreased by nearly three orders of magnitude due to settling in the reservoir. Concentrations then increased due to agricultural and urban impacts downstream from the reservoir. Nutrients in ground water in the study unit do not appear to be a widespread problem. However, localized areas that have elevated nitrate concentrations have been documented. The largest median nitrate concentration was found in water from wells located in the Basin and Range-mountains-urban data stratum (3.0 milligrams per liter) and the smallest median nitrate concentration was found in water from wells located in the Southern Rocky Mountainsmountains-forest data stratum (0.08 milligram per liter). Few (3 percent) nitrate concentrations in water from wells in all data strata were greater than 10 milligrams per liter, and most (82 percent) were less than 2 milligrams per liter. Comparison of nitrate concentrations in water from wells located in specific land-use settings across all hydrogeologic settings, with the exception of the Colorado Plateau, indicated that the largest median nitrate concentration was associated with rangeland land use and that larger nitrate concentrations were found in water from shallow wells. Water from wells located in areas of rangeland land use consistently had larger median nutrient concentrations than water from wells in areas of other land uses. The largest median ammonia concentration was in water from wells located in the Colorado Plateau-San Juan Basin-rangeland data stratum (0.27 milligram per liter). Most median ammonia concentrations were less than 0.03 milligram per liter, indicating that elevated ammonia concentrations are not a major issue in the study unit. The largest median orthophosphate concentration was found in water from wells located in the Southern Rocky Mountains-mountains-forest data stratum (0.15 milligram per liter) and the smallest was found in water from wells located in the Basin and Range-mountains-urban data stratum (0.02 milligram per liter). Most orthophosphate concentrations (85 percent) sampled were less than 0.2 milligram per liter, indicating that elevated orthophosphate concentrations are not a major issue in the study unit. Pesticide analyses were available for only 38 ground-water sampling sites in the Rio Grande Valley study unit. Diazinon, at a concentration of 0.01 microgram per liter, was the only pesticide detected and it was detected at only one site. More study is needed to determine if pesticides are affecting ground-water quality in the Rio Grande Valley study unit. Surface-water biological pesticide data were inadequate for in-depth analysis. The primary sources of data were the U.S. Fish and Wildlife Service and the U.S. Geological Survey. In the U.S. Fish and Wildlife Service study p,p'-DDE, a degradation product of DDT, was detected most frequently; highest concentrations were found at Stahman Farms in carp (6.3 micrograms per gram wet-weight) and at Hatch in Western kingbird (5.1 micrograms per gram wet-weight). In the U.S. Geological Survey study of Bosque del Apache National Wildlife Refuge no detectable organochlorine concentrations were found in plants, but detectable levels of p,p'-DDE were found in coot and carp, with a maximum concentration of 0.12 microgram per gram wet-weight found in coot.

Colorado, New Mexico, Texas↗
USGS2021

Technique to estimate generalized skew coefficients of annual peak streamflow for natural watershed conditions in Texas, Oklahoma, and eastern New Mexico

Reliable information about the frequency of annual peak streamflow is needed for floodplain management, objective assessment of flood risk, and cost-effective design of dams, levees, other flood-control structures, and roads, bridges, and culverts. Generalized skew coefficients are among the data needed for log-Pearson type III peak-streamflow frequency analyses of annual peak streamflows. A technique is presented to estimate generalized skew coefficients used for log-Pearson type III peak-streamflow frequency analyses of annual peak streamflow from natural watersheds (minimal regulation and minimal impervious cover). The estimation of generalized skew coefficients was based on annual and historical peak streamflow data from an initial set of 444 selected USGS streamgaging stations (streamgages) with at least 30 years of recorded annual peak streamflows from natural watersheds in Texas, Oklahoma, and the part of New Mexico east of the Great Continental Divide. The primary focus was to obtain information that could be used to update previously published generalized skew coefficients in Texas. Of the 444 candidate streamgages, 341 were used in the final construction of statistical models. Two generalized additive models (GAMs) were used to predict generalized skew based on a 2-dimensional smooth on projected Albers equal area coordinates of either (1) the locations of the centroids of the gaged watersheds or (2) the streamgage locations. To create maps of generalized skew coefficients, predictions were made on a 1-kilometer grid and contour lines were superimposed. The centroid-location map, with a mean-squared error (MSE) of 0.216, is preferred. Generalized skew coefficients from the centroid-location map, along with the MSE, are useful for computing weighted-skew values when conducting frequency analyses of annual peak streamflow following the guidelines set forth in Bulletin 17C. Based on the results of the study, text revision of the TxDOT Hydraulic Design Manual could be made.

New Mexico, Oklahoma, Texas↗