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At least 883 records · Page 49Linked to original sources
USGS2020

Sediment dynamics and implications for management: State of the science from long‐term research in the Chesapeake Bay watershed, USA

This review aims to synthesize the current knowledge of sediment dynamics using insights from long‐term research conducted in the watershed draining to the Chesapeake Bay, the largest estuary in the U.S., to inform management actions to restore the estuary and its watershed. The sediment dynamics of the Chesapeake are typical of many impaired watersheds and estuaries around the world, and this synthesis is intended to be relevant and transferable to other sediment‐impaired systems. The watershed's sediment sources, transport, delivery, and impacts are discussed with implications for effectively implementing best management practices (BMPs) to mitigate sediment issues. This synthesis revealed three key issues to consider when planning actions to reduce sediment loading: Scale, time, and land use. Geology and historical land use generated a template that current land use and climate, in addition to management, are acting upon to control sediment delivery. Important sediment sources in the Chesapeake include the Piedmont physiographic region, urban, and agricultural land use, and streambank erosion of headwater streams, whereas floodplain trapping is important along larger streams and rivers. Implementation of BMPs is widespread and is predicted to lead to decreased sediment loading; however, reworking of legacy sediment stored in stream valleys, with potentially long residence times in storage, can delay and complicate detection of the effects of BMPs on sediment loads. In conclusion, the improved understanding of sediment sources, storage areas, and transport lag times reviewed here can help target choices of BMP types and locations to better manage sediment problems—for both local streams and receiving waters.

New York, Pennsylvania, Maryland, Delaware, Virgin↗
USGS2022

Prairie grouse and wind energy: The state of the science and implications for risk assessment

How to shape the anticipated build-out of industrial-scale renewable energy in a way that minimizes risk to wildlife remains contentious. This challenge is well-illustrated in the grasslands and shrub-steppe of North America. Here, several endemic species of grouse are the focus of intensive, long-term conservation action by a host of governmental and non-governmental entities, many of whom are now asking: will anticipated increases in the number of wind-energy facilities exacerbate declines or prevent recovery of these species? To help answer this question, we synthesized the potential consequences of wind-energy development on prairie grouse. Published literature on behavior or demography of prairie-grouse at wind-energy facilities is sparse, with studies having been conducted at only 5 different facilities in the United States. Only two of these studies met the standard for robust impact analysis by collecting pre-construction data and using control sites or gradient designs. Published results from only one of the species Greater Prairie-Chicken were available for >1 facility. Most studies also drew conclusions based on short (<4 years) periods of study, which is potentially problematic when studying these highly philopatric species. Given these caveats, we found that, in the short-term, adult survival and nest success appear largely unaffected in populations exposed to wind-energy facilities. However, changes in habitat use by female Greater Sage-Grouse and female Greater Prairie-Chicken during some seasons and reduced lek persistence among male Greater Prairie-Chickens near wind turbines suggest behavioral responses that may have demographic consequences. Prairie grouse can coexist with wind-energy facilities in some cases, at least in the short term, but important uncertainties remain, including the potential for long-term, cumulative effects of the extensive development expected as states attempt to meet goals for generating electricity from renewable sources.

Wildlife Society Bulletin↗
USGS2000

The state and future of Mars polar science and exploration

As the planet's principal cold traps, the martian polar regions have accumulated extensive mantles of ice and dust that cover individual areas of ∼10 6 km 2 and total as much as 3–4 km thick. From the scarcity of superposed craters on their surface, these layered deposits are thought to be comparatively young—preserving a record of the seasonal and climatic cycling of atmospheric CO 2 , H 2 O, and dust over the past ∼10 5 –10 8 years. For this reason, the martian polar deposits may serve as a Rosetta Stone for understanding the geologic and climatic history of the planet—documenting variations in insolation (due to quasiperiodic oscillations in the planet's obliquity and orbital elements), volatile mass balance, atmospheric composition, dust storm activity, volcanic eruptions, large impacts, catastrophic floods, solar luminosity, supernovae, and perhaps even a record of microbial life. Beyond their scientific value, the polar regions may soon prove important for another reason—providing a valuable and accessible reservoir of water to support the long-term human exploration of Mars. In this paper we assess the current state of Mars polar research, identify the key questions that motivate the exploration of the polar regions, discuss the extent to which current missions will address these questions, and speculate about what additional capabilities and investigations may be required to address the issues that remain outstanding.

Icarus↗
USGS2017

Tributyltin: Advancing the science on assessing endocrine disruption with an unconventional endocrine-disrupting compound

Tributyltin (TBT) has been recognized as an endocrine disrupting chemical (EDC) for several decades. However, only in the last decade, was its primary endocrine mechanism of action (MeOA) elucidated—interactions with the nuclear retinoid-X receptor (RXR), peroxisome proliferator-activated receptor γ (PPARγ), and their heterodimers. This molecular initiating event (MIE) alters a range of reproductive, developmental, and metabolic pathways at the organism level. It is noteworthy that a variety of MeOAs have been proposed over the years for the observed endocrine-type effects of TBT; however, convincing data for the MIE was provided only recently and now several researchers have confirmed and refined the information on this MeOA. One of the most important lessons learned from years of research on TBT concerns apparent species sensitivity. Several aspects such as the rates of uptake and elimination, chemical potency, and metabolic capacity are all important for identifying the most sensitive species for a given chemical, including EDCs. For TBT, much of this was discovered by trial and error, hence important relationships and important sensitive taxa were not identified until several decades after its introduction to the environment. As recognized for many years, TBT-induced responses are known to occur at very low concentrations for molluscs, a fact that has more recently also been observed in fish species. This review explores the MeOA and effects of TBT in different species (aquatic molluscs and other invertebrates, fish, amphibians, birds, and mammals) according to the OECD Conceptual Framework for Endocrine Disruptor Testing and Assessment (CFEDTA). The information gathered on biological effects that are relevant for populations of aquatic animals was used to construct Species Sensitivity Distributions (SSDs) based on No Observed Effect Concentrations (NOECs) and Lowest Observed Effect Concentrations (LOECs). Fish appear at the lower end of these distributions, showing that they are as sensitive as molluscs, and for some species, even more sensitive. Concentrations in the range of 1 ng/L for water exposure (10 ng/g for whole-body burden) have been shown to elicit endocrine-type responses, whereas mortality occurs at water concentrations ten times higher. Current screening and assessment methodologies as compiled in the OECD CFEDTA are able to identify TBT as a potent endocrine disruptor with a high environmental risk for the original use pattern. If those approaches had been available when TBT was introduced to the market, it is likely that its use would have been regulated sooner, thus avoiding the detrimental effects on marine gastropod populations and communities as documented over several decades.

Book chapter↗
USGS2009

Natural resource assessment: an approach to science based planning in national parks

We conducted a natural resource assessment at two national parks, New River Gorge National River and Shenandoah National Park, to help meet the goals of the Natural Resource Challenge-a program to help strengthen natural resource management at national parks. We met this challenge by synthesizing and interpreting natural resource information for planning purposes and we identified information gaps and natural significance of resources. We identified a variety of natural resources at both parks as being globally and/or nationally significant, including large expanses of unfragmented, mixed-mesophytic forests that qualify for wilderness protection, rare plant communities, diverse assemblages of neotropical migratory birds and salamanders, and outstanding aquatic recreational resources. In addition, these parks function, in part, as ecological reserves for plants in and wildlife. With these significant natural resources in mind, we also developed a suite of natural resource management recommendations in light of increasing threats from within and outside park boundaries. We hope that our approach can provide a blueprint for natural resource conservation at publicly owned lands.

Environmental Management↗
USGS2015

Application of science-based restoration planning to a desert river system

Persistence of many desert river species is threatened by a suite of impacts linked to water infrastructure projects that provide human water security where water is scarce. Many desert rivers have undergone regime shifts from spatially and temporally dynamic ecosystems to more stable systems dominated by homogenous physical habitat. Restoration of desert river systems could aid in biodiversity conservation, but poses formidable challenges due to multiple threats and the infeasibility of recovery to pre-development conditions. The challenges faced in restoring desert rivers can be addressed by incorporating scientific recommendations into restoration planning efforts at multiple stages, as demonstrated here through an example restoration project. In particular, use of a watershed-scale planning process can identify data gaps and irreversible constraints, which aid in developing achievable restoration goals and objectives. Site-prioritization focuses limited the resources for restoration on areas with the greatest potential to improve populations of target organisms. Investment in research to understand causes of degradation, coupled with adoption of a guiding vision is critical for identifying feasible restoration actions that can enhance river processes. Setting monitoring as a project goal, developing hypotheses for expected outcomes, and implementing restoration as an experimental design will facilitate adaptive management and learning from project implementation. Involvement of scientists and managers during all planning stages is critical for developing process-based restoration actions and an implementation plan to maximize learning. The planning process developed here provides a roadmap for use of scientific recommendations in future efforts to recover dynamic processes in imperiled riverine ecosystems.

San Rafael River watershed↗
USGS2025

The Hawaiian Volcanoes Supersite: Open data for the benefit of science and society

The Hawaiian Volcanoes Supersite was established in 2008 with the goal of making large amounts of volcano monitoring data, especially satellite measurements, freely available at a site of international interest, scientific importance, and impactful natural hazards. The location was chosen because of the long history of volcanological research and innovation on the Island of Hawaiʻi, as well as the need for monitoring, assessing, and mitigating volcanic hazards for the local population. Ground-based data are provided by the U.S. Geological Survey Hawaiian Volcano Observatory, and several national space agencies have contributed thousands of satellite synthetic aperture radar and other data that would have otherwise required special grants or commercial purchase. Since the Hawaiian Volcanoes Supersite was initiated, the vast quantity of open space-based data has resulted in the development of new applications and methodologies, successful responses to volcanic crises, and research that has informed monitoring and hazards mitigation activities. While there remain opportunities for additional coordination among supersite users and for synergistic studies that make use of the full spectrum of available ground- and space-based data, the Hawaiian Volcanoes Supersite has achieved its goals of stimulating basic research to better understand Hawaiian volcanism and aiding in responses to hazardous geologic processes. The effort serves as a model for the benefits of open, low-latency, and comprehensive satellite data applied to disaster risk management and reduction, meeting a vision that has been laid out repeatedly in international agreements and accords.

Hawaii↗
USGS2002

Interactions between groundwater and surface water: The state of the science

The interactions between groundwater and surface water are complex. To understand these interactions in relation to climate, landform, geology, and biotic factors, a sound hydrogeoecological framework is needed. All these aspects are synthesized and exemplified in this overview. In addition, the mechanisms of interactions between groundwater and surface water (GW-SW) as they affect recharge-discharge processes are comprehensively outlined, and the ecological significance and the human impacts of such interactions are emphasized. Surface-water and groundwater ecosystems are viewed as linked components of a hydrologic continuum leading to related sustainability issues. This overview concludes with a discussion of research needs and challenges facting this evolving field. The biogeochemical processes within the upper few centimeters of sediments beneath nearly all surface-water bodies (hyporheic zone) have a profound effect on the chemistry of the water interchange, and here is where most of the recent research has been focusing. However, to advance conceptual and other modeling of GW-SW systems, a broader perspective of such interactions across and between surface-water bodies is needed, including multidimensional analyses, interface hydraulic characterization and spatial variability, site-to-region regionalization approaches, as well as cross-disciplinary collaborations.

Hydrogeology Journal↗
USGS2016

Assessments of species' vulnerability to climate change: From pseudo to science

Climate change vulnerability assessments (CCVAs) are important tools to plan for and mitigate potential impacts of climate change. However, CCVAs often lack scientific rigor, which can ultimately lead to poor conservation prioritization and associated ecological and economic costs. We discuss the need to improve comparability and consistency of CCVAs and either validate their findings or improve assessment of CCVA uncertainty and sensitivity to methodological assumptions.

Biodiversity and Conservation↗
USGS2007

The art and science of weed mapping

Land managers need cost-effective and informative tools for non-native plant species management. Many local, state, and federal agencies adopted mapping systems designed to collect comparable data for the early detection and monitoring of non-native species. We compared mapping information to statistically rigorous, plot-based methods to better understand the benefits and compatibility of the two techniques. Mapping non-native species locations provided a species list, associated species distributions, and infested area for subjectively selected survey sites. The value of this information may be compromised by crude estimates of cover and incomplete or biased estimations of species distributions. Incorporating plot-based assessments guided by a stratified-random sample design provided a less biased description of non-native species distributions and increased the comparability of data over time and across regions for the inventory, monitoring, and management of non-native and native plant species.

Environmental Monitoring and Assessment↗
USGS1974

Reference samples for the earth sciences

A revised list of reference samples of interest to geoscientists has been extended to include samples for the agronomist, the archaeologist and the environmentalist. In addition to the source from which standard samples may be obtained, references or pertinent notes for some samples are included. The number of rock reference samples is now almost adequate, and the variety of ore samples will soon be sufficient. There are very few samples for microprobe work. Oil shales will become more important because of the outlook for world petroleum resources. The dryland equivalent of a submarine basalt might be useful in studies of sea-floor spreading and of the geochemistry of basalts. The Na- and K-feldspars of BCS (British Chemical Standards—Bureau of Analysed Samples), NBS (National Bureau of Standards), and ANRT (Association Kationale de la Recherche Technique) could serve as trace-element standards if such data were available. Similarly, the present NBS flint and plastic clays, as well as their predecessors, might be useful for archaeological pottery studies. The International Decade for Ocean Exploration may stimulate the preparation of ocean-water standards for trace elements or pollutants and a standard for manganese nodules.

Geochimica et Cosmochimica Acta↗