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At least 199 records · Page 11Linked to original sources
USGS2026

Small creatures, big challenge: A review of current knowledge and assessment of research needs to inform water withdrawal management for the Duck River's freshwater mussel fauna

The Duck River is a remarkable national resource, boasting outstanding biodiversity (Ahlstedt et al. 2017). It contains 151 fish species, over 60 mussel species, and 22 snail species, many of which are federally listed (Etnier and Starnes 1993; Johnson et al. 2013; Ahlstedt et al. 2017; Womble and Rosenberger 2025a). The Duck River watershed is at a pivotal time in its management and ecological history due to significant growth in human population and economic activity. The consequent increase in surface water demand presents challenges for sustainable water resource management. The Tennessee Department of Environment and Conservation (TDEC) has permitted or proposed to permit eight water utilities to withdraw over 77 million gallons per day (mgd) from the Duck River, representing > 40% increase from previously permitted amounts (USFWS 2025). On November 20, 2024, Tennessee Governor Bill Lee signed Executive Order No 108 to ensure long-term stability of the Duck River watershed through balancing economic growth, water resource management, and environmental conservation. Some primary components of this plan are the creation of a Comprehensive Regional Drought Management Plan, the development of a Habitat Conservation Plan, and the establishment of the Duck River Watershed Planning Partnership (DRWPP). Although the planning partnership is not focused on a sole aspect of the Duck River, but the watershed as a whole, the mussel assemblages of the Duck River have been a particular focus due to their importance in providing ecosystem services, sensitivity to water quality, conservation status, and sensitivity to periodic drought conditions in this system. With multiple state and federal agencies involved in managing the Duck River’s unique water resources, a focused review on how future water management could affect the freshwater mussel communities in the Duck River will contribute to this process. Our objectives of this review are to: 1. Review the effects of changing flow regimes on mussels, with emphasis on the effect of droughts/low flows, highlighting key processes/factors affecting mussels. 2. Highlight critical data gaps that could allow future, evidence-based water management decisions in this system. 3. Propose research topics to address critical data gaps and enable evidence-based water management decisions that consider the needs of freshwater mussels. Freshwater mussels are a critical component of riverine ecosystems, providing ecosystem services including water filtration, nutrient cycling, and habitat provision (Vaughn et al. 2004; Haag 2012) that benefit human communities. Environmental flows, also referred to as ecological or e-flows, refer to the quantity, timing, and quality of water flows necessary to maintain the ecological health of rivers, wetlands, and other aquatic ecosystems (Acreman and Dunbar 2004; Acreman 2016). For freshwater mussels, environmental flows include maintaining a flow regime and associated water quality regimes that are favorable for both juveniles and adults while also seasonally supporting host fish and the survival of settling glochidia (i.e., larval mussels) in suitable environments (Gates et al. 2015). Freshwater mussels are adapted to the natural flow regime of their native streams, including seasonal variability in flows. As sedentary filter feeders, mussels require adequate water flow to provide oxygen and food (Allen and Vaughn 2009); however, they also require periods of low flow to increase access to fish hosts and to ensure juveniles are not displaced (Gates et al 2015). Mussels are sensitive to water quality conditions, including pollutants, sedimentation, and artificial alterations of temperature and pH (Strayer and Malcom 2012). Mussel community characteristics, including presence, abundance, and species richness, generally increase with stream size (e.g., stream order); however, responses to changes in flow conditions are often species-specific, and the magnitude and timing of extreme flow conditions have more predictive power for mussel community response than general changes in flow (Lopez and Vaughn 2021). Complex hydraulic variables, such as relative shear stress and Reynolds number, can be strong predictors of mussel community responses because they combine simple hydraulic variables (e.g., velocity, depth) with stream channel characteristics, such as substrate composition and dynamics. Droughts directly and indirectly affect mussels by influencing their physiology, behavior, reproduction, and ecosystem roles. Mass mussel die-offs during droughts and low water conditions are widely documented (Vaughn et al. 2015; Sousa et al. 2018; Dubose et al. 2019). Droughts can also lead to a shift in mussel community composition, with drought-tolerant species becoming more dominant while more sensitive species experience declines (Galbraith et al, 2010; Lopez et al. 2022; Vaughn and Atkinson 2025). Droughts affect mussels through direct mortality from stranding as well as physiological stress from altered water temperature and quality, reduced habitat and food availability and quality, increased predation and competition, disruption of reproductive cycles, and increased susceptibility to disease and pathogens. Although the effects of droughts, water withdrawals, and low flow conditions on mussels are an increasing area of study, there is a general paucity of data-driven consensus regarding optimal mitigation approaches and strategies (Cushway et al. 2024). Long-term management decisions regarding water withdrawals, particularly during extended or multi-year drought conditions, may consider factors beyond direct mortality such as the sublethal effects of drought and low flow conditions on freshwater mussels for a comprehensive understanding of the effects of prolonged low flows on freshwater mussels and aquatic communities.

Tennessee↗
USGS2016

Experimental challenge of a peridomestic avian species, European Starlings ( Sturnus vulgaris ), with novel Influenza A H7N9 virus from China

In 2013 a novel avian influenza H7N9 virus was isolated from several critically ill patients in China, and infection with this virus has since caused more than 200 human deaths. Live poultry markets are the likely locations of virus exposure to humans. Peridomestic avian species also may play important roles in the transmission and maintenance of H7N9 at live poultry markets. We experimentally challenged wild European Starlings ( Sturnus vulgaris ) with the novel H7N9 virus and measured virus excretion, clinical signs, and infectious dose. We found that European Starlings can be infected with this virus when inoculated with relatively high doses, and we predict that infected birds excrete sufficient amounts of virus to transmit to other birds, including domestic chickens. Infected European Starlings showed no clinical signs or mortality after infection with H7N9. This abundant peridomestic bird may be a source of the novel H7N9 virus in live poultry markets and may have roles in virus transmission to poultry and humans.

Journal of Wildlife Diseases↗
USGS2021

Moderate susceptibility to subcutaneous plague (Yersinia pestis) challenge in vaccine-treated and untreated Sonoran deer mice (Peromyscus maniculatus sonoriensis) and northern grasshopper mice (Onychomys leucogaster)

The variable response of wild mice to Yersinia pestis infection, the causative agent of plague, has generated much speculation concerning their role in the ecology of this potentially lethal disease. Researchers have questioned the means by which Y. pestis is maintained in nature and also sought methods for managing the disease. Here we assessed the efficacy of a new tool, the sylvatic plague vaccine (SPV), in wild-caught northern grasshopper mice ( Onychomys leucogaster ) and commercially acquired Sonoran deer mice ( Peromyscus maniculatus sonoriensis ). More than 40% of the animals survived a subcutaneous Y. pestis challenge of 175,000 colony forming units (over 30,000 times the white mouse 50% lethal dose) in both vaccine-treated and control groups. Our results indicate that SPV distribution is unlikely to protect adult mice from plague infection in field settings and corroborate the heterogeneous response to Y. pestis infection in mice reported by others.

Journal of Wildlife Diseases↗
USGS2003

Satellite telemetry and wildlife studies in India: Advantages, options and challenges

Greater spatial coverage, accuracy and non-invasiveness of satellite technology make it one of the best tools to track long-distance migrants, which is otherwise difficult using conventional radio telemetry. In this article, we review the evolution of satellite telemetry and its application. We provide examples of three recent studies in India that have demonstrated and created a widespread appreciation of the use and benefits of satellite telemetry among biologists and managers. We also discuss the future prospects of this technology vis-a-vis benefits and challenges in the Indian subcontinent.

Current Science↗
USGS1996

Film cameras or digital sensors? The challenge ahead for aerial imaging

Cartographic aerial cameras continue to play the key role in producing quality products for the aerial photography business, and specifically for the National Aerial Photography Program (NAPP). One NAPP photograph taken with cameras capable of 39 lp/mm system resolution can contain the equivalent of 432 million pixels at 11 ??m spot size, and the cost is less than $75 per photograph to scan and output the pixels on a magnetic storage medium. On the digital side, solid state charge coupled device linear and area arrays can yield quality resolution (7 to 12 ??m detector size) and a broader dynamic range. If linear arrays are to compete with film cameras, they will require precise attitude and positioning of the aircraft so that the lines of pixels can be unscrambled and put into a suitable homogeneous scene that is acceptable to an interpreter. Area arrays need to be much larger than currently available to image scenes competitive in size with film cameras. Analysis of the relative advantages and disadvantages of the two systems show that the analog approach is more economical at present. However, as arrays become larger, attitude sensors become more refined, global positioning system coordinate readouts become commonplace, and storage capacity becomes more affordable, the digital camera may emerge as the imaging system for the future. Several technical challenges must be overcome if digital sensors are to advance to where they can support mapping, charting, and geographic information system applications.

Photogrammetric Engineering and Remote Sensing↗
USGS2012

Improving PAGER's real-time earthquake casualty and loss estimation toolkit: a challenge

We describe the on-going developments of PAGER’s loss estimation models, and discuss value-added web content that can be generated related to exposure, damage and loss outputs for a variety of PAGER users. These developments include identifying vulnerable building types in any given area, estimating earthquake-induced damage and loss statistics by building type, and developing visualization aids that help locate areas of concern for improving post-earthquake response efforts. While detailed exposure and damage information is highly useful and desirable, significant improvements are still necessary in order to improve underlying building stock and vulnerability data at a global scale. Existing efforts with the GEM’s GED4GEM and GVC consortia will help achieve some of these objectives. This will benefit PAGER especially in regions where PAGER’s empirical model is less-well constrained; there, the semi-empirical and analytical models will provide robust estimates of damage and losses. Finally, we outline some of the challenges associated with rapid casualty and loss estimation that we experienced while responding to recent large earthquakes worldwide.

Conference Paper↗
USGS2013

The challenge of wolf recovery: an ongoing dilemma for state managers

“Dave, would you do another legal declaration on the wolf for us?” The weary voice on the phone belonged to Mike Jimenez, Northern Rocky Mountain Wolf Management and Science Coordinator for the U.S. Fish and Wildlife Service (FWS). He was calling from Wyoming to ask me to prepare a document to address a legal challenge to the FWS’s August 2012 delisting of the wolf (Canis lupus) in Wyoming, a highly controversial move. Mike’s tone reflected the reality that — as so many wildlife biologists know and live each day — wildlife management is mainly people management. This contention could not be truer for managing any wildlife species than for managing the wolf. Dubbed “the beast of waste and desolation” by Teddy Roosevelt (The Wilderness Hunter 1893/1900), wolves had been universally hated as prolific predators of valuable livestock and game. Around the turn of the 20th century, members of the U.S. Biological Survey and various state agents, ranchers, cowboys, and other frontiersmen poisoned and persecuted wolves, extirpating them from most of the contiguous United States (Young and Goldman 1944). By 1967, Minnesota and nearby Isle Royale National Park in Michigan held the only remaining wolves in the Lower 48 states, prompting the FWS to place the wolf on the Endangered Species List (established by the Endangered Species Preservation Act of 1966). The wolf then became the list’s poster species, and the timing was ideal: Silent Spring (Carson 1962) had just seeded and fertilized the environmental movement, which blossomed on Earth Day (April 22, 1970) into the environmental revolution. “Save the wolf!” became one of the movement’s rallying cries. And save the wolf we did.

The Wildlife Professional↗
USGS2013

Wildfire and invasive species in the west: challenges that hinder current and future management and protection of the sagebrush-steppe ecosystem: a Gap Report

The Western Association of Fish and Wildlife Agencies (WAFWA) to satisfy the 45-day report requirement identified in Cooperative Agreement (F13AC00353) between WAFWA and the U. S. Fish and Wildlife Service (FWS) submit this “Gap Report”. This report summarizes the policy, fiscal and science challenges that land managers encounter related to the control and reduction of the invasive plant/fire complex, especially as it relates to the threaten or endangered species listing status of the Greater sage-grouse ( Centrocercus urophasianus ). While this Gap Report identifies 22 technical, policy, planning and funding gaps, it should be considered a “work in-progress”. To address this effort a Wildfire/Invasive Initiative Work Group (WG) was formed. The WG consist of nationally recognized experts in fire ecology, Sage-grouse ecology and management, range management and plant ecology. The WG developed this Gap Report and will be developing the final report for this Cooperative Agreement. Thus, as the WG evaluates the wildfire/invasive issue and makes recommendation to address scientific and management shortcomings, additional gaps will be identified and included in the final report. Within this report, the WG has suggested the top 5 gaps. However, the actual priority of what should be addressed first will depend on the significance and sequence of the limiting factor, available funding, current work, roles and responsibilities of the specific agencies, etc. The WG will continue to meet on a regular basis to further develop and expand this list of gaps. Additionally, the WG will offer specific options to address the identified gaps. However, the WG recommends that the FWS, possibly through the State/Federal (Western Governors Association) Sage Grouse Task Force or the National Sage-grouse Executive Oversight Committee, establish a Subcommittee to specifically review this Gap Report and develop a multi-agency approach on how to address each gap. The WG will continue to endeavor to establish a priority list and identify the “low hanging fruit” that can be addressed in the short-term to affect the listing decision. Additionally, the WG will propose a longer-term strategy. However, to successfully establish such a strategy it will take buy-in and commitment at the highest levels in federal and state governments. In an effort to provide managers an opportunity to address the most important issues this coming fiscal year, we offer the following top 5 gaps. Beyond these top 5, the WG has identified 17 additional gaps that should be evaluated by both federal and state agencies as a means to help better manage the wildfire/invasive threat in the west.

Report↗
USGS2014

W(h)ither the Oracle? Cognitive biases and other human challenges of integrated environmental modeling

Integrated environmental modeling (IEM) can organize and increase our knowledge of the complex, dynamic ecosystems that house our natural resources and control the quality of our environments. Human behavior, however, must be taken into account. Human biases/heuristics reflect adaptation over our evolutionary past to frequently experienced situations that affected our survival and that provided sharply distinguished feedbacks at the level of the individual. Unfortunately, human behavior is not adapted to the more diffusely experienced, less frequently encountered, problems and issues that IEM typically seeks to address in the simulation of natural resources and environments. While seeking inspiration from the prophetic traditions of the Oracle of Delphi, several human biases are identified that may affect how the science base of IEM is assembled, and how IEM results are interpreted and used. These biases are supported by personal observations, and by the findings of behavioral scientists. A process for critical analysis is proposed that solicits explicit accounting and cognizance of potential human biases. A number of suggestions are made to address the human challenges of IEM, in addition to maintaining attitudes of watchful humility, open-mindedness, honesty, and transparent accountability. These include creating a new area of study in the behavioral biogeosciences, using structured processes for engaging the modeling and stakeholder community in IEM, and using “red teams” to increase resilience of IEM constructs and use.

Conference Paper↗
USGS2015

Blackbrush ( Coleogyne ramosissima Torr. ): State of our knowledge and future challenges

Covering 130,000 square miles and a wide range of elevations from desert to alpine in Arizona, Utah, Colorado, and New Mexico, the Colorado Plateau has long fascinated researchers. The Colorado Plateau VI provides readers with a plethora of updates and insights into land conservation and management questions currently surrounding the region. The Colorado Plateau VI’s contributors show how new technologies for monitoring, spatial analysis, restoration, and collaboration improve our understanding, management, and conservation of outcomes at the appropriate landscape scale for the Colorado Plateau. The volume’s chapters fall into five major themes: monitoring as a key tool for addressing management challenges, restoration approaches to improving ecosystem condition and function, collaboration and organizational innovations to achieve conservation and management objectives, landscape-scale approaches to understanding, and managing key species and ecological communities. Focusing on the integration of science into resource management issues over the Colorado Plateau, this volume includes contributions from dozens of leading scholars of the region. The Colorado Plateau VI proves a valuable resource to all interested in the conservation management, natural history, and cultural biological resources of the Colorado Plateau.

Arizona, Colorado, New Mexico, Utah↗
USGS2006

Natural glide slab avalanches, Glacier National Park, USA: A unique hazard and forecasting challenge

In a museum of avalanche phenomena, glide cracks and glide avalanches might be housed in the “strange but true” section. These oddities are uncommon in most snow climates and tend to be isolated to specific terrain features such as bedrock slabs. Many glide cracks never result in avalanches, and when they do, the wide range of time between crack formation and slab failure makes them highly unpredictable. Despite their relative rarity, glide cracks and glide avalanches pose a regular threat and complex forecasting challenge during the annual spring opening of the Going-to-the-Sun Road in Glacier National Park, U.S.A. During the 2006 season, a series of unusual glide cracks delayed snow removal operations by over a week and provided a unique opportunity to record detailed observations of glide avalanches and characterize their occurrence and associated weather conditions. Field observations were from snowpits, crown profiles and where possible, measurements of slab thickness, bed surface slope angle, substrate and other physical characteristics. Weather data were recorded at one SNOTEL site and two automated stations located from 0.6-10 km of observed glide slab avalanches. Nearly half (43%) of the 35 glide slab avalanches recorded were Class D2-2.5, with 15% Class D3-D3.5. The time between glide crack opening and failure ranged from 2 days to over six weeks, and the avalanches occurred in cycles associated with loss of snow water equivalent and spikes in temperature and radiation. We conclude with suggest ions for further study.

Montana↗
USGS2015

Dune management challenges on developed coasts

From October 26-28, 2015, nearly 100 members of the coastal management and research communities met in Kitty Hawk, NC, USA to bridge the apparent gap between the coastal dune research of scientists and engineers and the needs of coastal management practitioners. The workshop aimed to identify the challenges involved in building and managing dunes on developed coasts, assess the extent to which scientific knowledge can be applied to the management community, and identify approaches to provide means to bridge the gap between needs and potential solutions.

Conference Paper↗
USGS2002

Bear reintroduction: Lessons and challenges

Reintroduction is defined as an attempt to establish a species in an area that was once part of its historical range, but from which it has been extirpated or become extinct. Historically, one of the most successful programs was the reintroduction of 254 American black bears ( Ursus americanus ) from Minnesota to the Interior Highlands of Arkansas in the 1960s; that population has grown to >2,500 today. More recent efforts have involved fewer but better monitored animals and have sometimes employed techniques to improve site fidelity and survival. In Pennsylvania, for example, pregnant female American black bears were successfully translocated from winter dens, the premise being that the adult females would be less likely to return because of the presence of young cubs. That winter-release technique was compared to summer trapping and release in Tennessee; winter releases resulted in greater survival and reduced post-release movements. Homing has not been a problem for small numbers of brown bears ( Ursus arctos ) reintroduced to the Cabinet-Yaak ecosystem in Montana and Idaho and to the mountains of Austria and France. Reintroduction success appears to be correlated with translocation distance and is greater for subadults and females. As with any small population, reintroduced bear populations are susceptible to environmental variation and stochastic demographic and genetic processes. Although managers have focused on these biological barriers, sociopolitical impediments to bear reintroduction are more difficult to overcome. Poor public acceptance and understanding of bears are the main reasons some reintroduction programs have been derailed. Consequently, the public should be involved in the reintroduction process from the outset; overcoming negative public perceptions about bear reintroduction will be our greatest challenge.

Ursus↗
USGS2016

New challenges for grizzly bear management in Yellowstone National Park

A key factor contributing to the success of grizzly bear Ursus arctos conservation in the Greater Yellowstone Ecosystem has been the existence of a large protected area, Yellowstone National Park. We provide an overview of recovery efforts, how demographic parameters changed as the population increased, and how the bear management program in Yellowstone National Park has evolved to address new management challenges over time. Finally, using the management experiences in Yellowstone National Park, we present comparisons and perspectives regarding brown bear management in Shiretoko National Park.

Bulletin of the Shiretoko Museum↗
USGS2024

Challenges in developing vertical hazard for seismic analysis of concrete dams

The seismic response of concrete dams depends on both the horizontal (H) and vertical (V) components of ground motion (GM), and excluding the V components when conducting response history analyses (RHAs) may underestimate the seismic fragility. Although V components of GM time series could be selected to be consistent with the hazard, hazard curves for the V component (or for short, V hazard curves) are rarely available for evaluating such hazard consistency. One of the challenges in developing V hazard curves in the U.S. Geological Survey (USGS) National Seismic Hazard Model (NSHM) is the lack of ground motion models (GMMs) that directly estimate intensity measures (IMs) for the V component of GM. In this study, we compare alternative approaches of developing V hazard curves. Using a case study in California, we compare V hazard curves computed from GMMs for the V component of GM against those from applying GMMs for the V/H ratios and those from selecting multicomponent time series that are consistent with the H hazard. We discuss and invite feedback on issues such as availability of GMMs, applicability of GMMs, and choice of inputs for ground motion selection and modification (GMSM).

Conference Paper↗
USGS2017

Volcanic cloud evolution: Characteristics, observational capabilities and challenges

Volcanic clouds composed of solid particles, volcanic gases, and related aerosols evolve from the time of eruption until the cloud constituents are removed from the atmosphere. While airborne, they have the potential to cause damage to aircraft, ranging from acute encounters that can lead to an immediate hazard to flight safety, to chronic wear on aircraft components, to benign encounters where no observable impacts occur. We highlight the evolution of cloud properties through three stages: Stage 1 (recent), through Stage 2 (intermediate), to Stage 3 (final) and comment on the current observational capabilities and challenges of detection and characterization of volcanic clouds.

Conference Paper↗
USGS2022

Scenario Planning Around Resource Challenges (SPARC): A management-centered approach to scenario planning for climate adaptation

Scenario planning is a strategy or framework that aids making decisions under uncertainty. Inspired by widespread use in the areas of military and business, recent work has applied the strategy to anticipate the effects of climate change on natural resource management. Most scenario planning efforts identify scenarios based on uncertain response in two key drivers of change (e.g., climate, ecology, land use) and then consider the resultant effects on the system and possible changes to management protocols. We present an alternative implementation of scenario planning — Scenario Planning Around Resource Challenges (SPARC) — that produces scenarios that are driven directly by management concerns rather than by the leading scientific uncertainties. The three-step process entails (1) compiling information from the manager (resources, goals, priorities), (2) building scenarios from the leading possible outcomes suggested by the scientific literature and manager perspectives, and (3) running each scenario (i.e., outcome) one-by-one to consider adjustments to management protocols. In short, the unknowns become the scenarios that reflect management priorities. Rather than focusing on the dominant scientific uncertainties, managers spend their time considering only the uncertainties that directly affect the decisions they make. Here, we examine this approach using a case study from a landscape conservation design process led by the Desert Landscape Conservation Cooperative in the Madrean Ecoregion of southeastern Arizona, U.S.A.

Conference Paper↗
USGS2016

Estimating heterotrophic respiration at large scales: Challenges, approaches, and next steps

Heterotrophic respiration (HR), the aerobic and anaerobic processes mineralizing organic matter, is a key carbon flux but one impossible to measure at scales significantly larger than small experimental plots. This impedes our ability to understand carbon and nutrient cycles, benchmark models, or reliably upscale point measurements. Given that a new generation of highly mechanistic, genomic-specific global models is not imminent, we suggest that a useful step to improve this situation would be the development of “Decomposition Functional Types” (DFTs). Analogous to plant functional types (PFTs), DFTs would abstract and capture important differences in HR metabolism and flux dynamics, allowing modelers and experimentalists to efficiently group and vary these characteristics across space and time. We argue that DFTs should be initially informed by top-down expert opinion, but ultimately developed using bottom-up, data-driven analyses, and provide specific examples of potential dependent and independent variables that could be used. We present an example clustering analysis to show how annual HR can be broken into distinct groups associated with global variability in biotic and abiotic factors, and demonstrate that these groups are distinct from (but complementary to) already-existing PFTs. A similar analysis incorporating observational data could form the basis for future DFTs. Finally, we suggest next steps and critical priorities: collection and synthesis of existing data; more in-depth analyses combining open data with rigorous testing of analytical results; using point measurements and realistic forcing variables to constrain process-based models; and planning by the global modeling community for decoupling decomposition from fixed site data. These are all critical steps to build a foundation for DFTs in global models, thus providing the ecological and climate change communities with robust, scalable estimates of HR.

Ecosphere↗