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USGS2015

The Pacific northwest stream quality assessment

In 2015, the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) program is assessing stream quality in the Pacific Northwest. The goals of the Pacific Northwest Stream Quality Assessment (Pacific Northwest study) are to assess the quality of streams in the region by characterizing multiple water-quality factors that are stressors to aquatic life and to evaluate the relation between these stressors and biological communities. The effects of urbanization and agriculture on stream quality for the Puget Lowlands and Willamette Valley are the focus of this regional study. Findings will provide the public and policymakers with information regarding which human and environmental factors are the most critical in affecting stream quality and, thus, provide insights about possible approaches to protect or improve the health of streams in the region. The Pacific Northwest study will be the third regional study by the NAWQA program, and it will be of similar design and scope as the first two—the Midwest in 2013 and the Southeast in 2014 (Van Metre and others, 2012, 2014).

Oregon, Washington↗

USGS2010

Surficial geologic map of the Heath-Northfield-Southwick-Hampden 24-quadrangle area in the Connecticut Valley region, west-central Massachusetts

The surficial geologic map layer shows the distribution of nonlithified earth materials at land surface in an area of 24 7.5-minute quadrangles (1,238 mi2 total) in west-central Massachusetts. Across Massachusetts, these materials range from a few feet to more than 500 ft in thickness. They overlie bedrock, which crops out in upland hills and as resistant ledges in valley areas. The geologic map differentiates surficial materials of Quaternary age on the basis of their lithologic characteristics (such as grain size and sedimentary structures), constructional geomorphic features, stratigraphic relationships, and age. Surficial materials also are known in engineering classifications as unconsolidated soils, which include coarse-grained soils, fine-grained soils, and organic fine-grained soils. Surficial materials underlie and are the parent materials of modern pedogenic soils, which have developed in them at the land surface. Surficial earth materials significantly affect human use of the land, and an accurate description of their distribution is particularly important for assessing water resources, construction aggregate resources, and earth-surface hazards, and for making land-use decisions. This work is part of a comprehensive study to produce a statewide digital map of the surficial geology at a 1:24,000-scale level of accuracy. This report includes explanatory text, quadrangle maps at 1:24,000 scale (PDF files), GIS data layers (ArcGIS shapefiles), metadata for the GIS layers, scanned topographic base maps (TIF), and a readme.txt file.

Open-File Report↗

USGS2019

Population estimates of Antillean manatees in Puerto Rico: An analytical framework for aerial surveys using multi-pass removal sampling

Effective management of the threatened Antillean manatee ( Trichechus manatus manatus ) in Puerto Rico requires reliable estimates of population size. Estimates are needed to assess population responses to management actions, and whether recovery objectives have been met. Aerial surveys have been conducted since 1976, but none adjusted for imperfect detection. We summarize surveys since 1976, report on current distribution, and provide population estimates after accounting for apparent detection probability for surveys between June 2010 and March 2014. Estimates in areas of high concentration (hotspots) averaged 317 ± 101, three times higher than unadjusted counts (104 ± 0.56). Adjusted estimates in three areas outside hotspots also differed markedly from counts (75 ± 9.89 versus 19.5 ± 3.5). Average minimum island-wide estimate was 386 ± 89, similar to the maximum estimate of 360 suggested in 2005, but fewer than the 700 recently suggested by the Puerto Rico Manatee Conservation Center. Manatees were more widespread than previously understood. Improving estimates, locally or island-wide, will require stratifying the island differently and greater knowledge about factors affecting detection probability. Sharing our protocol with partners in nearby islands (e.g., Cuba, Jamaica, Hispaniola), whose populations share genetic make-up, would contribute to enhanced regional conservation through better population estimates and tracking range expansion.

Puerto Rico↗

USGS2010

Oblique Aerial Photography of the Arctic Coast of Alaska, Cape Sabine to Milne Point, July 16-19, 2009

The Arctic Coastal Plain of northern Alaska, an area of strategic economic importance to the United States, is home to remote Native American communities and encompasses unique habitats of global significance. Coastal erosion along the Arctic coast is chronic and widespread; recent evidence suggests that erosion rates are among the highest in the world (as high as ~16 m/yr) and may be accelerating. Coastal erosion adversely impacts energy-related infrastructure, natural shoreline habitats, and Native American communities. Climate change is thought to be a key component of recent environmental changes in the Arctic. Reduced sea-ice cover in the Arctic Ocean is one of the probable mechanisms responsible for increasing coastal exposure to wave attack and the resulting increase in erosion. Extended periods of permafrost melting and associated decreases in bluff cohesion and stability are another possible source of the increase in erosion. Several studies of selected areas on the Alaska coast document past shoreline positions and coastal change, but none have examined the entire North coast systematically. Results from these studies indicate high rates of coastal retreat that vary spatially along the coast. To address the need for a comprehensive and regionally consistent evaluation of shoreline change along the North coast of Alaska, the U.S. Geological Survey (USGS), as part of their Coastal and Marine Geology Program's (CMGP) National Assessment of Shoreline Change Study, is evaluating shoreline change from Peard Bay to the United States/Canadian border, using historical maps and photography and a standardized methodology that is consistent with other shoreline-change studies along the Nation's coastlines (see, for example, http://coastal.er.usgs.gov/shoreline-change/, last accessed February 12, 2010). This is the second in a series of publications containing photographs collected during reconnaissance surveys conducted in support of the National Assessment of Shoreline Change Study. An accompanying ESRI ArcGIS shape file (and plaintext copy) indicates the position of the aircraft and time when each photograph was taken. The USGS-CMGP Field Activity ID for the survey is A-5-09-AK, and more information on the survey and how to view the photographs using Google Earth software is available online at http://walrus.wr.usgs.gov/infobank/a/a509ak/html/a-5-09-ak.photos.kmz (last accessed February 12, 2010). The initial report ?Oblique aerial photography of the Arctic coast of Alaska, Nulavik to Demarcation Point, August 7-10, 2006? is available online at http://pubs.usgs.gov/ds/436/, and the associated Google Earth .kmz file is available at http://walrus.wr.usgs.gov/infobank/a/a106ak/html/a-1-06-ak.photos.kmz (last accessed February 12, 2010).

Data Series↗

USGS2014

Landscape and climate science and scenarios for Florida

The Peninsular Florida Landscape Conservation Cooperative (PFLCC) is part of a network of 22 Landscape Conservation Cooperatives (LCCs) that extend from Alaska to the Caribbean. LCCs are regional-applied conservation-science partnerships among Federal agencies, regional organizations, States, tribes, nongovernmental organizations (NGOs), private stakeholders, universities, and other entities within a geographic area. The goal of these conservation-science partnerships is to help inform managers and decision makers at a landscape scale to further the principles of adaptive management and strategic habitat conservation. A major focus for LCCs is to help conservation managers and decision makers respond to large-scale ecosystem and habitat stressors, such as climate change, habitat fragmentation, invasive species, and water scarcity. The purpose of the PFLCC is to facilitate planning, design, and implementation of conservation strategies for fish and wildlife species at the landscape level using the adaptive management framework of strategic habitat conservation—integrating planning, design, delivery, and evaluation. Florida faces a set of unique challenges when responding to regional and global stressors because of its unique ecosystems and assemblages of species, its geographic location at the crossroads of temperate and tropical climates, and its exposure to both rapid urbanization and rising sea levels as the climate warms. In response to these challenges, several landscape-scale science projects were initiated with the goal of informing decision makers about how potential changes in climate and the built environment could impact habitats and ecosystems of concern in Florida and the Southeast United States. In June 2012, the PFLCC, North Carolina State University, convened a workshop at the U.S. Geological Survey (USGS) Coastal and Marine Science Center in St. Petersburg to assess the results of these integrated assessments and to foster an open dialogue about science gaps and future research needs.

Florida↗

USGS2012

Analysis of streamflow-gaging network for monitoring stormwater in small streams in the Puget Sound Basin, Washington

The streamflow-gaging network in the Puget Sound basin was analyzed for its capacity to monitor stormwater in small streams. The analysis consisted of an inventory of active and inactive gages and an evaluation of the coverage and resolution of the gaging network with an emphasis on lowland areas. The active gaging network covers much of the Puget Lowland largely by gages located at sites on larger streams and rivers. Assessments of stormwater impacts and management will likely require streamflow information with higher spatial resolution than provided by the current gaging network. Monitoring that emphasizes small streams in combination with approaches for estimating streamflow at ungaged sites provides an alternative to expanding the current gaging network that can improve the spatial resolution of streamflow information in the region. The highest priority gaps in the gaging network are low elevation basins close to the Puget Sound shoreline and sites that share less than 10 percent of the drainage area of an active gage. Although small, lowland sites with long records of streamflow are particularly valuable to maintain in the region, other criteria for prioritizing sites in the gaging network should be based on the specific questions that stormwater managers need to answer.

Washington↗

USGS1994

Water quality of the Apalachicola-Chattahoochee-Flint and Ocmulgee River Basins related to flooding from Tropical Storm Alberto; pesticides in urban and agricultural watersheds; and nitrate and pesticides in ground water, Georgia, Alabama, and Florida

This report presents preliminary water-quality information from three studies that are part of the National Water-Quality Assessment (NAWQA) Program in the Apalachicola-Chattahoochee-Flint (ACF) River basin and the adjacent Ocmulgee River basin. During the period July 3-7, 1994, heavy rainfall from tropical storm Alberto caused record flooding on the Ocmulgee and Flint Rivers and several of their tributaries. Much of the nitrogen load transported during the flooding was as organic nitrogen generally derived from organic detritus, rather than nitrate derived from other sources, such as fertilizer. More than half the mean annual loads of total phosphorus and organic nitrogen were trans- ported in the Flint and Ocmulgee Rivers during the flood. Fourteen herbicides, five insecticides, and one fungicide were detected in floodwaters of the Ocmulgee, Flint, and Apalachicola Rivers. In a second study, water samples were collected at nearly weekly intervals from March 1993 through April 1994 from one urban and two agricultural watersheds in the ACF River basin, and analyzed for 84 commonly used pesticides. More pesticides were detected and at generally higher concentrations in water from the urban watershed than the agricultural water- sheds, and a greater number of pesticides were persistent throughout much of the year in the urban watershed. Simazine exceeded U.S. Environmental Protection Agency (EPA) drinking-water standards in one of 57 samples from the urban watershed. In a third study, 38 wells were installed in surficial aquifers adjacent to and downgradient of farm fields within agricultural areas in the southern ACF River basin. Even though regional aquifers are generally used for irrigation and domestic- and public-water supplies, degradation of water quality in the surficial aquifers serves as an early warning of potential contamination of regional aquifers. Nitrate concentrations were less than 3 mg/L as N (indicating minimal effect of human activities) in water from about two-thirds of the wells. Water from the remaining wells had elevated nitrate con- centrations, probably the result of human activity. Nitrate concentrations in two of these wells exceeded EPA drinking-water standards. Water samples from eight wells had pesticide concentrations above method detection limits. With the exception of two samples for shallow ground-water wells and one surface-water sample from the urban watershed, concentrations of nitrate nitrogen and detected pesticides were below EPA standards and guidelines for drinking water. However, concentrations of the insecticides chlorpyrifos, carbaryl, and diazinon in the surface-water samples approached or exceeded guidelines for protection of aquatic life.

Alabama, Florida, Georgia↗

USGS2002

Geologic map and digital database of the San Bernardino Wash 7.5 minute quadrangle, Riverside County, California

The geologic map and digital database of the San Bernardino Wash quadrangle are products of a regional geologic mapping effort undertaken in the eastern Transverse Ranges in and around Joshua Tree National Park. This investigation, part of the Southern California Areal Mapping Project (SCAMP), is conducted in cooperation with the California Geologic Survey and the National Park Service. In line with the goals of the National Cooperative Geologic Mapping Program (NCGMP), mapping of the San Bernardino Wash and other quadrangles has been directed toward generating a multipurpose digital geologic map database that is applicable to land-related investigations in the earth and biological sciences. This mapping is conducted to further understanding of bedrock geology and surficial processes in the region and to document evidence for seismotectonic activity in the eastern Transverse Ranges. It is also intended to serve as a base layer suitable for ecosystem and mineral resource assessment and for building a hydrogeologic framework for Pinto Basin. Initial investigations span Pinto Basin from the Hexie and Eagle Mountains northward into the Pinto Mountains (see fig. 1). Quadrangles mapped include the Conejo Well 7.5-minute quadrangle (Powell, 2001a), the Porcupine Wash 7.5-minute quadrangle (Powell, 2001b), the Pinto Mountain 7.5-minute quadrangle (Powell, 2002), and the San Bernardino Wash 7.5-minute quadrangle. Parts of the San Bernardino Wash quadrangle had been mapped previously at a variety of scales (Weir, and Bader, 1963; Hope, 1966, 1969; Jennings, 1967; Powell, 1981, 1993).

California↗

USGS1999

The ecological condition of estuaries in the Gulf of Mexico

The Gulf of Mexico is a vast natural resource encompassing the coastal areas of western Florida, Alabama, Mississippi, Louisiana, and Texas, as well as a portion of Mexico. Many estuaries flow into the Gulf of Mexico and serve as nursery grounds for fish, habitat for a wide variety of wildlife, shipping routes, and a source of recreation. Estuarine-dependent species constitute more than 95 percent of the commercial fishery harvests from the Gulf of Mexico, and many important recreational fishery species depend on estuaries during some part of their life cycle. Gulf estuaries are diverse and productive ecosystems that provide a variety of valuable resources, including fish and shellfish, recreation, transportation, and water supply. Assessing the overall condition of Gulf of Mexico estuaries required incorporating data from other federal, state, and local monitoring programs to augment the information on ecological indicators collected by the U.S. Environmental Protection Agency’s (USEPA) Environmental Monitoring and Assessment Program (EMAP). The resulting document would provide a synthesis of the available knowledge about the condition of Gulf of Mexico estuaries. This document is intended for use by scientists and other citizens concerned with the ecological condition of estuaries, as well as by managers and lawmakers interested in the sustained use of estuaries for commercial and recreational purposes. It also addresses public concerns about the aesthetic quality of coastal areas vital to tourism and recreation. By producing this report on the ecological condition of estuaries in the Gulf of Mexico, we have taken one step in assessing the health of this environmental resource. We have produced an environmental “report card” to be used as a guide in the evaluation of management decisions and research directions. This report is organized in three parts: (1) an introduction that gives background information on the Gulf of Mexico, estuarine ecology, and the factors that impact estuaries in the gulf, (2) the main section on priority ecological indicators used to measure the condition of estuaries in the gulf and (3) an ecological report card that summarizes the data on ecological indicators and provides a rating of the condition of estuaries in each gulf state and for gulf estuaries overall. Many of the ratings were based on the percent area of estuaries in each state exhibiting degraded or adverse levels of an indicator. Eutrophication, a condition of high nutrients often resulting in low oxygen levels and other adverse effects, is an important water quality concern for estuaries along the gulf coast. The National Oceanic and Atmospheric Administration (NOAA) has compared the Gulf of Mexico to other coastal regions like the middle Atlantic and has ranked the Gulf of Mexico as having the highest number of point sources of nutrients and the highest percentage of land use devoted to agriculture. We evaluated monitoring data for nitrogen, chlorophyll, and dissolved oxygen as indicators of eutrophication. Although most of the estuaries exhibited high nitrogen or chlorophyll or low dissolved oxygen concentrations at least once during a survey, many times these conditions were observed in small rivers or bayous rather than in the entire estuary. Often, the percent area affected was low. The gulf estuaries had moderate conditions overall for nutrients and dissolved oxygen. Definite nutrient problems were observed in >25% of the estuarine area in Louisiana and Texas and definite dissolved oxygen problems were observed in Alabama. Contaminants in estuarine sediments provide evidence of the accumulation of chemicals from anthropogenic sources. We compared the concentrations of sediment contaminants to established guideline values to determine the proportion of estuarine area that could have potential adverse effects on living organisms. Although detectable levels of contaminants were measured in almost every estuary in the Gulf of Mexico, <25% of the estuarine area in all states had contaminant concentrations that exceeded these guidelines. Wetlands are integral parts of estuarine systems. Declining acreage means habitat loss that may be the result of commercial and residential development, hydrologic alterations, or dredge and fill operations. The Gulf of Mexico region contains more than 50% of the coastal wetland acreage in the U.S. and yet it also has the highest rate of coastal wetland loss. Nine of the top ten estuarine drainage areas ranked by total wetland area are in the Gulf of Mexico region. The most current estimates of total wetland loss over the past 200 years range from 41% to 54% for the gulf states. Although coastal wetlands continue to be altered or destroyed, some estimates indicate that the rate of loss has slowed. All gulf states were rated as having severe problems with wetland loss. The condition of benthic (bottom-dwelling) invertebrates, fish and shellfish, birds, and threatened and endangered species was used to evaluate the health of estuarine fauna. Degraded benthic communities inhabited <25% of the estuarine area in all gulf states except for Texas. Commercial fish and shellfish landings may be used as an indicator of population stability while fish biomarkers are used to measure the health of individuals in the population. Commercial landings of the top four fisheries (shrimp, menhaden, blue crab, and oyster) are stable in the gulf states while fish biomarkers indicate fair to poor fish health in Alabama and Texas and good fish health elsewhere. Coastal and marine bird populations appear to be in good condition throughout the gulf. Four threatened or endangered species inhabit coastal areas in the Gulf of Mexico: brown pelican, Gulf sturgeon, manatee, and Kemp’s ridley sea turtle. In general, populations of these species are in good to fair condition in the gulf states. Public health indicators include shellfish bed closures and chemicals found in edible fish tissue. Harvest of shellfish (primarily oyster in the Gulf of Mexico) is restricted or prohibited when concentrations of bacteria or other pathogens reach levels that could impair human health. The gulf states contain the most acreage of shellfish-growing waters in the U.S. but also have the most acreage restricted for harvest. All gulf states except Mississippi have >25% of their shellfish-growing waters restricted for harvest, mostly due to pollution from wastewater treatment plants or other upstream sources. Advisories may be issued that limit consumption when the concentrations of chemicals in fish tissue exceed levels known to be harmful to humans. Although seafood consumption advisories have been issued in all gulf states, the percent of the fish population with high concentrations of contaminants is relatively low in the gulf overall.

Alabama, Florida, Louisiana, Mississippi, Texas↗

USGS2017

Sampling bees in tropical forests and agroecosystems: A review

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

Journal of Insect Conservation↗

USGS2007

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

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

California↗

USGS2010

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

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

Arizona, Sonora↗

USGS2018

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

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

Professional Paper↗

USGS2006

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

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

Open-File Report↗

USGS2013

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

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

Colorado;New Mexico↗

USGS2006

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

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

New Mexico↗

USGS2018

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

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

Louisiana↗

USGS1993

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

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

Open-File Report↗