Geology Reports⌕ Search

SEARCH · Geology Reports

Results for “Frontiers in Water”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3Linked to original sources
USGS2020

Stony coral tissue loss disease in Florida is associated with disruption of host–zooxanthellae physiology

Samples from eight species of corals ( Colpophyllia natans , Dendrogyra cylindrus , Diploria labyrinthiformis , Meandrina meandrites , Montastraea cavernosa , Orbicella faveolata, Pseudodiploria strigosa , and Siderastrea siderea ) that exhibited gross clinical signs of acute, subacute, or chronic tissue loss attributed to stony coral tissue loss disease (SCTLD) were collected from the Florida Reef Tract during 2016–2018 and examined histopathologically. The hallmark microscopic lesion seen in all eight species was focal to multifocal lytic necrosis (LN) originating in the gastrodermis of the basal body wall (BBW) and extending to the calicodermis, with more advanced lesions involving the surface body wall. This was accompanied by other degenerative changes in host cells such as mucocyte hypertrophy, degradation and fragmentation of gastrodermal architecture, and disintegration of the mesoglea. Zooxanthellae manifested various changes including necrosis (cytoplasmic hypereosinophilia, pyknosis); peripheral nuclear chromatin condensation; cytoplasmic vacuolation accompanied by deformation, swelling, or atrophy; swollen accumulation bodies; prominent pyrenoids; and degraded chloroplasts. Polyhedral intracytoplasmic eosinophilic periodic acid–Schiff-positive crystalline inclusion bodies (∼1–10 μm in length) were seen only in M. cavernosa and P. strigosa BBW gastrodermis in or adjacent to active lesions and some unaffected areas (without surface lesions) of diseased colonies. Coccoidlike or coccobacilloidlike structures (Gram-neutral) reminiscent of microorganisms were occasionally associated with LN lesions or seen in apparently healthy tissue of diseased colonies along with various parasites and other bacteria all considered likely secondary colonizers. Of the 82 samples showing gross lesions of SCTLD, 71 (87%) were confirmed histologically to have LN. Collectively, pathology indicates that SCTLD is the result of a disruption of host–symbiont physiology with lesions originating in the BBW leading to detachment and sloughing of tissues from the skeleton. Future investigations could focus on identifying the cause and pathogenesis of this process.

Florida↗
USGS1982

Pacific summary report 2: A revision of Outer Continental Shelf oil and gas activities in the Pacific (Southern California) and their onshore impacts: A summary report, May 1980

The Pacific Outer Continental Shelf (OCS) is an established hydrocarbon-producing region. Oil and gas have been produced from the Santa Barbara Channel (both State and Federal acreage) since 1896. Almost 77,000 barrels of oil are produced from the California Federal OCS each day as of December 1981, and leases on State tidelands produce about 40,000 barrels of oil per day. This highly developed area is, of course, but a small part of the Pacific OCS, which also includes Northern California, Washington, and Oregon. The petroleum industry has expressed interest in exploring frontier areas, and as frontier acreage is offered in future lease sales, exploration, development, and production may move out into deeper water. The technology is currently being developed and tested to allow deepwater exploration. To date, offshore drilling operations have resulted in the delineation of 11 offshore oil and gas fields and 2 gas fields in the Southern California OCS. A recent discovery off Point Arguello, California, may lead to delineation of a new field. Reserve estimates have been made for the known fields in the region. Remaining recoverable reserves are estimated at 787 million barrels of oil and over 1.7 trillion cubic feet of gas as of December 31, 1980. Estimates of undiscovered recoverable resources in the offshore Santa Maria Basin and Southern California OCS are over 3.5 billion barrels of oil and in excess of 5 trillion cubic feet of gas. To date, there have been seven oil and gas lease sales in the Pacific OCS Region. An average of one lease sale per year is scheduled through 1985. Industry interest indicates that the Santa Barbara Channel's potential has not yet been fully explored, and some basins to the south, as well as in the Santa Maria Basin, are now gaining considerable interest. Future exploratory activity in the San Pedro Bay and the Santa Maria Basin is likely to increase. Exploration, development, and production in the Pacific OCS Region are increasing at a moderate pace. Pipelines continue to be the preferred mode of transporting Pacific OCS hydrocarbons to shore. The State and the Federal Governments have expressed a commitment to the use of pipelines where possible and economically feasible. Tankers traveling in the Pacific and entering California ports carry, for the most part, imported oil. The region is active in OCS transportation planning; the Bureau of Land Management works through the Pacific States Regional Technical Working Group Committee. Onshore, the Petroleum Transportation Committee (formerly the Joint Government/Industry Pipeline Working Group) is evaluating a number of transportation scenarios. The nearshore and onshore petroleum processing facilities in the Pacific Region service onshore and offshore oil and gas exploration, development, and production, as well as the international oil market. Many of the onshore facilities have been in operation for years, supporting California's extensive onshore and offshore production. Several new facilities have been proposed, are currently under construction, or have recently opened. Shell Oil opened a crude oil distribution facility near Long Beach in December 1980. Operations began at Union Oil's Mandalay Beach separation and treatment plant in December 1981. The Pacific Offshore Pipeline Company, a subsidiary of the Pacific Lighting Corporation, is planning to build a gas treatment plant at Las Flores Canyon; completion of this project is scheduled for July 1983. It is expected that these new facilities, in addition to the established plants, will be able to accommodate any new OCS production in the near term from previously leased areas.

California↗
USGS2022

Selected crater and small caldera lakes in Alaska: Characteristics and hazards

This study addresses the characteristics, potential hazards, and both eruptive and non-eruptive role of water at selected volcanic crater lakes in Alaska. Crater lakes are an important feature of some stratovolcanoes in Alaska. Of the volcanoes in the state with known Holocene eruptive activity, about one third have summit crater lakes. Also included are two volcanoes with small caldera lakes (Katmai, Kaguyak). The lakes play an important but not well studied role in influencing eruptive behavior and pose some significant hydrologic hazards. Floods from crater lakes in Alaska are evaluated by estimating maximum potential crater lake water volumes and peak outflow discharge with a dam-break model. Some recent eruptions and hydrologic events that involved crater lakes also are reviewed. The large volumes of water potentially hosted by crater lakes in Alaska indicate that significant flowage hazards resulting from catastrophic breaching of crater rims are possible. Estimates of maximum peak flood discharge associated with breaching of lake-filled craters derived from dam-break modeling indicate that flood magnitudes could be as large as 10 3 –10 6 m 3 /s if summit crater lakes drain rapidly when at maximum volume. Many of the Alaska crater lakes discussed are situated in hydrothermally altered craters characterized by complex assemblages of stratified unconsolidated volcaniclastic deposits, in a region known for large magnitude (>M7) earthquakes. Although there are only a few historical examples of eruptions involving crater lakes in Alaska, these provide noteworthy examples of the role of external water in cooling pyroclastic deposits, acidic crater-lake drainage, and water-related hazards such as lahars and base surge.

Alaska↗
USGS1988

Heavy-Mineral Placer Potential Map of the U.S. Continental Shelf, Western and Northern Gulf of Mexico

The establishment of the Exclusive Economic Zone (EEZ) in 1983 by Presidential Proclamation opened for natural resource exploration a vast offshore frontier area contiguous to the United States and its territories. The EEZ extends from the seaward limit of state waters (3 nautical mi from shore) to 200 nautical mi offshore, and it includes the continental shelves. Within the context of the EEZ natural resource assessment effort, the purpose of this study is to delineate, on a regional basis, the potential for heavy-mineral placers on the U.S. Continental Shelf in the western and northern Gulf of Mexico from the United States-Mexico border to the Alabama-Florida state line. This map is intended to serve as a general guide for placer exploration. It shows favorable sea-floor areas for placer occurrence in water depths ranging from 0 to 100 fathoms (600 ft). The map can be used as a guide for focusing costly exploratory efforts, such as coring operations and geophysical surveys. The potential economic value of heavy-mineral placer concentrations on the U.S. Continental Shelf is a function of both geologic and economic variables. Geologic variables include the composition and concentration of the heavy-mineral assemblages and their environment of deposition. Economic variables include the current world market price of extracted metals, as well as the cost of mining, processing, and marketing the metals. These economic factors, in turn, are tempered by the nation1s socio-political climate, which determines its need for specific mineral resources at any given time.

Miscellaneous Field Studies Map↗
USGS2022

What’s It worth? Estimating the potential value of early warnings of cyanobacterial harmful algal blooms for managing freshwater reservoirs in Kansas, United States

Cyanobacterial blooms are an issue drawing increasing concern in freshwater lakes and reservoirs in the United States due to the real and sometimes perceived harms they can cause through cyanotoxin production or other effects. These types of blooms are often referred to as cyanobacterial harmful algal blooms (cyanoHABs). Cyanotoxin exposure can potentially lead to human health effects through recreation and consumption of drinking water and may impact fisheries, wildlife, domestic pets, and livestock. Characterizing the societal impacts of cyanotoxin production, exposure, and effects and estimating the potential value of information of an early warning system can inform and support freshwater lake and reservoir management decisions and future research directions. A Bayesian decision tree analysis was utilized to identify uses, users, and benefits of the information provided by this research. Specifically, the potential value related to a cyanoHAB early warning system, based on potential toxicity, was analyzed that would provide information two additional days earlier relative to cyanoHAB toxicity. The evaluation considers the application of this information for freshwater lake management - whether or not to post an advisory or warning to avoid recreational water contact. The model was parameterized with data from the state of Kansas and the value of avoided foregone recreation and avoided health effects was derived. The estimated annual value of information ranges between \$565 thousand to \$2.3 million (2018 United States Dollars (USD)) for the state of Kansas alone based on provided assumptions. The results demonstrate a lower bound of the value of a cyanoHAB early warning system and suggest additional research to understand how the use and value of this information could support research prioritization and further illustrate the return on research investment. This analysis does not incorporate the full suite of potential societal costs that may be associated with a cyanoHAB event such as drinking water treatment, impacts to irrigation, or power generation.

Kansas↗
USGS2019

Salmon, forage fish, and kelp

Kelp beds are prominent features of northeast Pacific coastlines. They are seasonal in nature, as are the communities that use them. Here, juvenile and adult Chinook salmon ( Oncorhynchus tshawytscha ) – key components of northeast Pacific marine food webs that link plankton and forage fishes to endangered killer whales – have just arrived at the coastal kelp beds (left) and are feeding on the large schools of forage fish such as young‐of‐the‐year herring, which are also migrating in great numbers near the shore. Juvenile herring and smelt will soon move offshore to grow and feed, and finally return as adults to spawn along shorelines. Rapid growth is critical to the survival of young salmon. They quickly learn to work together to herd the small, skittish prey into tight groups. The kelp beds play an important role for both the salmon and their prey, providing refuge for feeding salmon and enhanced prey resources for hungry forage fish, which in turn feed incessantly at the surface of the kelp beds, except when they are disrupted by lightning‐fast attacks by marauding salmon. By October, much of the kelp will be gone, as will the juvenile salmon and forage fish, replaced by their adult congeners (right) that have traveled for years and hundreds of miles to continue the cycle. Globally, kelp forests are in flux. Disturbances, including those induced by climate change, may have serious implications not only for this critical nearshore phase of salmon and forage fish, but also for the future viability of our cold‐water northeast Pacific marine ecosystems.

Frontiers in Ecology and the Environment↗
USGS2021

Dynamics of green and blue water supply stress index across major global cropland basins

Global food and water insecurity could be serious problems in the upcoming decades with growing demands from the increasing global population and more frequent effect of climatic extremes. As the available water resources are diminishing and facing continuous stress, it is crucial to monitor water demand and water availability to understand the associated water stresses. This study assessed the water stress by applying the water supply stress index (WaSSI) in relation to green (WaSSI G ) and blue (WaSSI B ) water resources across six major cropland basins including the Mississippi (North America), San Francisco (South America), Nile (Africa), Danube (Europe), Ganges-Brahmaputra (Asia), and Murray-Darling (Australia) for the past 17-years (2003–2019). The WaSSI G and WaSSI B results indicated that the Murray-Darling Basin experienced the most severe (maximum WaSSI G and WaSSI B anomalies) green and blue water stresses and the Mississippi Basin had the least. All basins had both green and blue water stresses for at least 35% (6 out of 17 years) of the study period. The interannual variations in green water stress were driven by both crop water demand and green water supply, whereas the blue water stress variations were primarily driven by blue water supply. The WaSSI G and WaSSI B provided a better understanding of water stress (blue or green) and their drivers (demand or supply driven) across cropland basins. This information can be useful for basin-specific resource mobilization and interventions to ensure food and water security.

Frontiers in Climate↗
USGS2022

The mysterious case of the missing razor clams

Oceans are changing and these changes are affecting animals that live there. Animals respond differently to changes in water temperature, food availability, or contaminants. Those responses can be seen in their genes. Gene transcription is a tool that allows scientists to see the response of an animal’s genes to its environment. We used gene transcription to compare two populations of Pacific razor clams in Alaska: one that has lots of clams and one that used to have lots but doesn’t anymore. We were surprised when we didn't find any differences in their gene responses! So, we had to think about what else might be influencing the number of clams in these two populations. As we “dug” for answers, we found out that there are differences between the populations that don‘t influence their genes but may impact their numbers, such as predation.

Frontiers for Young Minds↗
USGS1984

The Mid-Cretaceous Frontier Formation near the Moxa Arch, southwestern Wyoming

The Frontier Formation in the Green River Basin of Wyoming, Utah, and Colorado, consists of sandstone, siltstone, and shale, and minor conglomerate, coal, and bentonite. These strata were deposited in several marine and nonmarine environments during early Late Cretaceous time. At north-trending outcrops along the eastern edge of the overthrust belt, the Frontier is of Cenomanian, Turonian, and early Coniacian age, and commonly is about 610 m (2,000 ft) thick. The formation in that area conformably overlies the Lower Cretaceous Aspen Shale and is divided into the following members, in ascending order: Chalk Creek, Coalville, Allen Hollow, Oyster Ridge Sandstone, and Dry Hollow. In west-trending outcrops on the northern flank of the Uinta Mountains in Utah, the Frontier is middle and late Turonian, and is about 60 m (200 ft) thick. These strata disconformably overlie the Lower Cretaceous Mowry Shale. In boreholes on the Moxa arch, the upper part of the Frontier is of middle Turonian to early Coniacian age and unconformably overlies the lower part of the formation, which is early Cenomanian at the south end and probably Cenomanian to early Turonian at the north end. The Frontier on the arch thickens northward from less than 100 m (328 ft) to more than 300 m (984 ft) and conformably overlies the Mowry. The marine and nonmarine Frontier near the Uinta Mountains, marine and mnmarine beds in the upper part of the formation on the Moxa arch and the largely nonmarine Dry Hollow Member at the top of the Frontier in the overthrust belt are similar in age. Older strata in the formation, which are represented by the disconformable basal contact of the Frontier near the Uinta Mountains, thicken northward along the Moxa arch and westward between the arch and the overthrust belt. The large changes in thickness of the Frontier in the Green River Basin were caused mainly by differential uplift and truncation of the lower part of the formation during the early to middle Turonian and by the shoreward addition of progressively younger sandstone units at the top of the formation during the late Turonian and early Coniacian. The sandstone in cores of the Frontier, from boreholes on the Moxa arch and the northern plunge of the Rock Springs uplift, consists of very fine grained and fine-grained litharenites and sublitharenites that were deposited in deltaic and shallow-water marine environments. These rocks consist mainly of quartz, chert, rock fragments, mixed-layer illite-smectite, mica-illite, and chlorite. Samples of the sandstone have porosities of 4.7 to 23.0 percent and permeabilities of 0.14 to 6.80 millidarcies, and seem to represent poor to fair reservoir beds for oil and gas. The shale in cores of the Frontier Formation and the overlying basal Hilliard Shale, from the Moxa arch, Rock Springs uplift, and overthrust belt, was deposited in deltaic and offshore-marine environments. Samples of the shale are composed largely of quartz, micaillite, mixed-layer illite-smectite, kaolin, and chlorite. They also contain from 0.27 to 4.42 percent organic carbon, in humic and sapropelic organic matter. Most of the sampled shale units are thermally mature, in terms of oil generation, and a few probably are source rocks for oil and gas.

Professional Paper↗
USGS2023

Land development and road salt usage drive long-term changes in major-ion chemistry of streamwater in six exurban and suburban watersheds, southeastern Pennsylvania, 1999-2019

In urbanized areas, the “freshwater salinization syndrome” (FSS), which pertains to long-term increases in concentrations of major ions and metals in fresh surface waters, has been attributed to road salt application. In addition to FSS, the water composition changes as an influx of sodium (Na + ) in recharge may displace calcium (Ca 2+ ), magnesium (Mg 2+ ), potassium (K + ), and trace metals by reverse cation exchange. These changing ion fluxes can result in adverse impacts on groundwater and surface waters used for municipal supplies. Few datasets exist to quantify the FSS on a watershed scale or link its manifestation to potential controlling factors such as changes in urban development, land use/land cover (LULC), or wastewater treatment plant (WWTP) discharges in upstream areas. Here, we use two decades (1999–2019) of monthly streamwater quality data combined with daily streamflow for six exurban and suburban watersheds in southeastern Pennsylvania to examine the relations among Ca 2+ , Mg 2+ , K + , Na + , chloride (Cl − ), sulfate (SO 4 2- ), and alkalinity (HCO 3 − ) concentrations and upstream controlling factors. Flow-normalized annual and baseflow (August ̶ November) concentrations for Ca 2+ , Mg 2+ , Na + , and Cl − increased in all six watersheds over the 20-year study, providing evidence of FSS’s impacts on groundwater that sustains streamflow. Additionally, a redundancy analysis using 2019 flow-normalized values identified the following positive associations between solute concentrations and controlling variables: 1) Cl − , Mg 2+ , and Ca 2+ with impervious surface cover (ISC), 2) Na + and SO 4 2- with ISC and total WWTP discharge volume, and 3) HCO 3 − with agriculture and total WWTP discharge volume. From a human health perspective, 2019 flow-normalized Na + concentrations exceeded the U.S. Environmental Protection Agency’s 20 mg L -1 threshold for individuals restricted to a low sodium diet. Furthermore, indices used to evaluate the corrosivity of source waters to drinking water infrastructure and inform municipal water treatment practices, such as the Chloride to Sulfate Mass Ratio and Larson Ratio, increased between two- and seven-fold over the 20-year time. Collectively, the results elucidate the causal factors of the FSS in suburban and exurban watersheds and its potential impacts on human health and drinking water infrastructure.

Pennsylvania↗
USGS2011

Proceedings of the third USGS modeling conference, June 7-11, 2010, Broomfield, Colorado-Understanding and predicting for a changing world

The Third USGS Modeling Conference was held June 7th-11, 2010, in Broomfield, Colorado. The conference focused on the development and application of analytical and theoretical models and data availability that support managing the Nation's resources and help protect lives and property. Participants at the conference included scientists and managers from Department of the Interior (DOI) Bureaus; national and international Federal, State, and local agencies; academic institutions; and nongovernmental organizations. The conference was organized according to DOI priorities and the strategic directions of the USGS Science Strategy; the following themes were emphasized: (1) Understanding Ecosystems and Restoring America's Treasured Landscapes; (2) Climate Change and Impact; (3) New Energy Frontier and Minerals for America; (4) A National Hazards, Risk, and Resilience Assessment Program; (5) Role of Environment and Wildlife in Human Health; (6) A Water Census of the United States; and (7) New Methods of Investigation and Discovery. The conference theme-"Understanding and Predicting for a Changing World"-focused on the following goals: advance development and application of models; provide tools that address management issues; present state-of-the-art models ranging from individual phenomena to integrated systems; and foster a working community among scientists and managers.

Scientific Investigations Report↗
USGS2016

Alaska Arctic marine fish ecology catalog

The marine fishes in waters of the United States north of the Bering Strait have received new and increased scientific attention over the past decade (2005–15) in conjunction with frontier qualities of the region and societal concerns about the effects of Arctic climate change. Commercial fisheries are negligible in the Chukchi and Beaufort Seas, but many marine species have important traditional and cultural values to Alaska Native residents. Although baseline conditions are rapidly changing, effective decisions about research and monitoring investments must be based on reliable information and plausible future scenarios. For the first time, this synthesis presents a comprehensive evaluation of the marine fish fauna from both seas in a single reference. Although many unknowns and uncertainties remain in the scientific understanding, information presented here is foundational with respect to understanding marine ecosystems and addressing dual missions of the U.S. Department of the Interior for energy development and resource conservation.

Scientific Investigations Report↗
USGS2021

Influence of filter pore size on composition and relative abundance of bacterial communities and select host-specific MST markers in coastal waters of southern Lake Michigan

Water clarity is often the primary guiding factor in determining whether a prefiltration step is needed to increase volumes processed for a range of microbial endpoints. In this study, we evaluate the effect of filter pore size on the bacterial communities detected by 16S rRNA gene sequencing and incidence of two host-specific microbial source tracking (MST) markers in a range of coastal waters from southern Lake Michigan, using two independent data sets collected in 2015 (bacterial communities) and 2016–2017 (MST markers). Water samples were collected from river, shoreline, and offshore areas. For bacterial communities, each sample was filtered through a 5.0-μm filter, followed by filtration through a 0.22-μm filter, resulting in 70 and 143 filter pairs for bacterial communities and MST markers, respectively. Following DNA extraction, the bacterial communities were compared using 16S rRNA gene amplicons of the V3–V4 region sequenced on a MiSeq Illumina platform. Presence of human ( Bacteroides HF183) and gull (Gull2, Catellicoccus marimammalium ) host-specific MST markers were detected by qPCR. Actinobacteriota, Bacteroidota, and Proteobacteria, collectively represented 96.9% and 93.9% of the relative proportion of all phyla in the 0.22- and 5.0-μm pore size filters, respectively. There were more families detected in the 5.0-μm pore size filter (368) than the 0.22-μm (228). There were significant differences in the number of taxa between the two filter sizes at all levels of taxonomic classification according to linear discriminant analysis (LDA) effect size (LEfSe) with as many as 986 taxa from both filter sizes at LDA effect sizes greater than 2.0. Overall, the Gull2 marker was found in higher abundance on the 5.0-μm filter than 0.22 μm with the reverse pattern for the HF183 marker. This discrepancy could lead to problems with identifying microbial sources of contamination. Collectively, these results highlight the importance of analyzing pre- and final filters for a wide range of microbial endpoints, including host-specific MST markers routinely used in water quality monitoring programs. Analysis of both filters may increase costs but provides more complete genomic data via increased sample volume for characterizing microbial communities in coastal waters.

Illinois, Indiana, Wisconsin↗
USGS2022

Machine learning for understanding inland water quantity, quality, and ecology

This chapter provides an overview of machine learning models and their applications to the science of inland waters. Such models serve a wide range of purposes for science and management: predicting water quality, quantity, or ecological dynamics across space, time, or hypothetical scenarios; vetting and distilling raw data for further modeling or analysis; generating and exploring hypotheses; estimating physically or biologically meaningful parameters for use in further modeling; and revealing patterns in complex, multidimensional data or model outputs. An important research frontier is the injection of limnological knowledge into machine-learning models, which has shown great promise for increasing such models’ accuracy, trustworthiness, and interpretability. Here we describe a few of the most powerful machine learning tools, describe best practices for employing these tools and injecting knowledge guidance, and give examples of their applications to advance understanding of inland waters.

Book chapter↗
USGS1981

Gulf of Mexico summary report 2, August 1981: A revision of Outer Continental Shelf oil and gas activities in the Gulf of Mexico and their onshore impacts: A summary report, September 1980

The Gulf of Mexico Outer Continental Shelf (OCS) continues to be the most intensively developed offshore oil- and gas-producing region in the world. With the development of technology, exploration, development, and production are being extended to include areas off the coast of southwest Florida and deep-water areas near the Mississippi River Delta. Development in both areas requires careful analyses of local considerations. The hydrocarbon potential of the region, while not well established in the frontier portions, generally remains favorable. A total of 482 fields have been discovered to date in the federally regulated part of the Gulf of Mexico. Reserve estimates have been made for the 435 producing fields in the region. Through December 31, 1980, those fields have produced 5.0 billion barrels of oil and condensate, and 48.7 trillion cubic feet of gas. Remaining recoverable reserves are 3.1 billion barrels of oil and 40.2 trillion cubic feet of gas. Estimates of undiscovered recoverable resources for the Gulf of Mexico are 6.6 billion barrels of oil and 71.9 trillion cubic feet of gas. Since enactment of the Outer Continental Shelf Lands Act in 1953, there have been 42 oil and gas lease sales in the Gulf of Mexico. An average of three lease sales per year are scheduled through 1986. Since 1953, the Bureau of Land Management (BLM) has leased 3,119 tracts in the Gulf of Mexico; 1,825 leases are currently active. The distribution of leased tracts exhibits a regionwide pattern as shown by Lease Sales A62, 62, A66, and 66. Proposed Lease Sales 67, 69, 72, and 74 will probably continue that pattern. Tracts off the coast of southwest Florida in the Charlotte Harbor, Howell Hook, and Pulley Ridge Areas will be offered in upcoming sales. Operations on tracts in deepwater areas slated for future sales may require additional technology. Exploration, development, and production in the Gulf of Mexico Region are continuing at a rapid pace throughout the Gulf of Mexico. Between January 1, 1980, and April 15, 1981, 197 initial plans of exploration and 165 supplemental plans of exploration were submitted to the U.S. Geological Survey (USGS). During the same period, 107 initial and 131 supplemental plans of development/production were submitted to the USGS. As of May 1981, there were 121 offshore mobile drilling units operating in the Gulf of Mexico. Pipelines continue to be the preferred mode of transport for Gulf of Mexico OCS oil and gas production. Pipeline additions to the existing network average 69 miles (111 km) per month. At any given time, numerous pipeline projects are under way in the Gulf of Mexico. To supplement OCS oil and gas production several deepwater port projects, designed to handle imported crude oil, are being planned or constructed in the region. The process of transportation planning in the Gulf of Mexico is done by industry and government through BLM's Intergovernmental Planning Program and its Regional Technical Working Group (RTWG). The RTWG has completed the First Edition Gulf of Mexico Regional Transportation Management Plan. The nearshore and onshore facilities in the Gulf of Mexico service both the domestic onshore and offshore oil and gas industry as well as the global market. Most of the major centers along the Gulf Coast, including Houston, Corpus Christi, Galveston, Beaumont, Port Arthur, and Freeport, Texas; New Orleans, Lake Charles, Lafayette, Baton Rouge, Morgan City, and Houma, Louisiana; Pascagoula, Mississippi; Mobile, Alabama; and Port Manatee, Florida, have ties to the offshore industry. A wide array of services and support industries, ranging from small independent vendors to major international manufacturing contractors, can be found within the region. Profiles of selected centers reveal typical industries and patterns of activity that are characteristic throughout the Gulf Coast region.

Alabama, Florida, Louisiana, Mississippi, Texas↗
USGS2023

Gene expression and wildlife health: Varied interpretations based on perspective

We evaluated wildlife population health from the perspective of statistical means vs. variances. We outlined the choices necessary to provide the framework for our study. These consisted of spatial and temporal boundaries (e.g., choice of sentinel species, populations, time frame), measurement techniques (molecular to population level), and appropriate statistical analyses. We chose to assess the health of 19 sea otter populations, located in the north Pacific from the Aleutian Islands, AK, to Santa Barbara, CA, and varying in population growth rates and length of occupancy. Our focal metric was gene expression (i.e., mRNA transcripts) data that we had previously generated across sea otter populations as a measure of population health. We used statistical methods with different approaches (i.e., means vs. variances) and examined the subsequent interpretive outcomes and how these influence our assessment of “health.” Interpretations based on analyses using variances versus means overlapped to some degree. In general, sea otter populations with low variation in gene expression were limited by food resources and at or near carrying capacity. In populations where the variation in gene expression was moderate or high, four out of five populations were increasing in abundance, or had been recently increasing. Where we had additional information on sources of stressors at the level of the population, we were able to draw inferences from those stressors to specific gene expression results. For example, gene expression patterns of sea otters from Western Prince William Sound were consistent with long term exposure to petroleum hydrocarbons, whereas in Kachemak Bay, patterns were consistent with exposure to algal toxins. Ultimately, determination of population or ecosystem health will be most informative when multiple metrics are examined across disciplines in the context of specific scenarios and goals.

Alaska, British Columbia, California, Oregon, Wash↗
USGS2023

Editorial: Advanced physico-chemical technologies for water detoxification and disinfection

One of the most critical challenges we face today is access to clean water. Climate change, industrialization, high rates of urbanization, and population growth have resulted in many countries suffering from water crises, especially in the arid and semi-arid areas. Countries in different regions of the world have also been struggling over regional water availability and it is anticipated that these struggles may result in conflicts over shared water resources in these regions. Considering the adverse consequences of the water crisis, countries have been trying to increasingly cope with this problem of water availability by implementing sustainable water management plans and looking for alternative water supply sources.

Frontiers in Environmental Science↗