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At least 1,405 records · Page 78Linked to original sources
USGS2017

Sampling bees in tropical forests and agroecosystems: A review

Bees are the predominant pollinating taxa, providing a critical ecosystem service upon which many angiosperms rely for successful reproduction. Available data suggests that bee populations worldwide are declining, but scarce data in tropical regions precludes assessing their status and distribution, impact on ecological services, and response to management actions. Herein, we reviewed >150 papers that used six common sampling methods (pan traps, baits, Malaise traps, sweep nets, timed observations and aspirators) to better understand their strengths and weaknesses, and help guide method selection to meet research objectives and development of multi-species monitoring approaches. Several studies evaluated the effectiveness of sweep nets, pan traps, and malaise traps, but only one evaluated timed observations, and none evaluated aspirators. Only five studies compared two or more of the remaining four sampling methods to each other. There was little consensus regarding which method would be most reliable for sampling multiple species. However, we recommend that if the objective of the study is to estimate abundance or species richness, malaise traps, pan traps and sweep nets are the most effective sampling protocols in open tropical systems; conversely, malaise traps, nets and baits may be the most effective in forests. Declining bee populations emphasize the critical need in method standardization and reporting precision. Moreover, we recommend reporting a catchability coefficient, a measure of the interaction between the resource (bee) abundance and catching effort. Melittologists could also consider existing methods, such as occupancy models, to quantify changes in distribution and abundance after modeling heterogeneity in trapping probability, and consider the possibility of developing monitoring frameworks that draw from multiple sources of data.

Journal of Insect Conservation↗
USGS2007

Legacy mercury in Alviso Slough, south San Francisco Bay, California: Concentration, speciation and mobility

Mercury (Hg) is a significant contaminant in the waters, sediment and biota of San Francisco Bay, largely resulting from extensive historic regional mining activities. Alviso Slough represents one of the most mercury contaminated waterways entering south San Francisco Bay, as it is associated with the drainage of the New Almaden mercury mining district. Wetland habitat restoration of former salt manufacturing ponds adjacent to Alviso Slough is currently being planned. One management scenario being considered is a levee breach between Alviso Slough and Pond A8, which will allow reconnection of the salt pond with the tidal slough. This action is projected to increase the tidal prism within Alviso Slough and result in some degree of sediment remobilization as the main channel deepens and widens. The focus of the current study is to assess: a) the current mercury species composition and concentration in sediments within the Alviso Slough main channel and its associated fringing marsh plain, b) how much of each mercury species will be mobilized as a result of projected channel deepening and widening, and c) potential changes in inorganic reactive mercury bioavailability (for conversion to toxic methylmercury) associated with the mobilized sediment fraction. The current report details the field sampling approach and all laboratory analyses conducted, as well as provides the complete dataset associated with this project including a) a quantitative assessment of mercury speciation (total mercury, reactive mercury and methylmercury), b) estimates of the quantity of sediment and mercury mobilized based on 20-foot and 40-foot levee wall notch scenarios, and c) results from a sediment scour experiment examining the changes in the reactive mercury pool under four treatment conditions (high / low salinity and oxic / anoxic water). Ancillary sediment data also collected and reported herein include bulk density, organic content, magnetic susceptibility, percent dry weight, grain size, pH, oxidation-reduction potential, core photography, and detailed lithographic descriptions.

California↗
USGS2010

The Border Environmental Health Initiative: Investigating the transboundary Santa Cruz watershed

In 2004 the U.S. Geological Survey (USGS) launched the Border Environmental Health Initiative (BEHI), a major project encompassing the entire U.S.-Mexico border region. In 2009, a study of the Santa Cruz River Watershed (SCW), located in the border region of Arizona and Sonora, Mexico, was initiated as part of the BEHI. In this borderland region of the desert Southwest, human health and the ecosystems on which humans rely depend critically on limited water resources. Surface water is scarce during much of the year, and groundwater is the primary source for industrial, agricultural, and domestic use. In order to identify risks to water resources in the SCW, and the potential consequences to riparian ecosystems and ultimately human health, the USGS is using an interdisciplinary and integrative approach that incorporates the expertise of geographers, hydrologists, biologists, and geologists to track organic and inorganic contaminants and their effects from sources to sinks in sediment, water, plants, and animals. Existing groundwater and surface-water models are being used and modified to assess contaminant and sediment transport.

Arizona, Sonora↗
USGS2018

Geology and assessment of undiscovered oil and gas resources of the Long Strait Basin Province, 2008

The Long Strait Basin is both a stand alone petroleum province and an assessment unit (AU) that lies offshore in the East Siberian Sea north of Chukotka and south of Wrangel Island. This basin is known only on the basis of gravity data and a single proprietary seismic line. In the absence of more specific data, its position and regional setting suggest that it may have petroleum geologic characteristics similar to the nearby Hope Basin. Because the geology and petroleum potential of the Long Strait Basin are so poorly known, only a single AU was defined for this study area. An overall probability of ~0.08 (8 percent) of at least one petroleum accumulation larger than 50 million barrels of oil equivalent was determined on the basis of estimated probabilities of the occurrence of petroleum source, adequate reservoir, trap and seal, and favorable timing. Because this probability falls below the 10 percent probability cutoff used in the U.S. Geological Survey’s Circum-Arctic Resource Appraisal, no quantitative assessment of sizes and numbers of petroleum accumulations was conducted for this AU.

Professional Paper↗
USGS2006

Map showing geology, oil and gas fields, and geologic provinces of the Gulf of Mexico region

This map was created as part of a worldwide series of geologic maps for the U.S. Geological Survey’s World Energy Project, available on CD-ROM and through the Internet. The goal of the project is to assess the undiscovered, technically recoverable oil and gas resources of the world. Geologic provinces were created for ranking purposes in the World Petroleum Assessment 2000 (U.S. Geological Survey World Energy Assessment Team, 2000). A modified subset of these provinces are shown on the map, based on new bathymetric data and geologic knowledge. Geologic province boundaries are not intended to be taken for country boundaries or exclusive economic zone (EEZ) boundaries. The USGS World Petroleum Assessment 2000 - Description and Results can be found online at: http://pubs.usgs.gov/dds/dds-060 . Oil and gas fields are represented by a single geographic point in the center of the field and displays field type (oil or gas) only. The map includes three surface geology datasets, which were modified for display purposes.

Open-File Report↗
USGS2013

Geology and oil and gas assessment of the Todilto Total Petroleum System, San Juan Basin Province, New Mexico and Colorado: Chapter 3 in Total petroleum systems and geologic assessment of undiscovered oil and gas resources in the San Juan Basin Province, exclusive of Paleozoic rocks, New Mexico and Colorado

Organic-rich, shaly limestone beds, which contain hydrocarbon source beds in the lower part of the Jurassic Todilto Limestone Member of the Wanakah Formation, and sandstone reservoirs in the overlying Jurassic Entrada Sandstone, compose the Todilto Total Petroleum System (TPS). Source rock facies of the Todilto Limestone were deposited in a combined marine-lacustrine depositional setting. Sandstone reservoirs in the Entrada Sandstone were deposited in eolian depositional environments. Oil in Todilto source beds was generated beginning in the middle Paleocene, about 63 million years ago, and maximum generation of oil occurred in the middle Eocene. In the northern part of the San Juan Basin, possible gas and condensate were generated in Todilto Limestone Member source beds until the middle Miocene. The migration distance of oil from the Todilto source beds into the underlying Entrada Sandstone reservoirs was short, probably within the dimensions of a single dune crest. Traps in the Entrada are mainly stratigraphic and diagenetic. Regional tilt of the strata to the northeast has influenced structural trapping of oil, but also allowed for later introduction of water. Subsequent hydrodynamic forces have influenced the repositioning of the oil in some reservoirs and flushing in others. Seals are mostly the anhydrite and limestone facies of the Todilto, which thin to as little as 10 ft over the crests of the dunes. The TPS contains only one assessment unit, the Entrada Sandstone Conventional Oil Assessment Unit (AU) (50220401). Only four of the eight oil fields producing from the Entrada met the 0.5 million barrels of oil minimum size used for this assessment. The AU was estimated at the mean to have potential additions to reserves of 2.32 million barrels of oil (MMBO), 5.56 billion cubic feet of natural gas (BCFG), and 0.22 million barrels of natural gas liquids (MMBNGL).

Colorado;New Mexico↗
USGS2006

Magnetotelluric data collected near geophysically logged boreholes in the Española and Middle Rio Grande Basins, New Mexico

The Santa Fe region is growing rapidly. The Santa Fe Group aquifer in the Española Basin is the main source of municipal water for the region, and water shortfalls could have serious consequences. Future growth and land management in the region depend on accurate assessment and protection of the region's ground-water resources. An important issue in managing the ground-water resources is a better understanding of the hydrogeology of the Tertiary Santa Fe Group. The Santa Fe Group includes the sedimentary deposits that fill the Rio Grande rift and contain the principal ground-water aquifers. The U.S. Geological Survey (USGS) is conducting a series of multidisciplinary studies of the Española Basin in northern New Mexico. Detailed geologic mapping, high-resolution airborne magnetic surveys, electromagnetic surveys, and hydrologic, lithologic, and hydro-geochemical data are being used to better understand the aquifer systems. Magnetotelluric (MT) surveys were completed as part of these studies. The primary purpose of the MT surveys was to map changes in electrical resistivity with depth that are related to differences in various rock types that help control the properties of aquifers in the region. Resistivity modeling of the MT data can be used to investigate buried structures related to the basic geologic framework of the study area. The purpose of this report is to release MT sounding data collected near geophysically logged boreholes in the study area, including the nearby Middle Rio Grande Basin. This MT data can be used in subsequent resistivity modeling. No interpretation of the data is included in this report.

New Mexico↗
USGS2018

Use of remote sensing to detect and predict aquatic nuisance vegetation growth in coastal Louisiana: Summary of findings

On an annual basis, federal and state agencies are responsible for mapping and removing large expanses of aquatic nuisance vegetation from navigable waterways. This study set out to achieve four primary objectives: (1) utilize recent advancements in remote sensing techniques to classify the extent and distribution of aquatic vegetation in coastal ecosystems using satellite imagery, (2) assess primary aquatic vegetation growth and management efforts in coastal Louisiana, (3) statistically identify the ecological drivers that promote growth and infestation of aquatic nuisance vegetation, and (4) develop numerical models and a spatial tool to predict the probability of occurrence and growth of aquatic vegetation given ecological drivers. Moderate spatial resolution multispectral satellite imagery were used in conjunction with environmental variables from available data streams to generate regression models that predict aquatic vegetation occurrence in the eastern coastal region of south Louisiana. Geospatial tools were developed to execute the model logic using recent environmental conditions, thereby predicting aquatic vegetation occurrence and producing classified maps for end users. These products provide more efficient and enhanced capabilities for management of aquatic nuisance vegetation.

Louisiana↗
USGS1993

Methods for collecting benthic invertebrate samples as part of the National Water-Quality Assessment Program

Benthic invertebrate communities are evaluated as part of the ecological survey component of the U.S. Geological Survey's National Water-Quality Assessment Program. These biological data are collected along with physical and chemical data to assess water-quality conditions and to develop an understanding of the factors that affect water-quality conditions locally, regionally, and nationally. The objectives of benthic invertebrate community characterizations are to (1) develop for each site a list of tax a within the associated stream reach and (2) determine the structure of benthic invertebrate communities within selected habitats of that reach. A nationally consistent approach is used to achieve these objectives. This approach provides guidance on site, reach, and habitat selection and methods and equipment for qualitative multihabitat sampling and semi-quantitative single habitat sampling. Appropriate quality-assurance and quality-control guidelines are used to maximize the ability to analyze data within and among study units.

Open-File Report↗
USGS2014

Elders recall an earlier tsunami on Indian Ocean shores

Ten years on, the Indian Ocean tsunami of 26 December 2004 still looms large in efforts to reduce coastal risk. The disaster has spurred worldwide advances in tsunami detection and warning, tsunami-risk assessment, and tsunami awareness [Satake, 2014]. Nearly a lifetime has passed since the northwestern Indian Ocean last produced a devastating tsunami. Documentation of this tsunami, in November 1945, was hindered by international instability in the wake of the Second World War and, in British India, by the approach of independence and partition. The parent earthquake, of magnitude 8.1, was widely recorded, and the tsunami registered on tide gauges, but intelligence reports and newspaper articles say little about inundation limits while permitting a broad range of catalogued death tolls. What has been established about the 1945 tsunami falls short of what's needed today for ground-truthing inundation models, estimating risk to enlarged populations, and anchoring awareness campaigns in local facts. Recent efforts to reduce coastal risk around the Arabian Sea include a project in which eyewitnesses to the 1945 tsunami were found and interviewed (Fig. 1), and related archives were gathered. Results are being made available through UNESCO's Indian Ocean Tsunami Information Center in hopes of increasing scientific understanding and public awareness of the region's tsunami hazards.

Eos, Earth and Space Science News↗
USGS2005

Testing the generality of a trophic-cascade model for plague

Climate may affect the dynamics of infectious diseases by shifting pathogen, vector, or host species abundance, population dynamics, or community interactions. Black-tailed prairie dogs (Cynomys ludovicianus) are highly susceptible to plague, yet little is known about factors that influence the dynamics of plague epizootics in prairie dogs. We investigated temporal patterns of plague occurrence in black-tailed prairie dogs to assess the generality of links between climate and plague occurrence found in previous analyses of human plague cases. We examined long-term data on climate and plague occurrence in prairie dog colonies within two study areas. Multiple regression analyses revealed that plague occurrence in prairie dogs was not associated with climatic variables in our Colorado study area. In contrast, plague occurrence was strongly associated with climatic variables in our Montana study area. The models with most support included a positive association with precipitation in April-July of the previous year, in addition to a positive association with the number of "warm" days and a negative association with the number of "hot" days in the same year as reported plague events. We conclude that the timing and magnitude of precipitation and temperature may affect plague occurrence in some geographic areas. The best climatic predictors of plague occurrence in prairie dogs within our Montana study area are quite similar to the best climatic predictors of human plague cases in the southwestern United States. This correspondence across regions and species suggests support for a (temperature-modulated) trophic-cascade model for plague, including climatic effects on rodent abundance, flea abundance, and pathogen transmission, at least in regions that experience strong climatic signals. ?? 2005 EcoHealth Journal Consortium.

EcoHealth↗
USGS2004

Survival rates, mortality causes, and habitats of Pennsylvania white-tailed deer fawns

Estimates of survival and cause-specific mortality of white-tailed deer ( Odocoileus virginianus ) fawns are important to population management. We quantified cause-specific mortality, survival rates, and habitat characteristics related to fawn survival in a forested landscape and an agricultural landscape in central Pennsylvania. We captured and radiocollared neonatal (<3 weeks) fawns in 2000–2001 and monitored fawns from capture until death, transmitter failure or collar release, or the end of the study. We estimated survivorship functions and assessed influence on fawn survival of road density, habitat edge density, habitat patch diversity, and proportion of herbaceous habitat. We captured 110 fawns in the agricultural landscape and 108 fawns in the forested landscape. At 9 weeks after capture, fawn survival was 72.4% (95% Cl = 63.3–80.0%) in the agricultural landscape and 57.2% (95% Cl = 47.5–66.3%) in the forested landscape. Thirty-four-week survival was 52.9% (95% Cl = 42.7–62.8%) in the agricultural landscape and 37.9% (95% Cl = 27.7–49.3%) in the forested landscape. We detected no relationship between fawn survival and road density, percent herbaceous cover, habitat edge density, or habitat patch diversity (all P >0.05). Predation accounted for 46.2% (95% Cl = 37.6–56.7%) of 106 mortalities through 34 weeks. We attributed 32.7% (95% Cl = 21.9–48.6%) and 36.7% (95% Cl = 25.5–52.9%) of 49 predation events to black bears ( Ursus americanus ) and coyotes ( Canis latrans ), respectively. Natural causes, excluding predation, accounted for 27.4% (95% Cl = 20.1–37.3) of mortalities. Fawn survival in Pennsylvania was comparable to reported survival in forested and agricultural regions in northern portions of the white-tailed deer range. We have no evidence to suggest that the fawn survival rates we observed were preventing population growth. Because white-tailed deer are habitat generalists, home-range-scale habitat characteristics may be unrelated to fawn survival; therefore, future studies should consider landscape-related characteristics on fawn survival.

Pennsylvania↗
USGS2009

A Review and Synthesis of the Scientific Information Related to the Biology and Management of Species of Special Concern at Cape Hatteras National Seashore, North Carolina

The U.S. Geological Survey's Patuxent Wildlife Research Center (PWRC) conducted a study for the National Park Service (NPS) Southeast Region, Atlanta, GA, and Cape Hatteras National Seashore (CAHA) in North Carolina to review, evaluate, and summarize the available scientific information for selected species of concern at CAHA (piping plovers, sea turtles, seabeach amaranth, American oystercatchers, and colonial waterbirds). This work consisted of reviewing the scientific literature and evaluating the results of studies that examined critical life history stages of each species, and focused on the scientific findings reported that are relevant to the management of these species and their habitats at CAHA. The chapters that follow provide the results of that review separately for each species and present scientifically based options for resource management at CAHA. Although no new original research or experimental work was conducted, this synthesis of the existing information was peer reviewed by over 15 experts with familiarity with these species. This report does not establish NPS management protocols but does highlight scientific information on the biology of these species to be considered by NPS managers who make resource management decisions at CAHA. To ensure that the best available information is considered when assessing each species of interest at CAHA, this review included published research as well as practical experience of scientists and wildlife managers who were consulted in 2005. PWRC scientists evaluated the literature, consulted wildlife managers, and produced an initial draft that was sent to experts for scientific review. Revisions based on those comments were incorporated into the document. The final draft of the document was reviewed by NPS personnel to ensure that the description of the recent status and management of these species at CAHA was accurately represented and that the report was consistent with our work agreement. The following section summarizes the biological information relevant to resource management for the species of concern at CAHA.

Open-File Report↗
USGS2000

Oil and gas reserve growth-a model for the Volga-Ural Province, Russia

An understanding of reserve growth in known oil and gas fields has become a critical component of energy resource analysis. Significant statistical studies of reserve growth have been published in the U.S., whereas little information is available on other regions of the world. It may be expected that in many countries the magnitude of reserve growth is different from that in the U.S. because of differences in reporting systems and in exploration and production practices. This paper describes the results of a reserve growth study in a group of largest oil and gas fields of the Volga-Ural petroleum province, Russia. The dynamics of reserve growth in these fields shows rapid reserve additions during the first 5 years of field exploration and development, which results from intensive step-out and delineation drilling. Later reserve growth is slow and is related to improvements in recovery technologies and discoveries of new pools and extensions. These two stages of reserve growth are described by two different groups of empirical models. A comparison of these models with the models developed for the lower 48 states and Gulf Coast offshore of the U.S. demonstrates that the reserve growth in the Volga-Ural province is significantly lower than in the U.S. The proposed models may be used for assessment of future reserve additions in known fields of countries that presently have or recently had a centrally-planned economic system.

Conference Paper↗
USGS2013

Moving forward with imperfect information

This chapter summarized the scope of what is known and not known about climate in the Southwestern United States. There is now more evidence and more agreement among climate scientists about the physical climate and related impacts in the Southwest compared with that represented in the 2009 National Climate Assessment (Karl, Melillo, and Peterson 2009). However, there remain uncertainties about the climate system, the complexities within climate models, the related impacts to the biophysical environment, and the use of climate information on decision making. Uncertainty is introduced in each step of the climate planning-an-response process--in the scenarios used to drive the climate models, the information used to construct the models, and the interpretation and use of the model' data for planning and decision making (Figure 19.1). There are server key challenge, drawn from recommendations of the authors of this report, that contribute to these uncertainties in the Southwest: - There is a dearth of climate observations at high elevations and on the lands of Native nations. - There is limited understanding of the influence of climate change on natural variability (e.g. El Niño-Southern Oscillations, Pacific Decadal Oscillation), extreme events (droughts, floods), and the marine layer align coastal California. - Climate models, downscaling, and resulting projection of the physical climate are imperfect. Representing the influence of the diverse topography of the Southwest on regional climate is a particular challenge. - The impacts of climate change on key components of the natural ecosystems (including species and terrestrial ecosystems) are ill-defined. - The adaptive capacity of decision-making entities and legal systems to handle climate impacts is unclear. This creates a challenge for identifying vulnerabilities to climate in the Southwest. - Regulation, legislation, and political and social responses too climate all play important roles in our ability to adapt to climate impacts and mitigate greenhouse gas (GHG) emissions. - Climate change is one of multiple stresses affecting the physical, biological, social, and economic systems of the Southwest, with population growth (and its related resource consumption, pollution, and land-sue changes) being particularly important.

Book chapter↗
USGS1998

Geologic map of part of the Tyrrhena Patera region of Mars (MTM Quadrangle-20252)

Mars Transverse Mercator (MTM) -20252 quadrangle contains the volcano Tyrrhena Patera, a low, broad structure that has summit depressions and is dissected by prominent radial channels (fig. 1). Tyrrhena Patera is surrounded by cratered plains materials on the western edge of Hesperia P lanum, ~ 2,000 km northeast of the center of the Hellas basin (Greeley and Guest, 1987; U. S. Geological Survey, 1991). On the basis of Mariner 9 data, Tyrrhena Patera was interpreted to be a shield volcano, composed of fluid basic or ultrabasic lavas (Peterson, 1978; Pike, 1978). Analysis of Viking Orbiter images led Greeley and Spudis (1981) to suggest that Tyrrhena Patera comprises pyroclastic deposits p roduced by explosi ve hydromagmatic eruption ; Greeley and Crown (1990) support a pyroclastic origin for Tyrrhena Patera shield materials and assess several eruption styles for the volcano (see also Crown and Greeley, 1993).

IMAP↗
USGS2022

Compendium to invasive annual grass spatial products for the western United States, January 2010-February 2021

Invasive annual grasses (IAGs) degrade native plant communities, alter fire cycles, impact ecosystem processes, and threaten the persistence of some species. Therefore, controlling the spread of IAGs has become a land management priority in the western United States. A wide array of geospatial data has been developed in the last decade to help land managers combat the invasion and expansion of non-native grasses by identifying areas where these species are likely to occur. However, choosing the most appropriate spatial product to address specific management concerns is a daunting task for many land managers, particularly with the rapid increase in the number of IAG spatial products available. To aid potential users in assessing these products, we reviewed and summarized 23 datasets that captured the three IAG species of most concern to rangeland management— Bromus tectorum (cheatgrass), Taeniatherum caput-medusae (medusahead), and Ventenata dubia (ventenata). To be included in this review, products were required to include part of the western United States, be regional or National in scale, and have been published between January 2010 and February 2021. This review, part of a series of informational data resources, is the compendium to an Excel-readable database and provides a 2-page summary of each spatial data product to assist land managers in understanding and selecting the best available spatial data for their management needs.

western United States↗
USGS2018

Multi-Resource Analysis—Methodology and synthesis

This document introduces the Multi-Resource Analysis (MRA), a set of products that are being designed to integrate information on multiple natural resources in a region, combine that information with models of resource interrelationships and scenarios of change, and provide meaningful insights on the implications of those changes to people and the resources they value. The MRA builds from and enhances a wide range of existing U.S. Geological Survey assessment products. These enhancements will help natural resource managers better understand the connections among the resources they manage and the changes that might occur due to natural events and human decisions. This knowledge will help them identify solutions to landscape-scale management issues that best meet their objectives. MRA products are developed through a structured process that brings together scientists, decision makers, and other stakeholders to address relevant issues and decisions for a specified geographic region, ensuring that the analysis is directly relevant. This circular introduces the MRA, describes the envisioned process for developing a region-specific MRA, and discusses the various MRA components and products. The MRA process and products are shown through descriptions and examples drawn from two proof-of-concept studies and related work.

Circular↗