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At least 883 records · Page 49Linked to original sources
USGS2017

Connecting crustal seismicity and earthquake-driven stress evolution in Southern California

Tectonic stress in the crust evolves during a seismic cycle, with slow stress accumulation over interseismic periods, episodic stress steps at the time of earthquakes, and transient stress readjustment during a postseismic period that may last months to years. Static stress transfer to surrounding faults has been well documented to alter regional seismicity rates over both short and long time scales. While static stress transfer is instantaneous and long lived, postseismic stress transfer driven by viscoelastic relaxation of the ductile lower crust and mantle leads to additional, slowly varying stress perturbations. Both processes may be tested by comparing a decade-long record of regional seismicity to predicted time-dependent seismicity rates based on a stress evolution model that includes viscoelastic stress transfer. Here we explore crustal stress evolution arising from the seismic cycle in Southern California from 1981 to 2014 using five M ≥6.5 source quakes: the M 7.3 1992 Landers, M6.5 1992 Big Bear, M 6.7 1994 Big Bear, M 7.1 1999 Hector Mine, and M 7.2 2010 El Mayor-Cucapah earthquakes. We relate the stress readjustment in the surrounding crust generated by each quake to regional seismicity using rate-and-state friction theory. Using a log likelihood approach, we quantify the potential to trigger seismicity of both static and viscoelastic stress transfer, finding that both processes have systematically shaped the spatial pattern of Southern California seismicity since 1992.

California↗
USGS2008

Storm-driven sediment transport in Massachusetts Bay

Massachusetts Bay is a semi-enclosed embayment in the western Gulf of Maine about 50 km wide and 100 km long. Bottom sediment resuspension is controlled predominately by storm-induced surface waves and transport by the tidal- and wind-driven circulation. Because the Bay is open to the northeast, winds from the northeast ('Northeasters') generate the largest surface waves and are thus the most effective in resuspending sediments. The three-dimensional oceanographic circulation model Regional Ocean Modeling System (ROMS) is used to explore the resuspension, transport, and deposition of sediment caused by Northeasters. The model transports multiple sediment classes and tracks the evolution of a multilevel sediment bed. The surficial sediment characteristics of the bed are coupled to one of several bottom-boundary layer modules that calculate enhanced bottom roughness due to wave-current interaction. The wave field is calculated from the model Simulating WAves Nearshore (SWAN). Two idealized simulations were carried out to explore the effects of Northeasters on the transport and fate of sediments. In one simulation, an initially spatially uniform bed of mixed sediments exposed to a series of Northeasters evolved to a pattern similar to the existing surficial sediment distribution. A second set of simulations explored sediment-transport pathways caused by storms with winds from the northeast quadrant by simulating release of sediment at selected locations. Storms with winds from the north cause transport southward along the western shore of Massachusetts Bay, while storms with winds from the east and southeast drive northerly nearshore flow. The simulations show that Northeasters can effectively transport sediments from Boston Harbor and the area offshore of the harbor to the southeast into Cape Cod Bay and offshore into Stellwagen Basin. This transport pattern is consistent with Boston Harbor as the source of silver found in the surficial sediments of Cape Cod Bay and Stellwagen Basin.

Massachusetts↗
USGS2011

Widespread seismicity excitation throughout central Japan following the 2011 M=9.0 Tohoku earthquake and its interpretation by Coulomb stress transfer

We report on a broad and unprecedented increase in seismicity rate following the M=9.0 Tohoku mainshock for M ≥ 2 earthquakes over inland Japan, parts of the Japan Sea and Izu islands, at distances of up to 425 km from the locus of high (≥15 m) seismic slip on the megathrust. Such an increase was not seen for the 2004 M=9.1 Sumatra or 2010 M=8.8 Chile earthquakes, but they lacked the seismic networks necessary to detect such small events. Here we explore the possibility that the rate changes are the product of static Coulomb stress transfer to small faults. We use the nodal planes of M ≥ 3.5 earthquakes as proxies for such small active faults, and find that of fifteen regions averaging ~80 by 80 km in size, 11 show a positive association between calculated stress changes and the observed seismicity rate change, 3 show a negative correlation, and for one the changes are too small to assess. This work demonstrates that seismicity can turn on in the nominal stress shadow of a mainshock as long as small geometrically diverse active faults exist there, which is likely quite common.

Geophysical Research Letters↗
USGS2021

Group density, disease, and season shape territory size and overlap of social carnivores

1. The spatial organization of a population can influence the spread of information, behaviour, and pathogens. Territory size and territory overlap, components of spatial organization, provide key information as these metrics may be indicators of habitat quality, resource dispersion, contact rates, and environmental risk (e.g., indirectly transmitted pathogens). Furthermore, sociality and behaviour can also shape space use, and subsequently, how space use and habitat quality together impact demography. 2. Our study aims to identify factors shaping the spatial organization of wildlife populations and assess the impact of epizootics on space use. We also use network analysis to describe spatial organization and connectivity of social groups. 3. Here, we assessed the seasonal spatial organization of Serengeti lions and Yellowstone wolves at the group level. We examine the factors predicting mean territory size and mean territory overlap for each population using generalized additive models. We further explore the mechanisms by which disease perturbations could cause changes in spatial organization. 4. We demonstrate that lions and wolves were similar in that group-level factors, such as number of groups, shaped spatial organization more than population-level factors, such as population density. Factors shaping territory size were slightly different than factors shaping territory overlap; for example, wolf pack size was an important predictor of territory overlap, but not territory size. Lion spatial networks were more highly connected, while wolf spatial networks varied seasonally. We found that resource dispersion may be more important for driving territory size and overlap for wolves than for lions. Additionally, canine distemper epizootics may alter lion spatial organization, highlighting the importance of including behavioural and movement ecology in studies of pathogen transmission dynamics. 5. We provide insight about when we might expect to observe the impacts of resource dispersion, disease perturbations, and other ecological factors on spatial organization. Our work highlights the importance of monitoring and managing social carnivore populations at the group level. Future research should elucidate the complex relationships between demographics, social and spatial structure, abiotic and biotic conditions, and pathogen infections.

Journal of Animal Ecology↗
USGS2023

Doing the same thing over and over again and getting the same result: Assessing variance in wetland invertebrate assemblages

Past efforts to explain variation of invertebrate assemblages in freshwater wetlands have been less productive than anticipated. To explore why efforts are disappointing, we assembled large invertebrate data sets from North Dakota prairie potholes, California rock pools, and Georgia Carolina bay wetlands that addressed spatial (among wetlands) and temporal (among seasons and years) variation. We anticipated that these large data-set sizes would enable robust conclusions to be drawn, and each place had unique environmental conditions that might contribute to greater explanatory power. We used statistical techniques that partitioned variation in invertebrate assemblages into spatial and/or temporal components, and that also yielded a measure of the amount of unexplained variation; Permutational Multivariate Analysis of Variation and Principal Coordinates Analysis assessed whole assemblage variation, and Analysis of Variance or Analysis of Covariance assessed variation in taxon richness, total abundances, and abundances of wide-spread individual taxa. Across all locations, variation explained by spatial and temporal factors, and unexplained variation were of comparable magnitudes (i.e., similar R 2 values of ~ 50%). Review of other published studies indicate that this pattern is widespread. The 50% or more unexplained variation is typically ignored by researchers, who instead focus on explained fractions. We argue that, besides addressing explained spatial and temporal variation in invertebrate assemblages (e.g., control by hydrology, resources, predation), efforts to understand what contributes to currently unexplained variation, that is unrelated to local spatial or temporal controls (e.g., broad climatic and biogeographic patterns, organism physiology and behavior), will lead to a fuller comprehension of how invertebrates in freshwater wetlands are controlled.

Wetlands↗
USGS2017

Assessment of transfer patterns and origins of in-channel wood in large rivers using repeated field surveys and wood characterisation (the Isère River upstream of Pontcharra, France)

When and whence does wood enter large mountain alluvial rivers? How stable through time are characteristics and quantities of wood deposited in a reach? These simple questions related to the complex practice of wood budgeting are explored on the Isère River in France. We hypothesise that (i) the wood originates from the riparian zone all along the alluvial reach and that (ii) the characters and quantity of wood in the reach can vary through time according to flood occurrence and provenance. In order to validate these hypotheses, two complementary approaches were performed: (i) wood pieces were surveyed along 190 km river length and taxonomy, in-channel wood macromorphology, and dendrochemistry were used to infer wood origin (local vs. upstream, respective subbasin contributions) and transport conditions; (ii) wood movement was monitored using both tracking techniques in specific sampling plots and with an experiment orchestrated using wood placement coupled with a significant artificial flood. Surveys were done over a period of 3 years so as to include two distinct sampling events to explore wood deposition and mobilisation within a channel network under different flood conditions. One of the subbasins, the Arly River, underwent a 1-in-30-year flood in 2004, allowing us to assess its effect on in-channel wood quantity and characteristics. Results confirm that wood is primarily introduced by erosion from river banks but they are not always as close as expected from the sites of deposition. Temporal variability of wood introduced, deposited, and transferred downstream is also significant in terms of abundance and origin as shown by dendrochemical and macromorphological signatures. The types of wood observed along the channel length changes through time. Large flood signature can be detected from wood characteristics and uplands make a slight contribution. But in average, wood characteristics do not change much (no significant difference between years and tributaries in wood characteristics based on discriminant analysis). Data suggest that the interannual variability is fairly low, so that the diversity of wood characteristics is maintained by the complex and multiple sources of wood in the network. Further research is needed to better understand such patterns and to study physical breakage in space and time to better infer distance between sources and depositional zones.

Isère River↗
USGS2020

The influence of frost weathering on the debris flow sediment supply in an alpine basin

Rocky, alpine mountains are prone to mass wasting from debris flows. The Chalk Cliffs study area (central Colorado, USA) produces debris flows annually. These debris flows are triggered when overland flow driven by intense summer convective storms mobilizes large volumes of sediment within the channel network. Understanding the debris flow hazard in this, and similar alpine settings, requires determining the magnitude of sed- iment accumulation between debris flow seasons, and identifying the control on sediment production. To address these knowledge gaps, we measured changes in sediment produc- tion using a sediment retention fence to quantify how sedimentation was influenced by temperature at the plot scale. These measurements were extrapolated to a larger area, where we extended the sediment fence results to explore how rockfall sedimentation con- tributed to channel refilling between active debris flow periods. This work shows debris flow channel refilling is correlated with low temperatures and time in the frost-cracking window, implicating frost weathering mechanisms as a key driver of sedimentation. This sediment production process resulted in a large amount of sediment accumulation dur- ing a single winter season in our study reach (up to 0.4 m in some locations). Using these observations, we develop a channel refilling model that generally describes the mass bal- ance of debris flow watersheds in alpine areas.

Colorado↗
USGS2011

Geospatial characteristics of Florida's coastal and offshore environments: Distribution of important habitats for coastal and offshore biological resources and offshore sand resources

The Geospatial Characteristics GeoPDF of Florida's Coastal and Offshore Environments is a comprehensive collection of geospatial data describing the political boundaries and natural resources of Florida. This interactive map provides spatial information on bathymetry, sand resources, and locations of important habitats (for example, Essential Fish Habitats (EFH), nesting areas, strandings) for marine invertebrates, fish, reptiles, birds, and marine mammals. The map should be useful to coastal resource managers and others interested in marine habitats and submerged obstructions of Florida's coastal region. In particular, as oil and gas explorations continue to expand, the map can be used to explore information regarding sensitive areas and resources in the State of Florida. Users of this geospatial database will have access to synthesized information in a variety of scientific disciplines concerning Florida's coastal zone. This powerful tool provides a one-stop assembly of data that can be tailored to fit the needs of many natural resource managers. The map was originally developed to assist the Bureau of Ocean Energy Management, Regulation, and Enforcement (BOEMRE) and coastal resources managers with planning beach restoration projects. The BOEMRE uses a systematic approach in planning the development of submerged lands of the Continental Shelf seaward of Florida's territorial waters. Such development could affect the environment. BOEMRE is required to ascertain the existing physical, biological, and socioeconomic conditions of the submerged lands and estimate the impact of developing these lands. Data sources included the National Oceanic and Atmospheric Administration, BOEMRE, Florida Department of Environmental Protection, Florida Geographic Data Library, Florida Fish and Wildlife Conservation Commission, Florida Natural Areas Inventory, and the State of Florida, Bureau of Archeological Research. Federal Geographic Data Committee (FGDC) compliant metadata are provided as attached xml files for all geographic information system (GIS) layers.

Florida↗
USGS2011

Geospatial characteristics of Florida's coastal and offshore environments: Coastal habitats, artificial reefs, wrecks, dumping grounds, harbor obstructions and offshore sand resources

The Geospatial Characteristics GeoPDF of Florida's Coastal and Offshore Environments is a comprehensive collection of geospatial data describing the political boundaries and natural resources of Florida. This interactive map provides spatial information on bathymetry, sand resources, coastal habitats, artificial reefs, shipwrecks, dumping grounds, and harbor obstructions. The map should be useful to coastal resource managers and others interested in marine habitats and submerged obstructions of Florida's coastal region. In particular, as oil and gas explorations continue to expand, the map may be used to explore information regarding sensitive areas and resources in the State of Florida. Users of this geospatial database will have access to synthesized information in a variety of scientific disciplines concerning Florida's coastal zone. This powerful tool provides a one-stop assembly of data that can be tailored to fit the needs of many natural resource managers. The map was originally developed to assist the Bureau of Ocean Energy Management, Regulation, and Enforcement (BOEMRE) and coastal resources managers with planning beach restoration projects. The BOEMRE uses a systematic approach in planning the development of submerged lands of the Continental Shelf seaward of Florida's territorial waters. Such development could affect the environment. BOEMRE is required to ascertain the existing physical, biological, and socioeconomic conditions of the submerged lands and estimate the impact of developing these lands. Data sources included the National Oceanic and Atmospheric Administration, BOEMRE, Florida Department of Environmental Protection, Florida Geographic Data Library, Florida Fish and Wildlife Conservation Commission, Florida Natural Areas Inventory, and the State of Florida, Bureau of Archeological Research. Federal Geographic Data Committee (FGDC) compliant metadata are provided as attached xml files for all geographic information system (GIS) layers.

Florida↗
USGS2020

Testing prediction accuracy in short-term ecological studies

Applied ecology is based on an assumption that a management action will result in a predicted outcome. Testing the prediction accuracy of ecological models is the most powerful way of evaluating the knowledge implicit in this cause-effect relationship, however, the prevalence of predictive modeling and prediction testing are spreading slowly in ecology. The challenge of prediction testing is particularly acute for small-scale studies, because withholding data for prediction testing (e.g., via k -fold cross validation) can reduce model precision. However, by necessity small-scale studies are common. We use one such study that explored small mammal abundance along an elevational gradient to test prediction accuracy of models with varying degrees of information content. For each of three small mammal species, we conducted 5000 iterations of the following process: (1) randomly selected 75 % of the data to develop generalized linear models of species abundance that used detailed site measurements as covariates, (2) used an information theoretic approach to compare the top model with detailed covariates to habitat type-only and null models constructed with the same data, (3) tested those models’ ability to predict the 25 % of the randomly withheld data, and (4) evaluated prediction accuracy with a quadratic loss function. Detailed models fit the model-evaluation data best but had greater expected prediction error when predicting out-of-sample data relative to the habitat type models. Relationships between species and detailed site variables may be evident only within the framework of explicitly hierarchical analyses. We show that even with a small but relatively typical dataset ( n = 28 sampling locations across 125 km over two years), researchers can effectively compare models with different information content and measure models’ predictive power, thus evaluating their own ecological understanding and defining the limits of their inferences. Identifying the appropriate scope of inference through prediction testing is ecologically valuable and is attainable even with small datasets.

Maine, New Hampshire↗
USGS2021

Identification of low-frequency earthquakes on the San Andreas fault with deep learning

Low-frequency earthquakes are a seismic manifestation of slow fault slip. Their emergent onsets, low amplitudes, and unique frequency characteristics make these events difficult to detect in continuous seismic data. Here, we train a convolutional neural network to detect low-frequency earthquakes near Parkfield, CA using the catalog of Shelly (2017), https://doi.org/10.1002/2017jb014047 as training data. We explore how varying model size and targets influence the performance of the resulting network. Our preferred network has a peak accuracy of 85% and can reliably pick low-frequency earthquake (LFE) S-wave arrival times on single station records. We demonstrate the abilities of the network using data from permanent and temporary stations near Parkfield, and show that it detects new LFEs that are not part of the Shelly (2017), https://doi.org/10.1002/2017jb014047 catalog. Overall, machine-learning approaches show great promise for identifying additional low-frequency earthquake sources. The technique is fast, generalizable, and does not require sources to repeat.

Geophysical Research Letters↗
USGS2015

Geologic setting of the proposed Fallon FORGE Site, Nevada: Suitability for EGS research and development

The proposed Fallon FORGE site lies within and adjacent to the Naval Air Station Fallon (NASF) directly southeast of the town of Fallon, Nevada, within the large basin of the Carson Sink in west-central Nevada. The site is located on two parcels that include land owned by the NASF and leased and owned by Ormat Nevada, Inc. The Carson Sink in the vicinity of the Fallon site is covered by Quaternary deposits, including alluvial fan, eolian, and lacustrine sediments. Four wells penetrate the entire Neogene section and bottom in Mesozoic basement. Late Miocene to Quaternary basin-fill sediments are 0.5 to >1 km thick and overlie Oligocene-Miocene volcanic and lesser sedimentary rocks. The volcanic section is 0.5 to 1.0 km thick and dominated by Miocene mafic lavas. The Neogene section rests nonconformably on heterogeneous Mesozoic basement, which consists of Triassic-Jurassic metamorphic rocks intruded by Cretaceous granitic plutons. The structural framework is dominated by a gently west-tilted half graben cut by moderately to steeply dipping N- to NNEstriking normal faults that dip both east and west. Quaternary faults have not been observed within the proposed FORGE site. Fallon was selected for a potential FORGE site due to its extensional tectonic setting, abundance of available data, existing infrastructure, and documented temperatures, permeability, and lithologic composition of potential reservoirs that fall within the ranges specified by DOE for FORGE. Since the early 1970s, more than 45 wells have been drilled for geothermal exploration within the area. Four exploration wells within the FORGE site are available for use in the project. Several additional wells are available for monitoring outside the central FORGE site within the NASF and Ormat lease area, including numerous temperature gradient holes. There is an existing, ten-station micro-seismic earthquake (MEQ) array that has been collecting data since 2001; the MEQ array can be expanded to encompass the entire Fallon project. The well data indicate that a sizeable area (~4.5 km2 ) has adequate temperatures in crystalline basement but lacks sufficient permeability within the proposed FORGE site. There are two possible, competent target formations in Mesozoic basement for stimulation in the FORGE project area: 1) Jurassic felsic metavolcanic rocks/and or metaquartzite; and 2) Cretaceous granitic intrusions. These units make up at least 3 km3 in the project area and have target temperatures of ~175-215o C. The abundant well data and detailed geophysical surveys (e.g., gravity, MT, and seismic reflection) provide significant subsurface control for the site and will permit development of a detailed 3D model. The documented temperatures, low permeability, and basement lithologies, as well as abundant available data facilitate development of a site dedicated to testing and improving new EGS technologies and techniques, thus making Fallon an ideal candidate for FORGE.

GRC Transactions↗
USGS2014

Guidelines for a priori grouping of species in hierarchical community models

Recent methodological advances permit the estimation of species richness and occurrences for rare species by linking species-level occurrence models at the community level. The value of such methods is underscored by the ability to examine the influence of landscape heterogeneity on species assemblages at large spatial scales. A salient advantage of community-level approaches is that parameter estimates for data-poor species are more precise as the estimation process borrows from data-rich species. However, this analytical benefit raises a question about the degree to which inferences are dependent on the implicit assumption of relatedness among species. Here, we assess the sensitivity of community/group-level metrics, and individual-level species inferences given various classification schemes for grouping species assemblages using multispecies occurrence models. We explore the implications of these groupings on parameter estimates for avian communities in two ecosystems: tropical forests in Puerto Rico and temperate forests in northeastern United States. We report on the classification performance and extent of variability in occurrence probabilities and species richness estimates that can be observed depending on the classification scheme used. We found estimates of species richness to be most precise and to have the best predictive performance when all of the data were grouped at a single community level. Community/group-level parameters appear to be heavily influenced by the grouping criteria, but were not driven strictly by total number of detections for species. We found different grouping schemes can provide an opportunity to identify unique assemblage responses that would not have been found if all of the species were analyzed together. We suggest three guidelines: (1) classification schemes should be determined based on study objectives; (2) model selection should be used to quantitatively compare different classification approaches; and (3) sensitivity of results to different classification approaches should be assessed. These guidelines should help researchers apply hierarchical community models in the most effective manner.

Ecology and Evolution↗
USGS2020

Assessing the value of removing earthquake-hazard-related epistemic uncertainties, exemplified using average annual loss in California

To aid in setting scientific research priorities, we assess the potential value of removing each of the epistemic uncertainties currently represented in the US Geological Survey California seismic-hazard model, using average annual loss (AAL) as the risk metric of interest. Given all the uncertainties, represented with logic-tree branches, we find a mean AAL of $3.94 billion. The modal value is 17.5% lower than the mean, and there is a 78% chance that the true AAL value is more than 10% away from the mean, and a 5% chance that it is a factor 2.1 greater or lower than the mean. We quantify the extent to which resolving each uncertainty improves the AAL estimate. The most influential branch is one that adds additional epistemic uncertainty to ground motion models, but others are found to be influential as well, such as the rate of M ≥ 5 events throughout the region. We discuss the broader implications of our findings, and note that the time dependence caused by spatiotemporal clustering can be much more influential on AAL than the epistemic uncertainties explored here.

California↗
USGS2012

Satellite tracking and geospatial analysis of feral swine and their habitat use in Louisiana and Mississippi

Feral swine ( Sus scrofa ) is an invasive species that was first introduced to the continental United States in the 1500s by European explorers. Also known as feral hogs or feral pigs, the animals typically weigh about 200 pounds (up to 400 pounds), have characteristic tusks up to 3 inches long, are territorial, and live in groups, except for the boars, who are solitary and typically interact with sows only to breed. They have an average litter size of 5-6 piglets and occasionally two litters per year, and because they have few natural predators, survival of their young can be nearly 100 percent. Because of the detrimental impacts of this invasive species---including rooting, damaging agricultural lands, competing for food with and destroying the habitats of native animals, and spreading diseases and parasites---many public lands implement feral swine control programs on an annual basis. This activity is not enough to control or prevent an increase in swine populations, however, because of their distribution beyond the boundaries of public lands. Currently, little is known about feral swine populations, their habitat use and movement patterns, and the resulting habitat destruction in Louisiana and Mississippi. To abate this lack of knowledge, researchers at the U.S. Geological Survey National Wetlands Research Center (NWRC)---in cooperation with the U.S. Fish and Wildlife Service, the Louisiana Department of Wildlife and Fisheries, and several large landholding companies---are using collars equipped with Global Positioning System (GPS) receivers to track feral swine in Louisiana and Mississippi to examine population movement patterns, document destruction of habitat and wildlife, and help increase and facilitate removal. The NWRC researchers are using the "Judas pig" system of attaching GPS-satellite telemetry collars to select feral swine to (1) track movement patterns on the landscape, (2) document habitat destruction and effects on native wildlife, and (3) improve removal rates. Once a collar has been attached to an individual, usually a large boar or sow, it is released and returns to its group. The group's movements and locations can then be tracked through the movement of the collared individual, the "Judas pig," allowing researchers and managers to better target removal efforts. The use of GPS telemetry will allow the NWRC researchers to monitor feral swine movements daily. The results of this research will provide natural resource managers with more information for managing and responding to the impacts of this invasive species.

Louisiana;Mississippi↗
USGS2025

Triangulating habitat suitability for the locally extirpated California grizzly bear

Reintroducing locally extirpated wildlife species is often necessary to meet recovery goals. However, because current field data cannot be gathered about these species, efforts to identify suitable habitat are often complicated and controversial. Here we present a case study examining a novel approach for identifying suitable habitat for the locally extirpated brown bear, known as the “grizzly,” in California, USA. Once home to a large population of grizzlies, the last credible sighting of a grizzly in California was in 1924, but recent discussions have explored a reintroduction. To study potential grizzly bear habitat suitability in California, we use a multi-model approach in which we consider three indirect methods, or “analogies,” each of which incorporates both environmental and social variables. In the “historical analogy,” we used a unique record of human encounters and museum specimens to build a habitat model of grizzlies in California 150 years ago. In the “geographic analogy,” we used data about contemporary brown bears in Europe and North America to identify potential suitable habitat in California. In the “taxonomic analogy,” we examined data from other large carnivores currently extant in California to draw conclusions about grizzlies. Because these methods yield varying results, we adopt a process known in the social sciences as “triangulation” to compare them. We show that a triangulation approach can improve our understanding of potential suitable habitat, clarifying the strengths and weaknesses of various methods and producing robust yet conservative estimates. Our findings suggest that large areas of suitable habitat for grizzlies exist in California. However, we note that place-based social science research and long-term investment in co-existence would be necessary to maintain suitability. The “analogy and triangulation” approach demonstrates the value of multi-model approaches for habitat suitability, especially for reintroductions.

California↗
USGS2020

Forecasting the combined effects of anticipated climate change and agricultural conservation practices on fish recruitment dynamics in Lake Erie

Many aquatic ecosystems are experiencing multiple anthropogenic stressors that threaten their ability to support ecologically and economically important fish species. Two of the most ubiquitous stressors are climate change and non‐point source nutrient pollution. Agricultural conservation practices (ACPs, i.e. farming practices that reduce runoff, prevent erosion, and curb excessive nutrient loading) offer a potential means to mitigate the negative effects of non‐point source pollution on fish populations. However, our understanding of how ACP implementation amidst a changing climate will affect fish production in large ecosystems that receive substantial upstream sediment and nutrient inputs remains incomplete. Towards this end, we explored how anticipated climate change and the implementation of realistic ACPs might alter the recruitment dynamics of three fish populations (native walleye Sander vitreus and yellow perch Perca flavescens and invasive white perch Morone americana ) in the highly productive, dynamic west basin of Lake Erie. We projected future (2020–2065) recruitment under different combinations of anticipated climate change ( n = 2 levels) and ACP implementation ( n = 4 levels) in the western Lake Erie catchment using predictive biological models driven by forecasted winter severity, spring warming rate, and Maumee River total phosphorus loads that were generated from linked climate, catchment‐hydrology, and agricultural‐practice‐simulation models. In general, our models projected reduced walleye and yellow perch recruitment whereas invasive white perch recruitment was projected to remain stable or increase relative to the recent past. Our modelling also suggests the potential for trade‐offs, as ACP implementation was projected to reduce yellow perch recruitment with anticipated climate change. Overall, our study presents a useful modelling framework to forecast fish recruitment in Lake Erie and elsewhere, as well as offering projections and new avenues of research that could help resource management agencies and policy‐makers develop adaptive and resilient management strategies in the face of anticipated climate and land‐management change.

Michigan, Ohio, Indiana↗
USGS2006

An integrated monitoring approach using multiple reference sites to assess sustainable restoration in coastal Louisiana

Achieving sustainable resource management in coastal Louisiana requires establishing reference conditions that incorporate the goals and objectives of restoration efforts. Since the reference condition is usually considered sustainable, it can be a gauge to assess the present condition of a (degraded) system or to evaluate progress of management actions toward some target system state (the reference or desired conditions). In 2003, the Coastal Wetlands Planning, Protection, and Restoration Act (CWPPRA) Task Force and the Louisiana State Wetlands Authority adopted the “Coastwide Reference Monitoring System -- Wetlands” (CRMS--Wetlands) for Louisiana. This system will provide data from multiple reference sites to explore the properties of a sustained reference condition. CRMS--Wetlands provides links between project-specific and system-wide objectives, criteria for selecting reference sites or conditions, a more robust statistical design, and critical monitoring variables. In addition, a system-wide assessment and monitoring plan (SWAMP) is being developed that incorporates and evaluates existing monitoring efforts (to the extent possible) within a system-wide experimental design. The SWAMP will integrate monitoring of biological, chemical, physical, and climatological variables in four modules: wetlands (CRMS--Wetlands), barrier islands, inshore waters and rivers, and nearshore coastal waters. Data and information collected under SWAMP will contribute to developing a systems-synthesis model for coastal Louisiana. Regional restoration project leaders in coastal Louisiana acknowledge the mutual dependence of monitoring and modeling the coastal landscape. For example, experiments or measurements should not be conducted independently of modeling and vice versa. Assessment should be directed at reducing scientific uncertainty to improve confidence in modeling and monitoring tools and ultimately to assist management actions. An adaptive environmental assessment and management process prescribes modeling, monitoring, and research activities to be conducted from initial stages of restoration planning to optimize the ability to assess and achieve sustainable restoration.

Louisiana↗