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At least 1,081 records · Page 60Linked to original sources

Evaluation of Copernicus DEM and comparison to the DEM used for Landsat collection-2 processing

Having highly accurate and reliable Digital Elevation Models (DEMs) of the Earth’s surface is critical to orthorectify Landsat imagery. Without such accuracy, pixel locations reported in the data are difficult to assure as accurate, especially in more mountainous landscapes, where the orthorectification process is the most challenging. To this end, the Landsat Calibration and Validation Team (Cal/Val) compared the Copernicus DEM (CopDEM) to the DEM that is currently used in Collection-2 processing (called “Collection-2 DEM”). NGS ground-surveyed and lidar-based ICESat-2 points were used, and the CopDEM shows improvement to be less than 1 m globally, except in Asia where the accuracy and resolution of the DEM were greater for the CopDEM compared to the Collection-2 DEM. Along with slightly improved accuracy, the CopDEM showed more consistent results globally due to its virtually seamless source and consistent creation methods throughout the dataset. While CopDEM is virtually seamless, having greater than 99% of their data coming from a single source (Tandem-X), there are significantly more voids in the higher elevations which were mostly filled with SRTM derivatives. The accuracy of the CopDEM fill imagery was also compared to the Collection-2 DEM and the results were very similar, showing that the choice of fill imagery used by CopDEM was appropriate. A qualitative assessment using terrain-corrected products processed with different DEMs and viewing them as anaglyphs to evaluate the DEMs proved useful for assessing orbital path co-registration. While the superiority of the CopDEM was not shown to be definitive by the qualitative method for many of the regions assessed, the CopDEM showed a clear advantage in Northern Russia, where the Collection-2 DEM uses some of the oldest and least accurate datasets in the compilation of the Collection-2 DEM. This paper presents results from the comparison study, along with the justification for proceeding with using the Copernicus DEM in future Landsat processing. As of this writing, the Copernicus DEM is planned to be used in Collection-3 processing, which is anticipated to be released no earlier than 2025.

Remote Sensing↗

Candidate cave entrances on Mars

This paper presents newly discovered candidate cave entrances into Martian near-surface lava tubes, volcano-tectonic fracture systems, and pit craters and describes their characteristics and exploration possibilities. These candidates are all collapse features that occur either intermittently along laterally continuous trench-like depressions or in the floors of sheer-walled atypical pit craters. As viewed from orbit, locations of most candidates are visibly consistent with known terrestrial features such as tube-fed lava flows, volcano-tectonic fractures, and pit craters, each of which forms by mechanisms that can produce caves. Although we cannot determine subsurface extents of the Martian features discussed here, some may continue unimpeded for many kilometers if terrestrial examples are indeed analogous. The features presented here were identified in images acquired by the Mars Odyssey's Thermal Emission Imaging System visible-wavelength camera, and by the Mars Reconnaissance Orbiter's Context Camera. Select candidates have since been targeted by the High-Resolution Imaging Science Experiment. Martian caves are promising potential sites for future human habitation and astrobiology investigations; understanding their characteristics is critical for long-term mission planning and for developing the necessary exploration technologies.

Journal of Cave and Karst Studies↗

Pluvial and potential compound flooding in a coupled coastal modeling framework: New York City during post-tropical Cyclone Ida (2021)

Many coastal urban areas are prone to extreme pluvial flooding due to limitations in stormwater system capacity, with the additional potential for flooding compounded by storm surge, tides, and waves. Understanding and simulating these processes can improve prediction and flood risk management. Here, we adapt the Coupled Ocean–Atmosphere–Wave–Sediment Transport modeling framework (COAWST) to simulate pluvial flooding from post-tropical Cyclone Ida (2021) in the Jamaica Bay watershed of New York City (NYC). We modify the model to capture the volumetric effects of rainfall and parameterize soil infiltration and a stormwater conveyance system as the drainage rate. We generate a spatially continuous flood map of Ida with a root-mean-square error (RMSE) of 20 cm when compared to high-water marks, useful for understanding Ida's impacts and subsequent mitigation planning. Results show that over 23 km 2 and 4621 buildings were flooded deeper than 0.3 m during Ida. Sensitivity analyses are used to study the broader risk from events like Ida (pluvial flooding) as well as potential compound (pluvial–coastal) flooding. Spatial shifting of the storm track within a typical 12 h forecast uncertainty reveals a worst-case scenario that increases this flooded area to 62 km 2 (5907 buildings). Shifting Ida's rainfall to coincide with high tide increases this flooded area by 1 km 2 , a relatively small change due to the lack of significant storm surge. The application of COAWST to this storm event addresses a broader goal of developing the capability to model compound pluvial–coastal flooding by simultaneously representing coastal storm processes such as rain, tide, waves, erosion, and atmosphere–wave–ocean interactions. The sensitivity analysis results underscore the need for detailed flood risk assessments, showing that Ida, already NYC's worst rain event, could have been even more devastating with slight shifts in the storm track.

New York↗

Workshop proceedings: research and management in whitebark pine ecosystems

The purpose of this workshop is to exchange information on on-going and soon-to-be-initiated whitebark pine research and management projects. By doing so we hope to encourage future work on this valuable species. We also hope to promote the use of consistent methods for evaluation and investigation of whitebark pine, and to provide avenues of collaboration. Speakers will present information on a variety of topics related to whitebark pine management and research. Featured presentation topics include anthropomorphic utilization of whitepark pine forests, whitebark pine natural regeneration, blister rust and the decline of whitebark pine, blister rust resistance studies, ecological mapping of the species, restoration and management projects, and survey/monitoring techniques. Information gained from these presentations may hopefully be used in the planning of future projects for the conservation of whitebark pine.

Book↗

Assessment of frequency and duration of point counts when surveying for golden eagle presence

We assessed the utility of the recommended golden eagle ( Aquila chrysaetos ) survey methodology in the U.S. Fish and Wildlife Service 2013 Eagle Conservation Plan Guidance. We conducted 800-m radius, 1-hr point-count surveys broken into 20-min segments, during 2 sampling periods in 3 areas within the Intermountain West of the United States over 2 consecutive breeding seasons during 2012 and 2013. Our goal was to measure the influence of different survey time intervals and sampling periods on detectability and use estimates of golden eagles among different locations. Our results suggest that a less intensive effort (i.e., survey duration shorter than 1 hr and point-count survey radii smaller than 800 m) would likely be inadequate for rigorous documentation of golden eagle occurrence pre- or postconstruction of wind energy facilities. Results from a simulation analysis of detection probabilities and survey effort suggest that greater temporal and spatial effort could make point-count surveys more applicable for evaluating golden eagle occurrence in survey areas; however, increased effort would increase financial costs associated with additional person-hours and logistics (e.g., fuel, lodging). Future surveys can benefit from a pilot study and careful consideration of prior information about counts or densities of golden eagles in the survey area before developing a survey design. If information is lacking, survey planning may be best served by assuming low detection rates and increasing the temporal and spatial effort.

Idaho, New Mexico, Wyoming↗

USGS Workshop on Scientific Aspects of a Long-Term Experimental Plan for Glen Canyon Dam, April 10-11, 2007, Flagstaff, Arizona

Executive Summary Glen Canyon Dam is located in the lower reaches of Glen Canyon National Recreation Area on the Colorado River, approximately 15 miles upriver from Grand Canyon National Park (fig. 1). In 1992, Congress passed and the President signed into law the Grand Canyon Protection Act (GCPA; title XVIII, sec. 1801?1809, of Public Law 102-575), which seeks ?to protect, mitigate adverse impacts to, and improve the values for which Grand Canyon National Park and Glen Canyon National Recreation Area were established.? The Glen Canyon Dam Adaptive Management Program (GCDAMP) was implemented as a result of the 1996 Record of Decision on the Operation of Glen Canyon Dam Final Environmental Impact Statement to ensure that the primary mandate of the GCPA is met through advances in information and resources management (U.S. Department of the Interior, 1995). On November 3, 2006, the Bureau of Reclamation (Reclamation) announced it would develop a long-term experimental plan environmental impact statement (LTEP EIS) for operational activities at Glen Canyon Dam and other management actions on the Colorado River. The purpose of the long-term experimental plan is twofold: (1) to increase the scientific understanding of the ecosystem and (2) to improve and protect important downstream resources. The proposed plan would implement a structured, longterm program of experimentation to include dam operations, potential modifications to Glen Canyon Dam intake structures, and other management actions such as removal of nonnative fish species. The development of the long-term experimental plan continues efforts begun by the GCDAMP to protect resources downstream of Glen Canyon Dam, including Grand Canyon, through adaptive management and scientific experimentation. The LTEP EIS will rely on the extensive scientific studies that have been undertaken as part of the adaptive management program by the U.S. Geological Survey?s (USGS) Grand Canyon Monitoring and Research Center (GCMRC), one of the four research stations within the USGS Southwest Biological Science Center. On April 10 and 11, 2007, at the behest of Reclamation, the GCMRC convened a workshop with scientific experts to identify one or more scientifically credible, long-term experimental options for Reclamation to consider for the LTEP EIS that would be consistent with the purpose and need for the plan. Workshop participants included government, academic, and private scientists with broad experience in the Colorado River in Grand Canyon and regulated rivers around the world. Resource managers and GCDAMP participants were also present on the second day of the workshop. In advance of the workshop, Reclamation and LTEP EIS cooperating agencies identified 14 core scientific questions. Workshop participants were asked to consider how proposed options would address these questions, which fall primarily into four areas: (1) conservation of endangered humpback chub (Gila cypha) and other high-priority biological resources, (2) conservation of sediment resources, (3) enhancement of recreational resources, and (4) preservation of cultural resources. A secondary objective of the workshop was the evaluation of four long-term experimental options developed by the GCDAMP Science Planning Group (SPG) (appendix B). The flow and nonflow treatments called for in the four experimental options were an important starting point for workshop discussions. At the beginning of the workshop, participants were provided with the final LTEP EIS scoping report prepared by Reclamation. Participants were also advised that Reclamation had committed to ?make every effortEto ensure that a new population of humpback chub is established in the mainstem or one or more of the tributaries within Grand Canyon? in the 1995 Operation of Glen Canyon Dam Final Environmental Impact Statement (U.S. Department of the Interior, 1995). This decision was consistent with the U.S. Fish and Wildlife Service?s 1995 bi

Open-File Report↗

A centroid model of species distribution with applications to the Carolina wren Thryothorus ludovicianus and house finch Haemorhous mexicanus in the United States

Drastic shifts in species distributions are a cause of concern for ecologists. Such shifts pose great threat to biodiversity especially under unprecedented anthropogenic and natural disturbances. Many studies have documented recent shifts in species distributions. However, most of these studies are limited to regional scales, and do not consider the abundance structure within species ranges. Developing methods to detect systematic changes in species distributions over their full ranges is critical for understanding the impact of changing environments and for successful conservation planning. Here, we demonstrate a centroid model for range-wide analysis of distribution shifts using the North American Breeding Bird Survey. The centroid model is based on a hierarchical Bayesian framework which models population change within physiographic strata while accounting for several factors affecting species detectability. Yearly abundance-weighted range centroids are estimated. As case studies, we derive annual centroids for the Carolina wren and house finch in their ranges in the U.S. We further evaluate the first-difference correlation between species’ centroid movement and changes in winter severity, total population abundance. We also examined associations of change in centroids from sub-ranges. Change in full-range centroid movements of Carolina wren significantly correlate with snow cover days (r = −0.58). For both species, the full-range centroid shifts also have strong correlation with total abundance (r = 0.65, and 0.51 respectively). The movements of the full-range centroids of the two species are correlated strongly (up to r = 0.76) with that of the sub-ranges with more drastic population changes. Our study demonstrates the usefulness of centroids for analyzing distribution changes in a two-dimensional spatial context. Particularly it highlights applications that associate the centroid with factors such as environmental stressors, population characteristics, and progression of invasive species. Routine monitoring of changes in centroid will provide useful insights into long-term avian responses to environmental changes.

Ecography↗

Collections management plan for the U.S. Geological Survey Woods Hole Coastal and Marine Science Center samples repository

Since 2002, the Woods Hole Coastal and Marine Science Center Samples Repository has been supporting U.S. Geological Survey research by providing secure storage for geological, geochemical, and biological samples, organizing and actively inventorying these sample collections, and providing researchers access to these scientific collections for study and reuse. Over the years, storage facilities have changed, and new collections management strategies have been adapted as sample collections have grown and as research programs and focuses have shifted. The commitment of the samples repository to preserve and provide physical samples for future research, however, has remained the same. This report documents the collections management plan developed and implemented by the Woods Hole Coastal and Marine Science Center Samples Repository to manage the center’s scientific collections.

Massachusetts↗

Aligning climate models with stakeholder needs: Advances in communicating future rainfall uncertainties for south Florida decision makers

Changes in future precipitation are of great importance to climate data users in South Florida. A recent U.S. Geological Survey workshop, “Increasing Confidence in Precipitation Projections for Everglades Restoration,” highlighted a gap between standard climate model outputs and the climate information needs of some key Florida natural resource managers. These natural resource managers (hereafter broadly defined as “climate data users”) need more tailored output than is commonly provided by the climate modeling community. This study responds to these user needs by outlining and testing an adaptable methodology to select output from ensemble climate‐model simulations based on user‐defined precipitation drivers, using statistical methods common across scientific disciplines. This methodology is developed to provide a “decision matrix” that guides climate data users to specify the subset of models most important to their work based on each user's season (winter, summer, and annual) and the condition (dry, wet, neutral, and no threshold events) of interest. The decision matrix is intended to better communicate the subset of models best representing precipitation drivers. This information could increase users' confidence in climate models as a resource for natural resource planning and can be used to direct future dynamical downscaling efforts. This methodology is based in dynamical processes controlling precipitation via remote and local teleconnections. We also suggest that future climate studies in South Florida include high‐resolution climate model runs (i.e., ocean eddy resolving) in conjunction with dynamical downscaling to adequately capture precipitation variability.

South Florida↗

Science implementation of Forecast Mekong for food and environmental security

Forecast Mekong is a significant international thrust under the Delta Research and Global Observation Network (DRAGON) of the U.S. Geological Survey (USGS) and was launched in 2009 by the U.S. Department of State and the Foreign Ministers of Cambodia, Laos, Thailand, and Vietnam under U.S. Department of State Secretary Hillary R. Clinton's Lower Mekong Initiative to enhance U.S. engagement with countries of the Lower Mekong River Basin in the areas of environment, health, education, and infrastructure. Since 2009, the USGS has worked closely with the U.S. Department of State; personnel from Cambodia, Laos, Thailand, and Vietnam; nongovernmental organizations; and academia to collect and use research and data from the Lower Mekong River Basin to provide hands-on results that will help decisionmakers in future planning and design for restoration, conservation, and management efforts in the Lower Mekong River Basin. In 2012 Forecast Mekong is highlighting the increasing cooperation between the United States and Lower Mekong River Basin countries in the areas of food and environmental security. Under the DRAGON, Forecast Mekong continues work in interactive data integration, modeling, and visualization system by initiating three-dimensional bathymetry and river flow data along with a pilot study of fish distribution, population, and migratory patterns in the Lower Mekong River Basin. When fully developed by the USGS, in partnership with local governments and universities throughout the Mekong River region, Forecast Mekong will provide valuable planning tools to visualize the consequences of climate change and river management.

Phnom Penh↗

Using radar imagery for crop discrimination: a statistical and conditional probability study

A number of the constraints with which remote sensing must contend in crop studies are outlined. They include sensor, identification accuracy, and congruencing constraints; the nature of the answers demanded of the sensor system; and the complex temporal variances of crops in large areas. Attention is then focused on several methods which may be used in the statistical analysis of multidimensional remote sensing data. Crop discrimination for radar K-band imagery is investigated by three methods. The first one uses a Bayes decision rule, the second a nearest-neighbor spatial conditional probability approach, and the third the standard statistical techniques of cluster analysis and principal axes representation. Results indicate that crop type and percent of cover significantly affect the strength of the radar return signal. Sugar beets, corn, and very bare ground are easily distinguishable, sorghum, alfalfa, and young wheat are harder to distinguish. Distinguishability will be improved if the imagery is examined in time sequence so that changes between times of planning, maturation, and harvest provide additional discriminant tools. A comparison between radar and photography indicates that radar performed surprisingly well in crop discrimination in western Kansas and warrants further study.

Remote Sensing of Environment↗

Threats to desert tortoise populations: a critical review of the literature

Decision in resource management are generally based on a combination of sociopolitical, economic, and environmental factors, and may be biased by personal values. These three components often contradict each other resulting in controversy. Controversies can usually be reduced when solid scientific evidence is used to support or refute a decision. However, it is important to recognize that data often do little to alter antagonists' positions when differences in values are the bases if the dispute. But, supporting data can make the decision more defensible, both legally and ethically, especially if the data supporting all opposing viewpoints are included in the decision-making process. Resource management decisions must be made using the best scientific information currently available. However, scientific data vary in two important measures of quality: reliability and validity. The reliability of the data is a measure of the degree to which the observations or conclusion can be repeated. Validity of the data is a measure of the degree to which the observation or conclusion reflects what actually occurs in nature. How the data are collected strongly affects the reliability of validity of ecological conclusions that can be made. Research data potentially relevant to management come from different sources, and the source often provides clues to the reliability and, to a certain extent, validity of data. Understanding the quality of data being used to make management decisions helps to separate the philosophical or value-based aspects of arguments from the objective ones, thus helping to clarify the decisions and judgments that need to be made. The West Mojave Plan is a multispecies, bioregional plan for the management of natural resources within a 9.4 million-acre area of the Mojave Desert in California. The plan addresses the legal requirements for the recovery of the desert tortoise ( Gopherus agazzizii ), a threatened species, but also covers an additional approximately 80 species of plants and animals assigned special status by the Bureau of Land Management, U. S. Fish and Wildlife Service, and California Department of Fish and Game. Within the planning area, 28 separate jurisdictions (counties, cities, towns, military installations, etc.) seek programmatic prescriptions that will facilitate streamlined environmental review, result in expedited authorization for development projects, and protect listed and unlisted species into the foreseeable future to avoid or minimize conflicts between proposed development and species' conservation and recovery. All of the scientific data available concerning the biology and management of these approximately 80 species and their habitats must be evaluated to develop a scientifically credible plan. This document provides an overview and evaluation of the knowledge of the major threats to the persistence and recovery of desert tortoise populations. I was specifically asked to evaluate the scientific veracity of the data and reports available. I summarize the data presently available with particular focus on the West Mojave Desert, evaluate the scientific integrity of the data. and identify major gaps in the available knowledge. I do not attempt to provide in-depth details on each study or threat; for more details I encourage the reader to consult the individual papers or reports city throughout this report (many of which are available at most university libraries and at the West Mojave Plan office in Riverside, California). I also do not attempt to characterize or evaluate the past or present management actions, except where they have direct bearing on evaluation of threats, nor do I attempt, for the most part, to acquire, generate, or evaluate new or existing, but uninterpreted data.

California↗

Collections management plan for the U.S. Geological Survey Woods Hole Coastal and Marine Science Center Samples Repository

Since 2002, the Woods Hole Coastal and Marine Science Center Samples Repository has been supporting research by providing secure storage for geological, biological, and geochemical samples; maintaining organization and an active inventory of these sample collections; and providing researchers access to these scientific collections for study and reuse. Over the years, local storage facilities have changed and new collections management strategies have been adapted as sample collections have grown and as research programs and focuses have shifted. The commitment of the Samples Repository to preserve and provide physical samples for future research, however, has remained the same. This report documents the collections management plan developed and implemented by the Woods Hole Coastal and Marine Science Center Samples Repository to manage its scientific collections.

Open-File Report↗

Field Methods and Quality-Assurance Plan for Quality-of-Water Activities, U.S. Geological Survey, Idaho National Laboratory, Idaho

Water-quality activities conducted by the staff of the U.S. Geological Survey (USGS) Idaho National Laboratory (INL) Project Office coincide with the USGS mission of appraising the quantity and quality of the Nation's water resources. The activities are conducted in cooperation with the U.S. Department of Energy's (DOE) Idaho Operations Office. Results of the water-quality investigations are presented in various USGS publications or in refereed scientific journals. The results of the studies are highly regarded, and they are used with confidence by researchers, regulatory and managerial agencies, and interested civic groups. In its broadest sense, quality assurance refers to doing the job right the first time. It includes the functions of planning for products, review and acceptance of the products, and an audit designed to evaluate the system that produces the products. Quality control and quality assurance differ in that quality control ensures that things are done correctly given the 'state-of-the-art' technology, and quality assurance ensures that quality control is maintained within specified limits.

Open-File Report↗

Integrating principles and tools of decision science into value-driven watershed planning for compensatory mitigation

Several environmental policies strive to restore impaired ecosystems and could benefit from a consistent and transparent process — co-developed with key stakeholders — to prioritize impaired ecosystems for restoration activities. The Clean Water Act, for example, establishes reallocation mechanisms to transfer ecosystem services from sites of disturbance to compensation sites to offset aquatic resource functions that are unavoidably lost through land development. However, planning for the prioritization of compensatory mitigation areas is often hampered by decision-making processes that fall into a myopic decision frame because they are not co-produced with stakeholders. In this study, we partnered with domain experts from the North Carolina Division of Mitigation Services (NCDMS) to co-develop a real-world decision framework to prioritize catchments by potential for the development of mitigation projects following principles of a structured decision-making process and knowledge co-production. Following an iterative decision analysis cycle, domain experts revised foundational components of the decision framework and progressively added complexity and realism as they gained additional insights or more information became available. Through the course of facilitated in-person and remote interactions, the co-development of a decision framework produced three main ‘breakthroughs’ from the perspective of the stakeholder group: a) recognition of the problem as a multi-objective decision driven by several values in addition to biogeophysical goals (e.g., functional uplift; restoring or enhancing lost functionality of ecosystems), b) that the decision comprises a linked and sequential planning-to-implementation process, and c) future risk associated with land-use and climate change must be considered. We also present an interactive tool for ‘on-the-fly’ assessment of alternatives and tradeoff analysis, allowing domain experts to quickly test, react to, and revise prioritization strategies. The decision framework described in this study is not limited to the prioritization of compensatory mitigation activities across North Carolina, but rather serves as a framework to prioritize a wide range of restoration, conservation, and resource allocation activities in similar environmental contexts across the nation.

Ecological Applications↗

Anatomical and genetic variation of western Oxyloma (Pulmonata: Succineidae) concerning the endangered Kanab ambersnail ( Oxyloma haydeni kanabense ) in Arizona and Utah

The land snail genus Oxyloma (Pulmonata: Succineidae) includes the Federally endangered Kanab ambersnail (Oxyloma haydeni kanabense Pilsbry), which is known at the time of this study from only two locations in the United States: Three Lakes, Utah, and Vaseys Paradise, Arizona, on the Colorado River in Grand Canyon National Park. Since 1994, the Kanab ambersnail has received much attention because its presence at Vaseys Paradise has implications for the ecosystem-wide management of the Colorado River. This attention is primarily because an experimental high-flow release of water from Glen Canyon Dam in 1996 destroyed or degraded Kanab ambersnail habitat at Vaseys Paradise. This experimental high flow was designed to replicate natural flow regimes throughout the Grand Canyon river corridor. However, as a result of the habitat destruction at Vaseys Paradise, in 1996, the U.S. Fish and Wildlife Service ruled that no further experimental high-discharge floods could be carried out until additional Kanab ambersnail populations were discovered or established. This mandate created a situation where the management of a single endangered species conflicted directly with the management of an entire ecosystem. Although since 1996, the U.S. Fish and Wildlife Service has permitted the use of flows as high as stage heights equivalent to 44,000 cubic feet per second, higher flows were requested by various Grand Canyon stakeholders and scientists but were not possible owing to low storage of Lake Powell. Adding to the controversy about Oxyloma and the Kanab ambersnail were previous anatomical and genetic analyses of the genus, which showed that genetic characteristics of specimens did not correspond with their identifications based on traditional taxonomic criteria, raising questions about the validity of the taxonomy of Oxyloma and the protected status of Kanab ambersnails. Specifically, a previous study suggested that the endangered Kanab ambersnail population at Three Lakes was more closely related to other, non-endangered ambersnail populations across the Southwest. In contrast, the Kanab ambersnail population at Vaseys Paradise appeared to be genetically distinct from all other ambersnail populations studied. Management options for the ambersnail population at Vaseys Paradise, at the time of this study, conflict with ecosystem-wide measures proposed to benefit other natural resources in the Grand Canyon. The U.S. Fish and Wildlife Service will not revise the 1995 Kanab Ambersnail Recovery Plan until further genetic and anatomical analyses provide more fine-scale taxonomic resolution of the identity of Oxyloma populations on the Colorado Plateau and elsewhere in the American Southwest. Likewise, interagency cooperators cannot revise down-listing criteria for the Kanab ambersnail until substantial evidence is provided identifying distinct Oxyloma taxa or a larger group of conspecifics that reasonably could be managed as one species. Therefore, given the current controversy about the taxonomy of Oxyloma and the endangered Kanab ambersnail, new detailed analyses were completed of morphological and genetic variation from many Oxyloma specimens collected at 12 western North American locations. These new data have allowed us to evaluate many issues related to Kanab ambersnail taxonomy. Using this dataset, the study of shells and anatomy indicates that the holotype of Oxyloma haydeni kanabense plausibly can be regarded as a member of the same species as the populations of Oxyloma analyzed in this study. Additionally, the presence of gene flow among all populations is evidence that they are members of the same species. Almost all the observed genetic diversity can be accounted for by short-distance or long-distance dispersal events between populations in this study. Our major taxonomic conclusion is that all samples collected for this study were drawn from populations of the same species.

Arizona;Utah↗

California Deepwater Investigations and Groundtruthing (Cal DIG) I, volume 3 — Benthic habitat characterization offshore Morro Bay, California

Coastal and Marine Ecological Classification Standard (CMECS) geoform, substrate, and biotic component geographic information system (GIS) products were developed for the U.S. Exclusive Economic Zone (U.S. EEZ) of south-central California in the region of Santa Lucia Bank motivated by interest in development of offshore wind-energy capacity and infrastructure. The Bureau of Ocean Energy Management (BOEM), in coordination with the State of California and many other members of the California Task Force, issued calls for information in 2018 for the study area offshore of Morro Bay, California. The study area is in depths of 500 to 1,200 meters (m) and adjacent to a decommissioned nuclear power plant with a developed electric grid connection, and in an area of high wind resource. BOEM is the lead agency responsible for planning and leasing in the U.S. EEZ and funded this project to assess baseline conditions of, and the potential effects on, the seafloor environment. This project, carried out by the U.S. Geological Survey (USGS), resulted in three reports: one on biological analysis of seafloor video data, one on analysis of the geologic framework and hazards, and this report on seafloor habitat. The study area consists of 8,424 square kilometers (km 2 ) of multibeam echo sounder (MBES) data acquired during five surveys from 2016 to 2019. Remotely operated vehicle (ROV) video was acquired in 2019 to supervise the classification of the MBES data into habitats. Derivatives of the MBES data were classified into 16 unique biotopes, 6 substrate types, 28 modifier groups, and 22 geoforms. The study area substrate is predominantly soft sediment (mud and fine sand) covering 7,804 km 2 (92.7 percent) of the area. Mixed substrate areas on rocky banks, channel scarps, and the shelf break comprise 404 km 2 (4.8 percent) of the study area. Hard substrate areas are found predominantly on the tops and flanks of banks and on bank ridges that separate canyons incising the banks. Hard substrates comprise 211 km 2 of the study area (2.5 percent). After the bathymetry and backscatter raster images (rasters) were classified, manual editing was also done to remove noise artifacts. This effort was not completely successful and there are numerous erroneous small areas in the rasters that have been passed on to the CMECS polygon product. Nearly 120,000 annotations of organisms and their habitat were made from 25 video transects selected from 185 hours of ROV video. In total, 2,714 km 2 of seafloor were successfully assigned to biotopes. Some biotopes were assigned to separate areas spatially distant from the transects that define the biotope. Expected relations between physical habitat and biota such as the number of species and the substrate induration and rugosity were verified. Slope is typically a predictive variable and was used in the classification of habitat, but the ground truth used for biotic component analysis included very little steeply sloping area. Ground-truth ROV operations were reduced by the sea state; additional ground truth could improve the biotic results and increase confidence in the spatial distribution of classifications reported here.

California↗

Water Resources of the Basin and Range Carbonate-Rock Aquifer System, White Pine County, Nevada, and Adjacent Areas in Nevada and Utah - Draft Report

Summary of Major Findings This report summarizes results of a water-resources study for White Pine County, Nevada, and adjacent areas in east-central Nevada and western Utah. The Basin and Range carbonate-rock aquifer system (BARCAS) study was initiated in December 2004 through Federal legislation (Section 131 of the Lincoln County Conservation, Recreation, and Development Act of 2004) directing the Secretary of the Interior to complete a water-resources study through the U.S. Geological Survey, Desert Research Institute, and State of Utah. The study was designed as a regional water-resource assessment, with particular emphasis on summarizing the hydrogeologic framework and hydrologic processes that influence ground-water resources. The study area includes 13 hydrographic areas that cover most of White Pine County; in this report however, results for the northern and central parts of Little Smoky Valley were combined and presented as one hydrographic area. Hydrographic areas are the basic geographic units used by the State of Nevada and Utah and local agencies for water-resource planning and management, and are commonly defined on the basis of surface-water drainage areas. Hydrographic areas were further divided into subbasins that are separated by areas where bedrock is at or near the land surface. Subbasins represent subdivisions used in this study for estimating recharge, discharge, and water budget. Hydrographic areas represent the subdivision used for reporting summed and tabulated subbasin estimates.

Open-File Report↗