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At least 343 records · Page 19Linked to original sources
USGS2021

Kīlauea’s 2008–2018 summit lava lake—Chronology and eruption insights

The first eruption at Kīlauea’s summit in 25 years began on March 19, 2008, and persisted for 10 years. The onset of the eruption marked the first explosive activity at the summit since 1924, forming the new “Overlook crater” (as the 2008 summit eruption crater has been informally named) within the existing crater of Halemaʻumaʻu. The first year consisted of sporadic lava activity deep within the Overlook crater. Occasional small explosions deposited spatter and small wall-rock lithic pieces around the Halemaʻumaʻu rim. After a month-long pause at the end of 2008, deep sporadic lava lake activity returned in 2009. Continuous lava lake activity began in February 2010. The lake rose significantly in late 2010 and early 2011, before subsequently draining briefly in March 2011. This disruption of the summit eruption was triggered by eruptive activity on the East Rift Zone. Rising lake levels through 2012 established a more stable, larger lake in 2013, with continued enlargement over the subsequent 5 years. Lava reached the Overlook crater rim and overflowed on the Halemaʻumaʻu floor in brief episodes in 2015, 2016, and 2018, but the lake level was more commonly 20–60 meters below the rim during 2014–18. The lake was approximately 280×200 meters (~42,000 square meters) by early 2018 and formed one of the two largest lava lakes on Earth. A new eruption began in the lower East Rift Zone on May 3, 2018, causing magma to drain from the summit reservoir complex. The lava in Halemaʻumaʻu had drained below the crater floor by May 10, followed by collapse of the Overlook and Halemaʻumaʻu craters. The collapse region expanded as much of the broader summit caldera floor subsided incrementally during June and July. By early August 2018, the collapse sequence had ended, and the summit was quiet. The historical changes in May–August 2018 brought a dramatic end to the decade of sustained activity at Kīlauea’s summit. The unique accessibility of the 2008–18 lava lake provided new observations of lava lake behavior and open-vent basaltic outgassing. Data indicated that explosions were triggered by rockfalls from the crater walls, that the lake consisted of a low-density foamy lava, that cycles of gas pistoning were rooted at shallow depths in the lake, and that lake level fluctuations were closely tied to the pressure of the summit magma reservoir. Lava chemistry added further support for an efficient hydraulic connection between the summit and East Rift Zone. Notwithstanding the benefits to scientific understanding, the eruption presented a persistent hazard of volcanic air pollution (vog) that commonly extended far from Kīlauea’s summit.

Hawaii↗
USGS2017

Measuring the role of seagrasses in regulating sediment surface elevation

Seagrass meadows provide numerous ecosystem services and their rapid global loss may reduce human welfare as well as ecological integrity. In common with the other ‘blue carbon’ habitats (mangroves and tidal marshes) seagrasses are thought to provide coastal defence and encourage sediment stabilisation and surface elevation. A sophisticated understanding of sediment elevation dynamics in mangroves and tidal marshes has been gained by monitoring a wide range of different sites, located in varying hydrogeomorphological conditions over long periods. In contrast, similar evidence for seagrasses is sparse; the present study is a contribution towards filling this gap. Surface elevation change pins were deployed in four locations, Scotland, Kenya, Tanzania and Saudi Arabia, in both seagrass and unvegetated control plots in the low intertidal and shallow subtidal zone. The presence of seagrass had a highly significant, positive impact on surface elevation at all sites. Combined data from the current work and the literature show an average difference of 31 mm per year in elevation rates between vegetated and unvegetated areas, which emphasizes the important contribution of seagrass in facilitating sediment surface elevation and reducing erosion. This paper presents the first multi-site study for sediment surface elevation in seagrasses in different settings and species.

Scientific Reports↗
USGS1997

Status of the Sierra Nevada: the Sierra Nevada Ecosystem Project

The Sierra Nevada ecosystem project was requested by Congress in the Conference Report for Interior and related Agencies 1993 Appropriation Act, which authorized funds for a scientific review of the remaining old growth in the national forests of the Sierra Nevada in California, and for a study of the entire Sierra Nevada ecosystem by an independent panel of scientists, with expertise in diverse areas related to this issue. This CD-ROM is a digital version of the set of reports titled 'Sierra Nevada Ecosystem Project, final report to Congress' published in paper form by the Centers for Water and Wildland Resources of the University of California, Davis.

Data Series↗
USGS2008

7th U.S. / Japan Natural Resources (UJNR) Panel on Earthquake Research: Abstract volume and technical program

The U.S. / Japan Natural Resources (UJNR) Panel on Earthquake Research promotes advanced study toward a more fundamental understanding of the earthquake process and hazard estimation. The Panel promotes basic and applied research to improve our understanding of the causes and effects of earthquakes and to facilitate the transmission of research results to those who implement hazard reduction measures on both sides of the Pacific and around the world. Meetings are held every other year, and alternate between countries with short presentation on current research and local field trips being the highlights. The 5th Joint Panel meeting was held at Asilomar, California in October, 2004. The technical sessions featured reports on the September 28, 2004 Parkfield, California earthquake, progress on earthquake early warning and rapid post-event assessment technology, probabilistic earthquake forecasting and the newly discovered phenomenon of nonvolcanic tremor. The Panel visited the epicentral region of the M 6.0 Parkfield earthquake and viewed the surface ruptures along the San Andreas Fault. They also visited the San Andreas Fault Observatory at Depth (SAFOD), which had just completed the first phase of drilling into the fault. The 6th Joint Panel meeting was held in Tokushima, Japan in November, 2006. The meeting included very productive exchanges of information on approaches to systematic observation of earthquake processes. Sixty eight technical papers were presented during the meeting on a wide range of subjects, including interplate earthquakes in subduction zones, slow slip and nonvolcanic tremor, crustal deformation, recent earthquake activity and hazard mapping. Through our discussion, we reaffirmed the benefits of working together to achieve our common goal of reducing earthquake hazard, continued cooperation on issues involving densification of observation networks and the open exchange of data among scientific communities. We also reaffirmed the importance of making information public in a timely manner. The Panel visited sites along the east coast of Shikoku that were inundated by the tsunami caused by the 1946 Nankai earthquake where they heard from survivors of the disaster and saw new tsunami shelters and barriers. They also visited the Median Tectonic Line, a major onshore strike-slip fault on Shikoku. The 7th Joint Panel meeting was held in Seattle, Wash., U.S.A. from October 27-30, 2008.

Open-File Report↗
USGS2007

Vision for a worldwide fluvial-sediment information network

The nations of the world suffer both from the deleterious effects of some natural and human-altered fluxes of fluvial sediment and a lack of consistent and reliable information on the temporal and spatial occurrence of fluvial sediments. Decades ago, this difficulty was unavoidable due to a lack of understanding of the magnitude and scope of environmental influences exerted by fluvial sediment coupled with a dearth of tools for monitoring and studying the data. Such is no longer the case. Fluvial sediment has a broad influence on the environment and humanity. Data needs that were once limited primarily to reservoir and channel maintenance now include issues associated with public water supply; contaminated sediment management; productivity of agricultural lands; stream restoration and watershed health; in-stream biotic stability; post-wildfire channel morphology; dam decommissioning, rehabilitation, or removal; and legal requirements for sediment management (Gray and Glysson, 2005). The adverse effects of poorly managed or unmanaged sediment movement related to these and other issues are well-known qualitatively, and in some cases quantitatively. For example, physical, chemical, and biological damages attributable to fluvial sediment in North America alone are now estimated to range between $20 billion and $50 billion annually (Pimental and others, 1995; Osterkamp and others, 1998; 2004). Capabilities for monitoring, analyzing, storing, and sharing fluvial-sediment data have been developed and, in many cases, are sufficiently mature for consideration for global utilization. Hence, there is not only a strong and expanding need for a global effort to gauge and understand fluvial-sediment characteristics and processes better, but the knowledge and tools to achieve these ends are largely available and ready for their applicability to be evaluated. Given the increasing importance of erosion and sediment processes for water-resources management, an International Sedimentation Initiative (ISI, 2007a), under the United Nations Educational, Scientific, and Cultural Organization’s International Hydrologic Programme (IHP, 2007) was adopted in 2004. The ISI, the focus of which is on sustainable water-resources management on the global scale, features six major activities and projects, which are listed as part of the section entitled, “Relation of the WoFSIN concept to the thrusts of the International Sedimentation Initiative,” that precedes the “Conclusions” section of this paper. Based on the need for more, and more consistent and reliable fluvial-sediment information and on the existence of the ISI and other international and national sediment programs, we envision the need for a Worldwide Fluvial Sediment-Information Network (WoFSIN) with a focus on data acquisition, storage, and dissemination globally. Envisioned components of a WoFSIN, administered largely via the Internet and relying mostly on the benefits derived from existing resources and programs, follow that summary. The goal of the WoFSIN is to maximize the availability and usefulness of the world’s historical and current fluvial-sediment and ancillary data through collaboration with existing programs so as to require few additional resources in the long-term. Thus, the WoFSIN concept was developed recognizing that informed resource management is predicated on the availability of adequate and reliable information. The WoFSIN is described in the ensuing sections in stand-alone fashion, followed by a section that describes the complementary aspects of the WoFSIN and the International Sediment Initiative. Thus, our first objective is to describe the fundamental components of a WoFSIN. Our second objective is to identify overlap or gaps between the WoFSIN and ISI concepts that might be useful in refining the ISI’s ability to meet its global mission to develop decision support for sediment management at the global scale more fully, cost-effectively, and (or) with enhanced quality.

Conference Paper↗
USGS2024

Understanding gaps in early detection of and rapid response to invasive species in the United States: A literature review and bibliometric analysis

While concepts regarding invasive species establishment patterns and eradication possibilities have long been a topic of invasion biology, the specific terminology referring to early detection of and rapid response to (EDRR) invasive species emerged in scientific literature during the early 2000s. Since then, the EDRR approach has expanded to include a suite of detection, planning, and management tools. By conducting a systematic literature review, we attempt to characterize the field of EDRR in the United States and its territories as reflected by publication records. Specifically, we assessed publication data such as the number of publications per year, the most common journals where papers were published, and the relationship between author’s keywords for studies focusing on aquatic and terrestrial habitats. For publications that used invasive species occurrence or abundance data (whether collected for the purposes of the respective publication or acquired from another data source), we manually vetted additional information such as focal taxa, data collection years and locations, sources of other data used, and whether data or code were deposited in open access formats. We also conducted network analyses for the author institutions that coauthored papers together most frequently and for the references most cited by EDRR publications. Overall, we found that silos existed in terms of which author institutions worked together, which existing literature was cited, and which topics were frequently explored. We also found evidence of substantial gaps in data access and use. For example, although a wide variety of data sources for invasive species occurrences are available, these sources were seldom cited by published literature, and newly collected data was not often deposited into invasive species databases or other open-source data repositories. Considering the continued advocation for a centralized national EDRR information system, our study suggests that facilitating access to data, decision support tools, and other informational resources represents a key opportunity for improving EDRR capabilities.

Ecological Informatics↗
USGS2008

Coastal typology: An integrative "neutral" technique for coastal zone characterization and analysis

Typology, the 'study or systematic classification of types that have characteristics or traits in common', has become a commonly used term and technique in coastal zone studies over the past two decades. At least part of this is due to adoption by the first Land-Ocean Interactions in the Coastal Zone (LOICZ) project of a typological approach as a way to understand and organize the daunting diversity of natural and human systems comprising the world coastal zone, and to the concurrent development of tools and databases to support systematic applications. This paper reviews some of the history of the term 'typology' and the concepts and techniques that it subsumes, and discusses its adoption and adaptation in coastal studies. It also addresses the continued and increasing relevance of typology to the continuation of the LOICZ project and its objectives, and outlines the opportunities and challenges involved in realizing the potentials of the approach - both within LOICZ and for the scientific and coastal zone communities in general. ?? 2007 Elsevier Ltd. All rights reserved.

Estuarine, Coastal and Shelf Science↗
USGS2020

Sustainable fisheries management: Pacific salmon

What has happened to the salmon resource in the Pacific Northwest? Who is responsible and what can be done to reverse the decline in salmon populations? The responsibly falls on everyone involved - fishermen, resource managers and concerned citizens alike - to take the steps necessary to ensure that salmon populations make a full recovery. This collection of papers examines the state of the salmon fisheries in the Pacific Northwest. They cover existing methods and supply model approaches for alternative solutions. The editors stress the importance of input from and cooperation with all parties involved to create a viable solution. Grass roots education and participation is the key to public support - and ultimately the success - of whatever management solutions are developed. A unique and valuable scientific publication, Sustainable Fisheries Management: Pacific Salmon clearly articulates the current state of the Pacific salmon resource, describes the key features of its management, and provides important guidance on how we can make the transition towards sustainable fisheries. The solutions presented in this book provide the basis of a strategy for sustainable fisheries, requiring society and governmental agencies to establish a shared vision, common policies, and a process for collaborative management.

Book↗
USGS2003

The life and scientific contributions of Lyman J. Briggs

Lyman J. Briggs (1874–1963), an early twentieth century physicist at the U.S. Department of Agriculture (USDA), made many significant contributions to our understanding of soil-water and plant-water interactions. He began his career at the Bureau of Soils (BOS) in 1896. At age 23, Briggs published (1897) a description of the roles of surface tension and gravity in determining the state of static soil moisture. Concepts he presented remain central to this subject more than 100 yr later. With J.W. McLane, Briggs developed the “moisture equivalent” concept (a precursor to the idea of field capacity) and a centrifuge apparatus for measuring it. Briggs left the BOS at the end of 1905, under pressure from Milton Whitney, and moved to the Bureau of Plant Industry. Briggs' multi-state experiments with H.L. Shantz on water-use efficiencies showed that in a climate like that of the Great Plains, plants use water more productively in the cooler north than in the warmer south. In 1920, he moved from the USDA to the National Bureau of Standards (NBS), rising to Director in 1933. Among his other contributions to the American scientific community was his leadership, beginning in 1939, of a top secret committee that evolved into the Manhattan Project to develop an atomic bomb during World War II. A life-long baseball fan, Briggs at age 84, studied the speed, spin, and deflection of the curve ball, aided by manager Cookie Lavagetto and the pitching staff of the Washington Senators; he published these findings in a paper in the American Journal of Physics in 1959.

Soil Science Society of America Journal↗
USGS2016

Midcontinent Prairie-Pothole wetlands and climate change: An Introduction to the Supplemental Issue

The multitude of wetlands in the Prairie Pothole Region of North America forms one of Earth’s largest wetland complexes. The midcontinent location exposes this ecologically and economically important wetland system to a highly variable climate, markedly influencing ponded-water levels, hydroperiods, chemical characteristics, and biota of individual basins. Given their dominance on the landscape and recognized value, great interest in how projected future changes in climate will affect prairie-pothole wetlands has developed and spawned much scientific research. On June 2, 2015, a special symposium, “Midcontinent Prairie-Pothole Wetlands: Influence of a Changed Climate,” was held at the annual meeting of the Society of Wetland Scientists in Providence, Rhode Island, USA. The symposium’s twelve presenters covered a wide range of relevant topics delivered to a standing-room-only audience. Following the symposium, the presenters recognized the need to publish their presented papers as a combined product to facilitate widespread distribution. The need for additional papers to more fully cover the topic of prairie-pothole wetlands and climate change was also identified. This supplemental issue of Wetlands is the realization of that vision.

Prairie Pothole Region↗
USGS2003

Imaging spectroscopy: Earth and planetary remote sensing with the USGS Tetracorder and expert systems

Imaging spectroscopy is a tool that can be used to spectrally identify and spatially map materials based on their specific chemical bonds. Spectroscopic analysis requires significantly more sophistication than has been employed in conventional broadband remote sensing analysis. We describe a new system that is effective at material identification and mapping: a set of algorithms within an expert system decision‐making framework that we call Tetracorder. The expertise in the system has been derived from scientific knowledge of spectral identification. The expert system rules are implemented in a decision tree where multiple algorithms are applied to spectral analysis, additional expert rules and algorithms can be applied based on initial results, and more decisions are made until spectral analysis is complete. Because certain spectral features are indicative of specific chemical bonds in materials, the system can accurately identify and map those materials. In this paper we describe the framework of the decision making process used for spectral identification, describe specific spectral feature analysis algorithms, and give examples of what analyses and types of maps are possible with imaging spectroscopy data. We also present the expert system rules that describe which diagnostic spectral features are used in the decision making process for a set of spectra of minerals and other common materials. We demonstrate the applications of Tetracorder to identify and map surface minerals, to detect sources of acid rock drainage, and to map vegetation species, ice, melting snow, water, and water pollution, all with one set of expert system rules. Mineral mapping can aid in geologic mapping and fault detection and can provide a better understanding of weathering, mineralization, hydrothermal alteration, and other geologic processes. Environmental site assessment, such as mapping source areas of acid mine drainage, has resulted in the acceleration of site cleanup, saving millions of dollars and years in cleanup time. Imaging spectroscopy data and Tetracorder analysis can be used to study both terrestrial and planetary science problems. Imaging spectroscopy can be used to probe planetary systems, including their atmospheres, oceans, and land surfaces.

Journal of Geophysical Research E: Planets↗
USGS2007

Vegetation response to climate change in Alaska: examples from the fossil record

Preface: This report was presented as an invited paper at the Fish & Wildlife Service Climate Forum held in Anchorage, Alaska on February 21-23, 2007. The purpose of the talk was to provide some examples of past climate changes that appear to have caused significant responses in Alaskan vegetation. These examples are based on interpretations of dated fossil assemblages (pollen, spores and plant macrofossils) collected and interpreted by U.S. Geological Survey and collaborating scientists from other scientific organizations during the past several decades.

Alaska↗
USGS1983

Multichannel seismic measurements on the northern edge of the Bahaman-Cuban collision zone

This paper presents geophysical data obtained, in the western reaches of the Old Bahama Channel separating Cuba and the Bahamas (Figure 1). These data were collected as part of an ongoing investigation of Caribbean and Bahaman geology primarily conducted by University of Miami and the U.S. Geological Survey (USGS). The work was done on the R/V Gilliss of Rosenstiel School of Marine and Atmospheric Sciences, (RSMAS), University of Miami. The scientific party included members of the Woods Hole Oceanographic Institute (WHOI) and RSMAS.

Open-File Report↗
USGS2020

Multiple conceptualizations of nature are key to inclusivity and legitimacy in global environmental governance

Despite increasing scientific understanding of the global environmental crisis, we struggle to adopt the policies and practices science suggests we should. One of the reasons for this is the general absence of inclusive engagement and dialogue among a wide range of actors with distinct interactions with nature. Furthermore, there is little consideration of the role of language in understanding and shaping human-nature relations across different worldviews and cultures. In this paper, we propose that engagement and dialogue between the different actors involved in, or affected by, efforts to address the global environmental crisis can be strengthened by being mindful of the breadth of the diverse human-nature relations found around the globe. Examininge diverse conceptualizations of “nature” in more than 60 languages, we find that concpetualisaitions of nature fall into three broad clusters: inclusive conceptualizations where humans are viewed as an integral component of nature; non-inclusive conceptualizations where humans are separate from nature; and deifying conceptualizations where nature is understood and experienced within a spiritual dimension. Considering and respecting this rich repertoire for describing, thinking about and relating to nature can help us articulating global environmental governance in ways that resonate across cultures and worldviews. This repertoire also provides a resource we can draw on when defining policies, sustainability scenarios and practical interventions for the future thus offering opportunities for finding solutions to global environmental challenges, such as illustrated by the different laws granting legal personality to nature adopted around the world.

Environmental Science and Policy↗
USGS1902

The Geology and Petrography of Crater Lake National Park

Twenty years ago Crater Lake was unknown to the general public, but since then a knowledge of its remarkable features has been spread abroad through the press, and Congress recognized its worth as an educational feature and made it a national park by the act approved May 22, 1902. As defined in the bill, the park is 'bounded north by the parallel forty-three degrees four minutes north latitude, south by forty-two degrees forty-eight minutes north latitude, east by the meridian one hundred and twenty-two degrees west longitude, and west by the meridian one hundred and twenty-two degrees sixteen minutes west longitude, having an area of two hundred and forty-nine square miles'. The Ashland sheet of United States Geological Survey, on the scale of 4 miles to 1 inch, includes the area lying between meridians 122 deg and 123 deg and parallels 42 deg and 43 deg. This map includes the region between Ashland and Crater Lake. On account of the great scientific interest of Crater Lake a special map, known as the Crater Lake special sheet, was prepared on the scale of 1 mile to an inch, including the country immediately adjacent to Crater Lake, between meridians 122 deg and 122 deg 15' and parallels 42 deg 50' and 43 deg 4'. From these two maps the accompanying map of the Crater Lake National Park (Pl. 1) has been prepared. The two papers published here refer practically to the whole region included in the National Park. The one, Part I, treats primarily of the geology, the development of the great volcano, Mount Mazama, and its collapse, which gave birth to Crater Lake; the other, Part II, deals with the petrography, and gives a special description of the various rocks occurring in the park. Origin of the name Mount Mazama - A great impetus to the spread of information concerning Crater Lake was given by the Mazamas of Portland, Oreg., who held a meeting at the lake in August, 1896, which attracted many visitors. The principal features in the history of the lake had previously been made out, and the Mazamas, recognizing the fact that the great peak which was nearly destroyed in preparing the pit for the lake had no name, gave it the name of their own society. Upon the rim of the lake are a number of small peaks, each having its own designation. The term Mount Mazama refers to the whole rim encircling the lake. It is but a mere remnant of the once lofty peak, the real Mount Mazama, which rose far into the region of eternal snow. To get a basis for reconstructing the original Mount Mazama it is necessary to study in detail the structure and composition of its foundation, now so attractively displayed in the encircling cliffs of Crater Lake.

Oregon↗
USGS2003

Monitoring trends in bat populations of the United States and territories: Problems and prospects

Bats are ecologically and economically important mammals. The life histories of bats (particularly their low reproductive rates and the need for some species to gather in large aggregations at limited numbers of roosting sites) make their populations vulnerable to declines. Many of the species of bats in the United States (U.S.) and territories are categorized as endangered or threatened, have been candidates for such categories, or are considered species of concern. The importance and vulnerability of bat populations makes monitoring trends in their populations a goal for their future management. However, scientifically rigorous monitoring of bat populations requires well-planned, statistically defensible efforts. This volume reports findings of an expert workshop held to examine the topic of monitoring populations of bats. The workshop participants included leading experts in sampling and analysis of wildlife populations, as well as experts in the biology and conservation of bats. Findings are reported in this volume under two sections. Part I of the report presents contributed papers that provide overviews of past and current efforts at monitoring trends in populations of bats in the U.S. and territories. These papers consider current techniques and problems, and summarize what is known about the status and trends in populations of selected groups of bats. The contributed papers in Part I also include a description of the monitoring program developed for bat populations in the United Kingdom, a critique of monitoring programs in wildlife in general with recommendations for survey and sampling strategies, and a compilation and analysis of existing data on trends in bats of the U.S. and territories. Efforts directed at monitoring bat populations are piecemeal and have shortcomings. In Part II of the report, the workshop participants provide critical analyses of these problems and develop recommendations for improving methods, defining objectives and priorities, gaining mandates, and enhancing information exchange to facilitate future efforts for monitoring trends in U.S. bat populations.

Information and Technology Report↗
USGS2011

Development of a pan-Arctic monitoring plan for polar bears: Background paper

Polar bears (Ursus maritimus), by their very nature, and the extreme, remote environment in which they live, are inherently difficult to study and monitor. Monitoring polar bear populations is both arduous and costly and, to be effective, must be a long-term commitment. There are few jurisdictional governments and management boards with a mandate for polar bear research and management, and many have limited resources. Although population monitoring of polar bears has been a focus to some degree within most jurisdictions around the Arctic, of the 19 subpopulations recognised by the IUCN/Species Survival Commission Polar Bear Specialist Group (PBSG), adequate scientific trend data exist for only three of the subpopulations, fair trend data for five and poor or no trend data for the remaining 11 subpopulations (PBSG 2010a). There are especially critical knowledge gaps for the subpopulations in East Greenland, in the Russian Kara and Laptev seas, and in the Chukchi Sea, which is shared between Russia and the United States. The range covered by these subpopulations represents a third of the total area (approx. 23 million km2) of polar bears’ current range, and more than half if the Arctic Basin is included. If we use popular terms, we know close to nothing about polar bears in this portion of their range. As summer sea-ice extent, and to a lesser degree, spring-time extent, continues to retreat, outpacing model forecasts (Stroeve et al. 2007, Pedersen et al. 2009), polar bears face the challenge of adapting to rapidly changing habitats. There is a need to use current and synthesised information across the Arctic, and to develop new methods that will facilitate monitoring to generate new knowledge at a pan-Arctic scale. The circumpolar dimension can be lost when efforts are channelled into regional monitoring. Developing and implementing a plan that harmonises local, regional and global efforts will increase our power to detect and understand important trends for polar bears, with particular emphasis on how climate warming may differentially affect populations and habitats. Current knowledge is inadequate for a comprehensive understanding of the present and future impact of climate warming and its interaction with other stressors. The cumulative effects are unknown (Laidre et al. 2008). An integrated pan-Arctic research and monitoring plan will improve the ability to detect future trends, identify the most vulnerable subpopulations and guide effective conservation. There is a need to direct attention and resources where data are deficient to understand the mechanisms that drive trends, and to facilitate more effective and timely conservation response.

Report↗
USGS2016

Perspectives on bay-delta science and policy

The State of Bay–Delta Science 2008 highlighted seven emerging perspectives on science and management of the Delta. These perspectives had important effects on policy and legislation concerning management of the Delta ecosystem and water exports. From the collection of papers that make up the State of Bay–Delta Science 2016, we derive another seven perspectives that augment those published in 2008. The new perspectives address nutrient and contaminant concentrations in Delta waters, the failure of the Delta food web to support native species, the role of multiple stressors in driving species toward extinction, and the emerging importance of extreme events in driving change in the ecosystem and the water supply. The scientific advances that underpin these new perspectives were made possible by new measurement and analytic tools. We briefly discuss some of these, including miniaturized acoustic fish tags, sensors for monitoring of water quality, analytic techniques for disaggregating complex contaminant mixtures, remote sensing to assess levee vulnerability, and multidimensional hydrodynamic modeling. Despite these new tools and scientific insights, species conservation objectives for the Delta are not being met. We believe that this lack of progress stems in part from the fact that science and policy do not incorporate sufficiently long-term perspectives. Looking forward half a century was central to the Delta Visioning process, but science and policy have not embraced this conceptual breadth. We are also concerned that protection and enhancement of the unique cultural, recreational, natural resource, and agricultural values of the Delta as an evolving place, as required by the Delta Reform Act, has received no critical study and analysis. Adopting wider and longer science and policy perspectives immediately encourages recognition of the need for evaluation, analysis, and public discourse on novel conservation approaches. These longer and wider perspectives also encourage more attention to the opportunities provided by heavily invaded ecosystems. It is past time to turn scientific and policy attention to these issues.

California↗