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USGS2021

Simulation of dissolved organic carbon flux in the Penobscot Watershed, Maine

Dissolved organic carbon (DOC) is an important component of the carbon cycle as a measure of the hydrological transport of carbon between terrestrial carbon pools into soil pools and eventually into streams. As a result, changes in DOC in rivers and streams may indicate alterations in the storage of terrestrial carbon. Exploring the complex interactions between biogeochemical cycling and hydrologic processes, as well as the micro-climate variabilities that impact the rate of DOC fluxes, are challenging because the information is not readily available from in-situ measurements or from empirical models alone. This is particularly true of large-scale watersheds. The Penobscot Watershed is the largest watershed of the Gulf of Maine and the second largest in New England. Its typical soils, with high organic matter and a large forested and wetland landscape, result in higher DOC fluxes than what has been observed previously for most rivers in the northern temperate or boreal zones (Hope et al., 1994; Mulholland, 1997; Aitkenhead and McDowell, 2000). In this study, we emphasized the simulation of streamflow and DOC fluxes from the Penobscot Watershed (and several tributaries within the Penobscot Watershed) using the spatially distributed process-based Regional Hydro-Ecological Simulation System (RHESSys) model. Simulated results were evaluated using field measurements (streamflow, DOC fluxes) and remotely sensed products (Net Primary Production (NPP) and Leaf Area Index (LAI) from Moderate Resolution Imaging Spectroradiometer (MODIS). The average DOC flux for the Penobscot Watershed during 2004-2012 using the RHESSys model was 69 kg C/ha/year. The RHESSys simulated DOC flux is shown to correlate well with observed values, as well as with results previously reported from the empirical Load Estimator (LOADEST) model (71 kg C/ha/year) for 2004-2007 ( Huntington and Aiken, 2013). Our simulated results also show a temporal variation in the amount of DOC flux, indicating that the antecedent DOC concentration from one year can impact the DOC export in following years. Thus, DOC concentration is positively correlated with streamflow and antecedent precipitation, in agreement with previous studies (Ågren et al., 2010; Huntington and Aiken, 2013; Tian et al., 2013 ). The successful application of the rigorous RHESSys model in the Penobscot Watershed makes it a reasonable platform to test future scenarios impacting the hydrology and biogeochemistry within similar large complex watersheds.

Maine↗
USGS2011

Testing the effect of habitat structure and complexity on nekton assemblages using experimental oyster reefs

Structurally complex habitats are often associated with more diverse and abundant species assemblages in both aquatic and terrestrial ecosystems. Biogenic reefs formed by the eastern oyster ( Crassostrea virginica ) are complex in nature and are recognized for their potential habitat value in estuarine systems along the US Atlantic and Gulf of Mexico coasts. Few studies, however, have examined the response of nekton to structural complexity within oyster reefs. We used a quantitative sampling technique to examine how the presence and complexity of experimental oyster reefs influence the abundance, biomass, and distribution of nekton by sampling reefs 4 months and 16 months post-construction. Experimental oyster reefs were colonized immediately by resident fishes and decapod crustaceans, and reefs supported a distinct nekton assemblage compared to mud-bottom habitat. Neither increased reef complexity, nor age of the experimental reef resulted in further changes in nekton assemblages or increases in nekton abundance or diversity. The presence of oyster reefs per se was the most important factor determining nekton usage.

Journal of Experimental Marine Biology and Ecology↗
USGS2011

Mixed-source reintroductions lead to outbreeding depression in second-generation descendents of a native North American fish

Reintroductions are commonly employed to preserve intraspecific biodiversity in fragmented landscapes. However, reintroduced populations are frequently smaller and more geographically isolated than native populations. Mixing genetically, divergent sources are often proposed to attenuate potentially low genetic diversity in reintroduced populations that may result from small effective population sizes. However, a possible negative tradeoff for mixing sources is outbreeding depression in hybrid offspring. We examined the consequences of mixed‐source reintroductions on several fitness surrogates at nine slimy sculpin ( Cottus cognatus ) reintroduction sites in south‐east Minnesota. We inferred the relative fitness of each crosstype in the reintroduced populations by comparing their growth rate, length, weight, body condition and persistence in reintroduced populations. Pure strain descendents from a single source population persisted in a greater proportion than expected in the reintroduced populations, whereas all other crosstypes occurred in a lesser proportion. Length, weight and growth rate were lower for second‐generation intra‐population hybrid descendents than for pure strain and first‐generation hybrids. In the predominant pure strain, young‐of the‐year size was significantly greater than any other crosstype. Our results suggested that differences in fitness surrogates among crosstypes were consistent with disrupted co‐adapted gene complexes associated with beneficial adaptations in these reintroduced populations. Future reintroductions may be improved by evaluating the potential for local adaptation in source populations or by avoiding the use of mixed sources by default when information on local adaptations or other genetic characteristics is lacking.

Molecular Ecology↗
USGS2006

Use of Numerical Simulations in Surface-Water Studies by the U.S. Geological Survey in Missouri

Numerical simulations of surface-water systems can be a useful tool to predict and understand a variety of physical, chemical, and ecological processes. A number of applications have been conducted by the U.S. Geological Survey Missouri Water Science Center in conjunction with ecological and flood studies in Missouri. Numerical simulations can provide a physically based method to predict natural processes in situations where it is impractical to measure the results directly as a result of cost, time, or infrequent occurrence. Numerical simulations provide a means of analyzing 'What if?' scenarios. For example, a simulation can be used to estimate the effects of reservoirs in a basin on the timing and magnitude of downstream streamflows. Simulations also may provide a better understanding of a complex process, such as sediment transport and deposition during a large flood. Alternatively, numerical simulations can be used to quantify aquatic habitat that is defined by the hydraulic (depth and velocity) characteristics of streamflow. This report provides information on recent applications of numerical simulations of hydraulic, floodplain, and watershed processes.

Fact Sheet↗
USGS2019

Diurnal habitat selection of migrating Whooping Crane in the Great Plains

Available stopover habitats with quality foraging opportunities are essential for migrating waterbirds, including Whooping Crane ( Grus americana ). Several studies have evaluated habitats used by Whooping Crane for roosting throughout its migration corridor; however, habitats associated with foraging and other diurnal activities have received less attention. We used data collected from 42 Whooping Crane individuals that included 2169 diurnal use locations within 395 stopover sites evaluated during spring 2013 to fall 2015 to assess diurnal habitat selection throughout the U.S. portion of the migration corridor. We found that Whooping Crane selected wetland land-cover types (i.e., open water, riverine, and semipermanent wetlands) and lowland grasslands for diurnal activities over all other land-cover types that we evaluated, including croplands. Whooping Crane generally avoided roads, and avoidance varied based on land-cover class. There has been considerable alteration and destruction of natural wetlands and rivers that serve as roosting and foraging sites for migrating Whooping Crane. Given recent droughts and the likelihood of future landscape changes within the migration corridor, directing conservation efforts toward protecting and enhancing wetland stopover areas may prove critical for continued growth of the last remaining wild population of Whooping Crane. Future studies of this Whooping Crane population should focus on specific wetland complexes and riverine sites throughout the migration corridor to identify precise management actions that could be taken to enhance and protect these imperilled land-cover types.

Avian Conservation and Ecology↗
USGS2000

Approaches for assessment of terrestrial vertebrate responses to contaminants: moving beyond individual organisms

Conclusions: A need for a broader range ofinformation on effects of contaminants on individuals exists among the 4 classes of terrestrial vertebrates, especially mammals, reptiles, and amphibians. Separation of contaminant effects from other effects and reduction of speculative extrapolation within and among species requires information that can be produced only by combined field and laboratory investigations that incorporate seasonal or annual cycles and important spatial and interaction conditions. Assessments of contaminant effects at the population level and higher are frequently dependent on extrapolations from a lower organizational level. Actual measurements of the effects of contaminants on populations or communities, possibly in conjunction with case studies that establish relations between effects on individuals and effects on populations, are needed to reduce the uncertainty associated with these extrapolations. Associated with these assessment levels is the need for acceptable definitions of what we mean when we refer to a 'meaningful population change' or an 'effect on communities or ecosystems.' At these higher levels of organization we are also confronted with the need for procedures useful for separating contaminant effects from effects caused by other environmental conditions. Although the bulk of literature surveyed was of the focused cause-and-effect type that is necessary for proving relations between contaminants and wildlife, community or ecosystem field assessments, as sometimes performed with reptiles and amphibians, might be a useful alternative for estimating the potential of a contaminant to cause environmental harm. Assumptions about the special usefulness of reptiles and amphibians as environmental indicators ought to be tested with comparisons to mammals and birds. Information on the effects of contaminants above the individual level is needed to generate accurate estimates of the potential consequences of anthropogenic pollution (e.g., ecological risk assessments). However, realized population, or higher, levels of effects should not be part of regulatory guidelines because the threshold of harm would be too high to be used as a catalyst for action. Measures of realized population or community effects could be used to evaluate the effectiveness of regulatory actions and assess chronic or difficult environmental problems. Some of these information needs can be satisfied with modest effort and expense, but much of the suggested work that incorporates great complexity or long duration is likely to be difficult to accomplish. Cooperation among investigators with different specialties and a willingness by government, academia, and corporate organizations to support the most challenging work will be necessary. Because we are unlikely to have the financial resources to evaluate more than a small number of contaminants for effects at the levels of population, community, or ecosystem, we might need to thoroughly study a few contaminants and then extend the findings to functionally similar contaminants. If sufficient cooperation and organizational support does not materialize, the pursuit of estimation methods will overshadow the collection of actual information on relations between contaminants and wildlife.

Book chapter↗
USGS2012

USGS Environmental health science strategy: providing environmental health science for a changing world: Public review release

America has an abundance of natural resources. We have bountiful clean water, fertile soil, and unrivaled national parks, wildlife refuges, and public lands. These resources enrich our lives and preserve our health and wellbeing. These resources have been maintained because of our history of respect for their value and an enduring commitment to their vigilant protection. Awareness of the social, economic, and personal value of the health of our environment is increasing. The emergence of environmentally driven diseases caused by environmental exposure to contaminants and pathogens is a growing concern worldwide. New health threats and patterns of established threats are affected by both natural and anthropogenic changes to the environment. Human activities are key drivers of emerging (new and re-emerging) health threats. Societal demands for land and natural resources, a better quality of life, improved economic prosperity, and the environmental impacts associated with these demands will continue to increase. Natural earth processes, climate trends, and related climatic events will add to the environmental impact of human activities. These environmental drivers will influence exposure to disease agents, including viral, bacterial, prion, and fungal pathogens, parasites, natural earth materials, toxins and other biogenic compounds, and synthetic chemicals and substances. The U.S. Geological Survey (USGS) defines environmental health science broadly as the interdisciplinary study of relations among the quality of the physical environment, the health of the living environment, and human health. The interactions among these three spheres are driven by human activities, ecological processes, and natural earth processes; the interactions affect exposure to contaminants and pathogens and the severity of environmentally driven diseases in animals and people. This definition provides USGS with a framework for synthesizing natural science information from across the Bureau and providing it to environmental, natural resource, agricultural, and public-health managers. The USGS is a Federal science agency with a broad range of natural science expertise relevant to environmental health. USGS provides scientific information and tools as a scientific basis for management and policy decision making. USGS specializes in science at the environment-health interface, by characterizing the processes that affect the interaction among the physical environment, the living environment, and people, and the resulting factors that affect ecological and human exposure to disease agents. This report describes a 10-year strategy that encompasses the portfolio of USGS environmental health science. It summarizes national environmental health priorities that USGS is best suited to address, and will serve as a strategic framework for USGS environmental health science goals, actions, and outcomes for the next decade. Implementation of this strategy is intended to aid coordination of USGS environmental health activities and to provide a focal point for disseminating information to stakeholders. The "One Health" paradigm advocated by the World Health Organization (WHO, 2011), and the American Veterinary Medicine Association (AVMA, 2008), among others, is based on a general recognition that the health of humans, animals, and the environment are inextricably linked. Thus, successful efforts to protect that health will require increased interdisciplinary research and increased communication and collaboration among the broader scientific and health community. This strategy is built upon that paradigm. The vision, mission, and five cornerstone goals of the USGS Environmental Health Science Strategy were developed with significant input from a wide range of stakeholders. Vision - The USGS is a premier source of the environmental health science needed to safeguard the health of the environment, fish, wildlife, and people. Mission - The mission of USGS in environmental health science is to contribute scientific information to environmental, natural resource, agricultural, and public-health managers, who use that science to support sound decision making. USGS provides the science to: - Goal 1: Identify, prioritize, and detect contaminants and pathogens of emerging environmental concern. - Goal 2: Reduce the impact of contaminants on the environment, fish, wildlife, and people. - Goal 3: Reduce the impact of pathogens on the environment, fish, wildlife, and people. - Goal 4: Discover the complex interactions and combined effects of exposure to contaminants and pathogens. - Goal 5: Prepare for and respond to environmental impacts and related health threats of natural and anthropogenic disasters. Goals 1 through 4 are intended to provide science to address environmental health threats in a logical order, from informing prevention and preparedness, to supporting systematic management response to environmental health issues. Goal 4 addresses the interaction among contaminants and pathogens, an issue of emerging concern in environmental health science. Goal 5 acknowledges the fact that natural and anthropogenic disasters can cause immediate and prolonged adverse environmental health threats. This strategy proposes that USGS take the following strategic science actions to achieve each of the five goals of this strategy: Goal 1: Identify, prioritize, and detect contaminants and pathogens of emerging environmental concern. - Strategic Science Action 1. - Prioritize contaminants and pathogens of emerging concern to guide research, detection, and management activities. - Strategic Science Action 2. - Conduct surveillance and monitoring to provide early warning of emerging health threats. - Strategic Science Action 3. - Develop approaches and tools that identify vulnerable environmental settings, ecosystems, and species. Goal 2: Reduce the impact of contaminants on the environment, fish, wildlife, and people. - Strategic Science Action 1. - Systematically characterize the sources, occurrence, transport and fate of environmental contaminants to guide efforts to manage and mitigate contamination. - Strategic Science Action 2. - Evaluate the threats of contamination on the health of the environment, fish, wildlife, and people, and inform the associated management and protection efforts. - Strategic Science Action 3. - Characterize potential human exposure to support establishment of health-based standards or guidelines and contamination-reduction efforts. Goal 3: Reduce the impact of pathogens on the environment, fish, wildlife, and people. - Strategic Science Action 1. - Determine the biotic and abiotic factors that control the ecology of infectious diseases affecting natural populations of aquatic and terrestrial species and potential transmission to other animals and humans. - Strategic Science Action 2. - Establish how natural and anthropogenic environmental changes affect the distribution and severity of infectious diseases in natural populations of aquatic and terrestrial species and potential transmission to other animals and humans. - Strategic Science Action 3. - Develop surveillance systems to identify changing patterns of disease activity in priority geographic areas. Goal 4: Discover the complex interactions and combined effects of exposure to contaminants and pathogens. - Strategic Science Action 1. - Identify how exposure to one class of disease agents (contaminants or pathogens) can make an organism more susceptible to effects from exposure to the other class of disease agents. - Strategic Science Action 2. - Implement interdisciplinary studies that characterize the effects of combined exposure to pathogens and contaminants. Goal 5: Prepare for and respond to the environmental impacts and related health threats of natural and anthropogenic disasters. - Strategic Science Action 1. - Establish a formal interdisciplinary science capability to rapidly assess the environmental health risks associated with disasters. - Strategic Science Action 2. - Enhance methods to anticipate, prepare for, and identify environmental, ecological, and related health impacts of future disasters. This strategy is one of seven USGS science strategies developed concurrently: - Climate and Land Use Change - Core Science Systems - Ecosystems - Energy and Mineral Resources - Environmental Health - Natural Hazards - Water. This strategy describes how USGS will address the highest priority environmental health issues facing the Nation. The ultimate intended outcome of this science strategy is prevention and reduction of adverse impacts to the quality of the environment, the health of our living resources, and human health. Communication with, and receiving input from, partners and stakeholders regarding their science needs is essential for successful implementation of this strategy. It is incumbent on USGS to reach out to all stakeholders to ensure that USGS efforts are focused on the highest priority environmental health issues and that products are provided in the most timely and usable form to all those who can use them. USGS must reach out to the scientific community, internally and externally, to ensure that our efforts are integrated with and take full advantage of the activities of others.

Open-File Report↗
USGS2014

Advances in interpretation of subsurface processes with time-lapse electrical imaging

Electrical geophysical methods, including electrical resistivity, time-domain induced polarization, and complex resistivity, have become commonly used to image the near subsurface. Here, we outline their utility for time-lapse imaging of hydrological, geochemical, and biogeochemical processes, focusing on new instrumentation, processing, and analysis techniques specific to monitoring. We review data collection procedures, parameters measured, and petrophysical relationships and then outline the state of the science with respect to inversion methodologies, including coupled inversion. We conclude by highlighting recent research focused on innovative applications of time-lapse imaging in hydrology, biology, ecology, and geochemistry, among other areas of interest.

Hydrological Processes↗
USGS1998

Evaluating landscape health: Integrating societal goals and biophysical process

Evaluating landscape change requires the integration of the social and natural sciences. The social sciences contribute to articulating societal values that govern landscape change, while the natural sciences contribute to understanding the biophysical processes that are influenced by human activity and result in ecological change. Building upon Aldo Leopold's criteria for landscape health, the roles of societal values and biophysical processes in shaping the landscape are explored. A framework is developed for indicators of landscape health and integrity. Indicators of integrity are useful in measuring biological condition relative to the condition in landscapes largely unaffected by human activity, while indicators of health are useful in evaluating changes in highly modified landscapes. Integrating societal goals and biophysical processes requires identification of ecological services to be sustained within a given landscape. It also requires the proper choice of temporal and spatial scales. Societal values are based upon inter-generational concerns at regional scales (e.g. soil and ground water quality). Assessing the health and integrity of the environment at the landscape scale over a period of decades best integrates societal values with underlying biophysical processes. These principles are illustrated in two contrasting case studies: (1) the South Platte River study demonstrates the role of complex biophysical processes acting at a distance; and (2) the Kissimmee River study illustrates the critical importance of social, cultural and economic concerns in the design of remedial action plans. In both studies, however, interactions between the social and the biophysical governed the landscape outcomes. The legacy of evolution and the legacy of culture requires integration for the purpose of effectively coping with environmental change.

Journal of Environmental Management↗
USGS2017

Disturbance automated reference toolset (DART): Assessing patterns in ecological recovery from energy development on the Colorado Plateau

A new disturbance automated reference toolset (DART) was developed to monitor human land surface impacts using soil-type and ecological context. DART identifies reference areas with similar soils, topography, and geology; and compares the disturbance condition to the reference area condition using a quantile-based approach based on a satellite vegetation index. DART was able to represent 26–55% of variation of relative differences in bare ground and 26–41% of variation in total foliar cover when comparing sites with nearby ecological reference areas using the Soil Adjusted Total Vegetation Index (SATVI). Assessment of ecological recovery at oil and gas pads on the Colorado Plateau with DART revealed that more than half of well-pads were below the 25th percentile of reference areas. Machine learning trend analysis of poorly recovering well-pads (quantile < 0.23) had out-of-bag error rates between 37 and 40% indicating moderate association with environmental and management variables hypothesized to influence recovery. Well-pads in grasslands (median quantile [MQ] = 13%), blackbrush ( Coleogyne ramosissima ) shrublands (MQ = 18%), arid canyon complexes (MQ = 18%), warmer areas with more summer-dominated precipitation, and state administered areas (MQ = 12%) had low recovery rates. Results showcase the usefulness of DART for assessing discrete surface land disturbances, and highlight the need for more targeted rehabilitation efforts at oil and gas well-pads in the arid southwest US.

Colorado Plateau↗
USGS2010

Vegetation of eastern Unalaska Island, Aleutian Islands, Alaska

Plant communities of Unalaska Island in the eastern Aleutian Islands of western Alaska, and their relationship to environmental variables, were studied using a combined Braun-Blanquet and multivariate approach. Seventy relevés represented the range of structural and compositional variation in the matrix of vegetation and landform zonation. Eleven major community types were distinguished within six physiognomic–ecological groups: I. Dry coastal meadows: Honckenya peploides beach meadow, Leymus mollis dune meadow. II. Mesic meadows: Athyrium filix-femina – Aconitum maximum meadow, Athyrium filix-femina – Calamagrostis nutkaensis meadow, Erigeron peregrinus – Thelypteris quelpaertensis meadow. III. Wet snowbed meadow: Carex nigricans snowbed meadow. IV. Heath: Linnaea borealis – Empetrum nigrum heath, Phyllodoce aleutica heath, Vaccinium uliginosum – Thamnolia vermicularis fellfield. V. Mire: Carex pluriflora – Plantago macrocarpa mire. VI. Deciduous shrub thicket: Salix barclayi – Athyrium filix-femina thicket. These were interpreted as a complex gradient primarily influenced by soil moisture, elevation, and pH. Phytogeographical and syntaxonomical analysis of the plant communities indicated that the dry coastal meadows, most of the heaths, and the mire vegetation belonged, respectively, to the widespread classes Honckenyo–Elymetea, Loiseleurio–Vaccinietea, and Scheuchzerio–Caricetea, characterized by their circumpolar and widespread species. Amphi-Beringian species were likely diagnostic of amphi-Beringian syntaxa, many of these yet to be described.

Alaska↗
USGS2023

Spatio-temporal variability in the strength, directionality, and relative importance of climate on occupancy and population densities in a philopatric mammal, the American pika (Ochotona princeps)

Species distribution models (SDMs) have been widely employed to evaluate species–environment relationships. However, when extrapolated over broad spatial scales or through time, these models decline in their predictive ability due to variation in how species respond to their environment. Many models assume species–environment relationships remain constant over space and time, hindering their ability to accurately forecast distributions. Therefore, there is growing recognition that models could be improved by accounting for spatio-temporal nonstationarity – a phenomenon wherein the factors governing ecological processes change over space or time. Here, we investigated nonstationarity in American pika ( Ochotona princeps ) relationships with climatic variables in the Rocky Mountains (USA). We first compared broad-scale differences in pika–climate patterns for occupancy and population density across the Southern, Central, and Northern Rockies. Next, we investigated within-ecoregion variation across four mountain ranges nested within the Northern Rockies. Lastly, we tested whether species–climate relationships changed over time within the Central Rockies ecoregion. Across all analyses, we found varying levels of nonstationarity among the climate metrics for both occupancy and density. Although we found general congruence in temperature metrics, which consistently had negative coefficients, and moisture metrics (e.g., relative humidity), which had positive coefficients, nonstationarity was greatest for summer and winter precipitation over both space and time. These results suggest that interpretations from one ecoregion should not be applied to other regions universally – especially when using precipitation metrics. The within-ecoregion analysis found much greater variation in the strength-of-relationship coefficients among the four mountain ranges, relative to the inter-regional analysis, possibly attributable to smaller sample sizes per mountain range. Lastly, the importance of several variables shifted through time from significant to insignificant in the temporal analysis. Our results collectively reveal the overall complexity underlying species–environment relationships. With rapidly shifting conditions globally, this work adds to the growing body of literature highlighting how issues of spatio-temporal nonstationarity can limit the accuracy, transferability, and reliability of models and that interpretations will likely be most robust at local to regional scales. Diagnosing, describing, and incorporating nonstationarity of species–climate relationships into models over space and time could serve as a pivotal step in creating more informative models.

Frontiers in Ecology and Evolution↗
USGS2014

An application of Social Values for Ecosystem Services (SolVES) to three national forests in Colorado and Wyoming

Despite widespread recognition that social-value information is needed to inform stakeholders and decision makers regarding trade-offs in environmental management, it too often remains absent from ecosystem service assessments. Although quantitative indicators of social values need to be explicitly accounted for in the decision-making process, they need not be monetary. Ongoing efforts to map such values demonstrate how they can also be made spatially explicit and relatable to underlying ecological information. We originally developed Social Values for Ecosystem Services (SolVES) as a tool to assess, map, and quantify nonmarket values perceived by various groups of ecosystem stakeholders. With SolVES 2.0 we have extended the functionality by integrating SolVES with Maxent maximum entropy modeling software to generate more complete social-value maps from available value and preference survey data and to produce more robust models describing the relationship between social values and ecosystems. The current study has two objectives: (1) evaluate how effectively the value index, a quantitative, nonmonetary social-value indicator calculated by SolVES, reproduces results from more common statistical methods of social-survey data analysis and (2) examine how the spatial results produced by SolVES provide additional information that could be used by managers and stakeholders to better understand more complex relationships among stakeholder values, attitudes, and preferences. To achieve these objectives, we applied SolVES to value and preference survey data collected for three national forests, the Pike and San Isabel in Colorado and the Bridger–Teton and the Shoshone in Wyoming. Value index results were generally consistent with results found through more common statistical analyses of the survey data such as frequency, discriminant function, and correlation analyses. In addition, spatial analysis of the social-value maps produced by SolVES provided information that was useful for explaining relationships between stakeholder values and forest uses. Our results suggest that SolVES can effectively reproduce information derived from traditional statistical analyses while adding spatially explicit, social-value information that can contribute to integrated resource assessment, planning, and management of forests and other ecosystems.

Colorado;Wyoming↗
USGS2021

Accelerating ecological sciences from above: Spatial contrastive learning for remote sensing

The rise of neural networks has opened the door for automatic analysis of remote sensing data. A challenge to using this machinery for computational sustainability is the necessity of massive labeled data sets, which can be cost-prohibitive for many non-profit organizations. The primary motivation for this work is one such problem; the efficient management of invasive species -- invading flora and fauna that are estimated to cause damages in the billions of dollars annually. As an ongoing collaboration with the New York Natural Heritage Program, we consider the use of unsupervised deep learning techniques for dimensionality reduction of remote sensing images, which can reduce sample complexity for downstream tasks and decreases the need for large labeled data sets. We consider spatially augmenting contrastive learning by training neural networks to correctly classify two nearby patches of a landscape as such. We demonstrate that this approach improves upon previous methods and naive classification for a large-scale data set of remote sensing images derived from invasive species observations obtained over 30 years. Additionally, we simulate deployment in the field via active learning and evaluate this method on another important challenge in computational sustainability -- landcover classification -- and again find that it outperforms previous baselines.

Proceedings of the AAAI Conference on Artificial I↗
USGS2019

The rise of an apex predator following deglaciation

Aim Sea otters ( Enhydra lutris ) are an apex predator of the nearshore marine community and nearly went extinct at the turn of the 20th century. Reintroductions and legal protection allowed sea otters to re‐colonize much of their former range. Our objective was to chronicle the colonization of this apex predator in Glacier Bay, Alaska, to help understand the mechanisms that governed their successful colonization. Location Glacier Bay is a tidewater glacier fjord in southeastern Alaska that was entirely covered by glaciers in the mid‐18th century. Since then, it has endured the fastest tidewater glacier retreat in recorded history. Methods We collected and analysed several data sets, spanning 20 years, to document the spatio‐temporal dynamics of an apex predator expanding into an area where they were formerly absent. We used novel quantitative tools to model the occupancy, abundance and colonization dynamics of sea otters, while accounting for uncertainty in the data collection process, the ecological process and model parameters. Results Twenty years after sea otters were first observed colonizing Glacier Bay, they became one of the most abundant and widely distributed marine mammal. The population grew exponentially at a rate of 20% per year. They colonized Glacier Bay at a maximum rate of 6 km per year, with faster colonization rates occurring early in the colonization process. During colonization, sea otters selected shallow areas, close to shore, with a steep bottom slope, and a relatively simple shoreline complexity index. Main conclusions The growth and expansion of sea otters in Glacier Bay demonstrate how legal protection and translocation of apex predators can facilitate their successful establishment into a community in which they were formerly absent. The success of sea otters was, in part, a consequence of habitat that was left largely unperturbed by humans for the past 250 years. Further, sea otters and other marine predators, whose distribution is limited by ice, have the potential to expand in distribution and abundance, reshaping future marine communities in the wake of deglaciation and global loss of sea ice.

Alaska↗
USGS2000

Cruise report RV Ocean Surveyor cruise O-1-00-GM the bathymetry and acoustic backscatter of the Pinnacles area, northern Gulf of Mexico May 23, through June 10, 2000 Venice, LA to Venice, LA

An extensive deep (~100 m) reef tract occurs on the Mississippi-Alabama outer continental shelf (OCS). The tract, known as "The Pinnacles", is apparently part of a sequence of drowned reef complexes along the "40-fathom" shelf edge of the northern Gulf of Mexico (Ludwick and Walton, 1957). It is critical to determine the accurate geomorphology of deep-reefs because of their importance as benthic habitats for fisheries. The Pinnacles were mapped by Ludwick and Walton (1957) using a single-beam echo sounder but the spatial extent and morphology were interpreted from a series of widely separated, poorly navigated bathymetric profiles. Other recent studies, supported by Minerals Management Service (MMS), used towed sidescan sonars and single-channel seismic-reflection profiling. None of the existing studies provide the quality of geomorphic data necessary for reasonable habitat studies. The fish faunas of shallow hermatypic reefs have been well studied, but those of deep ahermatypic reefs have relatively ignored. The ecology of deep ahermatypic reefs is fundamentally different from hermatipic reefs because autochthonous intracellular symbiotic zooxanthellae (the carbon source for hermatypic corals) do not form the base of the trophic web. Instead, exogenous plankton, transported to the reef by currents, serves as the primary carbon source. Deep OCS reefs also lie below the practical working depths for SCUBA; consequently, remote investigations from a ship or in situ investigations using submersibles or ROVs are required. Community structure and trophodynamics of demersal fishes of the Pinnacles are presently the focus of USGS reseach. A goal of the research is to answer questions concerning the relataive roles played by geomorphology and surficial geology in the interaction with and control of biological differentiation. OCS reefs are important because we now know that such areas are important coral reef fish havens, key spawning 2 sites, and a critical early larval and juvenile habitats for economically important sport/food fishes. Also, deep-reef ecosystems as well as the fish populations they sustain are impacted by intensive oil-field development. It is now known that deep OCS reefs function as a key source of re-population (via seasonal and ontogenetic migration) of already heavily impacted inshore reefs. A reflection of this realization is the recent closure by the Gulf States Fisheries Management Council of a 600 mi 2 area of the Florida Middle Grounds (another unmapped major "40-fathom" OCS reef complex) to commercial fishing to preserve grouper spawning aggregations. It is known that the Pinnacles reefs support a lush fauna of ahermatypic hard corals, soft corals, black corals, sessile crinoids and sponges—together forming a living habitat for a well-developed fish fauna. The fish fauna comprises typical Caribbean reef fishes and Carolinian shelf fishes, plus epipelagic fishes, and a few deep-sea fishes. The base of the megafaunal invertebrate food web is plankton, borne by essentially continuous semi-laminar currents flowing predominantly out of the SW, up, along and across the shelf edge. These currents are intercepted by pinnacles reefs, which lie roughly in two linear tracts, parallel to the coastline (see fig. 1 in report). USGS research initiated in 1997 (Sulak et al., in progress) has demonstrated that the Pinnacles reef fish fauna is dominated by planktivorous fishes. Ongoing food habits, trophic web and stable isotope analyses by the USGS are reinforcing a basic picture of deep OCS reefs as ecosystems based on exogenous current-borne plankton. Long-term current meter deployments have demonstrated that the >3 m, <16m relief of the Pinnacles reefs disrupts the prevailing currents, inducing local complexity (F. Kelly, Texas A&M Univ., pers. comm.) favorable to plankton and planktivores. Geodetically accurate bathymetry maps, coregistered with calibrated acoustic backscatter maps, are critical to delineate benthic biotopes, and are essential to correlate biological community differentiation with the physical environment. Previous mapping of the Pinnacles area using the TAMU towed single-beam sidescan system (Anonymous., 1999) employed technology with inherent deficiencies in backscatter calibration, bathymetric precision, and geo-referencing. The resulting bathymetric interpretations of TAMU data are further degraded by ship-track-parallel artifacts that obliterate geomorphology rendering them inadequate to provide high-resolution mapping of individual target reefs (typical maximum relief 15 m, diameter 200-500 m). The sidescan-sonar surveys of the area (Laswell et al., 1990) suffer many of the same deficiencies as the TAMU data so they add no quantitative and little qualitative information about the geomorphology and surficial geology.

Gulf of Mexico, the Pinnacles area↗
USGS2017

Coastal habitat and biological community response to dam removal on the Elwha River

Habitat diversity and heterogeneity play a fundamental role in structuring ecological communities. Dam emplacement and removal can fundamentally alter habitat characteristics, which in turn can affect associated biological communities. Beginning in the early 1900s, the Elwha and Glines Canyon dams in Washington, USA, withheld an estimated 30 million tonnes of sediment from river, coastal, and nearshore habitats. During the staged removal of these dams—the largest dam removal project in history—over 14 million tonnes of sediment were released from the former reservoirs. Our interdisciplinary study in coastal habitats—the first of its kind—shows how the physical changes to the river delta and estuary habitats during dam removal were linked to responses in biological communities. Sediment released during dam removal resulted in over a meter of sedimentation in the estuary and over 400 m of expansion of the river mouth delta landform. These changes increased the amount of supratidal and intertidal habitat, but also reduced the influx of seawater into the pre-removal estuary complex. The effects of these geomorphic and hydrologic changes cascaded to biological systems, reducing the abundance of macroinvertebrates and fish in the estuary and shifting community composition from brackish to freshwater-dominated species. Vegetation did not significantly change on the delta, but pioneer vegetation increased during dam removal, coinciding with the addition of newly available habitat. Understanding how coastal habitats respond to large-scale human stressors—and in some cases the removal of those stressors—is increasingly important as human uses and restoration activities increase in these habitats.

Washington↗
USGS2025

Dynamic risk from Mexican wolves and mountain lions influences elk foraging behavior

Foraging time is a major component of ungulate activity budgets but can be limited by anti-predator behaviors (e.g., vigilance). Multitasking can reduce the nutritional costs of vigilance under heightened predation risk, but this may depend on the response of prey to risk from multiple predators across a complex spatiotemporal landscape. Mexican gray wolves ( Canis lupus baileyi ) and mountain lions ( Puma concolor ) are primary predators for elk ( Cervus canadensis ) in the Mexican wolf experimental population area in east-central Arizona and west-central New Mexico. We observed elk foraging across varying levels of wolf risk throughout all seasons and diel periods to quantify proportions of foraging, intense vigilance, and multitasking at the individual and herd levels. We quantified encounter and kill risk from Mexican wolves and mountain lions using habitat selection functions and utilization distributions. We modeled elk behaviors as functions of predicted risk for both predators in addition to temporal and environmental covariates and accounted for human presence. Our results indicate that individual elk reduced foraging in areas with higher predicted risk from Mexican wolves or mountain lions and increased intense vigilance and multitasking in areas with higher wolf risk. A reduction in the proportion of bedded elk in the herd during all diel periods under increased wolf risk supports previous findings. These results also suggest that elk compensate for higher intense vigilance and reduced foraging during foraging bouts by increasing cumulative foraging bouts per day at the cost of resting. Additionally, the probability of multitasking for individuals depended on an interaction between short- and long-term wolf risk, and the likelihood of intense vigilance was highest under the greatest combined spatial and temporal risk from wolves. This research provides insight into the fine-scale and complex behavioral responses of elk to their primary predators and implies a need for researchers to consider these non-consumptive effects in future studies of predator–prey dynamics.

Arizona, New Mexico↗