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At least 1,189 records · Page 66Linked to original sources
USGS2009

Multiscale sagebrush rangeland habitat modeling in southwest Wyoming

Sagebrush-steppe ecosystems in North America have experienced dramatic elimination and degradation since European settlement. As a result, sagebrush-steppe dependent species have experienced drastic range contractions and population declines. Coordinated ecosystem-wide research, integrated with monitoring and management activities, would improve the ability to maintain existing sagebrush habitats. However, current data only identify resource availability locally, with rigorous spatial tools and models that accurately model and map sagebrush habitats over large areas still unavailable. Here we report on an effort to produce a rigorous large-area sagebrush-habitat classification and inventory with statistically validated products and estimates of precision in the State of Wyoming. This research employs a combination of significant new tools, including (1) modeling sagebrush rangeland as a series of independent continuous field components that can be combined and customized by any user at multiple spatial scales; (2) collecting ground-measured plot data on 2.4-meter imagery in the same season the satellite imagery is acquired; (3) effective modeling of ground-measured data on 2.4-meter imagery to maximize subsequent extrapolation; (4) acquiring multiple seasons (spring, summer, and fall) of an additional two spatial scales of imagery (30 meter and 56 meter) for optimal large-area modeling; (5) using regression tree classification technology that optimizes data mining of multiple image dates, ratios, and bands with ancillary data to extrapolate ground training data to coarser resolution sensors; and (6) employing rigorous accuracy assessment of model predictions to enable users to understand the inherent uncertainties. First-phase results modeled eight rangeland components (four primary targets and four secondary targets) as continuous field predictions. The primary targets included percent bare ground, percent herbaceousness, percent shrub, and percent litter. The four secondary targets included percent sagebrush (Artemisia spp.), percent big sagebrush (Artemisia tridentata), percent Wyoming sagebrush (Artemisia tridentata wyomingensis), and sagebrush height (centimeters). Results were validated by an independent accuracy assessment with root mean square error (RMSE) values ranging from 6.38 percent for bare ground to 2.99 percent for sagebrush at the QuickBird scale and RMSE values ranging from 12.07 percent for bare ground to 6.34 percent for sagebrush at the full Landsat scale. Subsequent project phases are now in progress, with plans to deliver products that improve accuracies of existing components, model new components, complete models over larger areas, track changes over time (from 1988 to 2007), and ultimately model wildlife population trends against these changes. We believe these results offer significant improvement in sagebrush rangeland quantification at multiple scales and offer users products that have been rigorously validated.

Wyoming↗
USGS1969

Environmental impact of oil development in northern Alaska

It is reported that in the spring of 1969 a high official of one of the oil companies was flying over the area of oil development in the vicinity of Prudhoe Bay. He is quoted as saying "If the American people could see what we are doing to their land here, they would want to abolish the use of the reciprocating engine." The last really large area of wilderness in the United States is the' Brooks Range and the Arctic Coastal Plain which stretches from that range to the Arctic Ocean. The proving of the exploratory oil wells which have been drilled on the coastal plain in the vicinity of Prudhoe Bay makes it virtually certain that this heretofore mostly unknown country will rapidly and vigorously be exposed to a variety of changes caused by the influx of men and their equipment. Even within the first four months of 1969 the whole aspect of the central part of the region has been importantly changed by the drilling programs of several large oil companies. So suddenly was this change brought about that no long-range plans have been developed either to soften the effect of such development on the natural environment or even to record the progress of these effects. Yet the absence of a plan provides an inadvertent potential advantage in that there has' been no history of increasingly firm Federal policy which, in other places, has often made it difficult to take newly conceived action in line with the increasing societal interest in environmental preservation. The lack of firm Federal policy provides here a unique opportunity for the application of new rules and investigative techniques aimed at minimizing the adverse effects on the environment while5.at the same time, not unduly hindering the development of the natural resources. But the speed with which the changes are being wrought makes it imperative that the principles applicable here to environmental protection or preservation, be enunciated immediately and that from these principles flow farsighted regulations which reflect the new interest in combining resource development with environmental protection. The present report constitutes a brief summary of the conditions existing in northern Alaska in the spring of 1969, presenting some inferences on the environmental changes which can be expected in the future and offering some specific steps which, if taken immediately and positively, could greatly ameliorate the adverse effects of rapid development in the absence of positive steps for environmental protection. In that regard, then, this report is ephemeral in character because the conditions in northern Alaska will surely change with great rapidity. Considering the"fragility and sensitivity of the ecosystems existing there, the changes can be both harsh and permanent. Therefore, whatever value lies in the recommendations made here., the results of their application will depend on the promptness of their consideration, amendment, and application. Whatever form the actions might take for minimizing the harm to the environment, the urgency of the matter can hardly be overestimated.

Alaska↗
USGS1986

Review of the intensive culture of walleye fry

Efficient intensive culture of larval walleyes (Stizostedion vitreum) may soon be realized due to results of research on larval development, culture environment, preferred food organisms, and feeding techniques. Larval behavior and morphology (developmental state) can be used as indicators for appropriate handling and feeding techniques. Certain environmental conditions such as a rearing unit color that contrasts with food organisms, water temperatures of 18‐22°C, uniform lighting, and a stocking density of no more than 35,000 fish/m 3 reportedly contribute to increased growth and survival. Successful culture requires that suitable food such as cladocerans, copepods, and brine shrimp be continuously available at a high density (0.1 organism/mL). Cannibalism among walleye larvae has not been prevented but has been reduced through the use of suitable fish and food densities.

Progressive Fish-Culturist↗
USGS1987

Feed conversion indices: Controversy or convention?

Various methods of calculating and reporting the efficiency of food use in fish husbandry are examined. The effects of moisture content of feed and fish flesh, supplemental feeds augmented with natural feed items, differences in energy content due to feed formulations, and the usefulness of the various feed efficiency indices to aquaculturists and fish husbandry researchers are discussed.

Progressive Fish-Culturist↗
USGS1985

Abundance fluctuations among benthic invertebrates in two pacific estuaries

Long-term studies were used to examine (1) contrasting time scales and mechanisms of structural variations within two benthic communities and (2) the usefulness of long data sets for evaluating human impact. A 10-year study of a San Francisco Bay mudflat, the details of which are reported elsewhere, has revealed large short-term (on the order of months) variations in species abundances within a community composed predominantly of opportunistic species. The study site, located in a highly urbanized estuary, is subject to the influence of a nearby sewage-treatment facility. However, rapid changes in population size of the common species, in part due to periodic natural habitat disturbance, impedes the detection of anthropogenic influences on community composition. Only a very long-term data set may provide evidence of progressive change. Data collected for a 20-year period on the benthic community at 200 m depth in the main basin of Puget Sound, an environment subject to little apparent habitat disturbance show that numerical abundance of the common species can also change markedly. Here, however, numerical dominance shifts from one species to another at irregular, multiyear intervals. Recent increases in two heretofore rare species, and a significant increase in total numbers of individuals suggest that long-term changes may be occurring in this community. These two long-term data sets demonstrate the importance of measuring both the amplitude and the periodicity of fluctuations in population size of aquatic species as well as long-term fluctuations and patterns in environmental factors before attempting to demonstrate the effect of anthropogenic influences on aquatic communities. The results of these studies also demonstrate the usefulness of long-term data sets for revealing the potential importance of interactions among species in determining abundance patterns in the soft-bottom benthos.

Estuaries↗
USGS1896

Hydrographic surveys

This circular is intended to answer questions asked by correspondents regarding the progress and character of the work of the "Irrigation Survey" and of related investigations being carried on by the Division of Hydrography of the United States Geological Survey. It also gives a review of the legislation authorizing this work, together with a list of publications of the Geological Survey showing the results accomplished.

Division of Hydrography Circular↗
USGS2021

Supporting the development and use of native plant materials for restoration on the Colorado Plateau (Fiscal Year 2020 Report)

A primary focus of the Colorado Plateau Native Plant Program (CPNPP) is to identify and develop appropriate native plant materials (NPMs) for current and future restoration projects. Multiple efforts have characterized the myriad challenges inherent in providing appropriate seed resources to enable effective, widespread restoration and have identified a broad suite of research activities to provide the information necessary to overcome those challenges (e.g., Plant Conservation Alliance 2015; Breed et al. 2018; Winkler et al. 2018). Many of the most complex information needs relate to identifying the appropriate sources of plant species that can successfully establish in dryland environments, like the Colorado Plateau, where precipitation is generally low and highly variable. Providing this information requires synergistic research efforts that build upon insight gained from earlier investigations. The U.S. Geological Survey (USGS) Southwest Biological Science Center’s (SBSC’s) research activities that supported CPNPP in FY20 followed the FY20 Statement of Work to support a research framework that is continually adapting based on the needs of the restoration community and results from previous investigations; the long-term research framework is outlined in the 2019-2023 5-Year Research Strategy (hereafter referred to as the 5-year plan). This research framework provides support for the National Seed Strategy for Rehabilitation and Restoration (Plant Conservation Alliance, 2015), Department of Interior Secretarial Order #3347 ( Conservation Stewardship and Outdoor Recreation ), and Bureau of Land Management Leadership Priority #1 ( Create a conservation stewardship legacy second only to Teddy Roosevelt ). Research activities in FY20 centered on landscape genomics, implementing a common garden experiment near Vernal, UT, conducting experimental treatments using the GRID (Germination for Restoration Information and Decision-making) framework, and collecting seeds and leaf tissues in the field in preparation for future experiments. These activities were supported by five biological science technicians. The SARS-CoV-2 pandemic delayed some aspects of the FY20 workplan, especially for contract laboratory services and the construction of the GRID garden in Flagstaff, AZ. However, goals were largely met, and the overall progress of research remains on track with respect to the 5-year plan. While Dr. Rob Massatti was the only scientist supported by the SBSC-CPNPP agreement in FY20, other scientists, including Drs. John Bradford, Seth Munson, Mike Duniway, Sasha Reed, Matt Jones, and Daniel Winkler, spent a considerable amount of time providing expertise and support for individual projects. Work activities performed in support of each goal are discussed in turn.

Arizona, Colorado, New Mexico, Utah↗
USGS2019

Regional protocol framework for the inventory and monitoring of breeding Atlantic Coast Piping Plovers

This regional protocol provides a framework for quantifying the number of breeding pairs and productivity of Atlantic Coast piping plover (Charadrius melodus) populations during the breeding season. A primary purpose of this protocol is to standardize piping plover monitoring during the breeding season. The survey techniques described herein involve repeated visual counts of adults, nests, eggs, and chicks within a defined survey site (i.e., beach) as well as visual identification of potential threats to survival and productivity. Resulting data can be compiled and analyzed across multiple geographic units (i.e., sites, states, and recovery units) to assess progress toward recovery goals, inform local management decisions, assess management effectiveness, and improve monitoring efforts. This protocol framework was developed as part of the United States Fish and Wildlife Service (USFWS) National Wildlife Refuge System (NWRS) Inventory and Monitoring (I&M) Initiative in coordination with Ecological Services (ES) and state coordinators within the Southeast and Northeast Regions (4 and 5, respectively). Although this protocol framework is to be used primarily by NWRS to inform recovery goals, assist with local management decision-making, and meet State reporting requirements, the approach strives to assist monitoring efforts of nonNWRS partners, such as other federal agencies (e.g. National Park Service), State wildlife agencies, non-governmental organizations, and private landowners. This protocol framework and associated data management system (PIPLweb) aims to interface with existing data management and analysis tools (i.e., PIPLODES, NestStory, and PiperEx) to ensure that data collection is efficient and comparable across scales, and supports management decisions across partners. The content and structure of the protocol framework follows standards set forth in the USFWS’s How to Develop Survey Protocols: A Handbook (Version 1.0; 2013). The eight elements addressed include: introduction, sampling design, field methods, data management and analysis, reporting, personnel requirements and training, operational requirements, and references. A series of standard operating procedures (SOPs) provides greater detail on recommended methods and technical aspects of this protocol. Data entry, archival, and multi-scale analysis are handled through a secure web application (Plover Inventory and Productivity Library; PIPLweb) developed by the United States Geological Survey (USGS). When management activities and survey objectives are similar across management units, partners (Refuges, other federal agencies, State, NGOs, private) are encouraged to use this protocol framework to develop stepped-down site-specific survey protocols that include guidance for conducting on-the-ground monitoring and management plans.

Regional Protocol Framework↗
USGS1999

Influence of bacterial kidney disease on smoltification in salmonids: Is it a case of double jeopardy?

We investigated the effects of a chronic, progressive infection with Renibacterium salmoninarum (Rs), the causative agent of bacterial kidney disease (BKD), on selected aspects of smoltification in yearling juvenile spring chinook salmon (Oncorhynchus tshawytscha). After experimentally infecting fish with Rs using an immersion challenge, we sampled them every two weeks to monitor changes in gill Na+, K+-ATPase (ATPase), cortisol, infection level, mortality, growth, and other stress-related physiological factors during the normal time of parr-smolt transformation in fresh water (i.e., from winter to spring). A progressively worsening infection with Rs did not alter the normal changes in gill ATPase and condition factor associated with smoltification in juvenile chinook salmon. The infection did, however, lead to elevated levels of plasma cortisol and lactate and depressed levels of plasma glucose, indicating that the disease is stressful during the later stages. A dramatic proliferation of BKD was associated with maximal responses of indicators of smoltification, suggesting that the process of smoltification itself can trigger outbreaks of disease. Our results suggest mechanisms that probably influence the reported inability of Rs-infected fish to successfully adapt to sea water.

Aquaculture↗
USGS1991

Towable cage for studies of smoltification in Atlantic salmon

The floating towable cage described in this report was used successfully to hold and transport Atlantic salmon ( Salmo salar ) in estuarine waters. These rugged and versatile cages, constructed from readily available, inexpensive materials, were tied singly and in clusters to floating docks in fresh and brackish water, where they withstood strong currents, winds, floods, and tides for 2.5 months without visible damage.

Progressive Fish-Culturist↗
USGS2020

The community code verification exercise for simulating sequences of earthquakes and aseismic slip (SEAS)

Numerical simulations of sequences of earthquakes and aseismic slip (SEAS) have made great progress over past decades to address important questions in earthquake physics. However, significant challenges in SEAS modeling remain in resolving multiscale interactions between earthquake nucleation, dynamic rupture, and aseismic slip, and understanding physical factors controlling observables such as seismicity and ground deformation. The increasing complexity of SEAS modeling calls for extensive efforts to verify codes and advance these simulations with rigor, reproducibility, and broadened impact. In 2018, we initiated a community code-verification exercise for SEAS simulations, supported by the Southern California Earthquake Center. Here, we report the findings from our first two benchmark problems (BP1 and BP2), designed to verify different computational methods in solving a mathematically well-defined, basic faulting problem. We consider a 2D antiplane problem, with a 1D planar vertical strike-slip fault obeying rate-and-state friction, embedded in a 2D homogeneous, linear elastic halfspace. Sequences of quasi-dynamic earthquakes with periodic occurrences (BP1) or bimodal sizes (BP2) and their interactions with aseismic slip are simulated. The comparison of results from 11 groups using different numerical methods show excellent agreements in long-term and coseismic fault behavior. In BP1, we found that truncated domain boundaries influence interseismic stressing, earthquake recurrence, and coseismic rupture, and that model agreement is only achieved with sufficiently large domain sizes. In BP2, we found that complexity of fault behavior depends on how well physical length scales related to spontaneous nucleation and rupture propagation are resolved. Poor numerical resolution can result in artificial complexity, impacting simulation results that are of potential interest for characterizing seismic hazard such as earthquake size distributions, moment release, and recurrence times. These results inform the development of more advanced SEAS models, contributing to our further understanding of earthquake system dynamics.

Seismological Research Letters↗
USGS1989

The hydrothermal system in central Twin Falls County, Idaho

Thermal water in Twin Fall County has been used for space heating, large-scale greenhouse operations, and aquaculture since the mid-1970's. More recently, increased utilization of the thermal water has caused aquifer pressures to decline. Near the city of Twin Falls, water levels in some formerly flowing thermal wells have declined to below land surface. The thermal water is principally in the silicic volcanic rocks of the Idavada Volcanics. Electrical resistivity soundings indicate that thickness of the rocks ranges from about 700 to 3,000 ft and averages about 2,000 ft. Temperatures of water sampled range from 26 C to nearly 50 C in wells completed in the upper part of the reservoir near Twin Falls. Water from deeper parts of the reservoir may be warmer than 50 C. Most of the thermal water is a sodium bicarbonate type. The maximum fluoride concentration was 22 mg/L. Chloride concentrations between about 50 and 150 mg/L are the result of mixing of deep water with shallower, cooler water that has been affected by percolation of irrigation water. Carbon-14 concentrations in selected thermal water samples indicate ages of 1,000 to 15,000 years. The water becomes progressively older northward along proposed groundwater flowpaths. On the basis of transit times in the system of 10,000 to 15,000 years and the reservoir volume, recharge is estimated to be about 5 to 7 cu ft/sec. Net heat flux in the area is about 2.2 heat flow units.

Idaho↗
USGS2021

Unexpected diversity of Endozoicomonas in deep-sea corals

ABSTRACT: The deep ocean hosts a large diversity of azooxanthellate cold-water corals whose associated microbiomes remain to be described. While the bacterial genus Endozoicomonas has been widely identified as a dominant associate of tropical and temperate corals, it has rarely been detected in deep-sea corals. Determining microbial baselines for these cold-water corals is a critical first step to understanding the ecosystem services their microbiomes contribute, while providing a benchmark against which to measure responses to environmental change or anthropogenic effects. Samples of Acanthogorgia aspera , A. spissa , Desmophyllum dianthus , and D. pertusum ( Lophelia pertusa ) were collected from western Atlantic sites off the US east coast and from the northeastern Gulf of Mexico. Microbiomes were characterized by 16S rRNA gene amplicon surveys. Although D. dianthus and D. pertusum have recently been combined into a single genus due to their genetic similarity, their microbiomes were significantly different. The Acanthogorgia spp. were collected from submarine canyons in different regions, but their microbiomes were extremely similar and dominated by Endozoicomonas . This is the first report of coral microbiomes dominated by Endozoicomonas occurring below 1000 m, at temperatures near 4°C. D. pertusum from 2 Atlantic sites were also dominated by distinct Endozoicomonas , unlike D. pertusum from other sites described in previous studies, including the Gulf of Mexico, the Mediterranean Sea and a Norwegian fjord.

Marine Ecology Progress Series↗
USGS1963

Hydrogeology of the carbonate rocks of the Lebanon Valley, Pennsylvania

The Lebanon Valley, which is part of the Great Valley in southeastern Pennsylvania, is underlain by carbonate rocks in the southern part and by shale in the northern part. The carbonate rocks consist of alternating beds of limestone and dolomite of Cambrian and Ordovician age. Although the beds generally dip to the south, progressively younger beds crop out to the north, because the rocks are overturned. The stratigraphic units, from oldest to youngest, are: the Buffalo Springs Formation, Snitz Creek, Schaefferstown, Millbach, and Richland Formations of the Conococheague Group; the Stonehenge, Rickenbach, Epler, and Ontelaunee Formations of the Beekmantown Group; and the Annville, Myerstown, and Hershey Limestones.

Pennsylvania↗
USGS1995

Population biology of the Florida manatee: An overview

In the following overview we discuss progress toward meeting the three objectives of the 1992 workshop: to provide a synthesis of existing information about manatee population biology; to evaluate the strengths and weaknesses of current data sets and approaches to research on manatee population biology; and to provide recommendations for research. We discuss progress in six topics that were assigned to working groups at the workshop: aerial survey and estimation of population size, reproduction, age structure, mortality, photoidentification and estimation of survival, and integration and modeling of population data. The overview includes recommendations by working group participants (*2 0'Shea et al. 1992). This workshop on manatee population biology was the most recent conference on the topic since 1978 (*BrowneIl and Rails 1981). Partly as a result of recommendations made at the 1978 workshop, several long-term population-related research projects were established. Therefore, we also measure progress in relation to knowledge available at the time of the earlier workshop. Finally, we provide a brief synopsis of pertinent new information on manatee population biology that became available between the 1992 workshop and publication of the proceedings and our conclusions about the status of the Florida manatee.

Information and Technology Report↗
USGS2025

Gas chemistry and isotope data for volcano monitoring at the Lassen Volcanic Center, Lassen Volcanic National Park

This report presents chemical and isotopic compositions of volcanic gases collected from thermal areas within Lassen Volcanic National Park in northern California from 1974 through 2019. As the southernmost volcano in the Cascade Range and designated a very-high-threat volcano by the U.S. Geological Survey, the Lassen Volcanic Center (LVC) requires consistent monitoring to assess potential volcanic hazards. In 2014, the California Volcano Observatory established a gas geochemical monitoring program at LVC to provide baseline data to evaluate future changes.</p> Results demonstrate consistent spatial patterns in bulk gas chemistry that support a two-circulation-cell hydrothermal model previously established for LVC. Gas samples from circulation cell 1 thermal areas have higher helium isotope ratios (6.59–7.50 times the air value) than those from circulation cell 2 (5.86–6.52 times the air value), indicating a stronger magmatic signature. The Sulphur Works and Pilot Pinnacle thermal areas within circulation cell 1 consistently emit gases with the highest magmatic helium contents, suggesting gas at these areas best represents conditions in the underlying volcanic system. A slight decrease in helium isotope values since 1974 may indicate progressive dilution of magmatic helium-3 (3He) by radiogenic helium-4 (4He) in the absence of recent magma intrusion. Carbon isotope compositions of carbon dioxide across all thermal areas are relatively uniform (−9.7–−7.3 per mil), falling within the range observed at other Cascade Range volcanoes. Based on gas geochemical characteristics and site accessibility, the Sulphur Works and Pilot Pinnacle thermal areas represent optimal targets for continued monitoring of the LVC magmatic-hydrothermal system. This study includes the most comprehensive helium isotope dataset collected at LVC currently available and establishes critical baseline data for future volcanic monitoring efforts.</p>

Open-File Report↗
USGS2016

Late Pleistocene and Holocene tephrostratigraphy of interior Alaska and Yukon: Key beds and chronologies over the past 30,000 years

The Aleutian Arc-Alaska Peninsula and Wrangell volcanic field are the main source areas for tephra deposits found across Alaska and northern Canada, and increasingly, tephra from these eruptions have been found further afield in North America, Greenland, and Europe. However, there have been no broad scale reviews of the Late Pleistocene and Holocene tephrostratigraphy for this region since the 1980s, and this lack of data is hindering progress in identifying these tephra both locally and regionally. To address this gap and the variable quality of associated geochemical and chronological data, we undertake a detailed review of the latest Pleistocene to Holocene tephra found in interior Alaska and Yukon. This paper discusses nineteen tephra that have distributions beyond southwest Alaska and that have the potential to become, or already are, important regional markers. This includes three ‘modern’ events from the 20th century, ten with limited data availability but potentially broad distributions, and six that are widely reported in interior Alaska and Yukon. Each tephra is assessed in terms of chronology, geochemistry and distribution, with new Bayesian age estimates and geochemical data when possible. This includes new major-element geochemical data for Crater Peak 1992, Redoubt 1989–90, and two andesitic tephra from St Michael Island (Tephra D), as well as revised age estimates for Dawson tephra, Oshetna, Hayes set H, Aniakchak CFE II, and the White River Ashes, northern and eastern lobes.

Quaternary Science Reviews↗
USGS2014

Report of the committee on underground waters, 1938–39

In preparing the report of the Committee on Underground Waters of the Section of Hydrology for the final year of the triennium, it becomes evident that the collection of fundamental data relating to the hydrology of underground waters continues at a rate comparable to that maintained in the past few years, and perhaps even at an accelerated rate. Almost every extensive practical investigation of ground‐water supplies offers some opportunity for study of fundamental problems, in fact many of them require such fundamental study. With a larger number of investigations in progress, and with fairly liberal appropriations much new and valuable information is being discovered. Some idea of the increase in ground‐water studies since the organization of the Section of Hydrology may be given by a few statistics on the work of the Division of Ground‐Water of the Federal Geological Survey, which does the largest amount of ground‐water work in the United States. In 1932 the Division worked on about 50 projects in 25 States, in 15 of which and in Hawaii the investigations were made in cooperation with States, or other local Governmental agencies. During the current fiscal year work has been completed, or is in progress, on about 100 investigations in 35 States, Hawaii, and the Virgin Islands. The number of States cooperating on the work has increased to 24. During the current fiscal year about \$375,000 will be spent for ground‐water investigations by the Federal Geological Survey and cooperating organizations, as compared to about $175,000 spent during the fiscal year ended June 30, 1932.

Eos, Transactions, American Geophysical Union↗