Marisa Lubeck ( Phone: 303-526-6694 );
New research can help water resource managers quantify critical groundwater resources and assess the sustainability of long-term water use in Minnesota.
U.S. Geological Survey scientists recently estimated annual rates of potential recharge, or the natural replenishment of groundwater, over 15 years across Minnesota. According the study, the statewide mean annual potential recharge rate from 1996‒2010 was 4.9 inches per year (in/yr). Recharge rates increased from west to east across the state and April generally had the highest potential recharge.
Improved estimates of recharge are necessary because approximately 75 percent of drinking water and 90 percent of agricultural irrigation water in Minnesota are supplied from groundwater.
“Resource managers in Minnesota can use this study to help inform water use or water conservation guidelines throughout the state,” said USGS scientist and lead author of the report, Erik Smith.
To maintain a stable supply of groundwater, recharge rates must be high enough to compensate for water that is lost to streams, lakes and other surface-water bodies, or removed for uses such as agriculture. The scientists used data about daily precipitation, minimum and maximum daily temperatures, land cover and soil to model Minnesota’s recharge rates.
During the study period, mean annual potential recharge estimates across Minnesota ranged from less than 0.1 to 17.8 in/yr. Other findings include:
- The highest annual mean recharge estimate across the state was in 2010 at 7 inches, and the lowest mean recharge estimate was 1.3 inches in 2003.
- Some of the lowest potential recharge rates were in the Red River of the North Basin in northwestern Minnesota, generally between 1 and 1.5 in/yr.
- The highest potential recharge rates were in northeastern Minnesota and the Anoka Sand Plain in central Minnesota.
- Eighty-eight percent of the mean annual potential recharge rates were between 2 and 8 in/yr.
- April had the greatest monthly mean at 30 percent of the yearly recharge.
The USGS partnered with the Minnesota Pollution Control Agency on the new study.
For more information on groundwater in Minnesota, please visit the USGS Minnesota Water Science Center website.
The latest coal resource assessment of the Powder River Basin showcases the newly revised USGS’ assessment methodology, which, for the first time, includes an estimate of the reserve base for the entire basin.
The coal reserve base includes those resources that are currently economic (reserves), but also may encompass those parts of a resource that have a reasonable potential for becoming economically available within planning horizons. The complete, final assessment results are available in two USGS publications released today: Professional Paper 1809 and Data Series 912.
The Powder River Basin contains one of the largest resources of low-sulfur, low-ash, subbituminous coal in the world and is the single most important coal basin in the United States.
The most important distinction between this Powder River Basin coal assessment and other, prior assessments, was the inclusion of mining and economic analyses to develop an estimate of the portion of the total resource that is potentially recoverable, not just the original (in-place) resources. Prior resource assessments relied on net coal thickness maps for only selected beds, which provided only in-place resource estimates.
The key to performing the economic analyses was gathering and interpreting a sufficient amount of recent geological data from the extensive coal bed methane development over the past 20 years in the Powder River Basin. This wealth of new data was essential to enable modeling and mapping of all of the significant individual coal beds over the entire Powder River Basin for the first time.
The revised USGS assessment methodology resulted in an estimated original resource of about 1.16 trillion short tons in the Powder River Basin, of which 162 billion short tons are considered recoverable resources (coal reserve base) at a stripping ratio of 10:1 or less. An estimated 25 billion short tons of that coal reserve base met the definition of reserves. A 10:1 stripping ratio is approximately estimated by dividing the total thickness of rock mined to the total thickness of coal recovered.
The coal reserve base includes those resources that are currently economic (reserves), but also may encompass those parts of a resource that have a reasonable potential for becoming economically available. This reserve estimate does not mean that the total amount of coal left in the Powder River Basin could be produced by surface mining technologies. The costs of mining and coal sales prices are not static as both tend to increase over time if supported by demand. If future market prices continue to exceed mining costs, portions of the coal reserve base would be elevated to reserve status (and the converse).
The estimate of the current reserves along with the total coal reserve base provide more meaningful resource information for use by energy planners from local to national perspectives rather than just total in-place resource quantities..
Although no underground mining in the Powder River Basin is expected to occur in the foreseeable future, a substantial, deeper coal resource in beds 10–20 feet thick is estimated at 304 billion short tons in the region.
The USGS Energy Resources Program research efforts yield comprehensive, digital assessments of the quantity, quality, location, and accessibility of the Nation’s coal resources.
To learn more about this or other geologic assessments, please visit the USGS Energy Resources Program website. Stay up to date with USGS energy science by subscribing to our newsletter or by following us on Twitter.
Mining companies, land managers, and regulators now have a wealth of tools to aid in reducing potential mining impacts even before the mine gets started. USGS and various research partners released a special edition of papers specifically targeted at providing modern environmental effect research for modern mining techniques.
Minerals play an important role in the global economy, and, as rising standards of living have increased demand for those minerals, the number and size of mines have increased, leading to larger potential impacts from mining.
“Approaches to protecting the environment from mining impacts have undergone a revolution over the past several decades,” said USGS mineral and environmental expert Bob Seal. “The sustainability of that revolution relies on an evolving scientific understanding of how mines and their waste products interact with the environment.”
Many research conclusions are contained in the special issue, and some of the primary findings are listed here:
- USGS evaluated several tools for predicting pre-mining baseline conditions at a mine, even if no baseline was established. This will make it easier to remediate the mine after it closes.
- USGS also took tools used to screen mine waste for contaminants and tested them for predicting potential sources for contaminants before the mine even got started.
Mitigating while Mining
- Because slag is the byproduct of mineral processing, its physical and chemical properties depend a lot on what the original mined mineral material was.
- Slag from copper, zinc, or nickel may be less attractive for reuse, since it has a higher potential to negatively impact the environment than slag that came from iron or steel production.
- Gold mining runs a lower risk of contaminating the environment with cyanide if mines give enough time for it to safely evaporate and be broken down by sunlight.
- Mine drainage is incredibly complicated. It doesn’t come from a single source, but rather complex interactions between water, air, and micro-organisms like bacteria.
- Mine drainage is not just acid mine drainage—it can be basic, neutral, or even high in salts. All of these drainage types have their own impacts.
- Mine drainage concentrations in streams can actually change based on the time of day.
- USGS tested many of the existing techniques for figuring out what toxic contaminants wind up in stream sediments so managers know the right one for the right job.
- USGS also evaluated a new technique for predicting how toxic certain metals will be in aquatic environments.
The research papers are contained in a special issue of the journal Applied Geochemistry. This research was conducted by scientists from USGS and several collaborating organizations, including the Geological Survey of Canada, InTerraLogic, Montana Bureau of Mines and Geology, Montana Tech, SUNY Oneonta, the University of Maryland, the University of Montana, and the University of Waterloo.
USGS minerals research can help to identify problems before they become problems, or at the very least, help address the impacts that do exist. Learn more about USGS minerals research here, or follow us on www.twitter.com/usgsminerals.
A pine siskin stands on the branch of a northern conifer tree. Photo, USFWS National Digital Library. (High resolution image)
Weaving concepts of ecology and climatology, recent interdisciplinary research by USGS and several university partners reveals how large-scale climate variability appears to connect boom-and-bust cycles in the seed production of the boreal (northern conifer) forests of Canada to massive, irregular movements of boreal birds.
These boreal bird “irruptions” — extended migrations of immense numbers of birds to areas far outside their normal range — have been recorded for decades by birders, but the ultimate causes of the irruptions have never been fully explained.
“This study is a textbook example of interdisciplinary research, establishing an exciting new link between climate and bird migrations” said USGS acting Director Suzette Kimball. “A vital strength of our organization is our ability to pursue scientific issues across the boundaries of traditional academic disciplines.”
The investigation was based on statistical analysis of two million observations of the pine siskin (a finch, Spinus pinus) recorded since 1989 by Project FeederWatch, a citizen science program managed by the Cornell Lab of Ornithology. By methodically counting the birds they see at their feeders from November through early April, FeederWatchers help scientists track continent-wide movements of winter bird populations.
One of several nomadic birds that breed during summer in Canadian boreal forests, pine siskins feed on seed crops of conifers and other tree species. When seed is abundant locally, pine siskins also spend the autumn and winter there. In other years, they may irrupt, migrating unpredictably hundreds or even thousands of kilometers to the south and east in search of seed and favorable habitat. “Superflights” is the term applied to winters (e.g.1997-1998, 2012-2013) when boreal species have blanketed bird feeders across the U.S.
The irruptions of pine siskins and other boreal species follow a lagging pattern of intermittent, but broadly synchronous, accelerated seed production (“masting”) by trees in the boreal forest. Widespread masting in pines, spruces, and firs is driven primarily by favorable climate during the two or three consecutive years required to initiate and mature seed crops. Leading up to masting events, the green developing cones and the promise of abundant seed stimulate higher reproductive rates in birds.
However, seed production is expensive for trees and tends to be much reduced in the years following masting. Consequently, meager seed crops in the years following masting drive boreal birds to search elsewhere for food and overwintering habitat.
The key finding of the new research is that the two principal pine siskin irruption modes – North to South and West to East – correlate closely with spatial patterns of climate variability across North America that are well understood by climatologists. Not surprisingly, severely cold winters tend to drive birds south during the irruption year.
More subtly, the researchers found that favorable and unfavorable climatic conditions of regularly juxtaposed regions called “climate dipoles” two years prior to the irruption also appear to push and pull bird migrations across the continent.
USGS co-author Julio Betancourt commented, “Our study underscores the value of continent-wide biological monitoring. In this case, avid birders across the U.S. and Canada have contributed sustained observations of birds at the same broad geographic scale in which weather and climate have also been observed and understood.”
The research study, authored by Court Strong (University of Utah), Ben Zuckerberg (University of Wisconsin-Madison), Julio Betancourt (USGS-Reston), and Walt Koenig (Cornell University), was published May 11 online in the Proceedings of the National Academy of Sciences.
Storage tanks for produced water from natural gas drilling in the Marcellus Shale gas play of western Pennsylvania. USGS photo, Doug Duncan. (High resolution image)
In a study of 13 hydraulically fractured shale gas wells in north-central Pennsylvania, USGS researchers found that the microbiology and organic chemistry of the produced waters varied widely from well to well.
The variations in these aspects of the wells followed no discernible spatial or geological pattern but may be linked to the time a well was in production. Further, the study highlighted the presence of some organic compounds (e.g. benzene) in produced waters that could present potential risks to human health, if the waters are not properly managed.
Produced water is the term specialists use to describe the water brought to the land surface during oil, gas, and coalbed methane production. This water is a mixture of naturally occurring water and fluid injected into the formation deep underground to enhance production. A USGS Fact Sheet on produced water provides more background information and terminology definitions.
Although the USGS investigators found that the inorganic (noncarbon-based) chemistry of produced waters from the shale gas wells tested in the Marcellus region was fairly consistent from well to well and meshed with comparable results of previous studies (see USGS Energy Produced Waters Project), the large differences in the organic geochemistry (carbon-based, including petroleum products) and microbiology (e.g. bacteria) of the produced waters were striking findings of the study.
“Some wells appeared to be hotspots for microbial activity,” observed Denise Akob, a USGS microbiologist and lead author of the study, “but this was not predicted by well location, depth, or salinity. The presence of microbes seemed to be associated with concentrations of specific organic compounds — for example, benzene or acetate — and the length of time that the well was in production.”
The connection between the presence of organic compounds and the detection of microbes was not, in itself, surprising. Many organic compounds used as hydraulic fracturing fluid additives are biodegradable and thus could have supported microbial activity at depth during shale gas production.
The notable differences in volatile organic compounds (VOCs) from the produced waters of the tested wells could play a role in the management of produced waters, particularly since VOCs, such as benzene, may be a health concern around the well or holding pond. In wells without VOCs, on the other hand, disposal strategies could concentrate on issues related to the handling of other hazardous compounds.
Microbial activity detected in these samples could turn out to be an advantage by contributing to the degradation of organic compounds present in the produced waters. Potentially, microbes could also serve to help mitigate the effects of organic contaminants during the disposal or accidental release of produced waters. Additional research is needed to fully assess how microbial activity can best be utilized to biodegrade organic compounds found in produced waters.
The research article can be found in the most recent edition of Applied Geochemistry, Special Issue on Shale Gas Geochemistry.
If invasive bighead carp and silver carp spread into Lake Erie, there would be enough food available for these species of Asian carp to survive, according to a new study by the U.S. Geological Survey.
This information is critical in helping resource managers mitigate effects of an Asian carp invasion. If bighead and silver carp were to populate Lake Erie, they have the potential to damage native fish populations and the Great Lakes economy.
USGS scientists used satellite imagery of Lake Erie showing algae on the surface to determine how much food would be available for Asian carp. Green algae and blue-green algae, specifically floating algal blooms that can be seen on the surface, are a preferred food source for Asian carp. The water temperatures and algal concentrations detected in Lake Erie from 2002-2011 show that the bighead and silver carps could not only live in this environment, but could continue to grow. The full report is available online.
“Remote sensing imagery shows that Lake Erie has huge areas of available food that are often several times more concentrated than necessary for Asian carp growth, particularly in the western basin,” said USGS scientist Karl Anderson.
Food availability and water temperature are the greatest sources of uncertainty for predicting fish growth potential. Water temperature is a big factor in determining how much bighead and silver carps need to eat. Models developed by USGS scientists helped determine how much algae bighead and silver carps need to eat to survive.
For the past 10 years, algal blooms in Lake Erie have been increasing. Remote sensing images showed that the amount of algae doubled, and in some places quadrupled, from 2002-2011. Throughout the lake, algal blooms encompass several hundred to several thousands square kilometers. Specifically, the western part of Lake Erie has algal concentrations that are several times greater than what is needed for bighead or silver carp to survive.
Seasonal Habitat Quality and Landscape Characteristics Explain Genetic Differences Between Greater Sage-grouse Populations in Wyoming
FORT COLLINS, Colo. — Low-quality nesting and winter seasonal habitats are strong predictors of reduced gene flow between greater sage-grouse breeding locations, according to research just published in Ecology and Evolution and authored by the U.S. Geological Survey and their colleagues at the University of Waterloo.
The study compared the genetic differences between greater sage-grouse breeding areas with seasonal habitat distributions or combinations of landscape factors – such as amount of sagebrush habitat, agriculture fields or roads – to understand how each factor or combination of factors influence effective dispersal of sage-grouse across the state.
Understanding how habitat and landscape features impact the effective dispersal of a species is important for informing management and conservation decisions across large landscapes. Dispersal effectiveness can be measured by gene flow, the rate at which genetic material moves between populations. When populations become small and isolated, a reduction in gene flow can lead to reduced genetic diversity, making those populations potentially less resilient to environmental stressors.
“This research identified which seasonal habitats and individual landscape features facilitate and impede gene flow across the state of Wyoming – which is a stronghold for sage-grouse populations,” said Brad Fedy, one of the authors of the paper and a scientist at the University of Waterloo in Ontario.
Greater sage-grouse are dependent upon sagebrush, so two populations separated only by sagebrush habitat would be expected to have more individuals moving between them and be more genetically similar than two populations separated by a barrier to sage-grouse movement, such as a mountain range or forest.
Researchers found that the juxtaposition and quality of nesting and winter seasonal habitats were the greatest predictors of gene flow for greater sage-grouse in Wyoming. Furthermore, the combinations of high levels of forest cover and highly rugged (steep and uneven) terrain or low levels of sagebrush cover and highly rugged terrain were correlated with low levels of gene flow among sage-grouse populations.
“Maintaining natural levels of gene flow among populations helps ensure resilience for the species,” said Sara Oyler-McCance, a USGS research geneticist and a co-author on the study. “Ultimately, land managers can use this information to identify habitats that are most important for maintaining effective dispersal between populations and to improve future sage-grouse conservation efforts.”
Greater sage-grouse occur in parts of 11 U.S. states and 2 Canadian provinces in western North America. These birds rely on sagebrush ecosystems, which constitute the largest single North American shrub ecosystem and provide vital ecological, hydrological, biological, agricultural, and recreational ecosystem services. 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.
RESTON, Va.-- The latest tool designed to help manage the threatened piping plover is only a download away; iPlover is the first smartphone data collection application developed by the U.S. Geological Survey and will help those managing plover populations.
iPlover supports a long-established network of partners working to address ongoing impacts on plover populations, such as habitat gain or loss due to storms.
More importantly, data from the app is used to develop models that address long-term management concerns for habitat availability. It also improves the overall quality of coastal geologic information available to effectively manage this species.
The piping plover is a small shorebird that depends on open coastal beaches to breed and raise its young. Listed as threatened along the Atlantic coast in 1986, the piping plover’s conservation has been mandated by the Endangered Species Act. Although Atlantic Coast piping plover numbers have more than doubled since their listing nearly 30 years ago, they are still at risk. Recent estimates place the population at fewer than 2000 pairs, and climate change has introduced new threats to their coastal habitat.
Coastal beaches are dynamic systems and managing them for beach-dependent species like the piping plover requires collecting data on physical and biological characteristics that will be affected by sea level rise. Given the extensive Atlantic breeding range of the piping plover – spanning from North Carolina to Newfoundland – biologists have a lot of ground to cover.
The iPlover app supports the need for coordinated, synchronized data collection. It is a powerful new tool to help scientists and coastal resource managers consistently measure and assess the birds’ response to changes to their habitat. Rather than compiling data from multiple sources and formats, the app gives trained resource managers an easy-to-use platform where they can collect and instantly share data across a diverse community of field technicians, scientists, and managers. iPlover improves scientists’ data gathering and analysis capabilities by simplifying and facilitating consistent data collection and management that interfaces with models of shoreline change and beach geomorphology.
“The data come in from all of our study sites basically in real-time,” said Rob Thieler, USGS scientist and lead developer of the app. “It's already formatted, so data can be quickly plugged into our research models. This should really shorten the time between collecting the data, doing the science, and turning it into actionable information for management.”
“The USGS worked with diverse project partners to incorporate specific data collection needs and enable important stakeholders and partners to contribute data from hundreds of field observations within the plover’s U.S. Atlantic coastal breeding range,” said Andrew Milliken, coordinator of the North Atlantic Landscape Conservation Cooperative. “This included getting inputs from the U.S. Fish and Wildlife Service, National Park Service, state agencies and non-governmental organizations.”
“The app highlights the synergies and benefits of interagency and interdisciplinary science that advances conservation,” Milliken added. “The information collected will not only greatly improve our understanding of impacts from sea level rise, storms and beach management on piping plovers but also how managing for plovers can benefit other beach-dependent species, such as the American oystercatcher.”
Funding for iPlover was provided through the Department of Interior North Atlantic Landscape Conservation Cooperative as part of its Hurricane Sandy response. The app was developed by the USGS’ Woods Hole Coastal and Marine Science Center and the Center for Integrated Data Analytics.
“iPlover is a great example of the USGS’ ability to build and deliver a variety of science applications that use modern technology,” said Nate Booth, USGS Chief of Office of Water Information and former Lead Architect for the USGS Center for Integrated Data Analytics. “It offers research teams great gains in data collection efficiency so that more time can be spent on analyzing the data rather than managing it."
SEATTLE, Wash. — More than 1,000 dams have been removed across the United States because of safety concerns, sediment buildup, inefficiency or having otherwise outlived usefulness. A paper published today in Science finds that rivers are resilient and respond relatively quickly after a dam is removed.
“The apparent success of dam removal as a means of river restoration is reflected in the increasing number of dams coming down, more than 1,000 in the last 40 years,” said lead author of the study Jim O’Connor, geologist with the U.S. Geological Survey. “Rivers quickly erode sediment accumulated in former reservoirs and redistribute it downstream, commonly returning the river to conditions similar to those prior to impoundment.”
Dam removal and the resulting river ecosystem restoration is being studied by scientists from several universities and government agencies, including the USGS and U.S. Forest Service, as part of a national effort to document the effects of removing dams. Studies show that most river channels stabilize within months or years, not decades, particularly when dams are removed rapidly.
“In many cases, fish and other biological aspects of river ecosystems also respond quickly to dam removal,” said co-author of the study Jeff Duda, an ecologist with USGS. “When given the chance, salmon and other migratory fish will move upstream and utilize newly opened habitat.”
The increase in the number of dam removals, both nationally and internationally, has spurred the effort to understand the consequences and help guide future dam removals.
“As existing dams age and outlive usefulness, dam removal is becoming more common, particularly where it can benefit riverine ecosystems,” said Gordon Grant, Forest Service hydrologist. “But it can be a complicated decision with significant economic and ecologic consequences. Better understanding of outcomes enables better decisions about which dams might be good candidates for removal and what the river might look like as a result.”
Sponsored by the USGS John Wesley Powell Center for Analysis and Synthesis, a working group of 22 scientists compiled a database of research and studies involving more than 125 dam removals. Researchers have determined common patterns and controls affecting how rivers and their ecosystems respond to dam removal. Important factors include the size of the dam, the volume and type of sediment accumulated in the reservoir, and overall watershed characteristics and history.
EVERGLADES NATIONAL PARK, Fla.— The largest and longest Burmese Python tracking study of its kind -- here or in its native range -- is providing researchers and resource managers new information that may help target control efforts of this invasive snake, according to a new study led by the U.S. Geological Survey.
Among the findings, scientists have identified the size of a Burmese python’s home range and discovered they share some “common areas” that multiple snakes use.
“These high-use areas may be optimal locations for control efforts and further studies on the snakes’ potential impacts on native wildlife,” said Kristen Hart, a USGS research ecologist and lead author of the study. “Understanding habitat-use patterns of invasive species can aid resource managers in designing appropriately timed and scaled management strategies to help control their spread.”
Using radio and GPS tags to track 19 wild-caught pythons, researchers were able to learn how the Burmese python moved within its home range. The 5,119 days of tracking data led researchers to conclude that python home ranges are an average of 22 square kilometers, or roughly an area 3 miles wide-by-3 miles long, all currently within the park.
The study found pythons were concentrated in slough and coastal habitats, with tree islands being the principal feature of common-use areas, even in areas where they were not the predominant habitat type. The longest movements of individual pythons occurred most often during dry conditions, but took place during “wet” and “dry” seasons.
Burmese pythons are long-lived, large-bodied constricting snakes native to Southeast Asia. Highly adaptable, these ambush predators can reach lengths greater than 19 feet and produce large clutches of eggs that can range from eight to 107 eggs. Burmese pythons were first observed in South Florida’s Everglades National Park in 1979. Since then, they have spread throughout the park. Although recent research indicates the snakes may be having a significant effect on some populations of mid-sized mammals, it has also shown there is little risk to people who visit Everglades National Park.
Invasive species compete with native wildlife for food, and they threaten native biodiversity across the globe. With nearly 50 percent of the imperiled species in the US being threatened by exotic species, a major concern for land managers is the growing number of exotics that are successfully invading and establishing viable populations.
Florida is home to more exotic animals than any other state. Snakes in particular have been shown to pose a high risk of becoming invasive species. The establishment of Burmese pythons in South Florida poses a significant threat to both the sensitive Everglades ecosystem and native species of conservation concern. For example, in the park, wood storks, Florida panthers and Cape Sable seaside sparrows are all species of conservation concern that have home ranges near the common-use areas of the radio-tracked pythons.
The study, “Home Range, Habitat Use, and Movement Patterns of Non-Native Burmese Pythons in Everglades National Park, Florida, USA,” with authors from the USGS, University of Florida, National Park Service, and Davidson College, was published in the journal Animal Biotelemetry.