Polar bear laying down to dry after a swim in the Chukchi sea. (High resolution image)
ANCHORAGE, Alaska — A team of scientists led by the U.S. Geological Survey found that polar bears, increasingly forced on shore due to sea ice loss, may be eating terrestrial foods including berries, birds and eggs, but any nutritional gains are limited to a few individuals and likely cannot compensate for lost opportunities to consume their traditional, lipid-rich prey—ice seals.
“Although some polar bears may eat terrestrial foods, there is no evidence the behavior is widespread,” said Dr. Karyn Rode, lead author of the study and scientist with the USGS. “In the regions where terrestrial feeding by polar bears has been documented, polar bear body condition and survival rates have declined.”
The authors detail their findings in a review article in Frontiers in Ecology and the Environment. The scientists noted that over much of the polar bear’s range, terrestrial habitats are already occupied by grizzly bears. Those grizzly bears occur at low densities and are some of the smallest of their species due to low food quality and availability. Further, they are a potential competitor as polar bears displaced from their sea ice habitats increasingly use the same land habitats as grizzly bears.
“The smaller size and low population density of grizzly bears in the Arctic provides a clear indication of the nutritional limitations of onshore habitats for supporting large bodied polar bears in meaningful numbers,” said Rode. “Grizzly bears and polar bears are likely to increasingly interact and potentially compete for terrestrial resources.”
The study found that fewer than 30 individual polar bears have been observed consuming bird eggs from any one population, which typically range from 900 to 2000 individuals. “There has been a fair bit of publicity about polar bears consuming bird eggs. However, this behavior is not yet common, and is unlikely to have population-level impacts on trends in body condition and survival,” said Rode.
Few foods are as energetically dense as marine prey. Studies suggest that polar bears consume the highest lipid diet of any species, which provides all essential nutrients and is ideal for maximizing fat deposition and minimizing energetic requirements. Potential foods found in the terrestrial environment are dominated by high-protein, low-fat animals and vegetation. Polar bears are not physiologically suited to digest plants, and it would be difficult for them to ingest the volumes that would be required to support their large body size.
“The reports of terrestrial feeding by polar bears provide important insights into the ecology of bears on land,” said Rode. “In this paper, we tried to put those observations into a broader context. Focused research will help us determine whether terrestrial foods could contribute to polar bear nutrition despite the physiological and nutritional limitations and the low availability of most terrestrial food resources. However, the evidence thus far suggests that increased consumption of terrestrial foods by polar bears is unlikely to offset declines in body condition and survival resulting from sea ice loss.”
The review article was developed by researchers at the USGS, Washington State University, and Polar Bears International.
The USGS is leading studies of polar bear response to sea ice loss through its Changing Arctic Ecosystems Initiative. Current studies include examination of polar bear nutritional and behavioral ecology, linked to population-level consequences. For further information, visit the USGS Polar Bear Program.
A new online, interactive tool for estimating atrazine concentrations in streams and rivers is now available.
The online mapping tool can assist water managers, policy makers, and scientists in several ways, including:
- Understanding where and why pesticides occur in streams.
- Assessing geographic patterns in pesticide stream concentrations at many scales, ranging from the watershed to regional and national;
- Designing efficient and cost-effective monitoring programs and studies; and
- Identifying streams with the greatest likelihood to have concentrations that exceed a water-quality benchmark of potential concern.
“Assessment and management of pesticides require far more information on concentrations in streams and rivers than we can afford to directly measure for all the places and times of interest,” said Wes Stone, the USGS hydrologist who developed the model. “For these situations, statistical models can be used to estimate water-quality conditions at unmonitored locations under a range of possible circumstances.”
The estimates are based on a USGS statistical model — referred to as Watershed Regression for Pesticides (or “WARP”) — which also provides key statistics for each selected stream, including the probability that a pesticide may exceed a water-quality benchmark of potential concern, and a level of confidence and uncertainty associated with each estimate.
The release for atrazine is the first in a series of statistical models for other pesticides, each of which is based on USGS National Water-Quality Assessment (NAWQA) monitoring in streams from 1992-2011, agricultural pesticide use, and environmental characteristics, such as soil characteristics, hydrology, and climate.
Future updates will provide similar mapping and modeling for additional pesticides. Estimates and interactive mapping of pesticides for streams in the U.S. are available at this USGS website. The new website replaces an earlier version of the model for atrazine.
Several of the 2,798 new US Topo quadrangles for California now display public trails along with segments of the Pacific Crest National Scenic Trail. Also the new maps now show improved data layers such as public land survey information, map symbol redesign, enhanced railroad information and new road source data. Some of the data for the trails is provided to the USGS through a nationwide “crowdsourcing” project managed by the International Mountain Biking Association (IMBA).
“The USGS 7.5-minute quads have been the long time gold standard for wall to wall mapping in the United States.” said Tom Lupo, Deputy Director, Data and Technology Division, California Department of Fish and Wildlife. “To me, they are the second best thing the Federal government has ever done!”
For California recreationalists and visitors who want to explore the diverse west coast landscape on a bicycle seat, hiking, horseback or other means, the new trail features on the US Topo maps will come in handy. During the past two years the IMBA, in a partnership with the MTB Project, has been building a detailed national database of trails. This activity allows local IMBA chapters, IMBA members, and the public to provide trail data and descriptions through their website. MTB Project and IMBA then verify the quality of the trail data provided, ensure accuracy and confirm the trail is legal. This unique crowdsourcing venture has increased the availability of trail data available through The National Map mobile and web apps, and the revised US Topo maps.
Another trail system, provided through a USGS partnership with the U.S. Forest Service, is the Pacific Crest National Scenic Trail. This west-coast long NST joins the Pacific Northwest National Scenic Trail, the Ice Age National Scenic Trail, the North Country National Scenic Trail, and the Appalachian National Scenic Trail as being featured on the new US Topo quads around the nation. The USGS hopes to eventually include all National Scenic Trails in The National Map products.
The Pacific Crest National Scenic Trail is a treasured pathway through some of the most scenic terrain in the nation. Beginning in southern California at the Mexican border, the PCT travels a total distance of 2,650 miles through California, Oregon, and Washington until reaching the Canadian border. The PCT is one of the original National Scenic Trails established by Congress in the 1968 National Trails System Act and fifty-four percent of the trail lies within designated wilderness
Another important addition to the new California US Topo maps is the inclusion of Public Land Survey System data. PLSS is a way of subdividing and describing land in the US. All lands in the public domain are subject to subdivision by this rectangular system of surveys, which is regulated by the U.S. Department of the Interior.
These new maps replace the first edition US Topo maps for the Golden State and are available for free download from The National Map, the USGS Map Locator & Downloader website , or several other USGS applications.
To compare change over time, scans of legacy USGS topo maps, some dating back to the late 1800s, can be downloaded from the USGS Historical Topographic Map Collection
For more information on US Topo maps: http://nationalmap.gov/ustopo/Updated 2015 version of El Capitan, California quadrangle with orthoimage turned on. (1:24,000 scale) (high resolution image 1.4 MB) Scan of the 1909 USGS quadrangle of the Yosemite, California area, to include El Capitan, from the USGS Historic Topographic Map Collection. (1:250,000 scale) (high resolution image 2 MB) Updated 2015 version of the El Capitan, California quadrangle with orthoimage turned off to better see the various trail networks. (1:24,000 scale) (high resolution image 1.3 MB) The National Trails System was established by Act of Congress in 1968. The Act grants the Secretary of Interior and the Secretary of Agriculture authority over the National Trails System. The Act defines four types of trails. Two of these types, the National Historic Trails and National Scenic Trails, can only be designated by Act of Congress. National scenic trails are extended trails located as to provide for maximum outdoor recreation potential and for the conservation and enjoyment of nationally significant scenic, historic, natural, and cultural qualities of the area through which such trails may pass.
There are 11 National Scenic Trails:
- Appalachian National Scenic Trail
- Pacific Crest National Scenic Trail
- Continental Divide National Scenic Trail
- North Country National Scenic Trail
- Ice Age National Scenic Trail
- Potomac Heritage National Scenic Trail
- Natchez Trace National Scenic Trail
- Florida National Scenic Trail
- Arizona National Scenic Trail
- New England National Scenic Trail
- Pacific Northwest National Scenic Trail
ANCHORAGE, Alaska — In a new study published today, scientists from the U.S. Geological Survey and U.S. Fish and Wildlife Service harnessed a new type of DNA technology to investigate avian influenza viruses in Alaska. Using a “next generation” sequencing approach, which identifies gene sequences of interest more rapidly and more completely than by traditional techniques, scientists identified low pathogenic avian influenza viruses in Alaska that are nearly identical to viruses found in China and South Korea.
The viruses were found in an area of western Alaska that is known to be a hot spot for both American and Eurasian forms of avian influenza.
“Our past research in western Alaska has shown that 70 percent of avian influenza viruses isolated in this area were found to contain genetic material from Eurasia, providing evidence for high levels of intercontinental viral exchange,” said Andy Ramey, a scientist with the USGS Alaska Science Center and lead author of the study. “This is because Asian and North American migratory flyways overlap in western Alaska.”
The new study, led by the USGS, found low pathogenic H9N2 viruses in an Emperor Goose and a Northern Pintail. Both of the H9N2 viruses were nearly identical genetically to viruses found in wild bird samples from Lake Dongting, China and Cheon-su Bay, South Korea.
“These H9N2 viruses are low pathogenic and not known to infect humans, but similar viruses have been implicated in disease outbreaks in domestic poultry in Asia,” said Ramey.
There is no commercial poultry production in western Alaska and highly similar H9N2 virus strains have not been reported in poultry in East Asia or North America, so it is unlikely that agricultural imports influenced this result.
The finding provides evidence for intercontinental movement of intact avian influenza viruses by migratory birds. The USGS recently released a publication about the detection of a novel highly pathogenic H5N8 virus in the U.S. that is highly similar to the Eurasian H5N8 viruses. This suggests that the novel re-assortment may be adapted to certain waterfowl species, enabling it to survive long migrations. That virus, and associated strains, have now spread from early detections in wild and domestic birds in Pacific states to poultry outbreaks in Minnesota, Missouri and Arkansas.
“The frequency of inter-hemispheric dispersal events of avian influenza viruses by migratory birds may be higher than previously recognized,” said Ramey.
While some of the samples for the project came from bird fecal samples collected from beaches at Izembek National Wildlife Refuge, most of the samples came from sport hunters.
“For the past several years, we’ve worked closely with sport hunters in the fall to obtain swab samples from birds and that has really informed our understanding of wildlife disease in this area,” said Bruce Casler, formerly a biologist with the USFWS Izembek National Wildlife Refuge and a co-author of the study. None of the viruses found in harvested birds from Izembek Refuge are known to infect humans, but hunters should always follow safe meat handling and cooking guidelines when processing wild game.
The paper, “Dispersal of H9N2 influenza A viruses between East Asia and North America by wild birds” was published today in the journal Virology. A summary of all samples collected at the Izembek Refuge will be described in a subsequent publication.
Additional information about avian influenza can be found at the following web sites:Alaska is an international crossroads for millions of migratory birds that spend winter in Asia, Oceania, South America, and the lower-48 United States. (High resolution image 3 MB)
Cuba is among the top 10 producers of cobalt and nickel and has significant other mineral and petroleum resources, according to a new U.S. Geological Survey publication.
The report and accompanying map highlight the mineral resources available in Cuba, as well as detailing locations of petroleum exploration and development. The map also identifies mines, mineral processing facilities and petroleum facilities as well as information on location, operational status and ownership. It also addresses the current status of mineral industry projects, historical developments and trends of the Cuban economy with an emphasis on mineral industries and the supply of and demand for Cuba’s mineral resources.
“Cuba’s geology is complex, and the country has a variety of mineral commodity and energy resources,” said Steven Fortier, Director of the USGS National Minerals Information Center. “It is important that the public and industry have the latest information on the status of the mineral industry and the potential for natural resource development in Cuba.”
A few key points from the report are:
- In 2013, Cuba was estimated to be among the world’s top ten producers of cobalt and nickel, which are the country’s leading exports
- Cuba’s current crude oil and associated natural gas production from onshore and shallow water reservoirs is approximately 50,000 barrels per day of liquids and about 20,000 barrels per day oil equivalent of natural gas
- In 2013, the value of mining and quarrying activities accounted for 0.6 percent of Cuba’s gross domestic product, compared with 1.4 percent in 2000
- The value of production from Cuba’s industrial manufacturing sector increased by 88 percent between 1993 and 2013, whereas the sector’s share in the GDP decreased by 3 percent during the same period reflecting economic growth in other sectors of the economy
In 2004, the USGS released an assessment of the hydrocarbons of the North Cuba Basin and its three sub-basins. The total amount of undiscovered technically recoverable resources was estimated to be 9.8 trillion cubic feet of undiscovered natural gas, 4.6 billion barrels of crude oil, and 0.9 billion barrels of natural gas liquids. About 70 percent of this oil was estimated to be located no more than 50 to 80 kilometers (km) offshore along the length of the western and northern coasts of the island. To date, deepwater drilling has resulted in no commercially viable oil or gas discoveries.
Industrial minerals and manufactured industrial mineral products produced in Cuba include ammonia and ammonia byproducts, bentonite, cement, feldspar, high-purity zeolite minerals, gypsum, kaolin (a type of clay), lime, high-grade limestone, marble, sand, sulfuric acid, steel and urea. In 2013, an estimated 4,500 metric tons of zeolites was exported to Europe and other Latin American countries and in 2014 the majority of the country’s ammonium nitrate was intended for export.
In 2014, Cuba’s Ministry of Foreign Trade and Investment announced 246 development projects for which it sought foreign investment. The petroleum sector offered the greatest number of prospective investment opportunities followed by the manufacturing and mining sectors. In the energy sector, the country is offering joint ventures in petroleum extraction from onshore and offshore blocks and foreign investment opportunities are being offered in biomass and solar energy production and hydroelectric power.
The report ‘Recent trends in Cuba’s mining and petroleum extraction industries’ FS 2015-3032 is available online.
The U.S. Geological Survey expects to award up to $7 million in grants for earthquake hazards research in 2016.
“The USGS Earthquake Hazards Program annually provides grants to support research targeted toward improving our understanding of earthquake processes, hazards and risks,” said Bill Leith, USGS Senior Science Advisor for Earthquake and Geologic Hazards. “We seek cutting-edge proposals that will further our efforts to reduce losses from earthquakes, provide more accurate and timely earthquake information and forecasts and better inform the public about earthquake safety.”
Interested researchers can apply online at GRANTS.GOV under funding opportunity number G15AS00037. Applications are due May 19, 2015.
Every year the USGS awards earthquake research grants to universities, state geological surveys and private institutions. Past projects included:
- trench investigations to better understand the size and age of large earthquakes between Salt Lake City and Provo, Utah;
- the application of innovative techniques to map seismic hazards near the nation’s capital;
- exploring the use of rapid and precise GPS recordings to improve earthquake early warning;
- analysis of the potential for large earthquakes in the Gorgonio Pass, an area of complex faulting east of San Bernardino, California;
- investigation of recent earthquake activity along major fault lines crossing southeast Alaska; and
- studies to characterize and understand the causes of potentially induced earthquakes in California, Kansas, Wyoming, Texas, and Ohio.
A complete list of funded projects and reports can be found on the USGS Earthquake Hazards Program external research support website.
SPOKANE, Wash. — A new U.S. Geological Survey report covering major parts of the world’s largest mountain belt in central Asia estimates the existence of about five times as much copper in undiscovered deposits as has been identified to date. These areas host 20 known porphyry copper deposits, including the world class Oyu Tolgoi deposit in Mongolia that was discovered in the late 1990s.
The results of this new assessment estimate the probability that there may be as many as 97 undiscovered porphyry copper deposits within the assessed permissive tracts, which would represent nearly five times the 20 known deposits. Grade and tonnage models predict estimated resources associated with undiscovered deposits as mean values of 370,000,000 metric tons of copper, 10,000 t of gold, 7,700,000 t of molybdenum, and 120,000 t of silver. These estimated mean tonnages are predictions based on comparisons to known deposits of similar type.
Copper was one of the first metals ever extracted and used by humans, and it has been one of the important materials in the development of civilization. Because of its properties, of high ductility, malleability, and thermal and electrical conductivity, and its resistance to corrosion, copper has become a major industrial metal, ranking third after iron and aluminum in terms of quantities consumed.
USGS scientists worked in collaboration with colleagues in the China Geological Survey, the Centre for Russian and Central Eurasian Mineral Studies, and the Russian Academy of Sciences to complete the assessment. Participants evaluated applicable grade and tonnage models and estimated numbers of undiscovered deposits at different confidence levels for each permissive tract. The estimates were then combined with the selected grade and tonnage models using Monte Carlo simulations to generate probabilistic estimates of undiscovered resources. Additional resources in extensions of deposits with identified resources were not specifically evaluated.
The full report, USGS SIR 2010-5090-X, “Porphyry Copper Assessment of the Central Asian Orogenic Belt and eastern Tethysides— China, Mongolia, Russia, Pakistan, Kazakhstan, Tajikistan, and India,” is available online and includes a summary of the data used in the assessment, a brief overview of the geologic framework of the area, descriptions of permissive tracts and known deposits, maps, and tables. A geographic information system database that accompanies this report includes the tract boundaries and known porphyry copper deposits, significant prospects, and prospects. Assessments of overlapping younger rocks and adjacent areas are included in separate reports, which are also available online.
Appalachian coal and petroleum resources are still available in sufficient quantities to contribute significantly to fulfilling the nation’s energy needs, according to a recent study by the U.S. Geological Survey.
The Appalachian basin, which includes the Appalachian coalfields and the Marcellus Shale, covers parts of Alabama, Georgia, Kentucky, Maryland, New York, North Carolina, Ohio, Pennsylvania, Tennessee, Virginia and West Virginia.
“The study we conducted is a modern, in-depth collection of reports, cross sections and maps that describe the geology of the Appalachian basin and its fossil fuel resources,” said USGS scientist Leslie Ruppert, the study’s lead editor.
Petroleum resources, including oil and natural gas, remain significant in the Appalachian basin. Although both conventional oil and gas continue to be produced in the Appalachian basin, most new wells in the region are drilled in shale reservoirs, such as the famous Marcellus and Utica Shale, to produce natural gas.
The Appalachian basin contains significant coalbed methane and high-quality, thick, bituminous coal resources although the resource is deeper and thinner than the coal that has already been mined.
Although this volume is not a quantitative assessment of all notable geologic and fossil fuel localities in the Appalachian basin, the selected study areas and topics presented in the chapters pertain to large segments of the basin and a wide range of stratigraphic intervals. This updated geologic framework is especially important given the significance of shale gas in the basin.
This volume discusses the locations of coal and petroleum accumulations, the stratigraphic and structural framework, and the geochemical characteristics of the coal beds and petroleum in the basin, as well as the results of recent USGS assessments of coal, oil and gas resources in the basin.
Many of the maps and accompanying data supporting the reports in this volume are available from chapter I.1 as downloadable geographic information system (GIS) data files about the characteristics of selected coal beds and oil and gas fields, locations of oil and gas wells, coal production, coal chemistry, total petroleum system (TPS) boundaries and bedrock geology. Log ASCII Standard (LAS) files for geophysical (gamma ray) wireline well logs are included in other chapters.
USGS is the only provider of publicly available estimates of undiscovered technically recoverable oil and gas and coal resources of onshore lands and offshore state waters. This study of the Appalachian basin will underpin energy resource assessments and may be found online. To find out more about USGS energy assessments and other energy research, please visit the USGS Energy Resources Program website, sign up for our Newsletter, and follow us on Twitter.
The U.S. Geological Survey National Geospatial Program is pleased to announce the first round of awards resulting from the USGS Broad Agency Announcement (BAA) for the 3D Elevation Program (3DEP), initially issued on July 18, 2014. (Solicitation Number: G14PS00574).
The BAA is a publicly accessible process to develop partnerships for the collection of lidar and derived elevation data for 3DEP. The primary goal of 3DEP is to systematically collect nationwide lidar coverage (ifsar in Alaska) over an 8-year period to provide more than $690 million annually in new benefits to government entities, the private sector and citizens.
3DEP presents a unique opportunity for collaboration between all levels of government to leverage the services and expertise of private sector mapping firms that acquire the data, and to create jobs now and in the future. The USGS, along with other federal, state, local and private agencies, is establishing the collection program to respond to the growing needs for high-quality, three-dimensional mapping data of the United States.
“We are very excited about the high level interest in the BAA as demonstrated by the number and dollar value of the proposals we received,” said Kevin Gallagher, USGS Associate Director for Core Science Systems.
Current and accurate 3D elevation data are essential to help communities cope with natural hazards and disasters such as floods and landslides, support infrastructure, ensure agricultural success, strengthen environmental decision-making and bolster national security. Lidar, short for light detection and ranging, is a remote sensing detection system that works on the principle of radar, but uses light from a laser. Similarly, interferometric synthetic aperture radar (ifsar) is used to collect data over Alaska.
Federal funds to support this opportunity were provided by the USGS, the Federal Emergency Management Agency and the Natural Resources Conservation Service. The USGS is acting in a management role to facilitate planning and acquisition for the broader community, through the use of government contracts and partnership agreements.
The Fiscal Year 2015 Awards offered partnership funding to 29 proposals in 25 States and Territories. The FY15 body of work is expected to result in the influx of more than 95,000 square miles of public domain lidar point cloud data and derived elevation products into the 3DEP program.
More information about 3DEP including updates on current and future 3DEP partnership opportunities is available online.Map depicts the proposed body of work for 3DEP in Fiscal Year 2015. The BAA awards will add more than 95,000 square miles of 3DEP quality lidar data to the national database. (high resolution image 98 MB)
Media and the public are invited to attend a free meeting and field trips about South Dakota water issues on April 15 and 16 in Rapid City.
The 13th annual Western South Dakota Hydrology Meeting is an opportunity for local reporters, scientists, students and community members to meet and exchange ideas, discuss issues and explore new science related to critical water resources in South Dakota. A poster session and evening social will follow oral presentations on Wednesday, April 15.
Conference attendees may choose to participate in one of four free, optional field trips on Thursday, April 16. Please register for the conference by April 8 to participate in one of the following field trips:
- Post-flood geomorphic conditions in Keough Draw and Ward Draw
- Barrick Gold Corp and Sanford Lab wastewater treatment plants
- Rapid City stormwater management practices
- Belle Fourche Irrigation District operation and water conservation
Who: The conference keynote speakers are:
- Neik Veraart, Vice President for Louis Berger’s Environmental Planning and Resilience practice
- Robert Hirsch, U.S. Geological Survey research hydrologist and former USGS Chief Hydrologist and Associate Director for Water
- Robert Harmon, President and CEO of EnergyRM
Poster session and evening social: Wednesday, April 15, 5 p.m. to 7:30 p.m.
Optional field trips: Thursday April 16, at various times
Where: Rushmore Plaza Civic Center
444 N. Mount Rushmore Rd., Rapid City (MAP)
Details: The conference is free for media, the public and students, with an optional $20 lunch. Professional registration fee is $100. For professionals who wish to obtain credit for professional development, credits are available for technical sessions attended.
Register: All attendees are asked to register before April 8 by visiting the conference website or by contacting Janet Carter at 605-394-3215 or firstname.lastname@example.org
The annual conference typically draws more than 350 attendees. The preliminary 2015 program is available on the conference website.
The conference is organized by the USGS, South Dakota Department of Environment and Natural Resources, South Dakota Engineering Society, South Dakota School of Mines and Technology and West Dakota Water Development District.
For additional information about USGS water-resources studies in South Dakota, please visit the USGS South Dakota Water Science Center website.
Fish exposed to the endocrine-disrupting chemicals bisphenol A (BPA) or 17a-ethinylestradiol (EE2) in a laboratory have been found to pass adverse reproductive effects onto their offspring up to three generations later, according to a new study by the U.S. Geological Survey and the University of Missouri.
Aquatic environments are the ultimate reservoirs for many contaminants, including chemicals that mimic the functions of natural hormones. Fish and other aquatic organisms often have the greatest exposures to such chemicals during critical periods in development or even entire life cycles.
Scientists exposed fish to either BPA or EE2 for one week during embryonic development, while subsequent generations were never exposed. Future generations showed a reduced rate of fertilization and increased embryo mortality. The full study, published in the journal Scientific Reports, is available online.
“This study shows that even though endocrine disruptors may not affect the life of the exposed fish, it may negatively affect future generations,” said USGS visiting scientist and University of Missouri Assistant Research Professor, Ramji Bhandari. “This is the first step in understanding how endocrine disruptors affect future generations, and more studies are needed to determine what happens in the natural environment.”
There were no apparent reproductive abnormalities in the first two generations of fish, except for two instances of male to female sex reversal in adults of the EE2 exposed generation. Findings show a 30 percent decrease in the fertilization rate of fish two generations after exposure, and a 20 percent reduction after three generations. If those trends continued, the potential for declines in overall population numbers might be expected in future generations. These adverse outcomes, if shown in natural populations, could have negative impacts on fish inhabiting contaminated aquatic environments.
This study examined concentrations of EE2 and BPA that are not expected to be found in most environmental situations. However, concerns remain about the possibility of passing on adverse reproductive effects to future generations at lower levels. At this time, the ability to evaluate mixtures of estrogenic chemicals working jointly is limited.
The scientists studied BPA and EE2 because they are chemicals of environmental concern and represent different classes of endocrine disrupters. BPA is a chemical used primarily to manufacture polycarbonate plastics and epoxy resins, but is also an additive in other consumer products. Due to extensive use of these products in daily human life, the accumulation of BPA-containing waste in the environment has been a serious concern and a potential threat to public and wildlife health. EE2 is used in oral contraceptives designed for women, and about 16 – 68 percent of each dose is excreted from the body. As a result, EE2 has been found in aquatic environments downstream of wastewater treatment plants.
For more information on endocrine disruptors visit the USGS Columbia Environmental Research Center web page.
GAINESVILLE, Fla. – – Nearly 80 percent of radio-tracked marsh rabbits that died in Everglades National Park in a recent study were eaten by Burmese pythons, according to a new publication by University of Florida and U.S. Geological Survey researchers.
A year later, there was no sign of a rabbit population in the study area. The study demonstrates that Burmese pythons are now the dominant predator of marsh rabbits, and likely other mid-sized animals in the park, potentially upsetting the balance of a valuable ecosystem.
The study provides the first empirical evidence that the Burmese python caused reductions in marsh rabbit populations in the park, supporting previous studies that suggested pythons were a significant factor in declines of many other mid-sized mammals since becoming established there a few decades ago.
The estimated tens of thousands of Burmese pythons now populating the greater Everglades present a low risk to people in the park, according to previous research by USGS and NPS.
Scientists know that invasive pythons prey on native Everglades mammals, but they didn’t have experimental evidence that pythons could cause population declines or local extinction of mammals, said Robert McCleery, a UF assistant professor in wildlife ecology and conservation who led the study.
While a 2012 study showed that as pythons were proliferating, mammals were declining, it did not directly link the two phenomena. “This study does just that,” said Bob Reed, a USGS research herpetologist and study co-author.
“Mammals play an important role in the Everglades ecosystem, and so recovery of mammal populations is closely tied with recovering the overall health and functionality of this ecosystem,” McCleery said.
In most Florida wetlands, it’s easy to detect marsh rabbit populations by searching for their scat, but the researchers could not find evidence of rabbits in the parts of Everglades National Park they studied during intensive surveys prior to conducting their experiment.
In 2012, a group of scientists that included researchers from Davidson College, USGS and UF compared data on mammal populations from the 1990s – before pythons became widespread in Everglades National Park ─ to results of population surveys conducted between 2003 and 2011. The 2012 study found that significant mammalian population declines coincided in space and time with the proliferation of invasive pythons in the Everglades.
“Previous studies implicated pythons in mammal declines in the Everglades, but those studies were largely correlative,” said Reed. “This new study moves us from correlation to causation in terms of the impact of invasive pythons on native mammals.”
To conduct the most recent study, researchers found areas outside of the park that supported large and healthy populations of marsh rabbits. They moved 31 marsh rabbits into select areas in the park in two experimental populations. They also put 15 rabbits in the Loxahatchee National Wildlife Refuge, and captured, collared and released another 49 in Fakahatchee Strand State Park, where they knew there would be few, if any, pythons ─ and used those as control sites. All of the rabbits were equipped with radio-collars so that they could be regularly located.
The researchers radio-tracked the rabbits and found that 77 percent of those that died in the Everglades were eaten by Burmese pythons, and that there was no sign of a rabbit population in the areas where they released them in the park one year later. On the other hand, rabbits remained common at the control site after the experiment. Many animals eat marsh rabbits, but outside the park, they’re most often the victims of bobcats and coyotes.
Furthermore, the warmer and wetter the weather, the more rabbits were consumed by pythons in the park. The researchers suggested this may be because higher water levels allow the pythons to easily swim long distances while searching for food and because they feed more frequently when it’s hot.
Scientists chose to study the pythons’ impacts on marsh rabbit populations because the high reproductive rates of rabbits mean that their populations are typically resilient to predators, McCleery said. The conclusion that pythons are capable of eliminating marsh rabbit populations in Everglades National Park led the authors to suggest that the observed declines in other mid-sized mammal species in the park could also be due to predation by pythons.
The study was published online this week in the journal Proceedings of the Royal Academy B. McCleery’s co-authors include UF graduate student Adia Sovie, as well as Robert Reed, Kristen Hart and Margaret Hunter, all research wildlife biologists with the USGS.
Thousands of photos and videos of the seafloor and coastline—most areas never seen before—are now available and easily accessible online. This is critical for coastal managers to make important decisions, ranging from protecting habitats to understanding hazards and managing land use.
Imagery is available through the U.S. Geological Survey (USGS) Coastal and Marine Geology Video and Photograph Portal.
This USGS portal is unique, due to the sheer quantity and quality of data presented. It is the largest database of its kind, providing detailed and fine-scale representations of the coast. The "geospatial context" is also unique, with maps displaying imagery in the exact location where it was recorded.
Prior to development of the data portal, retrieving this imagery required internal USGS access with specific hardware and software. It was difficult to manage and challenging to share such a large amount of information.
"The USGS has been dedicated to developing a system that allows for convenient communication internally as well as to outside collaborators and the public to access our abundance of coastal and seafloor imagery," said USGS geographer Nadine Golden, who is the Lead Principal Investigator for the USGS portal. "The portal makes it easy for users to discover, obtain and disseminate information."
This portal contains coverage of the seafloor off California and Massachusetts, and aerial imagery of the coastline along the Gulf of Mexico and mid-Atlantic coasts. Additional video and photographs will be added as they are collected, and archived imagery will also be incorporated soon. Areas of future focus include data sets for Washington State’s Puget Sound, Hawaii and the Arctic.
"As part of an ongoing seafloor mapping partnership, Massachusetts has worked with the USGS Woods Hole Science Center to map more than 850 square miles of marine waters and collect extensive video footage and photographs of the seafloor," said Massachusetts Office of Coastal Zone Management Director Bruce Carlisle. "The Coastal and Marine Geology Video and Photograph Portal is a great resource, providing direct and easy access to this imagery. It will support several key elements of the recently updated Massachusetts Ocean Management Plan, including habitat characterization and the review of ocean development projects under the plan."
Information in this portal helps create coastal maps and representations of seafloor composition and habitats. It provides references for short- and long-term monitoring of changes to the coast, whether from anthropogenic modifications or natural occurrences. Hurricanes and extreme storms are of particular concern, and USGS imagery helps managers, emergency responders and researchers understand circumstances before, during and after such events. Other critical hazards include coastal flooding and sea-level rise, as well as assessments for earthquake and tsunami awareness.
Data also support coastal and marine spatial planning, including evaluation of sites for renewable ocean energy facilities as well as the development of communities and infrastructure. USGS science helps designate marine protected areas, define habitats, identify needs for ecosystem restoration, and inform regional sediment management decisions.
In total, approximately 100,000 photographs and have been collected as well as 1,000 hours of trackline video covering almost 2,000 miles of coastline. Imagery was taken by video and still cameras towed by boat or from aerial flights.
This effort supports the National Ocean Policy mandate to provide access to federal data resources.
How does it work? Start with the tutorial and then dive in!
In 2013, a successful video and photograph pilot interactive website was launched for the California Seafloor Mapping Program, and this helped build the newly released portal.
Also, check out a new crowdsourcing application called, "USGS iCoast – Did the Coast Change?" This application allows citizen scientists to identify changes to the coast by comparing aerial photographs taken before and after storms.
Learn more about USGS science by visiting the USGS Coastal and Marine Geology Program website.Screenshot from the USGS Coastal and Marine Geology Video and Photograph Portal. Zooming into an area of interest reveals lines where continuous video footage was acquired and dots where still photographs were taken. Clicking on a segment launches the video in a pop-up window. Photographs appear beside the video, changing as the video passes each point where a photograph was taken. (High resolution image)
The Gas Hydrates Project at the U.S. Geological Survey (USGS) contributed to a four-year international effort by multiple partners, including the United Nations Environmental Programme (UNEP), to formulate a just-released report entitled, “Frozen Heat: A Global Outlook on Methane Gas Hydrates.”
The two-volume report reviews the state-of-the-art in science and technology related to gas hydrates, providing information in a form accessible to policy makers and stakeholders. The USGS Gas Hydrates Project contributed scientific results, editing, and reviews to assist formulation of the report.
Gas hydrate is a frozen form of gas and water that occurs naturally at moderate pressure and low temperature. These conditions are characteristic of continuous permafrost and marine sediments at water depths greater than ~350 meters (~1150 ft). Methane, the primary component of natural gas, is the most common gas incorporated into global gas hydrate deposits. Gas hydrate sequesters about 1600 billion metric tons (~1800 billion US tons) of carbon or up to 25% of the global budget of carbon that can move around the earth-ocean-atmosphere system.
“The USGS plays an active leadership role in gas hydrate research nationally and internationally,” said USGS Energy Resources Program Coordinator Brenda Pierce. “Having USGS experts join with other scientists to present current scientific knowledge to a broad audience in this report serves an important part of our outreach mission.”
The first volume of the report focuses on the history of gas hydrate research and describes how and where gas hydrates form. USGS research featured prominently in this volume, as USGS scientists have studied the formation and occurrence of gas hydrates all over the world, including Alaska, the Gulf of Mexico, and internationally in countries like Japan, Korea, and India.
Volume I of the report also considers how gas hydrates interact with the environment on a small scale (for example, the link between gas hydrates and deep marine biological communities), and globally (for example, the interplay between gas hydrates and climate).
“We were pleased to work with U.S. and international partners to contribute scientific expertise to this effort,” said Carolyn Ruppel, Chief of the USGS Gas Hydrates Project. “The report dovetails with our Project’s emphasis on gas hydrates in the natural environment and on the climate and energy resource implications of methane hydrates.”
Volume 2 discusses gas hydrates as a potential energy resource, including consideration of the technology needed to extract gas from methane hydrates. USGS scientists have long been active in this research area and participated in tests of methane production from natural gas hydrates in permafrost areas, such as Alaska’s North Slope.
The USGS has a globally recognized research program studying natural gas hydrates in deepwater and permafrost settings worldwide. USGS researchers focus on the potential of gas hydrates as an energy resource, the impact of climate change on gas hydrates, and seafloor stability issues.
USGS bat conservation researchers and their partners are being recognized today with the U.S. Forest Service Wings Across the Americas Research Award for their contributions to the North American Bat Monitoring Program (NABat).
The award will be accepted on behalf of USGS contributions to NABat by Anne Kinsinger, USGS associate director for Ecosystems, at the North American Wildlife Resources Conference in Omaha, Nebr. USGS partners also being recognized are the U.S. Forest Service, National Park Service, U.S. Fish and Wildlife Service, Department of Defense, Environmental Protection Agency, Wildlife Conservation Society, Bat Conservation International, Bat Conservation Trust, Canadian Wildlife Service, University of California, University of Alberta and Colorado Parks and Wildlife.
“Research on bats is important not only because they are vital to the well-being of ecosystems, but also it is in the best interest of the economy due to the importance of bats for pest control and pollination of native and agricultural plants,” said Kinsinger. “USGS has focused considerable research on issues threatening the health and well being of bat populations in North America. Our participation in NABat provides valuable scientific information for bat conservation.”
Wings Across the Americas is an international program of the U.S. Forest Service that works with a wide range of partners here in the United States and overseas to conserve habitats and populations of birds, bats, butterflies and dragonflies. The award recognizes outstanding conservation work by U.S. Forest Service and partner agencies.
The novelty of the NABat program is a vision for collaborative monitoring of an imperiled species group with a sound statistical underpinning allowing for species distribution modeling across broad geographic regions. Participating USGS researchers provide specific expertise on statistical survey design, statistical analysis of bat acoustic and colony count data and database development informed by experience with many wildlife species such as bats, birds and amphibians.
NABat was developed in conjunction with specialists from other agencies, universities and NGOs in the United States, Canada, the United Kingdom and Mexico in response to growing concerns over threats to bats from continuing and emerging stressors including habitat loss and fragmentation, white-nose syndrome, wind energy development and climate change. There are currently no national programs to monitor and track bat populations in North America, and NABat seeks to assist in development of such programs that will provide managers and policy makers with the information they need to effectively manage bat populations, detect early warning signs of population declines and estimate extinction risk.
Efforts to date include four workshops and discussions supported by the Landscape Conservation Cooperatives National Council and the National Institute for Mathematical and Biological Synthesis to develop a national monitoring program. These workshops were attended by scientists and researchers from multiple agencies including FWS, USGS, USFS, NPS, University of Calgary and the Canadian Wildlife Service. In addition, the framework for NABat entitled “A Plan for a North American Bat Monitoring Program (NABat)” will be published in May 2015.
USGS recipients of the Wings Across the Americas award include FORT scientists Laura Ellison, Tom Stanley, Brian Cade, Paul Cryan and Sara Oyler-McCance; NOROCK scientists Kathryn M. Irvine and Steve Corn; UMESC scientist Wayne Thogmartin; Patuxent scientists John Sauer and Matthew Clement; NPWRC scientist Douglas Johnson; NWHC scientist Robin Russell; and CSU Cooperative Research Unit scientist William Kendall.
What Happens to the Water? Assessing Water Quality in Areas with Hydraulically Fractured Oil and Gas Wells
Jennifer LaVista ( Phone: 303-202-4764 );
More data and research are necessary to best understand the potential risks to water quality associated with unconventional oil and gas development in the United States, according to a recent U.S. Geological Survey study.
“We mined the national water-quality databases from 1970 - 2010 and were able to assess long-term trends in only 16 percent of the watersheds with unconventional oil and gas resources,” said Zack Bowen, USGS scientist and principal author of the article that appears in American Geophysical Union’s Water Resources Research. “There are not enough data available to be able to assess potential effects of oil and gas development over large geographic areas.”
There is not a national water-quality monitoring program in place that focuses on oil and gas development, so existing national water-quality databases and data on hydraulic fracturing were used to assess water-quality trends in oil and gas areas. The study found no widespread and consistent trends in water quality, such as chloride and specific conductance, in areas where unconventional oil and gas wells are prevalent. The amount of water-quality samples, where they are located and the varying constituents that are measured are limiting factors in existing national databases.
Hydraulic fracturing is presently the primary stimulation technique for oil and gas production in low-permeability, unconventional resource reservoirs. Comprehensive, published and publicly available information regarding the extent, location and character of hydraulic fracturing and potential effects on regional or national water quality in the United States is scarce. More information can be found on the USGS frequently asked questions on hydraulic fracturing.
While the earth contains enough potash to meet the increased global demand for crop production and U.S. supplies are likely secure, some regions lack potash deposits needed for optimal food crop yields. According to a recent USGS global assessment of potash resources, the costs of importing potash long distances can limit its use and imports are subject to supply disruptions.
“Global scarcity is not the issue with potash – transportation costs are,” said USGS scientist Greta Orris, who led the assessment. “We chose to assess potash because it is used primarily for fertilizer and with the increasing global population, the need for agricultural lands to be increasingly productive will continue,” said Orris.
The U.S. imports more than 80 percent of the potash it uses, mostly from the Elk Point Basin in Saskatchewan, Canada. The Elk Basin is the world’s largest source of potash, having provided at least 20 percent of the world’s potash supply for nearly 40 years.
The U.S. produces potash from deposits in Utah and New Mexico. While production from the Michigan basin recently ceased, a large potash resource exists there. Production and development of resources in Michigan have been hindered by low potash prices, dated production equipment, and poor transport infrastructure amongst other factors. A significant potash resource in Arizona has also been identified, but resources in other states tend to be relatively small.
This global assessment, which includes a summary report and accompanying database, is the most complete, up-to-date, GIS-based, global compilation of information on known and potential potash resources from evaporite sources. The database includes more than 900 known potash deposits with measured resources. It also outlines 84 tracts throughout the world where undiscovered future resources might be found.
“A significant finding of this assessment is that there appears to be little to no potential to develop potash mines in either China or India, where large populations create the need for highly productive agricultural land, which in turn requires large amounts of appropriate fertilizers,” said Orris. “High import costs have resulted in lower usage of potash fertilizers than commonly seen in the U.S., and the potential for the land to be less productive.”
Potash includes a variety of minerals, ores, or processed products that contain potassium, one of three primary plant nutrients essential for growing food crops and biofuels. Modern agriculture requires large quantities of potassium so crop production is adequate to feed a growing population as arable land acreage becomes more limited. While potassium can be derived from other sources, conventional potash deposits – those formed by evaporation -- are the only cost- effective source for large quantities of potassium needed for high-yield agriculture.
The known deposits include location, geology, resource, production and other descriptive information. Potash-bearing basins may host tens of millions to more than 100 billion metric tons of potassium. Examples include Elk Point Basin in Canada, the Pripyat Basin in Belarus, the Solikamsk Basin in western Russia, and the Zechstein Basin in Germany.
The biggest potash producers are Canada, Russia, Belarus, and Israel. In addition to China and India, other areas lacking conventional deposits include much of Africa, Australia, and South America.
For the 84 tracts, the quantities of undiscovered resources are not estimated in this report. Instead, the tracts are classified into six categories that rank their potential to provide potash resources in 25 to 50 years based on known resources in the tract, level of available information, and whether geologic or other deficiencies, such as lack of water, power, or other infrastructure, could prevent or delay development of deposits. Potash tracts that may have potash deposits in production within the next five years include those in Ethiopia and the Republic of Congo.
More information on global and domestic potash, including demand, production, and uses is available from the USGS.
LARAMIE, WY — Seeking insights to help moose, elk, mule deer and bighorn sheep populations, researchers from the University of Wyoming, the Wyoming Game and Fish Department, the U.S. Geological Survey and other partners will spend much of March capturing animals on their winter ranges in western and southern Wyoming.
Members of the public will have an opportunity to closely follow the work.
As scientists did during deer captures earlier this winter, researchers with the UW-headquartered Wyoming Migration Initiative (WMI) and personnel from Game and Fish plan to live-tweet the approximately three weeks of research activity and provide Facebook posts about the animal captures multiple times a day.
The tweets will be by WMI Director Matt Kauffman, a UW professor and U.S. Geological Survey scientist. Game and Fish biologists and wardens collaborating on these studies also will tweet from @wgfd. All updates will use the hashtags #wyodeer, #wyomoose, #wyoelk and #wyosheep. Included in the tweets will be maps and data graphics from the forthcoming “Atlas of Wildlife Migration,” a partnership effort with the University of Oregon InfoGraphics Lab cartographers. The USGS, tweeting from @usgs and @USGSCoopUnits, will help promote the discussion to a broader national audience.
WMI’s Facebook page is at www.facebook.com\migrationinitiative. Game and Fish is at www.facebook.com/WyoGFD. The photos, videos, updates and Twitter feed will be posted to a dedicated WMI webpage, www.migrationinitiative.org/capturelivetweetmarch2015.
“Capture and GPS-collar efforts are the primary tools researchers use to study these iconic animals and their movements,” Kauffman says. “Wyomingites care deeply about these herds and the habitats they occupy, so it’s a great opportunity for us to give them, and people beyond Wyoming, a closer view of how and why we are doing this research.”
“Many of these studies have been ongoing for several years in remote and hard-to-access areas of Wyoming. They are used to make important decisions about wildlife management,” says Game and Fish Communications Director Renny MacKay. “Social media allow us to give the public a new look at this valuable research.”
The eight studies that are part of this month’s field work are:
- Elk migrations into and out of Yellowstone National Park have been of interest for decades, and new GPS radio collar technology has advanced the mapping of these routes. The Wiggins Fork herd is the last gap in a detailed ecosystem-wide map of Yellowstone’s elk migrations. To fill that gap, researchers will capture and collar elk north of Dubois starting the week of March 2.
- Nutrition and behavioral response of moose to beetle-killed forest in the Snowy Mountains. The mountain pine beetle epidemic has transformed forested habitats in this range, with uncertain consequences for one of Wyoming's newest moose herds. Moose will be captured and collared March 5-9 between Centennial and Saratoga to assess nutrition and population growth, and to compare current moose movements to those from a pre-beetle kill study conducted in 2004-05.
- Researchers will capture deer March 10 near Pinedale to evaluate how habitat conditions and human disturbance affect fat levels of deer wintering on and near one of the largest natural gas fields in Wyoming.
- The nutritional dynamics of the famous Wyoming Range mule deer herd. The March 11 deer capture near Big Piney will continue to look at how many deer this range can support. The next step will be to track fawns to measure survival and cause of mortality.
- It is unknown how drought affects mule deer as they migrate -- and forage -- from low-elevation winter ranges to mountain summer ranges. This March 12-13 capture between Kemmerer, Cokeville and Evanston will help shed light on whether warming influences summer forage quality, and ultimately the survival and reproduction of migrants.
- The March 14-15 capture near Rock Springs aims to help advance the understanding of the benefits of migration and guide management and conservation of a spectacular 150-mile deer migration from the Red Desert north of Rock Springs to summer ranges in northwest Wyoming.
- This March 18 capture of elk between Baggs and Saratoga in the Sierra Madre Mountains is part of an assessment of elk movements before, during and after massive tree fall caused by mountain pine beetles.
- The interaction of nutrition and disease in bighorn sheep. Pneumonia in bighorn sheep continues to affect their population dynamics, yet it is unknown how ecological conditions affect susceptibility to disease. The March 19-21 capture of bighorns from three herds near Jackson, Dubois and Cody will investigate how nutrition interacts with disease to affect bighorn populations.
Kauffman says the WMI research team -- which also includes UW’s big game nutrition expert, Kevin Monteith; Western EcoSystems Inc. researcher Hall Sawyer; and Yale University biologist Arthur Middleton -- will provide information on the objectives of each study, and what has been learned from ongoing research, through photos, short video interviews, maps and graphics. They’ll also tweet links to existing papers, reports, news articles, interviews, YouTube videos and other information relevant to each study.
Funding for these projects is made possible through extensive collaborations among state and federal managers, sportsmen’s groups, nongovernmental organizations and private foundations. Additional partner details will be shared through Twitter and Facebook as the work progresses.
The public -- and other groups interested in the research -- are encouraged to add comments via Twitter or Facebook throughout the roughly three-week research effort.
CORVALLIS, Ore. — Greater sage-grouse nests found in natural gas development areas where mitigation actions were taken to minimize development impacts had slightly higher nest survival than similar areas where such actions were not taken, according to research by U.S. Geological Survey and others.
This site-scale study, conducted in a coal-bed methane area of the Powder River Basin in Wyoming, showed that enhanced mitigation efforts somewhat increased the probability of at least one sage-grouse egg hatching per nest in a particular nesting season.
Mitigation techniques are actions taken to avoid, minimize or offset the impacts of human activities on an ecosystem or a species, such as minimizing sagebrush removal and using remote monitoring of wells to reduce vehicle traffic.
The article, co-authored by the Big Horn Environmental Consultants, Boise State University, and USGS and published in the journal Wildlife Biology, looks at the application of science-based on-site mitigation techniques and sage-grouse nest survival in the Intermountain West.
“High nest survival is critical to the species’ continued existence,” said USGS emeritus scientist and co-author Dr. Mark Fuller. “These are ground-nesting birds that produce on average 6-10 eggs each year. Their nests are vulnerable to predation and other factors, making it difficult for the greater sage-grouse populations to maintain numbers.”
From 2008 to 2011, scientists monitored 296 greater sage-grouse nests in a coal-bed methane development where Anadarko Petroleum Corporation, in cooperation with the Bureau of Land Management, applied mitigation measures above and beyond base mitigation measures to determine if these measures would reduce negative impacts to greater sage-grouse. The base mitigation measures are required by the BLM in its 2003 Environmental Impact Statement for the Powder River Basin.
Over a 362-square-mile area, researchers measured nest survival in areas where the enhanced mitigation measures were applied, areas where only base techniques were used and in relatively unaltered areas without oil and gas development. Nest survival was determined by the evidence of at least one successfully hatched egg per nest, a standard measurement in avian scientific studies. Multiple studies have shown that poor nest survival rates can dramatically limit population growth in sage-grouse. Key findings include:
- Estimated nest survival rates were highest in unaltered areas with no oil or gas development (64 percent), next highest in areas where enhanced mitigation techniques were used (59 percent), and lowest in areas where base mitigation practices were used (54 percent).
- Of the mitigation measures implemented, piping discharge water to a treatment facility instead of constructing an on-site reservoir for produced waters had the greatest positive benefit on sage-grouse nest survival. Retention reservoirs result in direct habitat loss, may facilitate the spread of sage-grouse predators, and increase habitat for mosquitoes carrying the West Nile virus, thus expanding sage-grouse exposure to this disease.
- Reducing surface disturbance, particularly sagebrush removal, was also an important factor in nest success. The importance of sagebrush cover to sage-grouse nest survival is well known.
“In asking the question, does on-site mitigation reduce impacts of development on greater sage-grouse, we found that properly targeted mitigation can benefit greater sage-grouse nest survival in energy development areas,” said Chris Kirol, a research biologist with Big Horn Environmental Consultants and lead author of the study. “However, we also found that nests located in areas outside of energy development had the highest survival rates. Our results can help inform future adaptive management and greater sage-grouse conservation efforts in sagebrush habitat affected by energy development.”
Sagebrush habitat is increasingly being developed for oil and gas resources, and land managers face complex challenges in balancing energy demands with conservation measures for sagebrush-dependent species such as the greater sage-grouse. Agencies responsible for managing sagebrush habitat and greater sage-grouse populations encourage the use of adaptive management measures, such as science-based mitigation during oil and gas development and operations. Adaptive management is an approach for improving resource management by learning from and incorporating previous management outcomes into present plans.
Greater sage-grouse occur in parts of 11 U.S. states and 2 Canadian provinces in western North America. The U.S. Fish and Wildlife Service is formally reviewing the status of greater sage-grouse to determine if the species is warranted for listing under the Endangered Species Act.
After surveying and analyzing centuries of evidence in the floodplain of the lower Roanoke River, USGS researchers, along with colleagues from the universities of Wisconsin and North Carolina, have developed a highly accurate estimate of sediment deposition amounts along the course of the river over three timescales — annual, decadal, and centennial.
The investigators used a range of techniques, including evidence from clay pads, tree-rings, and pollen analyses, at numerous locations (58 transects, 378 stations) and employed GIS technology to model sediment deposition rates and characteristics to gain insight into the sediment dynamics of the Roanoke, one of the largest river flood plains on the mid-Atlantic coast.
The scientists found that sediment deposition rates from AD 1725 to 1850 were an order of magnitude higher than present deposition rates and still affect the sediment dynamics of today. These high rates have been attributed to land clearance and poor agricultural practices during and after the colonial period. This legacy sediment deposition formed high banks upstream and the large, wide levees found along the middle reaches of the river.
Furthermore, dam operations, most notably the Kerr Dam completed in 1953, have reduced deposition on natural levees but facilitated backswamp deposition. A GIS-model of current river dynamics indicates that little sediment presently reaches Albemarle Sound because it is trapped on the floodplain, generally benefitting lower floodplain ecosystems and mitigating the transport of excess nutrients to coastal marine systems.
The study findings highlight the important role played by landscape alteration, including post-Colonial forest clearance and dam emplacement, in controlling modern sediment dynamics. The use of multiple techniques to determine sediment deposition rates should improve capabilities of developing accurate sediment budgets along different reaches of the river. In turn, this will aid predictions of the response of the river and associated habitats to changing sea level.
The research was recently published in the journal Geomorphology.