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Publications recently added to the Pubs Warehouse

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Fish misidentification and potential implications to monitoring within the San Francisco Estuary, California

Released August 14, 2022 11:16 EST

2018, Journal of Fish and Wildlife Management (9) 467-485

J. E. Kirsch, J. L. Day, James Peterson, D. K. Fullerton

Fish monitoring programs often rely on the collection, species identification, and counting of individual fish over time to inform natural resource management decisions. Thus, the utility of the data used to inform these decisions can be negatively affected by species misidentification. Fish species misidentification bias can be minimized by confirming identification using genetic techniques, training observers, or adjusting monitoring data using estimates of incomplete detection and false-positive misidentification. Despite the existence of well-established fish identification training and quality control programs, there is considerable uncertainty about fish species false-positive misidentification rates and the effectiveness of fish identification training programs within the San Francisco Estuary. We evaluated the misidentification of fish species among Delta Juvenile Fish Monitoring Program observers by conducting five fish identification exams under controlled conditions at the Lodi Fish and Wildlife Office in Lodi, California, between 2012 and 2014. To assess the variability in false-positive misidentification, we fitted data to species and observer characteristics using hierarchical logistic regression. We found that fish species misidentification was fairly common, averaging 17% among 155 test specimens and 32 observers. False-positive misidentification varied considerably among species and was negatively related to fish size, the abundance of the species within monitoring samples, and observer experience. In addition, observers who were not formally trained or used as full-time observers were, on average, 6.0 times more likely to falsely identify a species. However, false-positive misidentification rates among observers and specimens still varied considerably after controlling for observer experience and training, and species and size, respectively. Our results could be used to improve fish identification training and testing, increase the accuracy of fish occupancy or abundance estimation, and justify the allocation of resources to continually use and formally train full-time observers within long-term monitoring programs operating in the system.

Could Kı̄lauea's 2020 post caldera-forming eruption have been anticipated?

Released August 12, 2022 08:37 EST

2022, Geophysical Research Letters (49)

Paul Segall, Kyle R. Anderson, Taiyi Wang

In 2018 Kīlauea volcano erupted a decade’s worth of basalt, given estimated magma supply rates, triggering caldera collapse. Yet, less than 2.5 years later Kīlauea re-erupted. At the 2018 eruption onset, pressure within the summit reservoir was ~20 MPa above magmastatic. By the onset of collapse this decreased by ~17 MPa. Analysis of magma surges at the 2018 fissures, following collapse events, implies excess pressure at the eruption end of only ~1 MPa. Given the new vent elevation, ∼11 − 12 MPa pressure increase was required to bring magma to the surface in December 2020. Analysis of GPS data between 8/2018 and 12/2020 shows there was a 73% probability that this condition was met at the onset of the 2020 eruption. Given a plausible range of possible vent elevations, there was a 40 to 88% probability of sufficient pressure to bring magma to the surface 100 days before the eruption.

Impacts of the ocean-atmosphere coupling into the very short range prediction system during the impact of Hurricane Matthew on Cuba

Released August 12, 2022 08:23 EST

2022, Ciência e Natura (44)

Liset Vázquez Proveyer, Maibys Sierra Lorenzo, Roberto Carlos Cruz Rodríguez, John C. Warner

The main goal of this investigation is analyzing the impact of insert the ocean-atmosphere coupling into the very short range prediction system of Cuba. The ocean-atmosphere coupled components of the Coupled Ocean-Atmosphere-Wave-Sediment Transport Modeling System are used for this purpose and the hurricane Matthew is selected as study case. Two experiments are performed: first, using a dynamic sea surface temperature, updated daily in the atmospheric model WRF; and second using adynamic coupling between the atmospheric and an oceanic models. For the simulated track, the best results are obtained with the coupled system. The impact of coupling on the maximum wind velocities and minimum central pressure is studied. In the coupled system the sea surface temperature has more influence in the surface latent heat fluxes. Also, with this methodology the dry footprint and the behavior of the precipitation field in the presence of a hurricane are studied. This analysis shows that the hurricane acts like an open and self-sustained system in the numerical experiments. The highest differences in the precipitation simulations are in the significant convective area inside the hurricane.

Using microbial source tracking to identify fecal contamination sources in South Oyster Bay on Long Island, New York

Released August 11, 2022 14:05 EST

2022, Scientific Investigations Report 2022-5082

Tristen N. Tagliaferri, Shawn C. Fisher, Christopher M. Kephart, Natalie Cheung, Ariel P. Reed, Robert J. Welk

The U.S. Geological Survey worked in cooperation with the New York State Department of Environmental Conservation to assess the potential sources of fecal contamination entering South Oyster Bay, a shallow embayment on the southern shore of Long Island, New York. Water samples are routinely collected by the New York State Department of Environmental Conservation in the bay and analyzed for fecal coliform bacteria, an indicator of fecal contamination, to determine the need for closure of shellfish beds for harvest and consumption. Fecal coliform and other bacteria are an indicator of the potential presence of pathogenic (disease-causing) bacteria. However, indicator bacteria alone cannot determine the biological or geographical sources of contamination; therefore, microbial source tracking was implemented to determine various biological sources of contamination. In addition, information such as the location, weather and season, and surrounding land use where a sample was collected help determine the geographical source and conveyance of land-based water to the embayment.

Analysis revealed that the most substantial source of fecal contamination to South Oyster Bay was stormwater, particularly during the summer months. The highest frequency of fecal coliform detections in source sites were under wet summer conditions, and the highest fecal coliform concentrations were under wet summer conditions at the Cedar Creek near Bay Place and Unqua Lake Culvert sites (more than 16,000 most probable number per 100 milliliters each). The human-associated Bacteroides marker was the most frequently detected microbial source tracking marker in South Oyster Bay (50 percent positive detections). The human marker was detected at least twice in all surface water source and receptor sites, except for the Massapequa Lake East Culvert source site that did not have any positive human marker detections. Canine contamination was prolific at source sites but was associated with low fecal coliform concentrations in the winter months. All detections of the canine-associated Bacteroides marker were in samples collected during the winter season and were associated with fecal coliform concentrations below the reporting limit, indicating that birds are not a persistent source of fecal coliform to South Oyster Bay. The absence of fecal coliform and human markers in groundwater samples collected throughout the larger study area indicates that water from cesspools or septic tanks do not contribute fecal coliform to the bay. Further, microbial source tracking markers were not detected in the sandy sediment collected at Zachs Bay. Based a classification scheme developed to convey the degree of fecal contamination to stakeholders and resource managers, the Cedar Creek near Bay Place and Unqua Lake Culvert sites were identified as locations that contribute substantial fecal contamination to South Oyster Bay.

Nesting and post-fledging predation risk influence diel patterns of songbird fledging

Released August 11, 2022 08:34 EST

2022, Ibis

Todd M. Jones, Scott J. Chiavacci, Thomas J. Benson, Michael P. Ward

Among stages of avian ontogeny, the act of nest departure or fledging is an abrupt transition into a new environment and a major leap toward independence for offspring. In altricial birds, the timing of fledging is notable in that many species tend to fledge early in the morning. Past studies have proposed nest predation as a key factor driving birds to fledge earlier in the morning (the ‘survival hypothesis’), whereby offspring avoid peak times of nest predation that may occur later in the day. A natural extension of this hypothesis is the predation of offspring post-fledging, whereby offspring are also timing their fledging with future survival prospects outside of the nest. However, few studies have investigated fledging behavior in the context of both nesting and post-fledging predation. To help fill this knowledge gap, we investigated factors driving the timing and duration of fledging across six songbird species in the context of offspring predation: daily nest mortality, post-fledging mortality, and diel patterns of nest predation risk. We found that >60% of songbirds fledged early in the morning, while the peaks in nest predation risk occurred later in the day. Furthermore, species under greater risk of nest predation fledged earlier in the day and in closer succession to their siblings. Parameters of post-fledging mortality were poor predictors of fledging timing, but broods of species under higher risk of post-fledging mortality fledged more rapidly. These results provide evidence in support of the survival hypothesis, and suggest that songbirds fledge in the morning to avoid peak times of nest predation risk that occur later in the day (~8 hours after civil dawn). Such results corroborate past research highlighting predation on dependent offspring as a key factor driving variation in life histories across animal taxa, however, estimates of post-fledging mortality suggests that nest predation alone does not fully explain variation in fledging behavior among species. Future research is therefore needed to investigate the contribution of other factors, such as energetics, parent-offspring conflict, and diel patterns of post-fledging survival, that may help to mediate diel patterns of fledging within and among songbird species.

Diatom influence on the production characteristics of hydrate-bearing sediments: examples from Ulleung Basin, offshore South Korea

Released August 10, 2022 08:58 EST

2022, Journal of Marine and Petroleum Geology (144)

Junbong Jang, William F. Waite, Laura A. Stern, Joo Yong Lee

The Ulleung Basin Gas Hydrate field expeditions in 2007 (UBGH1) and 2010 (UBGH2) sought to assess the Basin's gas hydrate resource potential. Coring operations in both expeditions recovered evidence of gas hydrate, primarily as fracture-filling (or vein type) morphologies in mainly silt-sized, fine-grained sediment, but also as pore-occupying hydrate in the coarser-grained layers of interbedded sand and fine-grained systems. A commonality across many of these occurrences is the presence of diatoms in the fine-grained sediment. Here we tested fine-grained sediment (median grain size <12.5 μm) associated with hydrate occurrences at four UBGH2 sites (UBGH2-2-2, UBGH2-3, UBGH2-6 and UBGH2-11) to investigate potential impacts of diatoms on efforts to extract methane from hydrate, or to tap hydrocarbon reservoirs beneath hydrate-bearing sediment. Two key considerations are: the extent to which diatoms control sediment mechanical properties, and the extent to which pore-water freshening, which occurs as gas hydrate breaks down during resource extraction, alters the diatom control on sediment mechanical properties. We conducted experiments to measure sediment index properties, sedimentation behavior and compressibility to address these considerations. We relied on scanning electron microscope (SEM) imagery and X-ray powder diffraction (XRD) to characterize the sediment mineralogy. Our high-level findings are that at the ∼20–45% (by volume) diatom concentrations observed at these UBGH2 sites, sediment compressibility increases with diatom content, but diatoms only appear to increase porosity and permeability at the highest diatom concentration (∼45%). Our measurements suggest in situ compression indices of 0.35–0.55 and permeabilities on the order of 0.01milliDarcies (1 × 10−17 m2) can be anticipated at these sites. Importantly, these properties are not expected to vary significantly upon pore water freshening that accompanies gas hydrate dissociation during production.

    Deciphering natural and anthropogenic nitrate and recharge sources in arid region groundwater

    Released August 10, 2022 08:39 EST

    2022, Science of the Total Environment (848)

    Benjamin S. Linhoff

    Recently, the subsoils of ephemeral stream (arroyos) floodplains in the northern Chihuahuan Desert were discovered to contain large naturally occurring NO3 reservoirs (floodplain: ~38,000 kg NO3-N/ha; background: ~60 kg NO3-N/ha). These reservoirs may be mobilized through land use change or natural stream channel migration which makes differentiating between anthropogenic and natural groundwater NO3 sources challenging. In this study, the fate and sources of NO3 were investigated in an area with multiple NO3 sources such as accidental sewer line releases and sewage lagoons as well as natural reservoirs of subsoil NO3. To differentiate sources, this study used a large suite of geochemical tools including δ15N[NO3], δ18O[NO3], δ15N[N2], δ13C[DIC], 14C, tritium (3H), dissolved gas concentrations, major ion chemistry, and contaminants of emerging concern (CEC) including artificial sweeteners. NO3 at sites with the highest concentrations (25 to 229 mg/L NO3-N) were determined to be largely sourced from naturally occurring subsoil NO3 based on δ15N[NO3] (<8 ‰) and mass ratios of Cl/Br (〈100) and NO3/Cl (>1.5). Anthropogenic NO3 was deciphered using mass ratios of Cl/Br (>120) and NO3/Cl (<1), δ15N[NO3] (>8 ‰), and CEC detections. Nitrogen isotope analyses indicated that denitrification is fairly limited in the field area. CEC were detected at 67 % of sites including 3H dead sites (<1 pCi/L) with low percent modern carbon-14 (PMC; <30 %). Local supply wells are 3H dead with low PMC; as 3H does not re-equilibrate and 14C is very slow to re-equilibrate during recirculation through infrastructure, sites with low PMC, 3H < 1 pCi/L, and CEC detections were interpreted as locations with substantial anthropogenic groundwater recharge. Neotame was used to identify locations of very recent (<15 years before present) or ongoing wastewater influxes to the aquifer. This work shows the important influence of naturally occurring subsoil NO3 reservoirs on groundwater in arid regions and the major contribution of artificial recharge.

    Assembling a safe and effective toolbox for integrated flea control and plague mitigation: Fipronil experiments with prairie dogs

    Released August 10, 2022 08:21 EST

    2022, PLoS ONE (17)

    David A. Eads, Travis Livieri, Tyler Tretten, John Hughes, Nick Kaczor, Emily Halsell, Shaun M. Grassel, Phillip Dobesh, Eddie Childers, David Lucas, Lauren Noble, Michele Vasquez, Anna Catherine Grady, Dean E. Biggins

    Heike Lutermann, editor(s)


    Plague, a widely distributed zoonotic disease of mammalian hosts and flea vectors, poses a significant risk to ecosystems throughout much of Earth. Conservation biologists use insecticides for flea control and plague mitigation. Here, we evaluate the use of an insecticide grain bait, laced with 0.005% fipronil (FIP) by weight, with black-tailed prairie dogs (BTPDs, Cynomys ludovicianus). We consider safety measures, flea control, BTPD body condition, BTPD survival, efficacy of plague mitigation, and the speed of FIP grain application vs. infusing BTPD burrows with insecticide dusts. We also explore conservation implications for endangered black-footed ferrets (Mustela nigripes), which are specialized predators of Cynomys.

    Principal findings

    During 5- and 10-day laboratory trials in Colorado, USA, 2016–2017, FIP grain had no detectable acute toxic effect on 20 BTPDs that readily consumed the grain. During field experiments in South Dakota, USA, 2016–2020, FIP grain suppressed fleas on BTPDs for at least 12 months and up to 24 months in many cases; short-term flea control on a few sites was poor for unknown reasons. In an area of South Dakota where plague circulation appeared low or absent, FIP grain had no detectable effect, positive or negative, on BTPD survival. Experimental results suggest FIP grain may have improved BTPD body condition (mass:foot) and reproduction (juveniles:adults). During a 2019 plague epizootic in Colorado, BTPDs on 238 ha habitat were protected by FIP grain, whereas BTPDs were nearly eliminated on non-treated habitat. Applications of FIP grain were 2–4 times faster than dusting BTPD burrows.


    Deltamethrin dust is the most commonly used insecticide for plague mitigation on Cynomys colonies. Fleas on BTPD colonies exhibit the ability to evolve resistance to deltamethrin after repeated annual treatments. Thus, more tools are needed. Accumulating data show orally-delivered FIP is safe and usually effective for flea control with BTPDs, though potential acute toxic effects cannot be ruled out. With continued study and refinement, FIP might be used in rotation with, or even replace deltamethrin, and serve an important role in Cynomys and black-footed ferret conservation. More broadly, our stepwise approach to research on FIP may function as a template or guide for evaluations of insecticides in the context of wildlife conservation.

    Research to inform passage spacing for migratory amphibians and to evaluate efficacy and designs for open elevated road segment (ERS) passages

    Released August 09, 2022 08:44 EST

    2022, Report

    Cheryl S. Brehme, Stephanie Barnes, Brittany Ewing, Cassie Vaughan, Michael Hobbs, Charles Tornaci, Philip Robert Gould, Sarah Holm, Hanna Sheldon, Robert N. Fisher

    This is a multifaceted project that includes three main areas of research targeted to inform effective crossing systems for migratory amphibians, a large group of species which are at very high risk from negative impacts from roads within their habitats (Glista et al. 2008, Hamer and McDonnell 2008, Semlitsch 2008, Brehme et al. 2018). The three projects presented in this report are:

    1) Movement distances along road barrier fencing and probabilities of reaching a passage: Case study with Yosemite toads in Sierra National Forest, CA.

    2) Effectiveness of a novel elevated road segment (ERS) road passage system prototype in providing connectivity for amphibians, reptiles, and small mammals: Case study in Sierra National Forest, CA.

    3) Concept designs and transportation engineering evaluation for the ERS on primary roads and highways.

    This research began in 2018 as part of a larger U.S. Geological Survey (USGS) research program in collaboration with the U.S. Forest Service (USFS), California Department of Transportation (Caltrans), and Western Transportation Institute (WTI; Montana State University) to inform best management practices for barrier and crossing systems for sensitive amphibians and reptiles in California (Langton and Clevenger 2021, Brehme and Fisher 2020). The funding from Department of Transportation (DOT) pooled fund partners (Parks Canada / Government of Canada, Federal Highway Administration (FHWA), U.S. State Departments of Transportation (AK, AZ, CA, CO, IA, MI, MN, NM, NV, OR, WA), Ontario Ministry of Transportation) and managed by the Nevada Department of Transportation (NDOT) supported 2021 field study efforts, analyses of fence movement distances for Yosemite toads, and analysis of the efficacy of a novel ERS passage system to Yosemite toads and other amphibians, reptiles and small mammals. Finally, this pooled fund project includes an assessment by transportation engineers in consultation with USGS and Caltrans to provide insight, guidance, and concept designs for similar crossing solutions that could be implemented on improved roads.

    This research is meant to inform the distances required between crossings to provide permeability for migratory amphibians (i.e., to allow movements necessary for population persistence across roads) as well as to assess the permeability of a new passage design for amphibians and other small animal species that may provide greater connectivity and offer an alternative to below grade tunnels. The results of these studies add to the current body of knowledge in road ecology and increase the choices of road passage designs for amphibians and other small wildlife species.

    Hydrogeologic framework, water levels, and selected contaminant concentrations at Valmont TCE Superfund Site, Luzerne County, Pennsylvania, 2020

    Released August 09, 2022 07:20 EST

    2021, Open-File Report 2021-1093

    Lisa A. Senior, Alex R. Fiore, Philip H. Bird

    The Valmont TCE Superfund Site, Luzerne County, Pennsylvania is underlain by fractured and folded sandstones and shales of the Pottsville and Mauch Chunk Formations, which form a fractured-rock aquifer recharged locally by precipitation. Industrial activities at the former Chromatex Plant resulted in trichloroethene (TCE) contamination of groundwater at and near the facility, which was identified in 1987 and led to listing as a Superfund site by the U.S. Environmental Protection Agency (EPA) in 1989. To address the problem of TCE concentrations in nearby residential wells that exceed the maximum contaminant level (MCL) of 5 micrograms per liter (μg/L), alternate water supplies were provided. A 2015 review of initial characterization and subsequent remediation by the EPA identified the need for an updated understanding of the complex hydrogeology and the conceptual site model. Additional contaminants present in groundwater at the site include some other volatile organic compounds (VOCs) and per- and polyfluoroalkyl substances (PFAS), predominantly consisting of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) present in concentrations that exceeded the EPA Health Advisory (HA) level of 5 nanograms per liter (ng/L) for combined PFOA and PFOS.

    In response to a request from the EPA in 2019, the U.S. Geological Survey (USGS) prepared cross sections and maps to provide more information about the hydrogeologic framework at and near the site and assist in improving the conceptual site model using water level and contaminant data collected by the EPA in 2020. The cross sections present lithologic correlations from available geophysical logs collected in wells from 2002 to 2014; they show alternating intervals of relatively elevated and reduced natural gamma activity that correspond to changes in lithology, with water-bearing zones and well screens commonly located at lithologic contacts, sometimes near thin coal seams. Water-bearing zones commonly are associated with fractures at or near lithologic contacts but also may be associated with fractures at or near apparent faulting. Recent (March 2020) water-level data shown on cross sections and maps indicate large downward vertical gradients and apparent radial gradients laterally to the northeast, northwest, and southwest that generally following topography. Recent (February to March 2020) data for TCE groundwater concentration shown on cross sections and maps indicate the highest TCE concentrations (greater than 3,000 μg/L and as much as 75,000 μg/L) and combined PFOA and PFOS concentrations (greater than 1,000 ng/L and up to at least 2,350 ng/L) are from shallow (less than 60 feet [ft] below land surface [bls]) and intermediate depth (60 to 100 ft bls) wells near the center of the former Chromatex Plant. TCE and PFAS (as combined PFOA and PFOS) contamination is present at greater depths, as much as 304 ft bls, as evidenced by samples collected from one well (a reconstructed former production well) near the plant, that contained concentrations of about 240 μg/L and 508 ng/L, respectively. The 2020 data also indicate that TCE and PFAS concentrations which exceed drinking-water MCL or HA levels are present in groundwater depths of less than 200 ft in an area that extends predominantly in a northeast direction from the former Chromatex Plant, and is apparently influenced by hydraulic gradients, lithology, and geologic structure.

    U.S. Geological Survey Benchmark Glacier Project

    Released August 08, 2022 12:45 EST

    2022, Fact Sheet 2022-3050

    Caitlyn Florentine, Lisa L. Mckeon

    The ​U.S. Geological Survey Benchmark Glacier Project combines decades of direct glaciological data with remote sensing data to advance the quantitative understanding of glacier-climate interactions. The global loss of glaciers, and consequent implications for water resources, sea level rise, and ecosystem function underscores the importance of U.S. Geological Survey glaciology research to facilitate adaptive strategies.

    U.S. strong-motion programs

    Released August 08, 2022 11:32 EST

    1980, Conference Paper, Proceedings of the seventh world conference on earthquake engineering. Istanbul, Turkey, Sept. 8-13, 1980

    Roger D. Borcherdt, R. B. Matthiesen

    No abstract available.

    Soil carbon consequences of historic hydrologic impairment and recent restoration in coastal wetlands

    Released August 06, 2022 08:20 EST

    2022, Science of the Total Environment (848)

    Meagan Eagle, Kevin D. Kroeger, Amanda C. Spivak, Faming Wang, Jianwu Tang, Omar I. Abdul-Aziz, Khandker S. Ishtiaq, Jennifer A. O'Keefe Suttles, Adrian G. Mann

    Coastal wetlands provide key ecosystem services, including substantial long-term storage of atmospheric CO2 in soil organic carbon pools. This accumulation of soil organic matter is a vital component of elevation gain in coastal wetlands responding to sea-level rise. Anthropogenic activities that alter coastal wetland function through disruption of tidal exchange and wetland water levels are ubiquitous. This study assesses soil vertical accretion and organic carbon accretion across five coastal wetlands that experienced over a century of impounded hydrology, followed by restoration of tidal exchange 5 to 14 years prior to sampling. Nearby marshes that never experienced tidal impoundment served as controls with natural hydrology to assess the impact of impoundment and restoration. Dated soil cores indicate that elevation gain and carbon storage were suppressed 30–70 % during impoundment, accounting for the majority of elevation deficit between impacted and natural sites. Only one site had substantial subsidence, likely due to oxidation of soil organic matter. Vertical and carbon accretion gains were achieved at all restored sites, with carbon burial increasing from 96 ± 33 to 197 ± 64 g C m−2 y−1. The site with subsidence was able to accrete at double the rate (13 ± 5.6 mm y−1) of the natural complement, due predominantly to organic matter accumulation rather than mineral deposition, indicating these ecosystems are capable of large dynamic responses to restoration when conditions are optimized for vegetation growth. Hydrologic restoration enhanced elevation resilience and climate benefits of these coastal wetlands.

    Trends analysis of Rangeland Condition Monitoring Assessment and Projection (RCMAP) fractional component time series (1985–2020)

    Released August 05, 2022 11:36 EST

    2022, GIScience & Remote Sensing (59) 1243-1265

    Hua Shi, Matthew B. Rigge, Kory Postma, Brett Bunde

    Rangelands have a dynamic response to climate change, fire, and other anthropogenic disturbances. The Rangeland Condition, Monitoring, Assessment, and Projection (RCMAP) product aims to capture this response by quantifying the percent cover of eight rangeland components, associated error, and trends across the western United States using Landsat from 1985 to 2020. The current generation of RCMAP has been improved with more training data, regional-scale Landsat composites, and more robust change detection. We assess the temporal patterns in each component with a linear model and a structural change method that determines break points using an 8-year temporal moving window. The linear and structural change methods generally agreed on patterns of change, but the latter found breaks more often, with at least one break point in most pixels. The structural change model provides more robust statistics on the significant minority of pixels with non-monotonic trends, while detrending some interannual signal potentially superfluous from a long-term perspective. Although break point density within one year of fire and vegetation treatments was ~10× and ~4× that of unburned areas, respectively, break point detection in the correct year of fire was only moderately accurate. Climate responses in break points proved more robust, with strong spatiotemporal relation in break point density with both aridity index values and aridity index change. Break point density strongly responds to both increased and decreased aridity and is reflective of ecosystem resilience. Data provide spatiotemporal information on the occurrence of breaks, but even more importantly, attribute those change events to specific component(s).

    Microbial community response to a bioaugmentation test to degrade trichloroethylene in a fractured rock aquifer, Trenton, N.J

    Released August 05, 2022 08:46 EST

    2022, Microbial Ecology (98)

    Jennifer C. Underwood, Denise M. Akob, Michelle Lorah, Thomas E. Imbrigiotta, Ronald W. Harvey, Claire R. Tiedeman

    Bioaugmentation is a promising strategy for enhancing trichloroethylene (TCE) degradation in fractured rock. However, slow or incomplete biodegradation can lead to stalling at degradation byproducts such as 1,2-dichloroethene (cis-DCE) and vinyl chloride (VC). Over the course of 7 years, we examined the response of groundwater microbial populations in a bioaugmentation test where an emulsified vegetable oil solution (EOS®) and a dechlorinating consortium (KB-1®), containing the established dechlorinator Dehalococcoides (DHC), were injected into a TCE-contaminated fractured rock aquifer. Indigenous microbial communities responded within 2 days to added substrate and outcompeted KB-1®, and over the years of monitoring, several other notable turnover events were observed. Concentrations of ethene, the end product in reductive dechlorination, had the strongest correlations (P< .05) with members of Candidatus Colwellbacteria but their involvement in reductive dechlorination is unknown and warrants further investigation.DHC never exceeded 0.6% relative abundance of groundwater microbial communities, despite its previously presumed importance at the site. Increased concentrations of carbon dioxide, acetic acid, and methane were positively correlated with increasing ethene concentrations; however, concentrations of cis-DCE and VC remained high by the end of the monitoring period suggesting preferential enrichment of indigenous partial dechlorinators over bioaugmented complete dechlorinators. This study highlights the importance of characterizing in situ microbial populations to understand how they can potentially enhance or inhibit augmented TCE degradation.

    Assessing population genomic structure and polyploidy: A crucial step for native plant restoration

    Released August 05, 2022 08:17 EST

    2022, Restoration Ecology

    Bryce A. Richardson, Robert Massatti, Nurul Islam-Faridi, Skylar Johnson, Francis F. Kilkenny

    Establishing an effective restoration program requires baseline genetic information to make sound decisions for seed increase and transfer. For many plants this information is lacking, especially among native forbs that are critical for pollinator health. Erigeron speciosus is a widespread, perennial forb occupying montane environments in the western United States and Canada. This species is important in fostering pollinator diversity. Our study examines the population genetic patterns across the species range using reduced-representation sequencing and surveys for genome duplication using flow cytometry and cytology. These genomic tools provide critical information for seed increase and seed transfer, necessary for restoration programs. Population genetic differentiation (FST) average was 0.13 and ranged from 0.05 to 0.24 among 23 collection sites. Model-based Bayesian clustering supported a model with collection sites grouped into two populations, occupying distinct geographic regions of this species range. A genetic distance-based neighbor-joining tree also supported this division. Flow cytometry of 53 samples from 17 populations had 2C values that ranged from 1.7 to 3.6 pg with a mean 2C value of 2.3 pg. Putative triploids were found in two individuals from one collection site. The spatial distribution of genetic structure supports regionally based taxonomic descriptions of two varieties: speciosus in the North and macranthus in the South. This assessment of genetic structure and genome duplication describes an effective approach in developing baseline genetic information for restoration species, especially those species that may harbor complex taxonomy and polyploidy.

    Bedrock depth influences spatial patterns of summer baseflow, temperature and flow disconnection for mountainous headwater streams

    Released August 05, 2022 08:08 EST

    2022, Hydrology and Earth System Sciences (26) 3989-4011

    Martin Briggs, Phillip J. Goodling, Zachary Johnson, Karli M. Rogers, Nathaniel P. Hitt, Jennifer Burlingame Hoyle Fair, Craig D. Snyder

    In mountain headwater streams, the quality and resilience of summer cold-water habitat is generally regulated by stream discharge, longitudinal stream channel connectivity and groundwater exchange. These critical hydrologic processes are thought to be influenced by the stream corridor bedrock contact depth (sediment thickness), a parameter often inferred from sparse hillslope borehole information, piezometer refusal and remotely sensed data. To investigate how local bedrock depth might control summer stream temperature and channel disconnection (dewatering) patterns, we measured stream corridor bedrock depth by collecting and interpreting 191 passive seismic datasets along eight headwater streams in Shenandoah National Park (Virginia, USA). In addition, we used multi-year stream temperature and streamflow records to calculate several baseflow-related metrics along and among the study streams. Finally, comprehensive visual surveys of stream channel dewatering were conducted in 2016, 2019 and 2021 during summer low flow conditions (124 total km of stream length). We found that measured bedrock depths along the study streams were not well-characterized by soils maps or an existing global-scale geologic dataset where the latter overpredicted measured depths by 12.2 m (mean) or approximately four times the average bedrock depth of 2.9 m. Half of the eight study stream corridors had an average bedrock depth of less than 2 m. Of the eight study streams, Staunton River had the deepest average bedrock depth (3.4 m), the coldest summer temperature profiles and substantially higher summer baseflow indices compared to the other study steams. Staunton River also exhibited paired air and water annual temperature signals suggesting deeper groundwater influence, and the stream channel did not dewater in lower sections during any baseflow survey. In contrast, Paine Run and Piney River did show pronounced, patchy channel dewatering, with Paine Run having dozens of discrete dry channel sections ranging from 1 to greater than 300 m in length. Stream dewatering patterns were apparently influenced by a combination of discrete deep bedrock (20+ m) features and more subtle sediment thickness variation (1–4 m) depending on local stream valley hydrogeology. In combination, these unique datasets show the first large-scale empirical support for existing conceptual models of headwater stream disconnection based on spatially variable underflow capacity and shallow groundwater supply.

    Status of water-level altitudes and long-term water-level changes in the Chicot and Evangeline (undifferentiated) and Jasper aquifers, greater Houston area, Texas, 2021

    Released August 05, 2022 07:27 EST

    2022, Scientific Investigations Report 2022-5065

    Christopher L. Braun, Jason K. Ramage

    Since the early 1900s, groundwater withdrawn from the primary aquifers that compose the Gulf Coast aquifer system—the Chicot and Evangeline (undifferentiated) and Jasper aquifers—has been the primary source of water in the greater Houston area, Texas. This report, prepared by the U.S. Geological Survey in cooperation with the Harris-Galveston Subsidence District, City of Houston, Fort Bend Subsidence District, Lone Star Groundwater Conservation District, and Brazoria County Groundwater Conservation District, is one in an annual series of reports depicting the status of water-level altitudes and water-level changes in aquifers in the greater Houston area.

    In contrast to previous reports, the Chicot and Evangeline aquifers are treated as a single hydrogeologic unit in this report. In 2021, shaded depictions of water-level altitudes for the Chicot and Evangeline aquifers (undifferentiated) ranged from 300 feet (ft) below the North American Vertical Datum of 1988 (NAVD 88) to 300 ft above NAVD 88. The largest decline in water-level altitudes indicated by the 1977–2021 long-term water-level-change map for the Chicot and Evangeline aquifers (undifferentiated) was in the north-central part of The Woodlands, Tex., whereas the 1990–2021 long-term water-level-change map for the Chicot and Evangeline aquifers (undifferentiated) depicts a large area of decline in water-level altitudes in northwestern Harris County, northwest of Jersey Village, Tex. The largest rise in water-level altitudes in the Chicot and Evangeline aquifers (undifferentiated) was observed in a relatively large area in southeastern Harris County for 1977–2021, whereas the largest rise in water-level altitudes for 1990–2021 was in a relatively large area in central Harris County.

    In 2021, shaded depictions of water-level altitudes for the Jasper aquifer ranged from 250 ft below NAVD 88 to 300 ft above NAVD 88. The 2000–21 long-term water-level-change map for the Jasper aquifer depicts water-level declines throughout most of the study area where water-level-altitude data from the Jasper aquifer were collected, with the largest decline in northern Harris County southwest of The Woodlands.

    Treatment of the Chicot and Evangeline aquifers as a single hydrogeologic unit and use of geostatistical interpolation methods to develop gridded surfaces of water-level altitudes and water-level changes in the Chicot and Evangeline aquifers (undifferentiated) and Jasper aquifer, greater Houston area, Texas, 2021

    Released August 05, 2022 07:26 EST

    2022, Scientific Investigations Report 2022-5064

    Jason K. Ramage, Christopher L. Braun, John H. Ellis

    The greater Houston area of Texas includes approximately 11,000 square miles and encompasses all or part of 11 counties (Harris, Galveston, Fort Bend, Montgomery, Brazoria, Chambers, Grimes, Liberty, San Jacinto, Walker, and Waller). From the early 1900s until the mid-1970s, groundwater withdrawn from the three primary aquifers that compose the Gulf Coast aquifer system—the Chicot, Evangeline, and Jasper aquifers—had been the primary source of water for the greater Houston area. The withdrawal of groundwater was unregulated prior to 1975, resulting in land-surface subsidence caused by large water-level declines in the greater Houston area.

    This report, prepared by the U.S. Geological Survey in cooperation with the Harris-Galveston Subsidence District, City of Houston, Fort Bend Subsidence District, Lone Star Groundwater Conservation District, and Brazoria County Groundwater Conservation District, describes updates to the ways in which water-level altitudes and water-level changes in the greater Houston area are presented relative to previous U.S. Geological Survey reports. The first update involves presenting water-level altitudes and water-level changes as a combined (undifferentiated) representation of the Chicot and Evangeline aquifers. The second update concerns the methods used to depict water-level altitudes and water-level changes in the greater Houston area in interpretive reports, with geostatistical interpolation methods replacing manual contouring methods.

    The Chicot and Evangeline aquifers have historically been described as distinct hydrogeologic units for the purpose of water-level mapping. A confining unit does not separate these two aquifers in the study area, and water-level data from colocated wells screened in these aquifers indicate that there is likely a substantial degree of hydrogeologic connection. From a groundwater-flow perspective, these two aquifer units predominantly function as a single unit. Hence, the decision was made to combine the Chicot and Evangeline aquifers into a single, undifferentiated hydrogeologic unit for the purposes of assessing water-level altitudes and water-level changes over time. The 2020 water-level altitudes for the Chicot, Evangeline, and Jasper aquifers were re-created in this report from computer algorithms of the contoured datasets as gridded surfaces to demonstrate the similarity of results from geostatistical interpolation methods to those from manual contouring methods.

    Science facilitation: Navigating the intersection of intellectual and interpersonal expertise in scientific collaboration

    Released August 05, 2022 06:20 EST

    2022, Humanities and Social Sciences Communications (9)

    Amanda E. Cravens, Megan Siobhan Jones, Courtney Ngai, Jill Zarestky, Hannah B. Love

    Today’s societal challenges, such as climate change and global pandemics, are increasingly complex and require collaboration across scientific disciplines to address. Scientific teams bring together individuals of varying backgrounds and expertise to work collaboratively on creating new knowledge to address these challenges. Within a scientific team, there is inherent diversity in disciplinary cultures and preferences for interpersonal collaboration. Such diversity contributes to the potential strength of the created knowledge but can also impede progress when teams struggle to collaborate productively. Facilitation is a professional practice-based form of interpersonal expertise that supports group members to do their best thinking. Although facilitation has been demonstrated to support group functioning in a wide range of contexts, its role in supporting scientific teams has been largely overlooked. This essay defines scientific facilitation as a form of interactional expertise and explains how facilitating scientific teams requires skills in managing interpersonal interactions as well as understanding how different types of disciplinary knowledge integrate in the creation of new knowledge. Next, it explains how this science facilitation expertise may be developed through metacognition. Finally, it provides examples of how scientific facilitation could be more widely incorporated into research by describing three pathways to expand the use of facilitation theory and techniques in collaborative scientific research: developing facilitation skills among scientists leading teams, using broadly trained facilitators, and using specialised science facilitators. The strengths and risks of each path are discussed, and criteria are suggested for selecting the right approach for a given team science project.

    Distribution and trends of endemic Hawaiian waterbirds

    Released August 04, 2022 09:34 EST

    2022, Waterbirds (44) 425-437

    Eben H. Paxton, Kevin W. Brinck, Adonia Henry, Afsheen Siddiqi, Rachel A. Rounds, Jennifer Chutz

    Four endemic species of wetland-dependent waterbirds occur on the main Hawaiian Islands, all of which have experienced sharp population declines and are listed as endangered species. Twice per year, state-wide surveys are conducted to count waterbirds, but these surveys are evaluated only infrequently. We used a state-space approach to evaluate long-term (1986–2016) and short-term (2006–2016) trends and current distribution and abundance of endemic Hawaiian waterbirds. The most numerous species was the Ae‘o, or Hawaiian Stilt (Himantopus mexicanus knudseni), with a 5-year estimated average abundance of 1,932 individuals, followed by ‘Alae Ke‘oke‘o, or Hawaiian Coot (Fulica alai), with 1,815 individuals, Alae ‘Ula, or Hawaiian Common Gallinule (Gallinula galeata sandvicensis) with 927 individuals, and the Koloa Maoli, or Hawaiian Duck (Anas wyvilliana) with 931 individuals. All four species had positive trends over the long-term, but short-term and island specific trends were more variable, and in some cases negative. These results provide valuable information to help guide management of Hawaii’s threatened and endangered endemic waterbirds.

    Understory plant communities show resistance to drought, hurricanes, and experimental warming in a wet tropical forest

    Released August 04, 2022 09:23 EST

    2022, Frontiers in Forests and Global Change (5)

    Aura M. Alonso-Rodríguez, Tana E. Wood, Jamarys Torres-Díaz, Molly A. Cavaleri, Sasha Reed, Benedicte Bachelot

    Global climate change has led to rising temperatures and to more frequent and intense climatic events, such as storms and droughts. Changes in climate and disturbance regimes can have non-additive effects on plant communities and result in complicated legacies we have yet to understand. This is especially true for tropical forests, which play a significant role in regulating global climate. We used understory vegetation data from the Tropical Responses to Altered Climate Experiment (TRACE) in Puerto Rico to evaluate how plant communities responded to climate warming and disturbance. The TRACE understory vegetation was exposed to a severe drought (2015), 2 years of experimental warming (4°C above ambient in half of the plots, 2016–2017 and 2018–2019), and two major hurricanes (Irma and María, September 2017). Woody seedlings and saplings were censused yearly from 2015 to 2019, with an additional census in 2015 after the drought ended. We evaluated disturbance-driven changes in species richness, diversity, and composition across ontogeny. We then used Bayesian predictive trait modeling to assess how species responded to disturbance and how this might influence the functional structure of the plant community. Our results show decreased seedling richness after hurricane disturbance, as well as increased sapling richness and diversity after warming. We found a shift in species composition through time for both seedlings and saplings, yet the individual effects of each disturbance were not significant. At both ontogenetic stages, we observed about twice as many species responding to experimental warming as those responding to drought and hurricanes. Predicted changes in functional structure point to disturbance-driven functional shifts toward a mixture of fast-growing and drought-tolerant species. Our findings demonstrate that the tropical forest understory community is more resistant to climatic stressors than expected, especially at the sapling stage. However, early signs of changes in species composition suggest that, in a warming climate with frequent droughts and hurricanes, plant communities might shift over time toward fast-growing or drought-tolerant species.

    A comprehensive assessment of mangrove species and carbon stock on Pohnpei, Micronesia

    Released August 04, 2022 09:07 EST

    2022, PLoS ONE (17)

    Victoria Woltz, Elitsa I. Peneva-Reed, Zhiliang Zhu, Eric L. Bullock, Richard A. MacKenzie, Maybeleen Apwong, Ken Krauss, Dean B. Gesch

    Sotirios Koukoulas, editor(s)

    Mangrove forests are the most important ecosystems on Pohnpei Island, Federated States of Micronesia, as the island communities of the central Pacific rely on the forests for many essential services including protection from sea-level rise that is occurring at a greater pace than the global average. As part of a multi-component assessment to evaluate vulnerabilities of mangrove forests on Pohnpei, mangrove forests were mapped at two points in time: 1983 and 2018. In 2018, the island had 6,426 ha of mangrove forest. Change analysis indicated a slight (0.76%) increase of mangrove area between 1983 and 2018, contrasting with global mangrove area declines. Forest structure and aboveground carbon (AGC) stocks were inventoried using a systematic sampling of field survey plots and extrapolated to the island using k-nearest neighbor and random forest species models. A gridded or wall to wall approach is suggested when possible for defining carbon stocks of a large area due to high variability seen in our data. The k-nearest neighbor model performed better than random forest models to map species dominance in these forests. Mean AGC was 167 ± 11 MgC ha-1, which is greater than the global average of mangroves (115 ± 7 MgC ha-1) but within their global range (37–255 MgC ha-1) Kauffman et al. (2020). In 2018, Pohnpei mangroves contained over 1.07 million MgC in AGC pools. By assigning the mean AGC stock per species per area to the map, carbon stock distributions were visualized spatially, allowing future conservation efforts to be directed to carbon dense stands.

    Freshwater unionid mussels threatened by predation of Round Goby (Neogobius melanostomus)

    Released August 04, 2022 08:57 EST

    2022, Scientific Reports (12)

    Kyle Clark, Deborah D. Iwanowicz, Luke R. Iwanowicz, Sara Mueller, Joshua Wisor, Casey Bradshaw-Wilson, W. Bane Schill, Jay R. Stauffer Jr., Elizabeth W. Boyer

    Indigenous freshwater mussels (Unionidae) are integral to riverine ecosystems, playing a pivotal role in aquatic food webs and providing ecological services. With populations on the decline worldwide, freshwater mussels are of conservation concern. In this study, we explore the propensity of the invasive Round Goby (Neogobius melanostomus) fish to prey upon indigenous freshwater mussels. First, we conducted lab experiments where Round Gobies were given the opportunity to feed on juvenile unionid mussels and macroinvertebrates, revealing rates and preferences of consumption. Several Round Gobies consumed whole freshwater mussels during these experiments, as confirmed by mussel counts and x-ray images of the fishes. Next, we investigated Round Gobies collected from stream habitats of the French Creek watershed, which is renowned for its unique and rich aquatic biodiversity. We developed a novel DNA metabarcoding method to identify the specific species of mussels consumed by Round Goby and provide a new database of DNA gene sequences for 25 indigenous unionid mussel species. Several of the fishes sampled had consumed indigenous mussels, including the Elktoe (non-endangered), Creeper (non-endangered), Long Solid (state endangered), and Rayed Bean (federally endangered) species. The invasive Round Goby poses a growing threat to unionid mussels, including species of conservation concern. The introduction of the invasive Round Goby to freshwaters of North America is shaping ecosystem transitions within the aquatic critical zone having widespread implications for conservation and management.

    Flexible multimethod approach for seismic site characterization

    Released August 04, 2022 08:50 EST

    2022, Journal of Seismology

    William J. Stephenson, Alan Yong, Antony Martin

    We describe the flexible multimethod seismic site characterization technique for obtaining shear-wave velocity (VS) profiles and derivative information, such as the time-averaged VS of the upper 30 m (VS30). Simply stated, the multimethod approach relies on the application of multiple independent noninvasive site characterization acquisition and analysis techniques utilized in a flexible field-based approach through a decision process based on primary factors such as the investigator’s available equipment, field logistics (e.g., available array deployment space, urban versus rural), geologic setting, and funding among other primary factors. In a multimethod approach, sites ideally should be characterized using both active and passive noninvasive (i.e., no drilling and only minimal disturbance to the ground surface) methods. Almost without exception, we recommend the use of at least one active-source technique for analyzing surface waves, which in the current state of practice would include one or more of the following: spectral analysis of surface waves (SASW; commonly Rayleigh waves) and multichannel analysis of surface waves (MASW; Rayleigh and/or Love waves). In addition, passive-source microtremor array methods (MAMs) using linear (one-dimensional) and two-dimensional arrays may be appropriate or even required for characterizing a given site. Similarly, the microtremor horizontal-to-vertical spectral ratio (mHVSR) method can be valuable for identifying shallow rock sites. Finally, P- and SH-wave seismic refraction methods warrant consideration, especially at rock and shallow-rock sites.

    Plague circulation in small mammals elevates extinction risk for the endangered Peñasco least chipmunk

    Released August 04, 2022 08:39 EST

    2022, Global Ecology and Conservation (38)

    Amanda R. Goldberg, David A. Eads, Dean E. Biggins

    Wildlife diseases are a major concern for species survival around the world. Vector-borne diseases, in particular, are problematic for both humans and wildlife. Plague is an introduced disease to North America where many species have low natural resistance to infection by the causative bacterium, Yersinia pestis. Plague in the United States is often associated with large-scale epizootic events that impact rodent populations. However, we need more information regarding the effects of plague at enzootic levels and in species that rarely if ever experience epizootic events. New Mexico is a state that experiences regular epizootic plague events in several species of rodents but comparatively less is known about enzootic plague impacts within rodent communities in New Mexico. The Peñasco least chipmunk (Neotamias minimus atristriatus) is state-listed as endangered in New Mexico and is a candidate for listing under the federal Endangered Species Act. It likely has been extirpated from the southern portion of its range and is now observed only at high elevations in isolated areas in the White Mountains. We evaluated plague presence in the more abundant small mammal species associated with these chipmunks. We used an F1 antigen plague-specific vaccine and a placebo injection to test whether plague was present and reducing survival in western deer mouse (Peromyscus sonoriensis) and vole (Microtus spp.) populations in the Lincoln National Forest. The effect of plague on survival differed among years and sites. Monthly apparent survival was up to 60 % higher for rodents given the vaccine compared to those given a placebo. Our results suggest that plague is likely impacting the small mammal community in the Lincoln National Forest and is even present at higher elevation sites where the Peñasco least chipmunk was most recently extirpated. Because least chipmunks are highly susceptible to plague, our results suggest that this disease may be an important factor in the population decline of the Peñasco least chipmunk.

    Reestablishing a foundational species: limitations on post-wildfire sagebrush seedling establishment

    Released August 04, 2022 08:22 EST

    2022, Ecosphere (13)

    Robert Arkle, David Pilliod, Matthew Germino, Michelle Jeffries, Justin L. Welty

    Improving post-wildfire restoration of foundational plant species is crucial for conserving imperiled ecosystems. We sought to better understand the initial establishment of sagebrush (Artemisia sp.), a foundational shrubland species over a vast area of western North America, in the first 1–2 years post-wildfire, a critical time period for population recovery. Field data from 460 sagebrush populations sampled across the Great Basin revealed several patterns. Sagebrush seedlings were uncommon in the first 1–2 years after fire, with none detected in 69% of plots, largely because most fires occurred in areas of low resistance to invasive species and resilience to disturbance (hereafter, R&R). Post-fire aerial seeding of sagebrush dramatically increased seedling occupancy, especially in low R&R areas, which exhibited a 3.4-fold increase in occupancy over similar unseeded locations. However, occupancy models and repeat surveys suggested exceptionally high mortality, as occupancy rates declined by as much as 50% between the first and second years after fire. We found the prevalence of “fertile island” microsites (patches beneath fire-consumed sagebrush) to be the best predictor of seedling occupancy, followed by aerial seeding status, native perennial grass cover, and years since fire. In populations where no sagebrush seeding occurred, seedlings were most likely to occur in locations with a combination of high fertile island microsite cover and close proximity to a remnant sagebrush plant. These important attributes were only present in 13% of post-fire locations, making them rare across the Great Basin. Finally, in the absence of fertile islands and remnant plants, seedling establishment was not observed in any unseeded areas, and rarely in seeded locations. Thus, local extirpation of sagebrush could have important, long-term implications for sagebrush reestablishment following future fires if there are no mature individuals to leave behind fertile islands or serve as remnant individuals. These findings highlight the importance of landscape legacy effects and could help guide where and how big sagebrush restoration is conducted in the future.

    Sediment and nutrient retention on a reconnected floodplain of an Upper Mississippi River tributary, 2013–2018

    Released August 04, 2022 07:15 EST

    2022, Scientific Investigations Report 2022-5030

    Lynn A. Bartsch, Rebecca M. Kreiling, Lance R. Gruhn, Jessica D. Garrett, William B. Richardson, Greg M. Nalley

    The connection of rivers with their floodplains has been greatly reduced in agricultural drainage basins, especially in the Upper Mississippi River Basin. The restriction of the Mississippi River from its floodplain has reduced the sediment trapping and nutrient deposition capabilities of the floodplain, exacerbating water quality problems in the river and in downstream waterbodies. A small part of the Maquoketa River, a tributary to the Upper Mississippi River, was permanently reconnected to its floodplain in 2010 when a levee failure resulted in breaches in two locations. This study quantified the water quality benefits of that reconnection from October 2013 through September 2018. As part of the study, data from groundwater monitoring wells were used to determined hydraulic connectivity and surface-water/groundwater mixing; soil samples were collected in the floodplain to quantify floodplain sediment and nutrient retention potential during postflood and dry, interflood periods; and sensors were placed in the Maquoketa River to quantify total suspended solids, nitrogen, and phosphorus concentrations and loads.

    The floodplain aquifer in the study area had low hydraulic gradients toward the Maquoketa (mean of 0.017) and Mississippi Rivers (mean of 0.0029) and reducing water-quality conditions (dissolved oxygen less than 1.0 milligram per liter [mg/L] and nitrate less than 0.04 mg/L as nitrogen) capable of denitrification. A specific conductance-based mixing indicated precipitation was the predominate source of groundwater; however, specific conductance-based mixing analysis was unable to distinguish between the river or direct precipitation as the source.

    The floodplain was fully inundated five times during the study: in June–July 2014, March 2015, January 2017, February 2018, and September 2018. During the March 2015 flood (the only inundation event with sufficient duration to leave quantifiable sediment deposition in the study area), the equivalent of 0.91 percent of the nitrate load and 3.8 percent of the phosphorus load was deposited as sediment on the floodplain. Potential nitrogen losses on the floodplain because of denitrification ranged from 250 kilograms per day (kg/d) as nitrogen in March 2015 to 668 kg/d as nitrogen in October 2014. Potential denitrification rates indicate that when the soil is inundated, inorganic nitrogen present in the soil and in the water column is rapidly denitrified. Soil phosphorus measurements indicated that floodplain soils contain a mean of 365 milligrams per kilogram as phosphorus but still have the capacity to remove phosphorus from flood waters of the Maquoketa River depending on the surface water phosphorus concentration. Results from this study indicate that restoration of even small river-floodplain connections can improve water quality in the Upper Mississippi River.

    Beyond the teleseism: Introducing regional seismic and geodetic data into routine USGS finite‐fault modeling

    Released August 04, 2022 06:35 EST

    2022, Seismological Research Letters

    Dara Elyse Goldberg, Pablo Koch, Diego Melgar, Sebastian Riquelme, William L. Yeck

    The U.S. Geological Survey (USGS) National Earthquake Information Center (NEIC) routinely produces finite‐fault models following significant earthquakes. These models are spatiotemporal estimates of coseismic slip critical to constraining downstream response products such as ShakeMap ground motion estimates, Prompt Assessment of Global Earthquake for Response loss estimates, and ground failure assessments. Because large earthquakes can involve slip over tens to hundreds of kilometers, point‐source approximations are insufficient, and it is vital to rapidly assess the amount, timing, and location of slip along the fault. Initially, the USGS finite‐fault products were computed in the first several hours after a significant earthquake, using teleseismic body wave and surface wave observations. With only teleseismic waveforms, it is generally possible to obtain a reliable model for earthquakes of magnitude 7 and larger. Here, we detail newly implemented updates to NEIC’s modeling capabilities, specifically to allow joint modeling of local‐to‐regional strong‐motion accelerometer, Global Navigation Satellite System (GNSS), and Interferometric Synthetic Aperture Radar (InSAR) observations in addition to teleseismic waveforms. We present joint inversion results for the 2015 

    Groundwater resources of the Harney Basin, southeastern Oregon

    Released August 03, 2022 15:24 EST

    2022, Fact Sheet 2022-3052

    Stephen B. Gingerich, C. Amanda Garcia, Henry M. Johnson

    In response to increasing groundwater demand and declining groundwater levels in the Harney Basin of southeastern Oregon, the U.S. Geological Survey and the Oregon Water Resources Department conducted a cooperative groundwater-availability study during 2016–22. This Fact Sheet summarizes the results of this study. Full details of the study are provided in Gingerich and others (2022a, 2022b), Garcia and others (2022), and the other supporting documents listed on the last page of this Fact Sheet.

    Evidence gaps and diversity among potential win–win solutions for conservation and human infectious disease control

    Released August 03, 2022 07:10 EST

    2022, The Lancet Planetary Health (6) e694-e705

    Skylar R. Hopkins, Kevin D. Lafferty, Chelsea L. Wood, Sarah H Olson, Julia C Buck, Giulio A. De Leo, Kathryn Fiorella, Johanna Fornberg, Andres Garchitorena, Isabel J. Jones, Armand Kuris, Laura H Kwong, Christopher LeBoa, Ariel Elizabeth Leon, Andrea Lund, Andrew J MacDonald, Daniel Metz, Nicole Nova, Alison J. Peel, Justin V. Remais, Tara E. Stewart Merrill, Maya Wilson, Matthew Bonds, Andrew Dobson, David Lopez-Carr, Meghan Howard, Lisa Mandle, Susanne H. Sokolow

    As sustainable development practitioners have worked to “ensure healthy lives and promote well-being for all” and “conserve life on land and below water”, what progress has been made with win–win interventions that reduce human infectious disease burdens while advancing conservation goals? Using a systematic literature review, we identified 46 proposed solutions, which we then investigated individually using targeted literature reviews. The proposed solutions addressed diverse conservation threats and human infectious diseases, and thus, the proposed interventions varied in scale, costs, and impacts. Some potential solutions had medium-quality to high-quality evidence for previous success in achieving proposed impacts in one or both sectors. However, there were notable evidence gaps within and among solutions, highlighting opportunities for further research and adaptive implementation. Stakeholders seeking win–win interventions can explore this Review and an online database to find and tailor a relevant solution or brainstorm new solutions.

      Longitudinal water-temperature profiles in Mill Creek, Mason County, Washington

      Released August 02, 2022 13:27 EST

      2022, Scientific Investigations Report 2022-5063

      Andrew S. Gendaszek, Richard W. Sheibley, Erica Marbet, Joe Puhn, Catherine Seguin

      In streams supporting Pacific salmon (Oncorhynchus spp.) within the southern Puget Lowland, high water temperatures during late summer are a primary water-quality concern. The metabolic rates of fish and other ectothermic (in other words, cold-blooded) species are regulated by water temperature; salmon and other cold-water fish have specific thermal tolerances outside of which they are susceptible to infection, disease, increased predation, and decreased reproductive success. Mill and Gosnell Creeks, which collectively drain a 30-square mile area of the Puget Lowland in Mason County, Washington, support several species of anadromous salmonids. Whereas previous studies documented relatively cool water temperatures in Gosnell Creek, which drains the watershed upstream from Lake Isabella, water temperatures in Mill Creek, which heads at the outlet of Lake Isabella, regularly exceed thermal tolerances for cold-water fish. The occurrence and distribution of cold-water anomalies in less-than-ambient water temperatures in Mill Creek, however, have not been assessed. In this report, we present spatially and temporally continuous measurements of near-streambed water temperature measured using fiber-optic distributed temperature sensing for three reaches of Mill Creek during August–September 2020 when the water temperatures of streams in western Washington were near their annual maximum. Water temperature was collected every hour and averaged spatially over 1.015-meter sections of the fiber-optic cable deployed at the streambed of Mill Creek. The lengths of the fiber-optic cables deployed in Reaches A, B, and C were 883, 270, and 1,014 meters, respectively. Daily maximum water temperature and daily temperature variability, as measured by standard deviation of water temperature during the deployment, progressively decreased downstream as distance from Lake Isabella increased. However, no abrupt decreases in daily maximum or standard deviation of water temperature were detected in longitudinal temperature profiles of any of the three reaches. Collectively, these results suggest that warm water discharged from Lake Isabella was progressively buffered downstream as it equilibrated with downstream heat fluxes mediated by physical processes including riparian shading and diffuse groundwater input. Although parts of the surveyed reaches associated with deep pools were cooler than other locations, no large (less than 2 °C) water-temperature anomalies characteristic of discrete sources of cold groundwater or surface-water inputs were measured in any of the three surveyed reaches.

      Element concentrations and grain size of sediment from the Similkameen River above Enloe Dam (Enloe Reservoir) near Oroville, Washington, 2019

      Released August 02, 2022 12:15 EST

      2022, Scientific Investigations Report 2022-5073

      Stephen E. Cox, Christopher A. Curran, Andrew R. Spanjer, Chad C. Opatz, Renee K. Takesue, J. Lynn Bell

      In 2019, the U.S. Geological Survey conducted a reconnaissance survey of concentrations of 41 trace elements present in bed sediment in the reservoir on the Similkameen River upstream from Enloe Dam, near Oroville, Washington. The Similkameen River drains a watershed containing highly mineralized geologic deposits with current (2019) and historical mining activity. Results of this survey indicated that surface and subsurface sediment are substantially enriched in element concentrations of silver (Ag), arsenic (As), gold (Au), bismuth (Bi), cadmium (Cd), copper (Cu), manganese (Mn), antimony (Sb), selenium (Se), tin (Sn), and tellurium (Te) relative to average concentrations found in upper continental-crustal material. Conversely, concentrations of mercury (Hg) and lead (Pb) in sediment above Enloe Dam (Enloe Reservoir) were generally less than average concentrations in upper continental-crustal material (Hg = 0.05 milligrams per kilogram [mg/kg]; Pb =17 mg/kg). Concentrations of most trace elements were higher in the less than 63-micrometer fraction (silt) and tended to be higher in subsurface than in surface sediment. The concentrations of trace elements were compared to consensus-based aquatic toxicity reference concentrations, Washington State Department of Ecology sediment management standards, and average concentrations of upper continental-crustal material. Arsenic concentrations were consistently elevated above these criteria among samples and often exceeded sediment management standards and aquatic toxicity reference values (both threshold effects and probable effects concentrations). High concentrations of As were measured in sediment with proportionally more material in the less than 63-micrometer size fraction; this result may be related to the presence of ore-processing waste material that has entered the aquatic system from approximately 125 years of mining operations in the basin. Elevated concentrations of chromium and copper that exceed the same criteria as arsenic (As) were measured less consistently and predominantly in the fine-grain size fraction.

      Documenting the multiple facets of a subsiding landscape from coastal cities and wetlands to the continental shelf

      Released August 02, 2022 09:34 EST

      2022, Open-File Report 2022-1064

      James G. Flocks, Eileen McGraw, John Barras, Julie Bernier, Mike Bradley, Devin L. Galloway, James Landmeyer, W. Scott McBride, Christopher Smith, Kathryn Smith, Christopher Swarzenski, Lauren Toth

      Land subsidence is a settling, sinking, or collapse of the land surface. In the southeastern United States, subsidence is frequently observed as sinkhole collapse in karst environments, wetland degradation and loss in coastal and other low-lying areas, and inundation of coastal urban communities. Human activities such as fluid extraction, mining, and overburden alteration can cause or exacerbate subsidence, which can result in damage to infrastructure and resources. Subsidence is a hazard that takes place throughout the United States; however, a systematic approach to recognize and develop informed responses to the drivers of subsidence has not yet been fully established. To address this problem, the U.S. Geological Survey (USGS) Southeast Region (SER) funded the gathering of a team of interdisciplinary USGS scientists to promote scientific collaboration. Southeast Region scientists welcomed scientists from other regions (see table 1.1 in Appendix 1) in September 2018 at the St. Petersburg Coastal and Marine Science Center (SPCMSC) in Florida for the first workshop of the Subsidence Flex Team (SFT) (see Appendix 2 for agenda). The SFT set out to review subsidence-related research and technology and develop a unifying framework for describing the processes and hazards associated with land subsidence. A more comprehensive understanding of subsidence hazards could help to inform regional vulnerability assessments that would prove invaluable to the public, community developers, policy makers, and resource managers in both inland and coastal states. The SFT analyzed USGS strengths and weaknesses to identify existing infrastructure and capabilities that could be leveraged to create a comprehensive and far-reaching subsidence-monitoring and mitigation program. Over the course of the 2-day workshop, interdisciplinary understandings of the processes and hazards related to subsidence were explored through individual presentations and group discussion. With all perspectives considered, the SFT recommended that subsidence-related research develop scientific approaches and metrics by which the subsidence component can be isolated and quantified in order to protect both the environment and human infrastructure from harm.

      Management of diseases in free-ranging wildlife populations

      Released August 02, 2022 08:46 EST

      2022, Book chapter

      Mark L. Drew, Jonathan M. Sleeman

      Eric Miller, Nadine Lamberski, Paul Calle, editor(s)

      Diseases are increasingly threatening the conservation of wildlife species. Spillover of pathogens into humans and domestic animals may negatively impact public health and the economy, requiring increased proactive management actions. The North American Wildlife Management Model provides the philosophical basis for managing wildlife and underpins all management options. Diseases in wildlife populations may be managed by manipulation of the environment, manipulation of the host, manipulation of the agent, and modification of human behavior. Important considerations include setting management goals, and metrics to assess success. Future strategies include using systems and One Health approaches to develop interventions that optimize outcomes for humans, animals, and the environment.

      Future directions to manage wildlife health in a changing climate

      Released August 02, 2022 08:33 EST

      2022, EcoHealth

      Erik K. Hofmeister, Emily Cornelius Ruhs, Lucas Fortini, M. Camille Hopkins, Lee C. Jones, Kevin D. Lafferty, Jonathan M. Sleeman, Olivia Erin LeDee

      In September 2019 The Economist wrote an obituary to Okjökull, a glacier in western Iceland that was declared “dead” in 2014, a victim of climate change. Although a few wildlife species have already incurred such a fate (e.g., the Bramble Cay melomys [Melomys rubicola]) (Fulton 2017), many more are on the path to climate-driven extinction (Andermann et al. 2020; Ceballos et al. 2015; He et al. 2019; Roman-Palacios and Wiens 2020; Sanchez-Bayo and Wyckhuys 2019; WWF 2020).

      Reproducibility and variability of earthquake subsidence estimates from saltmarshes of a Cascadia estuary

      Released August 02, 2022 08:26 EST

      2022, Journal of Quaternary Science

      Jason Scott Padgett, Simon E. Engelhart, Harvey M. Kelsey, Robert C. Witter, Niamh Cahill

      We examine fossil foraminiferal assemblages from 20 sediment cores to assess sudden relative sea-level (RSL) changes across three mud-over-peat contacts at three salt marshes in northern Humboldt Bay, California (~44.8°N, -124.2°W). We use a validated foraminiferal-based Bayesian transfer function to evaluate the variability of subsidence stratigraphy at a range of 30-6000 m across an estuary. We use the consistency in RSL reconstructions to support estimates of coseismic subsidence from megathrust earthquakes. To assess the variability of subsidence estimates, we analyzed: nine examples of the 1700 CE earthquake (average of 0.64 ±0.14 m subsidence; range of 0.24 ±0.27 to 1.00 ±0.44 m), five examples of the ca. 875 cal a BP earthquake (average of 0.43 ±0.16 m; range of 0.41 ±0.36 to 0.48 ±0.39 m), and six examples of the ca. 1120 cal a BP earthquake (average of 0.70±0.18 m; range of 0.47 ±0.36 to 0.80 ±0.49 m). Our subsidence estimate results suggest ~±0.3 m of within-site (intra-site) variability, which is consistent with previous research. We also identify inconsistencies between sites (inter-site) at northern Humboldt Bay greater than one-sigma uncertainties, driven by variable foraminiferal assemblages in the mud overlying the 1700 CE subsidence contact. Therefore, we recommend at least two quantitative microfossil reconstructions across the same stratigraphic sequence from different marsh sites within an estuary to account for estimate variability and provide increased confidence in vertical coseismic deformation estimates. Our results have broad implications for quantitative, microfossil-based reconstructions of coseismic subsidence at temperate coastlines globally.

      Sclerochronological records of environmental variability and bivalve growth in the Pacific Arctic

      Released August 02, 2022 06:54 EST

      2022, Progress in Oceanography

      David J. Reynolds, Vanessa R. von Biela, Kenneth H. Dunton, David C. Douglas, Bryan A. Black

      The Pacific Arctic region has experienced, and is projected to continue experiencing, rapid climate change. Large uncertainties exist in our understanding of the impact these physical changes have on the region’s ecology. This is, in part, due to the lack of long-term data. Here we investigate bivalve mollusc growth increment width chronologies (sclerochronologies) to develop a long-term biological data series in an Arctic species and address the hypothesis that benthic production in the Pacific Arctic region is in decline with implications for predators (e.g., walrus, whales, seals, and sea ducks). Growth increments formed in the shells of two bivalve mollusc species, Astarte borealis and Liocyma fluctuosa, were examined using conventional sclerochronological techniques. The A. borealis and L. fluctuosa samples exhibited measured longevities of >148 and >18 years, respectively, in the coastal waters of Alaska’s Chukchi Sea. Dendrochronology crossdating techniques facilitated the development of two robust (expressed population signal >0.85) independent growth increment width chronologies. These chronologies provide evidence of the growth conditions through time for each species (1985-2015 for A. borealis and 1997-2014 for L. fluctuosa). Linear regression analyses identified that both species grew more rapidly in years with warmer sea surface temperature and lower sea ice concentration. The results provide evidence that benthic ecosystems are benefiting from the warmer conditions and reduced sea ice that have accompanied recent Arctic climate trends. This result is encouraging for benthic predators in the eastern Chukchi Sea as it alleviates the concern that their benthic prey has already become food limited by weakened pelagic-benthic coupling. More broadly, this initial A. borealis chronology is among the longest biological data series for any Arctic species and highlights the feasibility of multicentennial biological data for the Arctic.

      The 2018 eruption of Mount Veniaminof, Alaska

      Released August 01, 2022 13:11 EST

      2022, Scientific Investigations Report 2022-5075

      Christopher F. Waythomas, Hannah R. Dietterich, Gabrielle M. Tepp, Taryn M. Lopez, Matthew W. Loewen

      The 2018 eruption of Mount Veniaminof occurred from September 3–4 to December 27, lasting about 114 days. This report summarizes the types of volcanic unrest that accompanied the eruption and provides a chronology of events and observations. Information about the 2018 eruption was derived from geophysical instrumentation on or near the volcano that included an eight-station seismic network and regional infrasound sensors. Other observations came from frequent satellite images of the eruption, occasional aerial photographs and videos contributed by passing pilots, and web-camera views of the volcano from Perryville, Alaska, about 35 kilometers (km) south of the volcano. Eruptive activity involved small vents on the upper south flank of a cinder cone (cone A) within the ice-filled caldera that characterizes Mount Veniaminof. The 2018 eruption consisted of occasional explosive emissions of ash and gas (reaching up to 6,000 meters above sea level), episodes of low-level lava fountaining, Strombolian explosive activity, and effusion of lava flows. By the end of the eruption, lava covered an area of about 600,000 square meters (m2) on the lower south flank of cone A. The lava flows melted into ice and snow, slowly creating melt depressions around the flow margins. No unusual outflows of water were observed exiting the caldera through the main drainage northwest of the cone. Minor ash emissions were generated throughout the eruptive period, and trace amounts of ash fell on Perryville on October 25 and November 21–22. There were no reports of aircraft encounters with ash clouds. The amount of lava and ash erupted from early September to late December 2018 resulted in the generation of about 1,200,000 cubic meters (m3) of lava and 20,000–30,000 m3 of ash, which would characterize the 2018 activity as having an eruption magnitude of 1–2 on the Volcanic Explosivity Index (VEI) scale.

      Crowd-sourced SfM: Best practices for high resolution monitoring of coastal cliffs and bluffs

      Released August 01, 2022 09:25 EST

      2022, Continental Shelf Research (245)

      Phillipe Alan Wernette, Ian M. Miller, Andrew C. Ritchie, Jonathan Warrick

      Structure from motion (SfM) photogrammetry is an increasingly common technique for measuring landscape change over time by deriving 3D point clouds and surface models from overlapping photographs. Traditional change detection approaches require photos that are geotagged with a differential GPS (DGPS) location, which requires expensive equipment that can limit the ability of communities and researchers to perform frequent (i.e. daily, weekly, and/or monthly) surveys. Crowd-sourced photos can lower the barrier to entry and substantially increase the frequency of surveys, although such photos often lack accurate location information and can vary in quality. This paper presents a SfM approach for monitoring environmental change in high relief coastal environments that does not require all photos have DGPS location information and does not require field survey data. A 1.5 km section of coastal bluffs near the Elwha River Delta (Washington state) is used to demonstrate the efficacy of this approach. Photos of the bluff were collected with a digital SLR camera or phone camera while either on foot along the beach or from a boat as part of monitoring following removal of two large dams along the Elwha River during 2011–2013. Only 33% of photos had DGPS location information, whereas most photos had no location information or locations that were accurate to a couple of meters. All photos were processed using 3D, 4D, and fixed-floating (FF) SfM alignment methods and the resulting dense point clouds are used to compare the different alignment approaches with crowd-sourced photo sets. Results demonstrate that 4D and FF approaches are more likely to reconstruct and are more accurate than the 3D approach. While the 4D and FF have comparable accuracies, the FF approach is several orders of magnitude more efficient, as this method can leverage camera location information from relatively few photos to improve the accuracy of all aligned and derived products. Effectively utilizing crowd-sourced photos in SfM change detection can improve the frequency of surveying a landscape in a more cost-effective approach that also has potential for citizen-science engagement and communication. This is especially important for data-poor environments such as high-relief coastal cliffs and bluffs, where near-nadir imagery and LIDAR may fail to accurately capture near-vertical cliffs or bluff faces. Based on the analysis of different photo alignment and filtering approaches, we present suggested best practices for engaging citizen scientists in coastal cliff and bluff monitoring efforts through collecting photos amenable for SfM reconstruction.

      Defining fine-scaled population structure among continuously distributed populations

      Released August 01, 2022 08:27 EST

      2022, Methods in Ecology and Evolution

      Michael O'Donnell, David R. Edmunds, Cameron L. Aldridge, Julie A. Heinrichs, Adrian P. Monroe, Peter S. Coates, Brian G. Prochazka, Steve E. Hanser, Lief A. Wiechman

      1. Understanding wildlife population structure and connectivity can help managers identify conservation strategies, as structure can facilitate the study of population changes and habitat connectivity can provide information on dispersal and biodiversity. To facilitate the use of wildlife monitoring data for improved adaptive management, we developed a novel approach to define hierarchical tiers (multiple scales) of population structure.
      2. We defined population structure by combining graph theory with biological inference about dispersal capability (based on movement, gene flow, and habitat condition) and functional processes affecting movement (e.g. habitat selection across scales of landscape preferences). First, we developed least-cost paths between high fidelity sites (habitat patches) using a cost surface, informed from functional processes of habitat characteristics to account for resistance of inter-patch movements. Second, we combined the paths into a multi-path graph construct. Third, we used information on potential connectivity (dispersal distances) and functional connectivity (permeability of fragmented landscapes based on selection preferences) to decompose the graph into hierarchical tiers of connected subpopulations, denoting the degree that dispersal affected population structure.
      3. As a case study, we applied our approach across the greater sage-grouse (Centrocercus urophasianus) range, a species of conservation concern in western United States. We described the relative importance of local populations and where to potentially avoid landscape disturbances that may negatively affect population connectivity using centrality measures supported by graph theory, and we demonstrated close alignment of the resulting population structure with population densities.
      4. This method can be adapted for other species with site fidelity and used as a management tool to evaluate population trends and responses to landscape changes across different temporal and spatial scales.

      Rural turtles: Estimating the occupancy of Northwestern Pond Turtles and non-native red-eared sliders in agricultural habitats in California's Sacramento Valley and Sacramento-San Joaquin River Delta

      Released August 01, 2022 07:16 EST

      2022, Northwestern Naturalist (103) 97-109

      Jonathan P. Rose, Brian J. Halstead, Alexandria M. Fulton

      The Northwestern Pond Turtle (Actinemys marmorata; WPT) was once widespread throughout the Sacramento Valley and the Sacramento-San Joaquin River Delta. Much of its historical range has been converted into agricultural land, reducing and altering aquatic habitat and surrounding uplands. Red-eared Sliders (Trachemys scripta elegans; RES) have been introduced throughout much of the existing WPT range, particularly near urban centers, potentially competing with WPT for resources. Previous surveys for turtles in central California have primarily focused on rivers, lakes, and protected wetlands. Little is known about where WPT and RES occur in the vast expanses of agricultural land across the Sacramento Valley and Sacramento-San Joaquin River Delta. Using aquatic hoop nets, we surveyed 142 locations (102 irrigation canal sites, 39 wetlands, 1 tidally influenced slough) across 8 counties during the summers of 2018 and 2019. Both species were detected in agricultural habitats. Using occupancy modeling, we estimated that WPT occur at 44 (95% CRI = 38–53) of our trapping sites and RES occur at 51 (41–66) sampled sites. Co-occurrence of these 2 species was rare; the species were found together at only 6 sites. RES were primarily found in restored wetlands near major roads and the Sacramento metropolitan area, whereas WPT were more commonly found farther from urban areas in wider canals. Our work provides a picture of how WPT and RES occupy this modified agroecosystem that can inform future conservation efforts.

      Mapping structural control through analysis of land-surface deformation for the Rialto-Colton groundwater subbasin, San Bernardino County, California, 1992–2010

      Released July 29, 2022 10:58 EST

      2022, Open-File Report 2022-1030

      Justin T. Brandt

      The locations of many faults in and near the Rialto-Colton groundwater subbasin are not precisely known because the spatial density of existing lithologic and hydrologic data used to infer the locations of faults can be sparse. The U.S. Geological Survey, in cooperation with the San Bernardino Valley Municipal Water District, analyzed structural control of groundwater flow in and near the Rialto-Colton groundwater subbasin using Interferometric Synthetic Aperture Radar (InSAR) methods. Faults commonly are barriers to groundwater flow, and the high spatial resolution of InSAR imagery can be used to infer the locations of buried faults where groundwater pumping occurs. InSAR results have revealed three areas in and near the Rialto-Colton groundwater subbasin where buried faults are interpreted as groundwater-flow barriers: the northwestern area about 3 miles northwest of the City of Rialto, the San Jacinto fault area west of the City of San Bernardino, and the southeastern area about 2 miles southeast of the City of Colton. The InSAR results were combined with knowledge gained from previous studies to better define the location and extent of faults acting as groundwater-flow barriers. New data about faults acting as groundwater-flow barriers can be incorporated into future conceptual and hydrologic models of the Rialto-Colton groundwater subbasin and provide water managers information to help effectively manage groundwater resources.

      Methods of data collection and analysis for an assessment of karst aquifer systems between Albany and Buffalo, New York

      Released July 29, 2022 10:25 EST

      2021, Scientific Investigations Report 2021-5094

      Bradley A. Sporleder, Benjamin N. Fisher, Douglas S. Keto, William M. Kappel, James E. Reddy, Laura M. DeMott

      The U.S. Geological Survey, in cooperation with the New York State Department of Environmental Conservation, catalogued aquifers and closed depressions in a karst-prone area between Albany and Buffalo, New York to provide resource managers information to more efficiently manage and protect groundwater resources. The New York State Department of Environmental Conservation has been working with the agricultural industry to raise awareness of karst aquifer contamination susceptibility and how to reduce effects on surface water and groundwater resources, especially in karst areas. There is also a need to make industries, State and local regulators, planners, and the public aware of New York’s karst resources to properly protect and manage these resources and the quality of surface water and groundwater that flows through the karst aquifer.

      Publicly available geospatial data were identified, collated, and analyzed for a region of karst terrain extending from Albany to Buffalo. The region was divided into 10 subareas. A series of geospatial datasets were assembled to determine the location and extent of karstic rock; bedrock geology and depth to bedrock; average water-table configuration; surficial geology; soil type, thickness, and hydraulic conductivity; land cover; and closed depressions in the land surface.

      Repeated glaciation and recession across New York have left the landscape pockmarked with closed depressions, which may or may not be related to the underlying bedrock. Closed depressions in areas where carbonate or evaporite karst are present are of primary concern to this study because of the increased potential of karst aquifer contamination from focused recharge. Closed depressions present in areas not associated with karst bedrock can also be evaluated to better understand their ability to transmit surface water to the groundwater system. Information on closed depressions can be used to develop land-management plans to protect local and regional water resources.

      Sub-indicator: Cladophora

      Released July 29, 2022 08:20 EST

      2022, Report, State of the Great Lakes 2022 technical report

      David Depew, Harvey A. Bootsma, Todd Howell, Megan McCusker, Mary Anne Evans

      Every three years the Great Lakes Executive Committee reports on the status of the Great Lakes' ecosystem based on 9 indicators and several sub-indicators. This sub-indicator technical report supports assessment of the Nutrients and Algae Indicator by evaluating the status of Cladophora and other benthic algae that can grow to nuisance levels. Based on established criteria, the overall status for Cladophora was poor, indicating overabundance. The status was also poor for Lakes Michigan, Erie, and Ontario; but fair for Lake Huron and good for Lake Superior.

      Spatiotemporal changes in influenza A virus prevalence among wild waterfowl inhabiting the continental United States throughout the annual cycle

      Released July 29, 2022 07:05 EST

      2022, Scientific Reports (12)

      Cody M. Kent, Andrew M. Ramey, Joshua T. Ackerman, Justin Bahl, Sarah N. Bevins, Andrew S. Bowman, Walter Boyce, Carol Cardona, Michael L. Casazza, Troy D. Cline, Susan E. W. De La Cruz, Jeffrey S. Hall, Nichola J. Hill, Hon S. Ip, Scott Krauss, Jennifer M. Mullinax, Jacqueline M. Nolting, Magdalena Plancarte, Rebecca L. Poulson, Jonathan A. Runstadler, Richard D. Slemons, David E. Stallknecht, Jeffery D Sullivan, John Y. Takekawa, Richard J. Webby, Robert G. Webster, Diann J. Prosser

      Avian influenza viruses can pose serious risks to agricultural production, human health, and wildlife. An understanding of viruses in wild reservoir species across time and space is important to informing surveillance programs, risk models, and potential population impacts for vulnerable species. Although it is recognized that influenza A virus prevalence peaks in reservoir waterfowl in late summer through autumn, temporal and spatial variation across species has not been fully characterized. We combined two large influenza databases for North America and applied spatiotemporal models to explore patterns in prevalence throughout the annual cycle and across the continental United States for 30 waterfowl species. Peaks in prevalence in late summer through autumn were pronounced for dabbling ducks in the genera Anas and Spatula, but not Mareca. Spatially, areas of high prevalence appeared to be related to regional duck density, with highest predicted prevalence found across the upper Midwest during early fall, though further study is needed. We documented elevated prevalence in late winter and early spring, particularly in the Mississippi Alluvial Valley. Our results suggest that spatiotemporal variation in prevalence outside autumn staging areas may also represent a dynamic parameter to be considered in IAV ecology and associated risks.

      Interspecific and local variation in Tern chick diets across nesting colonies in the Gulf of Maine

      Released July 29, 2022 06:57 EST

      2022, Waterbirds (44) 397-414

      Keenan Yakola, Adrian Jordaan, Stephen Kress, Paula Shannon, Michelle Staudinger

      The Gulf of Maine, USA is home to four colonial co-nesting tern species: Least Tern (Sternula antillarum), Common Tern (Sterna hirundo), Arctic Tern (Sterna paradisaea), and the federally endangered Roseate Tern (Sterna dougallii). Over three decades of visual observations of chick provisioning were compiled for a comparative dietary study in the region, including the first detailed descriptions of Least and Roseate Tern chick diets. Three prey groups comprised the majority of chick diets among tern species between 1986–2017: hake (Urophycis spp. or Enchelyopus cimbrius) 28–37% frequency of occurrence (FO), sand lance (Ammodytes americanus or A. dubius) 8–22% FO, and herring (Clupea spp. or Alosa spp.) 3–30% FO. Dietary contributions varied across species and islands. At two inshore colonies, Common Tern diets contained higher amounts of sand lance (30–42% FO), while offshore islands contained lesser amounts (5–9% FO). Overall dietary diversity (H′) was similar between Common (H′ = 1.57) and Arctic Terns (H′ = 1.74) and notably lower in Roseate (H′ = 1.24) and Least Terns (H′ = 1.37), whose diets were primarily piscivorous. The degree of dietary plasticity and general feeding ecology provided by baseline dietary information can inform holistic assessments of risk to ongoing and future disturbances from fishing and climate change.

      Proceedings of the Highly Pathogenic Avian Influenza and Wild Birds Webinar Series, August 2–5, 2021

      Released July 28, 2022 09:05 EST

      2022, Open-File Report 2022-1066

      M. Camille Hopkins, Giavanna Haddock, J. Russ Mason, Andrew M. Ramey

      In light of ongoing and geographically widespread highly pathogenic avian influenza (HPAI) outbreaks in wild birds throughout much of Eurasia during 2020–21, the Interagency Steering Committee for Avian Influenza Surveillance in Wild Migratory Birds disseminated an informational memorandum in January 2021 to highlight the need for enhanced surveillance and heightened awareness in North America. This was followed by coordination of this August 2021 international HPAI webinar series facilitated by the U.S. Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) Veterinary Services Training Program. In addition to heightening awareness, the webinars provided an opportunity for information exchange and facilitated virtual discussions between Federal, State, academic, and international partners on the ongoing Eurasian outbreak, lessons learned from the 2014–15 North American HPAI outbreak, and associated challenges and opportunities.

      Fifty years of Landsat science and impacts

      Released July 28, 2022 08:08 EST

      2022, Remote Sensing of Environment (280)

      Michael A. Wulder, David P. Roy, Volker C. Radeloff, Thomas Loveland, Martha C. Anderson, David M. Johnson, Sean Healey, Zhe Zhu, Theodore A. Scambos, Nima Pahlevan, Matthew Hansen, Noel Gorelick, Christopher J. Crawford, Jeffery G. Masek, Txomin Hermosilla, JoAnn C. White, Alan S. Belward, Crystal Schaaf, Curtis E. Woodcock, Justin L. Huntington, Leo Lymburner, Patrick Hostert, Feng Gao, Alexi Lyapustin, Jean-Francois Pekel, Peter Strobl, Eric Vermote, Bruce D. Cook

      Since 1972, the Landsat program has been continually monitoring the Earth, to now provide 50 years of digital, multispectral, medium spatial resolution observations. Over this time, Landsat data were crucial for many scientific and technical advances. Prior to the Landsat program, detailed, synoptic depictions of the Earth's surface were rare, and the ability to acquire and work with large datasets was limited. The early years of the Landsat program delivered a series of technological breakthroughs, pioneering new methods, and demonstrating the ability and capacity of digital satellite imagery, creating a template for other global Earth observation missions and programs. Innovations driven by the Landsat program have paved the way for subsequent science, application, and policy support activities. The economic and scientific value of the knowledge gained through the Landsat program has been long recognized, and despite periods of funding uncertainty, has resulted in the program's 50 years of continuity, as well as substantive and ongoing improvements to payload and mission performance. Free and open access to Landsat data, enacted in 2008, was unprecedented for medium spatial resolution Earth observation data and substantially increased usage and led to a proliferation of science and application opportunities. Here, we highlight key developments over the past 50 years of the Landsat program that have influenced and changed our scientific understanding of the Earth system. Major scientific and programmatic impacts have been realized in the areas of agricultural crop mapping and water use, climate change drivers and impacts, ecosystems and land cover monitoring, and mapping the changing human footprint. The introduction of Landsat collection processing, coupled with the free and open data policy, facilitated a transition in Landsat data usage away from single images and towards time series analyses over large areas and has fostered the widespread use of science-grade data. The launch of Landsat-9 on September 27, 2021, and the advanced planning of its successor mission, Landsat-Next, underscore the sustained institutional support for the program. Such support and commitment to continuity is recognition of both the historic impact the program, and the future potential to build upon Landsat's remarkable 50-year legacy.

      Field-trip guide to continental arc to rift volcanism of the southern Rocky Mountains—Southern Rocky Mountain, Taos Plateau, and Jemez Mountains volcanic fields of southern Colorado and northern New Mexico

      Released July 27, 2022 13:25 EST

      2022, Scientific Investigations Report 2017-5022-R

      Ren A. Thompson, Kenzie J. Turner, Peter W. Lipman, John A. Wolff, Michael A. Dungan

      The southern Rocky Mountains of northern New Mexico and southern Colorado preserve the Oligocene to Pleistocene record of North American continental arc to rift volcanism. The 35–23 million year old (Ma) southern Rocky Mountain volcanic field (SRMVF), spectacularly preserved in the San Juan Mountains of southern Colorado, records the evolution of large andesitic stratovolcanoes to complex caldera clusters, from which at least 22 major ignimbrite sheets (each 150–5,000 cubic kilometers) were erupted. Outflow deposits of the SRMVF preserved along the broadly uplifted northwest flank of the northern Rio Grande rift basin (the San Luis Valley) provide critical structural and temporal constraints on the inception of crustal extension. Coincident with waning stages of SRMVF caldera-forming volcanism (~25.4 Ma), extensional tectonism was accompanied by a transition from bimodal early Miocene to intermediate-composition late Miocene and dominantly basaltic Pliocene rift volcanism of the Taos Plateau in the southern San Luis Basin. Concomitant rift volcanism in the Española Basin and bordering Jemez Mountains of northern New Mexico records a similar Miocene eruptive history dominated by intermediate-composition volcanism that transitioned locally to Pliocene rift-related basaltic volcanism of the Cerros del Rio volcanic field and culminated in eruptions of the iconic rhyolitic Pleistocene Bandelier Tuff and formation of the Valles Caldera along the northwestern rift-basin margin.

      This 6-day, 7-night field trip will focus, in broadly equal proportions, on rift-related extensional volcanism of the Jemez Mountains and Taos Plateau regions during the first half of the trip, and on caldera-forming volcanism of the southern Rocky Mountain volcanic field during the second half of the trip. The 35-million-year volcanic history of the region highlighted by new geologic mapping, high-resolution geochronology, petrologic, geochemical, and geophysical data facilitates discussion of (1) the magmatic response to the tectonic transition from subducted-slab arc to continental-rift volcanism; (2) the nature and temporal evolution of rift magmas; (3) fault controls on the spatial evolution of rift magmatism; (4) the diversity of continental-arc ignimbrite volcanism and associated lavas; (5) ignimbrite caldera structure and associated intrusions in three-dimension; (6) the role of recycled crystal mush and magmatic cumulates during growth of Cordilleran batholiths; and (7) high-precision geochronologic contributions to interpretation of relations between regional tectonic and volcanic processes. Most stops will be along roads, but there will be moderate hikes on trails of less than 1-hour duration covering 1–2 kilometers (0.6–1.2 miles) with modest elevation gain of <150 meters (<492 feet).

      The route will progress in reverse stratigraphic order, starting in the Jemez Mountains of New Mexico and proceed northward to San Luis Basin and San Luis Hills before turning west to the southeast and central San Juan Mountains. Our last full day takes us to the little-visited and only recently mapped, Bonanza caldera of the northeastern San Juan Mountains and on the final day, we leave the San Luis Valley to briefly explore the Tertiary subvolcanic plutons of the Collegiate Range along the west side of the Arkansas Valley rift valley, en route to Denver.

      The authors of all daily contributions acknowledge the helpful reviews by Amy Gilmer and Joe Colgan and thank Christine Chan and Jeremy Havens for assistance with figures, tables, and guidebook text.

      Groundwater-level monitoring from January 17 to March 3, 2022, Hālawa area, O‘ahu, Hawai‘i

      Released July 27, 2022 13:13 EST

      2022, Open-File Report 2022-1069

      Rylen K. Nakama, Jackson N. Mitchell, Delwyn S. Oki

      A reported fuel release in November 2021 at the Red Hill Bulk Fuel Storage Facility within the naval reservation at Red Hill led to the shutdown of several production wells in the Hālawa area, O‘ahu, Hawai‘i. Red Hill Shaft—one of the high-capacity production wells that shut down—was reactivated on January 29, 2022. Submersible pressure transducers were deployed at 20 wells in the Hālawa area to measure groundwater levels and evaluate the regional groundwater-level response to the resumption of groundwater withdrawals from Red Hill Shaft. Groundwater levels measured in wells from January 17 to March 3, 2022, ranged between 16 and 20 feet at all sites and generally between 17 and 19 feet at most sites. Average groundwater-level decreases measured in wells 10 days after the January 29, 2022, resumption of withdrawal from Red Hill Shaft ranged from about 0.1 to 0.4 foot. In general, greatest decreases in groundwater levels occurred in wells closest to Red Hill Shaft.

      The groundwater-level data contain uncertainty because of several potential sources of error associated with (1) the accuracy of the measuring tapes and submersible pressure transducers used, (2) the accuracy of the measuring-point altitude at the top of each well, (3) the stability of the submersible pressure transducers’ suspension depth in each well, (4) well plumbness and alignment, and (5) human error. Because of the potential sources of error, comparability of groundwater-level data may be affected. Some sources of uncertainty, including the accuracy of measuring-point altitudes, can be addressed and lead to improved accuracy and comparability of groundwater levels. Data collected for this study are available in the U.S. Geological Survey National Water Information System database.

      Groundwater quality in selected Stream Valley aquifers, eastern United States

      Released July 26, 2022 14:14 EST

      2022, Fact Sheet 2022-3037

      James A. Kingsbury

      Groundwater provides nearly 50 percent of the Nation’s drinking water. To help protect this vital resource, the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) Project assesses groundwater quality in aquifers that are important sources of drinking water (Burow and Belitz, 2014). The stream-valley aquifers constitute one of the important aquifer systems being evaluated.

      Temporal and spatial relationships of Yellowfin Tuna to deepwater petroleum platforms in the northern Gulf of Mexico

      Released July 26, 2022 08:31 EST

      2022, Marine and Coastal Fisheries: Dynamics, Management, and Ecosystem Science (14)

      Melissa E. Price, Michael T. Randall, Kenneth J. Sulak, Randy E. Edwards, Margaret Lamont

      In 2006–2007, 110 Yellowfin Tuna Thunnus albacares were tagged with acoustic transmitters near deepwater oil platforms and one drillship in the northern Gulf of Mexico off the Mississippi River delta to determine the extent to which platforms act as fish aggregating devices (FADs). Vemco acoustic receivers were installed on six deepwater platforms to detect the presence of tagged individuals. Five of 12 Yellowfin Tuna captured in 2006 were detected in 2007, demonstrating multi-year presence in the region. Ninety Yellowfin Tuna were detected in 2007, resulting in 221 platform residencies and 32 single detections. Duration of residence at a platform was positively correlated with the platform's depth, and the number of transitions decreased with platform-to-platform distance. In total, 109 movements between platforms by 46 (51%) different individuals were detected, traveling distances of up to 98.2 km. Yellowfin Tuna displayed interactions with deepwater platforms in the northern Gulf of Mexico similar to their interactions with FADs and other studied geological features, by way of aggregating or using them as meeting points, landmarks, and stopovers within a movement corridor. The large number of oil and gas platforms located in the northern Gulf of Mexico may have a significant effect on distribution, retention, and migration of Yellowfin Tuna populations in this area of the gulf.

      Crustal permeability changes observed from seismic attenuation: Impacts on multi-mainshock sequences

      Released July 25, 2022 17:05 EST

      2022, Frontiers in Earth Science

      Luca Malagnini, Thomas E. Parsons, Irene Munafo, Simone Mancini, Margarita Segou, Eric L. Geist

      We use amplitude ratios from narrowband-filtered earthquake seismograms to measure variations of seismic attenuation over time, providing unique insights into the dynamic state of stress in the Earth’s crust at depth. Our dataset from earthquakes of the 2016-2017 Central Apennines sequence allows us to obtain high-resolution time histories of seismic attenuation (frequency band: 0.5-30 Hz) characterized by strong earthquake dilatation-induced fluctuations at seismogenic depths, caused by the cumulative elastic stress drop after the sequence, as well as damage-induced ones at shallow depths caused by energetic surface waves.
      Cumulative stress drop causes negative dilatation, reduced permeability, and seismic attenuation, whereas strong-motion surface waves produce an increase in crack density, and so in permeability and seismic attenuation. In the aftermath of the main shocks of the sequence, we show that the M ≥ 3.5 earthquake occurrence vs. time and distance is consistent with fluid diffusion: diffusion signatures are associated with changes in seismic attenuation during the first days of the Amatrice, Visso-Norcia, and Capitignano sub-sequences. We hypothesize that coseismic permeability changes create fluid diffusion pathways that are at least partly responsible for triggering multi-mainshock seismic sequences. Here we show that anelastic seismic attenuation fluctuates coherently with our hypothesis.

      Water-quality trends in surface waters of the Jemez River and Middle Rio Grande Basin from Cochiti to Albuquerque, New Mexico, 2004–19

      Released July 25, 2022 15:37 EST

      2022, Scientific Investigations Report 2022-5062

      Allison K. Flickinger, Zachary M. Shephard

      Municipal water supply for Albuquerque, New Mexico, is provided, in part, through diversion of surface water from the Rio Grande by way of the San Juan-Chama Drinking Water Project diversion structure. Changes in surface-water quality along the Rio Grande and its tributaries upstream from the San Juan-Chama Drinking Water Project diversion structure are not well characterized. This study describes the methods and results of an analysis of surface-water-quality trends for selected constituents in the Rio Grande upstream from Albuquerque. Trends were evaluated for differing time periods ranging from 2004 to 2019 by using the Seasonal Kendall Tau (SKT) test and the Weighted Regressions on Time, Discharge, and Season (WRTDS) model.

      Water-quality data at three long-term sites were used for the trend analyses in this study, with the Cochiti and Alameda sites along the Rio Grande and the Jemez Canyon Dam site along the Jemez River, a tributary of the Rio Grande. The proximity of the Cochiti and Jemez Canyon Dam sites to dams is a drawback to the analysis because it is difficult to differentiate between the influence of dam management and the influence of streamflow on water-quality trends. The data used also did not fully meet desired levels of seasonal sampling density and had shorter periods of record than typically used for trend analysis, and this should be considered in the interpretation of these results.

      Study results indicate that concentrations, and thereby fluxes, are influenced by changes in streamflow at the Alameda site. Most trends from the WRTDS results, obtained by using flow-normalization, were downward for constituents at the Alameda site. Most constituents that were analyzed for trends by using SKT did not have a significant trend at any of the sites included in this study, indicating either that the water quality in the Middle Rio Grande Basin has been stable during the study period or that not enough samples were collected during different seasons to characterize the range of concentration variability with streamflow. The SKT test results indicate upward trends in concentrations of the following constituents: aluminum and antimony at the Alameda site, nitrate and nitrate plus nitrite at the Cochiti site, and potassium and antimony during the spring season at Jemez Canyon Dam. The SKT test results indicate a downward trend in cobalt at the Cochiti site that is subject to bias in the cobalt concentrations. SKT test results also indicate small, downward trends in Kjeldahl nitrogen at the Alameda and Cochiti sites.

      Concentrations of water-quality constituents were also compared to Federal and State water-quality standards to provide context and relevance to the results. No concentrations were above the national primary or secondary drinking water standards at the Alameda and Cochiti sites, but the Jemez Canyon Dam site did have concentrations above the U.S. Environmental Protection Agency primary drinking water standard for arsenic and above the national secondary drinking water standards for dissolved solids and aluminum. The Alameda and Cochiti sites are on reaches of the Rio Grande that are listed as impaired for gross alpha particles and the Alameda site is on a reach of the Rio Grande that is listed as impaired for Escherichia coli, but there were no consistent changes in concentrations of these constituents at the impaired locations.

      Dryland mechanisms could widely control ecosystem functioning in a drier and warmer world

      Released July 25, 2022 07:27 EST

      2022, Nature Ecology & Evolution

      José M Grünzweig, Hans J. De Boeck, Ana Rey, Maria J Santos, Ori Adam, Michael Bahn, Jayne Belnap, Gaby Deckmyn, Stefan C Dekker, Omar Flores, Daniel Gliksman, David Helman, Kevin R. Hultine, Lingling Liu, Ehud Meron, Yaron Michael, Efrat Sheffer, Heather L. Throop, Omer Tzuk, Dan Yakir

      Responses of terrestrial ecosystems to climate change have been explored in many regions worldwide. While continued drying and warming may alter process rates and deteriorate the state and performance of ecosystems, it could also lead to more fundamental changes in the mechanisms governing ecosystem functioning. Here we argue that climate change will induce unprecedented shifts in these mechanisms in historically wetter climatic zones, towards mechanisms currently prevalent in dry regions, which we refer to as ‘dryland mechanisms’. We discuss 12 dryland mechanisms affecting multiple processes of ecosystem functioning, including vegetation development, water flow, energy budget, carbon and nutrient cycling, plant production and organic matter decomposition. We then examine mostly rare examples of the operation of these mechanisms in non-dryland regions where they have been considered irrelevant at present. Current and future climate trends could force microclimatic conditions across thresholds and lead to the emergence of dryland mechanisms and their increasing control over ecosystem functioning in many biomes on Earth.

      Ground-water levels and quality at Crex Meadows Wildlife Area, Burnett County, Wisconsin

      Released July 23, 2022 12:00 EST

      1990, Water-Resources Investigations Report 89–4129

      G.L. Patterson

      During 1984, above-normal ground-water levels flooded the fields and basements in the vicinity of the Crex Meadows Wildlife Area. In response to concerns of neighboring farmers and homeowners, the Wisconsin Department of Natural Resources and the U.S. Geological Survey began a cooperative study to assess ground-water conditions in the area and to determine the causes of above-normal ground-water levels in and around the Crex Meadows Wildlife Area.

      Data from an inventory of water levels in the Crex Meadows area measured in 1935 and 1937 were compared with data collected in 1986 and 1987. The comparison indicates that 1986 water levels were 5 to 10 feet higher throughout the area than in 1935 and 1937. Water levels declined about 5 feet throughout much of the area during 1987 and were only 0–5 feet higher than in the late 1930's. Hydrographs of water levels measured from 1985 to the fall of 1987 also indicate that water levels rose in 1985 and 1986 and fell abruptly in 1987.

      Water levels in two wells, one in northern Burnett County and the other in Polk County, were compared to those in the wildlife area to determine whether the wetland impoundments contributed significantly to above-normal water levels measured in 1986 or whether levels were high throughout northwestern Wisconsin. Water-levels at long-term observation wells Bt-2 (1936–present) and Pk-40 (1951–present) (13 miles northeast and 20 miles southeast of Crex Meadows, respectively) during 1986 were the highest of record.

      Long-term discharge records for the St. Croix River upstream (Danbury) and downstream (St. Croix Falls) from Crex Meadows indicate that the river reached its highest historical discharge volume during 1986.

      Hydrographs showing cumulative departure from mean annual precipitation at two stations (Danbury and St. Croix Falls) indicate that the above-normal ground-water levels in 1986 were preceded by several years of above-normal precipitation. It is probable that the above-normal ground-water levels and surface- water discharge throughout the area can be attributed to above-normal precipitation. Groundwater- level fluctuations corresponded directly to variations in precipitation during 1985–87.

      Chemical analyses of water samples from 20 observation wells indicate that calcium and bicarbonate are the predominant ions in ground water in the Crex Meadows area. Iron concentrations ranged from 45 to 45,000 micrograms per liter, and 17 of 20 samples exceeded the 300-micrograms-per-liter recommended drinking-water standard of the Wisconsin Department of Natural Resources.

      Barium enrichment in the non-spinose planktic foraminifer, Globorotalia truncatulinoides

      Released July 23, 2022 06:42 EST

      2022, Geochimica et Cosmochimica Acta (333) 184-199

      Julie N. Richey, Jennifer S. Fehrenbacher, Caitlin E. Reynolds, Catherine Z. Davis, Howard J. Spero

      Observations of elevated barium-to-calcium ratios (Ba/Ca) in Globorotalia truncatulinoides have been attributed to contaminant phases, deep calcification depth and diagenetic processes. Here we investigate intra- and inter-test Ba/Ca variability in the non-spinose planktic foraminifer, G. truncatulinoides, from a sediment trap time series in the northern Gulf of Mexico to gain insights into the environmental influences on barium enrichment in this and other non-spinose species. We use laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to differentiate between the elemental composition of the crust and lamellar calcite in non-encrusted (<150 m calcification depth) and encrusted (>150 m calcification depth) specimens of G. truncatulinoides. We find that the Ba/Ca ratio in lamellar calcite is between two and three orders of magnitude higher (10–280 μmol/mol) than that of the crust (0–3 μmol/mol). We include seasonal water column profiles of the Ba/Ca ratio in the northern Gulf of Mexico and determine that the vertical gradient in seawater barium concentration cannot account for the intra-test Ba/Ca variations in G. truncatulinoides. We find the Ba/Ca ratio of the crust to be within the range observed in co-occurring spinose species of foraminifera (pink and white chromotypes of Globigerinoides ruber, and Orbulina universa) while the range of Ba/Ca in lamellar calcite is consistent with co-occurring non-spinose foraminifera (Pulleniatina obliquiloculata, Globorotalia menardii, G. tumida, and Neogloboquadrina dutertrei). Our data are consistent with the hypothesis that G. truncatulinoides calcifies in a marine snow aggregate microenvironment that is enriched in barium relative to ambient seawater. We suggest that G. truncatulinoides crust is formed after the rhizopodia retract and the foraminifer detaches from its marine snow substrate.

      Groundwater quality in the Surficial Aquifer System, Southeastern United States:

      Released July 22, 2022 14:28 EST

      2022, Fact Sheet 2022-3035

      James A. Kingsbury

      Groundwater provides nearly 50 percent of the Nation’s drinking water. To help protect this vital resource, the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) Project assesses groundwater quality in aquifers that are important sources of drinking water (Burow and Belitz, 2014). The surficial aquifer system constitutes one of the important aquifer systems being evaluated.

      Trends in groundwater levels, and orthophosphate and nitrate concentrations in the Middle Snake River Region, south-central Idaho

      Released July 22, 2022 09:58 EST

      2022, Scientific Investigations Report 2022-5060

      Kenneth D. Skinner

      The U.S. Geological Survey (USGS) evaluated nitrate and orthophosphate concentrations in groundwater for temporal trends (monotonic and step trends) for the middle Snake River region (Cassia, Gooding, Jerome, Lincoln, Minidoka, and Twin Falls Counties) in south-central Idaho using the Regional Kendall test (monotonic trends) and the Wilcoxon signed rank test (step trends). The study evaluated two trend periods: 2000–09 and 2010–19/20. The study area was divided into six hydrogeologic zones (HZs) that had similar geologic and hydrologic characteristics and that correlated with county boundaries where possible. Two well networks sampled by the USGS National Water Quality Program within the HZs were also evaluated.

      The northern Gooding County HZ had statistically significant increasing nitrate concentration trends for both the monotonic and step trends in the early trend period, while the Cassia and Jerome/Southern Gooding County HZs only had one of the statistical tests with statistically significant increasing nitrate concentrations. The Minidoka County HZ had conflicting results between the two statistical tests for the early time period with a statistically significant increasing monotonic trend in nitrate concentration and a statistically significant decreasing step trend. The differing results between these two statistical tests indicates the significance of concentration data during the middle of the time period. Both the Lincoln and Twin Falls County HZs did not have statistically significant trends for either test during either time period as well as the Northern Gooding County HZ for the latter time period. The Minidoka County HZ had statistically significant nitrate trends for both tests in the latter time period along with one of the trend tests for the Cassia and Jerome/Southern Gooding County HZ. Most of the nitrate concentration trend rates are low from 0.01 to 0.12 milligram per liter per year (mg/L/year) with the northern Gooding County HZ having the highest trend rate during the early time period of 0.28 mg/L/year for the step trend and 0.55 mg/L/year for the monotonic trend.

      All the HZs and both well networks had statistically significant increasing orthophosphate-concentrations trends in groundwater for the early time period except for the Lincoln County HZ and the step-trend for the Minidoka County HZ. Orthophosphate concentration trend rates for the early period were low, ranging from 0.001 to 0.015 mg/L/year. Only two HZs and the well networks had enough orthophosphate concentration data available in the latter time period to do statistical analysis. The two HZs (Minidoka and Southern Gooding/Jerome County) both have decreasing orthophosphate concentration trends, with only the monotonic trend for the Southern Gooding/Jerome County HZ being statistically significant at 90 percent with a rate of −0.001 mg/L/year.

      Groundwater levels in two well networks in the eastern Snake River Plain aquifer were also evaluated for trends (monotonic and step), with both networks having statistically significant declining groundwater levels for the 1993–2009 trend period. The latter trend period (2010–20) had statistically significant declining groundwater levels for the A&B well network and statistically significant increasing groundwater levels for the Jerome/Gooding well network, which is downgradient from an aquifer recharge area.

      Graphite as an electrically conductive indicator of ancient crustal-scale fluid flow within mineral systems

      Released July 22, 2022 06:56 EST

      2022, Earth and Planetary Science Letters (594)

      Benjamin Scott Murphy, Jan Marten Huizenga, Paul A. Bedrosian

      Magnetotelluric (MT) imaging results from mineral provinces in Australia and in the United States show an apparent spatial relationship between crustal-scale electrical conductivity anomalies and major magmatic-hydrothermal iron oxide-apatite/iron oxide-copper-gold (IOA-IOCG) deposits. Although these observations have driven substantial interest in the use of MT data to image ancient fluid pathways, the exact cause of these anomalies has been unclear. Here, we interpret the conductors to be the result of graphite precipitation from CO2-rich magmatic fluids during cooling. These fluids would have exsolved from mafic magmas at mid- to lower-crustal depths; saline magmatic fluids that could drive mineralization were likely derived from related, more evolved intrusions at shallower crustal levels. In our model, the conductivity anomalies then mark zones that once were the deep roots of ancient magmatic-hydrothermal mineral systems.

      WHISPers—Providing situational awareness of wildlife disease threats to the Nation—A fact sheet for the biosurveillance community

      Released July 21, 2022 14:15 EST

      2022, Fact Sheet 2022-3022

      Bryan J. Richards, Kimberli J. Miller, C. LeAnn White

      Solutions for emerging infectious disease and bioterror threats can be improved by incorporating integrated biodefense strategies, including improved surveillance for animal and zoonotic diseases, strong national leadership, and effective management tools. Active biosurveillance for disease events is key to early detection, warning, and overall situational awareness and enables better communication, coordination, decision making, and data-driven responses. The national biosurveillance infrastructure has well-established channels for human and domestic animal health data through the Centers for Disease Control and Prevention and U.S. Department of Agriculture, and State, county, and local authorities. Wildlife disease information, however, has been more challenging to acquire and access, in part, due to the comparatively small infrastructure and resources dedicated to wildlife health and also because regulatory authority for wildlife and wildlife health is split among Federal, State, Tribal, and indigenous natural resource authorities. To address these issues, the Wildlife Health Information Sharing Partnership-event reporting system (WHISPers; was developed by the U.S. Geological Survey National Wildlife Health Center to promote collaboration and sharing of wildlife health information and to provide situational awareness and timely information about wildlife disease threats. WHISPers is a free science gateway and data portal that provides interactive query, display, reporting, and export capabilities for wildlife health event summary information.

      Light attenuation and erosion characteristics of fine sediments in a highly turbid, shallow, Great Basin Lake—Malheur Lake, Oregon, 2017–18

      Released July 21, 2022 13:47 EST

      2022, Scientific Investigations Report 2022-5056

      Tamara M. Wood, Cassandra D. Smith

      Malheur Lake is a large, shallow, turbid lake in southeastern Oregon that fluctuates widely in surface area in response to yearly precipitation and climatic cycles. High suspended-sediment concentrations (SSCs) likely are negatively affecting the survival of aquatic plants by reducing the intensity of solar radiation reaching the plants, thus inhibiting photosynthesis. This study was designed to determine the types of suspended material, the erodibility of the lakebed, the attenuation of photosynthetically active radiation (PAR) through the water column, and the effects of wind and precipitation on SSC.

      Two sites in the lake were monitored for approximately 5 months during the summer growing season each year (2017–19). At these sites, turbidity, chlorophyll a fluorescence (a surrogate for concentration), and underwater PAR measurements were collected continuously, and discrete samples were collected every 2 weeks and analyzed for SSC, loss on ignition, and chlorophyll a concentration. Underwater PAR profile measurements were collected during site visits, and a nearby meteorological station recorded terrestrial PAR and wind speeds.

      About 18 percent of suspended material in the water was organic and mostly detrital. Nearly 100 percent of all suspended material was fine material (less than 63 micrometers), and more than 90 percent of the surficial lakebed material was fine material. The high concentrations of fine material in the water column can be expected to strongly attenuate light.

      SSC was significantly higher at both sites in 2018 compared to 2017 and 2019; the interannual differences were mostly due to the lower amount of precipitation in 2018, which resulted in shallower lake depths. Three years of SSC values multiplied by water depth showed a seasonal pattern: concentrations were often highest in early spring, lowest in summer, and intermediate in autumn.

      Episodic wind events with speeds of 5–10 meters per second caused rapid increases in turbidity above background that lasted for a few days. However, a baseline SSC value multiplied by water depth (estimated to be 0.11 kilograms per square meter) was present between wind events and even under ice, suggesting a persistent suspension of very fine, highly erodible material. Terrestrial and underwater PAR measurements were used to develop a relation between PAR attenuation and turbidity that can be used in modeling restoration scenarios. Calculated bottom shear stress caused by wind-generated waves ranged from 0 to 0.4 pascals (Pa). Erosion experiments indicated variability in the bottom sediments from the two lake sites, but much of the lakebed is highly erodible at a threshold of 0.05 to 0.1 Pa.

      Restoration actions may target the persistent turbidity (for example, the use of flocculation) or transient turbidity (for example, construction of wave-reduction barriers), with a goal of attaining approximately 36 micromoles photons per square meter per second of PAR at the lakebed to promote emergence of sago pondweed and other desirable plants. Currently, that threshold often is reached from 4 to 34 centimeters (cm) below the water surface in 1 meter water depth, depending on wind conditions, but halving persistent turbidity would increase the upper end of the range to 55 cm. Additional studies regarding the effects of (1) sediment drying on resuspension and (2) nutrient inputs and internal cycling on phytoplankton populations would help determine the most appropriate restoration strategies.

      Occurrence and transport of aerially applied herbicides to control invasive buffelgrass in Rincon Mountain District, Saguaro National Park, Arizona

      Released July 21, 2022 11:01 EST

      2022, Fact Sheet 2022-3029

      Nicholas V. Paretti, Bruce Gungle

      Resource managers of the Saguaro National Park are concerned about the spread of the invasive species Cenchrus ciliaris L. (buffelgrass) and the threat it poses to desert ecosystems. Glyphosate-based herbicide treatments seem to be one of a few viable options to control the spread of buffelgrass in the mountainous terrain of the National Park. The U.S. Geological Survey completed a 4-year study with the National Park Service that investigated the potential for glyphosate and associated byproducts to remain in soil and transport with stormwater runoff to ecologically important surface waters after aerial application of glyphosate-based herbicides. The results of this study are helping managers and park administrators better understand the long-term effects of treating buffelgrass with glyphosate-based herbicides.

      Update and recalibration of the Rio Grande Transboundary Integrated Hydrologic Model, New Mexico and Texas, United States, and northern Chihuahua, Mexico

      Released July 21, 2022 09:50 EST

      2022, Scientific Investigations Report 2022-5045

      Andre B. Ritchie, Amy E. Galanter, Allison K. Flickinger, Zachary M. Shephard, Ian M. Ferguson

      The Rio Grande Transboundary Integrated Hydrologic Model (RGTIHM) was developed through an interagency effort between the U.S. Geological Survey and the Bureau of Reclamation to provide a tool for analyzing the hydrologic system response to the historical evolution of water use and potential changes in water supplies and demands in the Hatch Valley (also known as Rincon Valley in the study area) and Mesilla Basin, New Mexico and Texas, United States, and northern Chihuahua, Mexico. Reclamation operates the Rio Grande Project (RGP) to store and deliver surface water for irrigation and municipal use within the study area and in the El Paso Valley south of the El Paso Narrows.

      Biases in the RGTIHM’s simulation of streamflow and aquifer storage depletion and the availability of new estimates of historical agricultural consumptive use in the study area initiated an update and recalibration of the RGTIHM. In addition to the new estimates of historical agricultural consumptive use, updates were made to more accurately represent the natural system and included adjustments to the initial groundwater levels; streamflow rating tables; Rio Grande, canal, and drain streambed elevations; tributary streambed elevations; surface-water inflows and diversions; RGP surface-water deliveries and canal waste; on-farm efficiency; the routing of surface-water runoff within the MODFLOW Farm Process; and general head boundaries used to simulate interbasin groundwater flow. Model settings, including the assignment of hydraulic conductivity and storage properties to model layers and the MODFLOW solver package, were adjusted to improve numerical stability, and the model was recalibrated to better simulate the natural system. The updated and recalibrated RGTIHM demonstrates a robust ability to simulate the spatially and temporally variable measurements, estimates, or reports of hydraulic head, surface-water flows, agricultural pumping, RGP surface-water deliveries and canal waste, and decadal aquifer storage changes, with improvements over the previous version of the model.

      Herbivory changes biomass allocation but does not induce resistance among clones of an invasive plant

      Released July 21, 2022 09:21 EST

      2022, Arthropod-Plant Interactions (16) 297-307

      Zoe Becker, Paul J. Ode, Natalie West, Ian Pearse

      Inducible responses to herbivores can be either localized or spread systemically throughout a plant. The ways in which clonal plants integrate their response to herbivores among clonal ramets is not well understood. Yet, this is important to understand the impacts that herbivores may have on clonal plants. We conducted a factorial split-plot greenhouse experiment to determine whether resistance is induced among ramets and how biomass allocation changes among ramets following herbivore damage to one of them. We manipulated the presence of two herbivores, Pieris rapae and Trichoplusia ni, and the root connection of ramets of the clonal invasive weed, Lepidium draba. We found local inducible resistance on the ramet where an herbivore fed, but not in neighboring ramets. Biomass allocation shifted in response to herbivores. Feeding by the generalist caterpillar T. ni resulted in a greater belowground biomass relative to shoot biomass in the local plant, but only when the clonal connection was intact. In contrast, herbivores had little impact on the root mass fraction of neighboring ramets. Herbivory to the local ramet increased the regrowth of neighboring ramets that lacked clonal connection, a trend that was driven by the specialist herbivore P. rapae. Herbivores did not induce systemic resistance among ramets of L. draba, but herbivores, especially the specialist, did alter how neighboring ramets regrow after grazing or mowing. Our observations suggest that individual ramets have fairly autonomous responses to herbivores, and that coordination among ramets, when present, may happen via signals that do not depend on root connections.

      Geomorphic controls on floodplain connectivity, ecosystem services, and sensitivity to climate change: An example from the lower Missouri River

      Released July 21, 2022 08:53 EST

      2022, Water Resources Research (58)

      R. B. Jacobson, Kristen L. Bouska, Edward Bulliner, Garth A. Lindner, Craig Paukert

      Floodplains of large rivers are exploited for agricultural production, industrial and municipal development, and transportation infrastructure. Recently, increased frequency of costly floods has prompted consideration of whether offsetting benefits might accrue from management of floodplains for ecosystem services. We employed a simple inundation model for 800 km of the Lower Missouri River, USA, to evaluate spatial and temporal distributions of ecological floodplain inundation metrics and how those distributions might vary with levee removal and climatic change. The model evaluates inundation at 30 × 30 m resolution on a daily basis over 82 years of record. We quantified provisioning of waterfowl habitat and potential denitrification. Spatial variability is affected by ongoing geomorphic adjustments that affect floodplain connectivity. Statistical models indicate that available floodplain area and recent aggradation are predictive of most inundation metrics. Connectivity is sensitive to climate-change scenarios that predict increased floodplain inundation during spring waterfowl migrations; the greatest sensitivity to future climate exists where channel-floodplain geomorphology presently enhances floodplain connectivity. Evaluation of floodplain denitrification indicates that on average, the nonleveed part of the floodplain could denitrify 0.05%–1.7% of the mean annual nitrogen load of the river. Levee removal could increase this rate to only 3.6% of the nitrogen load. The capacity of floodplain connectivity to influence certain ecosystem services is highly variable in space along the Lower Missouri River and may be appreciably influenced by climate change. Hence, decisions to optimize management of large-river floodplains are likely to be highly location dependent.

      The not-so-dead of winter: Underwater light climate and primary productivity under snow and ice cover in inland lakes

      Released July 21, 2022 08:43 EST

      2022, Inland Waters

      Andrew J. Bramburger, Ted Ozersky, Greg M. Silsbe, Christopher J. Crawford, Leif Olmanson, Krill Shchapov

      As global surface temperatures continue to rise as a result of anthropogenic climate change, effects in temperate lakes are likely to be more pronounced than in other ecosystems. Decreases in snow and ice cover extent and duration, as well as extended periods of summer stratification have been observed in temperate lake systems throughout the Anthropocene. However, the effects of changing snow and ice cover upon lacustrine communities remain largely uninvestigated. Here, we examined underwater light climate and associated primary productivity patterns under snow-covered and clear lake ice in 6 inland lakes in Minnesota, USA, spanning gradients of water column optical properties (blue, green, brown) associated with trophic status and organic material content. In all lakes, snow cover influenced not only the intensity, but also the spectral signature of light penetrating into the water column. Specifically, the wavelength of maximum penetration was shifted towards longer wavelengths under snow cover in green (eutrophic) lakes, while it was shifted towards shorter wavelengths in blue and brown lakes. Volumetric primary productivity was often higher than anticipated (e.g. ∼1200 mg · m-3 · d-1; L. Minnetonka, snow-covered ice). Carbon assimilation rates were lower under snow-covered ice throughout the water column in all lake types, except immediately under cleared ice in eutrophic lakes, where it is likely that phytoplankton were photo-inhibited due to penetration of intense, short-wavelength light. These findings suggest that changing patterns of snow and ice cover under ongoing climate change scenarios can affect patterns of phytoplankton primary productivity in sensitive aquatic ecosystems.

      Land cover change effects on stormflow characteristics across broad hydroclimate representative urban watersheds in the United States

      Released July 21, 2022 08:09 EST

      2022, Water (14)

      Kul Bikram Khand, Gabriel B. Senay

      Urban development alters stormflow characteristics and is associated with increasing flood risks. The long-term evaluation of stormflow characteristics that exacerbate floods, such as peak stormflow and time-to-peak stormflow at varying levels of urbanization across different hydroclimates, is limited. This study investigated the long-term (1980s to 2010s) effects of increasing urbanization on key stormflow characteristics using observed 15 min streamflow data across six broad hydroclimate representative urban watersheds in the conterminous United States. The results indicate upward trends in peak stormflow and downward trends in time-to-peak stormflow at four out of six watersheds. The watershed in the Great Plains region had the largest annual increasing (decreasing) percent change in peak stormflow (time-to-peak stormflow). With the current change rates, peak stormflow in the Great Plains region watershed is expected to increase by 55.4% and have a 2.71 h faster time-to-peak stormflow in the next decade.

      Mississippi and Landsat

      Released July 20, 2022 21:20 EST

      2022, Fact Sheet 2022-3062

      U.S. Geological Survey

      Mississippi holds a significant place in the cultural and economic history of the United States. For example, the Magnolia State was a hotbed for the Delta blues, an early 20th century musical genre with tremendous cultural effects in the United States and around the world. The “Delta” in Delta blues is the Mississippi River Delta, the largest delta in the United States. The Mississippi River is one of the longest in the Nation, having 1,800 navigable miles that serve as a natural transportation corridor that is foundational to America’s economic fortunes.

      This important waterway forms Mississippi’s western border, and the fertile alluvial soils that fan out across its western third served to bolster its early economy and remain key drivers of its agriculture sector. These soils continue to support cotton, soybeans, corn, and agricultural products for which Mississippi is a national leader: rice and farmed catfish.

      Such heavy reliance on the land necessitates a strong understanding of the health of—and threats to—the landscape. Spikes in extreme heat and associated wildfire dangers, the increasing frequency of powerful hurricanes on the Gulf Coast, and annual tornadoes all stand as challenges to the Magnolia State’s land resources.

      The U.S. Geological Survey Landsat program serves a critical role in mapping, monitoring, and understanding changes across Mississippi. Here are a few examples of how Landsat benefits the State.

      Alabama and Landsat

      Released July 20, 2022 21:15 EST

      2022, Fact Sheet 2022-3060

      U.S. Geological Survey

      Alabama’s warm climate and rich soil bolster its agriculture and timber industries, but they also offer ideal conditions for natural playgrounds, enjoyed by humans and the wildlife that call the open green spaces home. Alabama has 21 State parks and 11 national parks, monuments, and trails across its diverse geography.

      Cotton is no longer king in the Cotton State, but it remains a part of the fabric of its multibillion-dollar agriculture sector. The State also produces poultry, cattle, calves, corn, lumber, soybeans, and catfish.

      The State is home to Dauphin Island, the first land mass seen by migratory birds and pollinators upon their return from South America. Dauphin Island acts as a landing zone for hundreds of species, including sandpipers, plovers, and herons, and protects Alabama’s coastline. Since 1961, Dauphin Island has been the home of the Audubon Bird Sanctuary.

      The varied landscapes of the Cotton State face challenges from climate change, land change, and extreme weather. Satellite imagery from the U.S. Geological Survey Landsat Program can offer insight and understanding in these and other areas. Here are some ways Landsat benefits Alabama.

      Tennessee and Landsat

      Released July 20, 2022 20:14 EST

      2022, Fact Sheet 2022-3063

      U.S. Geological Survey

      From the flat, rich soil of western Tennessee to the Appalachian Mountains in the east, and rolling hills in between, “the Volunteer State” enjoys a wealth of natural resources.

      The Tennessee, Cumberland, and Mississippi Rivers supply economically crucial navigation routes, along with recreation for residents and visitors. Additionally, 14 million acres of hardwood and softwood forests cover roughly one-half of the State, contributing an estimated $24 billion and nearly 100,000 jobs to Tennessee’s economy. Within a span of more than 400 miles, the State’s diverse agricultural products include cotton, corn, soybeans, poultry, horses, cattle, goats, hay, vegetables, nursery crops, and tobacco.

      Energy production is important to Tennessee and the region, and power sources range from coal and nuclear to hydroelectric sources. Tourism also is a key industry, and music attractions and historical sites are balanced by natural features such as the Great Smoky Mountains National Park, which recorded 14.1 million visits and ranked second for most visited National Park Service site in the United States in 2021.

      Landsat imagery’s broad geographic scale and rich historical archive have proven useful to land managers and State agencies for monitoring natural resources. Here are several ways Landsat has benefited Tennessee.

      Rhode Island and Landsat

      Released July 20, 2022 20:10 EST

      2022, Fact Sheet 2022-3065

      U.S. Geological Survey

      Rhode Island is an oasis of natural calm surrounded by heavily urbanized East Coast areas, which may explain why the smallest State in the United States is such a popular tourist destination for residents of New York, Pennsylvania, and New Jersey, or perhaps its popularity is a measure of the Ocean State’s abundant wildlife and picturesque views. Although small in land area, Rhode Island claims the largest estuary in New England in the 147-square-mile Narragansett Bay. Locals and visitors feast on clams caught in the bay, trek to glimpse shorebirds, or boat to 1 of 30 islands.

      As with any coastal State, the natural wonders of Rhode Island face threats related to sea level rise and warming ocean temperatures. State agencies also work to fend off foes like the invasive Lymantria dispar (Linnaeus, 1758; spongy moth) and protect the forests that cover more than one-half of Rhode Island.

      The U.S. Geological Survey Landsat Program, with 50 years of recurring Earth observations from space, offers a unique and freely available public data source for the study of land and coastal change across Rhode Island and the United States. Here are just a few of the ways Landsat imagery has been used to benefit the State.

      Delaware and Landsat

      Released July 20, 2022 20:04 EST

      2022, Fact Sheet 2022-3064

      U.S. Geological Survey

      Delaware’s status as the first State to ratify the U.S. Constitution is a well-known point of pride. “The First State” is among Delaware’s nicknames, alongside “the Blue Hen State,” “the Diamond State,” and “the Small Wonder,” the last of which relates to Delaware’s diminutive land area—larger only than Rhode Island.

      Less well known, perhaps, is Delaware’s geographic distinction as the State with the lowest average elevation. Most of its land area rises no more than 80 feet above sea level. In fact, about 32,000 acres of Cypress Swamp, sometimes called the Great Cypress Swamp, stretch across its southern border.

      These low elevations put Delaware at particular risk of sea level rise associated with climate change. Sea levels are rising more quickly than average for the Mid-Atlantic Region, which includes Delaware. The State has seen its coastal waters rise more than 1 foot over the past century.

      The Landsat Program’s 50-year archive of repeat Earth observations offers an indispensable record of land change along the Nation’s coastlines. Imagery collected by Landsat satellites can inform studies of the coastline losses, flooding extents, and land cover conversions that affect climate resilience in Delaware. Landsat data also can support plans to mitigate those effects. Here are a few examples of the ways Delaware benefits from Landsat.

      Louisiana and Landsat

      Released July 20, 2022 17:37 EST

      2022, Fact Sheet 2022-3059

      U.S. Geological Survey

      Louisiana holds a unique historical, economic, and cultural position in the national consciousness. Its off-shore oil operations help fuel the U.S. economy. The Port of South Louisiana is the busiest in the United States by cargo volume; the nearby Port of New Orleans is the sixth busiest. The former French and Spanish colony served as a key connection to the Caribbean long before U.S. independence, and Louisiana’s multinational effects soon melded into a Creole culture that had an outsized effect on America.

      That heritage remains a powerful draw for the tourism industry in Louisiana. Gulf Coast breezes carry the aromas of tropical flowers, sweet beignets, and savory crawfish through the 13 colorful blocks of New Orleans’ French Quarter. Interwoven with the sounds of jazz, rock, country music, and zydeco, the city’s charms delight more than 18 million visitors each year.

      The proximity of the Gulf Coast and the city’s elevation, however—just 6.5 feet above sea level—also offer an ominous warning of the ever-present threat of climate change and natural disaster. Hurricane Katrina battered New Orleans in 2005, an incident tied to more than 1,800 deaths that marks one of the most notorious U.S. weather-related tragedies in the 21st century. Climate change has amplified threats from tropical storms. Through more frequent and powerful storms, sea level rise threatens low-lying areas such as Lake Charles and creates unpredictable weather patterns that threaten the cities and agricultural operations to the north.

      Landsat data offer rich information that can aid in early warning, disaster response, and the monitoring of recovery from natural disasters. Its historic, unparalleled 50-year archive of repeat Earth observations also serves to guide resiliency plans and feeds modeling that can help States like Louisiana prepare for coming coastal and inland change. Here are just a few examples of how Landsat has been used to study and understand Louisiana.

      Iowa and Landsat

      Released July 20, 2022 17:32 EST

      2022, Fact Sheet 2022-3061

      U.S. Geological Survey

      Iowa is famous for plenty of reasons—its State Fair butter sculptures, its first-in-the-Nation presidential caucuses, and the Iowa Hawkeyes football team, whose mascot doubles as the State nickname—but “corn” might be the first word to cross the mind of a non-Iowan.

      Iowa consistently leads the United States in corn production and in the production of hogs, which in turn consume a sizable share of the corn grown there. Corn also drives Iowa’s ethanol industry, which put nearly 4.5 billion gallons of fuel into the supply chain in 2020—more than any other State.

      Iowa owes its agricultural dominance largely to its fertile soils, making land management decisions critical to its future. Changes to land cover, more intensive land use, unusual precipitation patterns, and temperature changes, coupled with an influx of extreme weather events—some of which can be tied to or exacerbated by climate change—have placed pressure on the productive farm ground of Iowa’s 99 counties.

      Landsat Program satellites can be especially useful in the monitoring and management of croplands across the United States. Backed by a 50-year record of Earth surface change, Landsat satellites can detect the details of vegetation health by peering into the infrared and near-infrared parts of the electromagnetic spectrum. Iowa has long served as a proving ground for Landsat-based agricultural research, and its residents and leaders have benefited from that work. Here are a few examples of how the Landsat Program benefits Iowa.

      New Hampshire and Landsat

      Released July 20, 2022 16:16 EST

      2022, Fact Sheet 2022-3058

      U.S. Geological Survey

      At its widest point, a mere 80 miles separate the eastern and western borders of New Hampshire. Its northern and southern borders are just 175 miles apart. Even so, few States can boast as much rugged natural beauty per mile as the Nation’s fifth smallest.

      Nestled within New Hampshire are 93 State parks teeming with moose, Ursus americanus (Pallas, 1780; black bears), coyotes, beavers, river otters, and foxes. The largest section of White Mountain National Forest cuts across north-central New Hampshire, drawing visitors to its lakes, streams, mountain peaks, and hardwood forests. New Hampshire also is home to Lake Winnipesaukee, the State’s largest lake, notable for its floating post offices, the annual “ice-out” contest that sees residents vying to guess the date its surface ice dissipates, and its supporting role in films such as “On Golden Pond” and “What About Bob?” However, the scenic forests of New Hampshire face challenges in the form of invasive species such as Lymantria dispar (Linnaeus, 1758; spongy moth), Adelges piceae (balsam woolly adelgid), and Agrilus planipennis (emerald ash borer). In recent years, New Hampshire’s lakes and streams have seen more cyanobacterial blooms as well.

      The U.S. Geological Survey Landsat Program offers a consistent, reliable, and historically unmatched source of Earth observations that can aid in the mapping, monitoring, and management of New Hampshire’s land and water resources. Here are a few ways Landsat data have been used in the Granite State.

      Geohydrology and water quality of the northern and central parts of the Tug Hill glacial aquifer, Jefferson and Oswego Counties, north-central New York

      Released July 20, 2022 15:18 EST

      2022, Scientific Investigations Report 2022-5039

      Todd S. Miller, Benjamin N. Fisher, William M. Kappel

      The northern and central parts of the Tug Hill glacial aquifer consist of a 29-mile-long, crescent-shaped, mixture of glaciofluvial, glaciolacustrine, and recent alluvial deposits of predominantly sand and gravel on the western side of the Tug Hill Plateau in Jefferson and Oswego Counties in north-central New York. Approximately 11,400 people are supplied by groundwater that is withdrawn from municipal and nonmunicipal wells in the northern and central parts of the aquifer. In addition, many farms, several industries, and a large New York State fish hatchery also rely on the water from the aquifer.

      In the early 2000s, anticipated developmental pressures from potential new industries (including a proposed water-bottling plant in the central part of the Tug Hill glacial aquifer) and expansion of the Fort Drum military base north of Watertown (with the projected increase in population extending into the northern part of the aquifer) prompted the Tug Hill Commission, local municipal officials, and representatives from the New York State Department of Environmental Conservation to initiate a geohydrologic study with the U.S. Geological Survey. The information from this study is intended to help the state, counties, and local communities make sound policy decisions about their use of this large groundwater resource.

      The northern part of the Tug Hill glacial aquifer is a combination of glaciofluvial outwash and alluvial sand and gravel in the Sandy Creek Valley northeast of Adams, New York, and mostly glaciolacustrine beach and deltaic sand or sand and gravel north and south of the village of Adams. The southern and eastern areas of the central part of the aquifer are composed mostly of glaciofluvial sediments such as kames, kame moraines, and kame terraces, whereas most of the western areas of the central part are composed mostly of glaciolacustrine sediments such as deltaic sand and beach sand and gravel.

      The northern and central parts of the aquifer are unconfined. Recharge to the northern and central parts of the aquifer is from three main sources: (1) precipitation that falls directly onto the aquifer; (2) unchannelized runoff (overland flow) and groundwater from till and bedrock in the Tug Hill Plateau that seeps into the eastern side of the aquifer; and (3) streams that drain the Tug Hill Plateau and flow across and lose water to the aquifer. Groundwater discharges to springs, seeps, headwaters of streams, and wetlands in the middle area of the central part of the aquifer and along the entire western boundary of the northern and central parts of the aquifer; pumping wells; artificial ditches; and deeply incised streams in the northern and central parts of the aquifer. The groundwater discharge to such streams is critical in supporting the salmonid fishery in the central part of the aquifer.

      Groundwater levels were measured on July 17, 2014, at 22 wells throughout the northern and central parts of the aquifer. Water-table contours were drawn on the basis of the measured July 2014 water levels, historical water-level data, and surface-water levels where surface water in the channels was expected to be hydraulically connected to the groundwater system. The water table generally slopes from east to west throughout the northern and central parts of the aquifer; this slope also indicates that the direction of groundwater flow is generally from east to west.

      Water-quality samples were collected from 23 stream sites during base-flow conditions, and groundwater-quality and other types of environmental samples were collected from 20 wells in the northern and central parts of the Tug Hill glacial aquifer. The results of the sampling indicate that surface water and groundwater are generally of good quality.

      Comparison of the median concentration values of major ions in groundwater samples indicated that hardness in the northern part of the aquifer was about twice as great, and concentrations of calcium and sodium were more than three times as great, as in the central part of the aquifer. As was the case with surface water, the much greater median concentrations in groundwater of calcium, hardness, and alkalinity in the northern part of the aquifer are due to the dissolution of limestone that underlies most of that area and to the high-carbonate content of the clasts in the sand and gravel. There was little to no difference among the median values for bromide, fluoride, silica, and iron in the two parts of the aquifer. Concentrations of most other major ions were slightly greater in the northern part than in the central part of the Tug Hill glacial aquifer, except for magnesium, whose concentration was greater in the central part. Median concentrations of nutrients were generally greatest in surface water and groundwater in the northern part of the aquifer.

      Kansas and Landsat

      Released July 20, 2022 14:55 EST

      2022, Fact Sheet 2022-3057

      U.S. Geological Survey

      Kansas seems synonymous with agriculture, and rightly so—87 percent of Kansas land is devoted to it. As a key contributor to the State’s economy, agriculture makes Kansas one of the top producers of wheat, grain sorghum, and cattle in the country, but the State at the geographic center of the conterminous United States contains much more than fields and pastures.

      Deciduous woodlands sprawl throughout the east. Tallgrass prairie—the only extensive stand remaining in the country—covers the east-central Flint Hills with more than 500 species of plants, many of them wildflowers, including the Sunflower State’s nickname inspiration. Near the center of Kansas, Cheyenne Bottoms—the largest marsh in the interior United States at 41,000 acres—welcomes migrating birds, including the endangered Grus americana (Linnaeus, 1758; whooping crane), by the thousands in the spring and fall. To the south, the inland saltwater marshes of Quivira National Wildlife Refuge attract many more.

      Farther west, chalk outcroppings like Castle Rock and Monument Rocks rise above the landscape as fossil-bearing remnants of a sea floor from millions of years ago. Oil and natural gas fields exist throughout the State. After two University of Kansas professors discovered helium in a sample from one natural gas well in 1905, Kansas became a substantial supplier. The Landsat Program provides tools for monitoring and managing our conservation lands and their many resources. Here are several ways Landsat helps Kansas.

      Nebraska and Landsat

      Released July 20, 2022 14:47 EST

      2022, Fact Sheet 2022-3056

      U.S. Geological Survey

      The rolling plains of Nebraska occupy a storied place in the American psyche. For those living outside the Midwest, the Cornhusker State may be seen as a symbol of the Nation’s heartland, cropped border to border, with country churches and barely standing barns to be found around every turn of its gravel roads.

      Although the pioneer history and agricultural heritage of the 37th State lend credence to this idyllic view, Nebraska’s varied landscapes and modern economy make the reality of life in the State more complex than its rural image would suggest.

      Agriculture remains Nebraska’s top industry, but manufacturing now represents 12 percent of the State’s gross domestic product. The financial services and insurance industries account for 8 percent of the gross domestic product in Nebraska, which is the headquarters of Berkshire Hathaway and Mutual of Omaha, the latter of which is named after Nebraska’s largest city, which grew nearly 12 percent between 2010 and 2020. Cropland is indeed a prominent feature in Nebraska, but the State also is home to 8 State parks, 5 national parks, 2 national forests, and 3 national grasslands. The grasses and dunes of the Nebraska Sand Hills that stretch across the north-central quarter of the State are a National Natural Landmark.

      Data from the Landsat satellite program contribute to the study and management of Nebraska’s land in myriad ways, from monitoring crop productivity and aiding in rangeland management to tracking damage from floods, droughts, or hurricanes. Land cover maps produced using data pulled from the 50-year Landsat archive can offer important insights into urban growth, land use trends, and land change patterns. Here are a few examples of how Landsat has been used in Nebraska.

      Wisconsin and Landsat

      Released July 20, 2022 13:13 EST

      2022, Fact Sheet 2022-3055

      U.S. Geological Survey

      Wisconsin could be called a State of icons, and many of the icons can trace their roots to the abundant resources within its four borders. Big beer companies in Milwaukee that began in the 1800s made their beer from water from nearby lakes and rivers, kept it cool with ice from those same sources, and stored it in containers made of harvested wood from State forests. Dairy and cheese factories rely on milk from dairy farms with fields and pastures and generate billions in revenue for the State’s economy. The Wisconsin Dells, Door County, and the Northwoods draw tourists with their natural beauty and recreation opportunities.

      Wisconsin contains more than 17 million acres of hardwood and coniferous forest, much of it on land reforested since the large-scale timber cutting of the 1800s and early 1900s. The Badger State boasts nearly 15,000 lakes within its borders and touches two Great Lakes—a bit of Lake Superior and a considerable length of western Lake Michigan. Wisconsin ranks second in the Nation for milk production, but it ranks first for cheese, cranberries, snap beans, and milk goats.

      Data and imagery from Landsat Earth observation systems assist agencies and land managers in monitoring these resources and planning for future management. Here are several ways Landsat benefits Wisconsin.

      Assessment of fecal contamination sources to Alley Creek, Queens County, New York, August 2020–June 2021

      Released July 20, 2022 13:00 EST

      2022, Scientific Investigations Report 2022-5068

      Shawn C. Fisher, Christopher M. Kephart, Natalie Cheung, Tristen N. Tagliaferri

      Alley Creek, a tributary to Little Neck Bay in Queens County, New York, has been designated by the New York State Department of Environmental Conservation as impaired (Class I) for fecal coliform because of pollution from combined sewer overflow, including stormwater runoff. The U.S. Geological Survey, in cooperation with the New York City Department of Environmental Protection, conducted a 1-year study from August 2020 to June 2021 using microbial source tracking (MST) methods to assess potential host sources of fecal contamination (for example, human, canine, and waterfowl) from the following: three outfall sites, TI–025, TI–008, and TI–024; an artesian well (Q277) adjacent to Alley Creek; and natural waters within the Alley Creek watershed and Little Neck Bay. In addition to analyzing for MST markers, field measurements such as water temperature and specific conductance, samples for total suspended solids, and fecal indicator bacteria (FIB; enterococci and fecal coliform) were collected. Pharmaceutical compounds were also collected for analysis, and the results of sampling were compared spatially and temporally to help support management decisions related to mitigation of fecal sources to Alley Creek. Factors that could affect concentrations, including tidal conditions, seasonality, and weather conditions, also were assessed. A sediment resuspension laboratory experiment was designed to replicate tidal activity in Alley Creek using sediment collected in the sewers and on the shoreline, as well as water collected from Oakland Lake. These sediment samples were assessed to understand the relation between sediment resuspension and FIB in the water column. The human MST markers used for this study, Bacteroides HF183/BacR287, and crAssphage CPQ_056 and CPQ_064, were detected in most samples (27 of 28) collected at the three outfall sites along Alley Creek, whereas the canine marker BacCan was less prevalent (20 of 28 samples) but exhibited a pattern of relative concentrations similar to the human markers. The waterfowl MST GFD marker was detected in 7 of 28 samples collected at the three outfall sites. Human MST markers were not detected at Oakland Lake (which drains through a combined sewer line to Alley Creek at TI–008), indicating minimal or nonexistent influence of sewage contamination in the lake. Groundwater samples collected from Q277 did not contain any MST markers, and concentrations of fecal coliform were less than 10 colony forming units per 100 milliliters. Although FIB did not correlate well with total suspended solids for individual sample sets, samples collected following precipitation and high-turbidity events were typically found to have higher concentrations of FIB than dry-weather samples. Results from the pharmaceutical compounds analysis provided additional evidence for determining known and suspected human sources when coupled with MST markers. Together, the MST, pharmaceutical, and FIB data generated by this study, along with supplementary data such as locations of point sources, locations of wildlife populations, and tidal exchange data, may provide reliable information on source identification and transport mechanisms of fecal contamination to Alley Creek.

      Aerial counts for surface-nesting seabirds at Lehua Island and Moku Manu Islet and Ulupaʻu Crater, Oʻahu, in 2019

      Released July 20, 2022 12:35 EST

      2022, Data Report 1161

      Josh Adams, Emily C. Kelsey, Jennilyn Stenske, Jonathan J. Felis

      Among important seabird breeding sites in the main Hawaiian Islands, Lehua Island offshore Niʻihau and Moku Manu Islets offshore Oʻahu support diverse and abundant seabird breeding populations. Both offshore islands provide excellent nesting habitat for surface-nesting boobies (Sula spp.) and terns but, of the two, only Moku Manu supports relatively large breeding populations of Sooty Tern (Onychoprion fuscatus) and Brown Noddy (Anous stolidus). Additionally, Ulupaʻu Crater, near Moku Manu on Oʻahu, is one of only a few sites within the eight main Hawaiian islands and the only site on the main island of Oʻahu that supports a nesting population of Red-footed Boobies (Sula sula). Despite their importance for informing renewable offshore energy planning off Hawaiʻi, robust and accurate seabird population survey data exist and are available for some locations (Lehua; Raine and others, 2021), but at Moku Manu and Ulupa‘u Crater, recent information are not yet available (E. VanderWerf, written commun. 2021). In this study, we completed comprehensive aerial photographic counts at these three sites for six surface-nesting seabird species present during the 2019 breeding season: Brown Booby (Sula leucogaster), Red-footed Booby, Masked Booby (S. dactylatra), Great Frigatebird (Fregata minor), Sooty Tern, and Brown Noddy. We estimated 5,782, 102, and 1,446 nesting pairs of Red-footed Boobies at Lehua, Ulupaʻu Crater, and Moku Manu, respectively. At Lehua and Moku Manu, we estimated 692 and 65 nesting pairs of Brown Boobies, respectively. At Moku Manu, we estimated 95 nesting pairs of Masked Boobies, one of only three nesting locales for this species in the main Hawaiian Islands. Based on digital photograph counts of sampled areas and area-based extrapolation, we estimated 17,938 terns (mostly Sooty Tern with fewer Brown Noddy) on Moku Manu. We observed Great Frigatebirds roosting at the two island sites, but we did not detect any sign of nesting for this species. We found that inter-observer counts for behavioral classifications (nesting, roosting, unknown) ranged in precision (D=0.13–0.31), but generally, counts among photographs accounting for all seabird targets (D=0.10–0.22) and for boobies classified as nesting (D=0.13–0.18) were more precise than for roosting and unknown categories (D=0.13–0.31), indicating that at least some of the variation in count precision relates to differences in how independent counters identified behavioral classifications. The nesting population sizes (and number of terns present on Moku Manu) present during aerial counts likely are minimum estimates because individuals among these species can exhibit asynchronous nesting phenologies, and not all members of the nesting populations would be expected to be attending the sites when we surveyed. The results of these counts provide current and accurate abundance estimates for these species that can serve as benchmarks for future management and monitoring and as important components of population-level assessments aimed at quantifying seabird vulnerability to potential offshore wind energy development in the main Hawaiian Islands.

      Seasonal and long-term clarity trend assessment of Lake Tahoe, California–Nevada

      Released July 20, 2022 12:11 EST

      2022, Scientific Investigations Report 2022-5070

      Ramon C. Naranjo, Paul Work, Alan Heyvaert, Geoffrey Schladow, Alicia Cortes, Shohei Watanabe, Lidia Tanaka, Sebnem Elci

      The clarity of Lake Tahoe, observed using a Secchi disk on a regular basis since the late 1960s, continues to be a sentinel metric of lake health. Water clarity is influenced by physical and biological processes and has declined in the five decades of monitoring, revealing differences between summer (June–September) and winter (December–March). This document summarizes key findings of a study of Lake Tahoe water clarity, including long-term variability and the relative importance of several influencing variables and processes.

      This study, prepared in cooperation with the Nevada Division of Environmental Protection, focused on (1) an apparent divergence in clarity trends between summer and winter periods, (2) observed changes in in-lake physical and ecological variables that may influence or control seasonal and annual clarity trends, and (3) five research hypotheses regarding lake clarity that were developed by Lake Tahoe management agencies. Previously collected data were used to complete this study. Trend analysis confirmed that winter clarity stabilized (that is, there is no longer a statistically significant trend up or down) during the last 20 years. Evaluation of clarity for selected months in the 50-year Secchi disk clarity dataset showed that only two summer months, July and August, had statistically significant decreases in clarity from 2000–19. Different subsets of available data were analyzed to reveal the presence or absences of trends for each season, decade, and month.

      Five hypotheses related to lake clarity were part of the study described by this report. Hypothesis 1 stated that clarity is controlled predominantly by the distribution and volumetric density of fine particles in suspension. This hypothesis was studied using available data describing in-lake fine (0–20 micrometers) particles from 2008–19. Water clarity was negatively correlated with in-lake particle abundance, with particles in the 1.0-4.6 μm range having the greatest effect, consistent with light-scattering theory. Estimated abundances of diatoms of the genus Cyclotella also were found to be negatively correlated with clarity.

      Data limitations precluded a complete investigation of hypothesis 2, which stated that the observed improvements in winter water clarity are a response to decreasing fine suspended-sediment concentrations in the lake resulting from load reductions from upland sources in and near urbanized areas. Data describing fine-sediment loading from urban areas to the lake were only available since 2014, and only once or twice per month. A slight, statistically significant, negative correlation was identified between urban fine-particle loading and monthly lake clarity with a 4-month lag. Particle abundance in monitored streams is highly correlated with simultaneous particle abundance in the lake.

      Hypothesis 3 stated that changing hydrodynamic conditions in the lake are increasing thermal stability and resistance to mixing. Trend analyses performed on stability index and buoyancy frequency time series computed from long-term observations of lake temperatures support the hypothesis that hydrodynamic conditions have evolved since 1969 to increase the lake’s resistance to mixing. The date of maximum mixing in winter has become progressively earlier in the year. Lake density stratification, defined using the stability index, is commencing earlier in the year and extending a month longer than in the early years of the monitoring program.

      Hypothesis 4 stated that the trend of decreasing summer clarity is a result of earlier, prolonged, and more intense stratification. Statistically significant correlations were found between summer clarity and (1) date of onset of stratification, (2) duration of stratification, and (3) buoyancy frequency.

      Hypothesis 5 stated that ecological (food web) interactions are causing changes in the trends of seasonal or annual clarity; data supporting hypothesis 5 were limited to examples from other systems and to intermittent monitoring of Lake Tahoe and Emerald Bay. The resulting narrative assessment was motivated by a 6-year study of Mysis shrimp disappearance and return in Emerald Bay. The available data and a large body of published literature are consistent with the inference that Mysis shrimp-induced food web changes are causing changes in the trends of seasonal or annual clarity. This food-web study focused on the relations between introduced Mysis shrimp, the native cladocerans (Daphnia and Bosmina) that were largely eliminated following Mysis introduction, and the effect on fine particles within the lake. The records of Mysis and other zooplankton data for Lake Tahoe are episodic and have large gaps. Consequently, statistical analyses could not be conducted to compare zooplankton data with other variables. The long-term record, however, indicates that the key effect was a change to the phytoplankton assemblage, where larger diatoms disappeared, likely due to Mysis grazing, only to be replaced by Cyclotella that are an order-of-magnitude smaller and have increased the abundance and volumetric density of total fine particles in suspension (biotic and abiotic).

      Occurrence of per- and polyfluoroalkyl substances and inorganic analytes in groundwater and surface water used as sources for public water supply in West Virginia

      Released July 20, 2022 11:40 EST

      2022, Scientific Investigations Report 2022-5067

      Mitchell A. McAdoo, Gregory T. Connock, Terence Messinger

      Per- and polyfluoroalkyl substances (PFAS) are widely observed anthropogenic compounds found in water supplies worldwide and increasingly linked with adverse health effects in humans. In 2019, the West Virginia Legislature recognized the contamination risk to public source-water supplies posed by PFAS and passed a resolution that required a statewide PFAS study. The purpose of the resolution was to understand the occurrence and distribution of PFAS contamination throughout the State’s rivers, lakes, and groundwater aquifers. The U.S. Geological Survey has worked in cooperation with the West Virginia Department of Environmental Protection and West Virginia Department of Health and Human Resources to collect raw-water samples at 279 public-water systems across West Virginia. Public-water systems sampled for this study were identified by the West Virginia Department of Health and Human Resources and included all community water systems in the State and all daycares and schools that operate their own water systems.

      Raw source water was sampled for both groundwater and surface-water sites at the first available tap in the public-water system, prior to any treatment. One hundred and seventy-three samples were collected from groundwater sources and 106 samples were collected from surface-water sources. Parameters collected at the time of sampling included pH, specific conductance, water temperature, dissolved oxygen, turbidity, and alkalinity. PFAS was analyzed at all 279 sites, major ions and trace elements were analyzed at 272 sites, and nutrients were analyzed at 270 sites.

      The type of source water used for public supply in West Virginia is generally dependent on geology with more groundwater sites sampled in high-yield aquifers such as karst and alluvium. Surface-water sites were more evenly distributed throughout the State and are often the only source used in areas underlain by lower-yielding fractured-rock aquifers. Twenty-four percent of the sites sampled for this study had at least 1 PFAS detected, 47 of which were in groundwater sources and 20 in surface-water sources. Five sites exceeded the U.S. Environmental Protection Agency’s health advisory for combined perfluorooctanoate and perfluorooctanesulfonate concentrations of 70 nanograms per liter. These sites were located in highly susceptible karst and alluvial groundwater aquifers on the east and west sides of the State.

      Higher PFAS concentrations were more commonly found in groundwater than surface-water sources, and high concentrations and PFAS detections were generally concentrated in the Ohio River Valley and West Virginia’s eastern panhandle. PFAS was rarely detected in groundwater sites in fractured-rock aquifers and abandoned underground coal-mine aquifers in the Appalachian Plateaus Physiographic Province had very little PFAS detected. These data represent a baseline summary of source water in West Virginia. Additional studies may be needed to understand exposure to private homeowners with domestic-water sources, variability of PFAS concentrations over time, and PFAS in finished drinking water as evaluated by current and future drinking-water regulations.

      Presented abstracts from the U.S. Geological Survey 2020 Rocky Mountain Region Science Exchange (September 15–17, 2020)

      Released July 20, 2022 10:00 EST

      2022, Open-File Report 2022-1040

      Patrick J. Anderson, Anne C. Tillery, editor(s)

      The U.S. Geological Survey Rocky Mountain Region hosted scientists, managers, program coordinators, and leadership team members for a virtual Science Exchange during September 15–17, 2020. The Science Exchange had 216 registered participants and included 48 talks over the 3-day period. Invited speakers presented information about the novel U.S. Geological Survey Earth Monitoring, Analysis, and Prediction (EarthMAP) concept. Scientists showcased their research and participated in discussions related to the EarthMAP concept and EarthMAP applications. In addition, the Colorado River Basin Pilot Project, one of the first EarthMAP Pilot Projects, was unveiled during the Science Exchange. This report provides synopses of session objectives and corresponding abstracts that were presented along with author affiliations and email address of the lead author. In addition, web links are provided for related programs and projects, and associated publications are referenced.

      Concentrations of per- and polyfluoroalkyl substances (PFAS) in selected rivers and streams in Massachusetts, 2020

      Released July 20, 2022 09:55 EST

      2022, Data Report 1160

      Jennifer G. Savoie, Denise M. Argue

      Water samples collected from 27 rivers and streams in Massachusetts were analyzed to characterize the presence and concentrations of per- and polyfluoroalkyl substances (collectively known as PFAS) in surface waters across the Commonwealth. Sampling sites were selected in urban rivers where PFAS were expected to be present, such as those that receive treated municipal wastewater, and in rural rivers that were not known to be affected by municipal wastewater. The samples were collected three times in 2020 from 64 sites, and were analyzed for 24 PFAS, 18 of which are included in the United States Environmental Protection Agency’s Method 537.1.

      Samples were collected when the instantaneous flow of the rivers and streams was at base-flow condition to minimize PFAS input or dilution from stormwater runoff and overland flow. The analyses detected PFAS in samples from all 27 rivers and streams. The number of PFAS detected in each sample ranged from 2 to 16. Concentrations of individual PFAS ranged from no detectable concentrations (less than 1.74 nanograms per liter) to 109 nanograms per liter. Samples from sites associated with wastewater treatment facilities in urban areas had a larger number and variety of PFAS present, and at higher concentrations, than in samples from the more rural rivers. This report includes a summary of the chemical data and physical properties of both environmental and quality-control samples, and a description of procedures for the collection and processing of the samples.

      Intake efficiency field results for Federal Interagency Sedimentation Project bag samplers

      Released July 20, 2022 08:30 EST

      2022, Open-File Report 2022-1036

      Adam E. Manaster, Mark N. Landers, Timothy D. Straub

      The Federal Interagency Sedimentation Project (FISP) standardizes and advances sediment science among federal agencies. It is important to ensure that the FISP bag samplers perform isokinetically under all tested and approved conditions and collect samples that are representative of the stream or river cross-section. A measure of a sampler’s isokinetic behavior is its intake efficiency, which is defined as the ratio of the velocity through the nozzle entrance of the sampler to the ambient stream velocity. The intake efficiencies of all FISP bag samplers and nozzle sizes were evaluated for this report. Samples were obtained across 31 U.S. Geological Survey streamflow-gaging stations between July 15, 2013, and June 17, 2020, where data were collected with all four bag samplers (US D-96, D-96-A1, D-99, and DH-2), each using various 3/16-inch, 1/4-inch, or 5/16-inch diameter nozzles.

      Water temperature and ambient stream velocity outside the nozzle are two of several factors that are known to affect the intake efficiency of bag samplers. A regression curve was fitted to these data through LOWESS (locally weighted scatterplot smoothing), and a Kruskal-Wallis test was executed for the various samplers and nozzle sizes. Based on these results, there is no statistical evidence to indicate that water temperature and stream velocity have a noticeable effect on intake efficiency when the samplers are deployed under isokinetic conditions. Likewise, there is no statistical evidence to indicate that the type of bag sampler and nozzle diameter have a direct effect on intake efficiency.

      Predicting larval alewife transport in Lake Michigan using hydrodynamic and Lagrangian particle dispersion models

      Released July 20, 2022 06:53 EST

      2022, Limnology and Oceanography

      Mark D Rowe, Sara E Prendergast, Karen M Alofs, David Bunnell, Edward S. Rutherford, Eric J. Anderson

      Several species of fish in large lakes and marine environments have a pelagic larval stage, and are subject to variable transport that can ultimately regulate survival and recruitment success. Alewife, Alosa pseudoharengus, are subject to transport by complex coastal currents during their pelagic larval stage (~ 30 d). We assessed backward-trajectory simulations, consisting of a Lagrangian particle dispersion model linked to the Finite Volume Community Ocean Model, to estimate likely hatch locations of aged larval alewife collected from locations on both the eastern and western sides of Lake Michigan during July 2015. We used four deployments of three satellite-tracked drifter buoys in coastal waters to assess model skill in estimating the origin of a drifter from its final location. We found that the trajectories of drifters varied greatly, depending on wind events and associated coastal transport processes, including upwelling/downwelling and coastal jet currents. In 2 of 12 cases, the backward trajectory simulations failed to predict the drifter origin, associated with transport of 170 km in a narrow coastal jet current. In the remaining 10 cases, the known drifter origin was within 3.5 km of the spatial patch of predicted possible origins for a scenario of horizontal diffusivity (188 m2 s−1) consistent with the offshore model grid resolution. Modeled backward trajectories estimated that alewife originated from the same side of the lake where they were collected, within ~ 100 km of the collection site. Our paper demonstrates the utility of hydrodynamic models to estimate a region of origin for aged larval fish.

      Remote sensing application for landslide detection, monitoring along eastern Lake Michigan (Miami Park, MI)

      Released July 20, 2022 06:51 EST

      2022, Remote Sensing (14)

      Guzalay Sataer, Mohamed Sultan, Mustafa Kemal Emil, John A. Yellich, Monica Palaseanu-Lovejoy, Richard Becker, Esayas Gebremichael, Karem Abdelmohsen

      We assessed the nature and spatial and temporal patterns of deformation over the Miami Park bluffs on the eastern margin of Lake Michigan and investigated the factors controlling its observed deformation. Our approach involved the following steps: (1) extracting bluff deformation rates (velocities along the line of sight of the satellite) using a stack of Sentinel-1A radar imagery in ascending acquisition geometry acquired between 2017 and 2021 and applying the Intermittent Small Baseline Subset (ISBAS) InSAR time series analysis method; (2) generating high-resolution (5 cm) elevation models and orthophotos from temporal unmanned aerial vehicle (UAV) surveys acquired in 2017, 2019, and 2021; and (3) comparing the temporal variations in mass wasting events to other relevant datasets including the ISBAS-based bluff deformation time series, lake level (LL) variations, and local glacial stratigraphy. We identified areas witnessing high line-of-sight (LOS) deformation rates (up to −21 mm/year) along the bluff from the ISBAS analysis and seasonal deformation patterns associated with freeze-thaw cycles, suggesting a causal effect. The acceleration of slope failures detected from field and UAV acquisitions correlated with high LLs and intensified onshore wave energy in 2020. The adopted methodology successfully predicts landslides caused by freezes and thaws of the slope face by identifying prolonged slow deformation preceding slope failures, but it does not predict the catastrophic landslides preceded by short-lived LOS deformation related to LL rise.

      The evolution of rock friction is more sensitive to slip than elapsed time, even at near-zero slip rates

      Released July 20, 2022 06:45 EST

      2022, Proceedings of the National Academy of Sciences (119)

      Pathikrit Bhattacharyaa, Allan Rubin, Terry Tullis, Nicholas M. Beeler, Keishi Okazaki

      For many decades, frictional strength increase at low slip rates has been ascribed to time-dependent contact-area growth across the sliding interface. As a result, phenomenological models that correctly predict contact-area growth, as observed in laboratory experiments, have also been widely assumed to be appropriate descriptors of frictional strength evolution. We present experiments that impose more than 5-orders-of-magnitude slip-rate reductions on granite to show that frictional strength evolution in these rocks unequivocally refutes such models. Instead, the data suggest that, even at subnanometric slip rates, frictional strength dominantly evolves with accrued slip. This remarkable slip-sensitivity of friction requires changes of intrinsic strength of the interface with slip that are absent from popular conceptual models of friction at the microscopic contact scale.

      Geologic framework, anthropogenic impacts, and hydrodynamics contribute to variable sediment availability and shoreface morphology at the Rockaway Peninsula, NY

      Released July 20, 2022 06:39 EST

      2022, Journal of Marine Science and Engineering (10)

      Emily A. Wei, Jennifer L. Miselis

      Recent field and modeling studies have shown that barrier island resiliency is sensitive to sediment fluxes from the shoreface, making it important to evaluate how shoreface sediment availability varies in coastal systems. To do this, we assessed shoreface geology and morphology along the Rockaway Peninsula, NY, USA. We find that spatial variability in shoreface volume is influenced by sediment accommodation above the Holocene-Pleistocene (H-P) contact, historical barrier island evolution, and natural and engineered morphologic features, suggesting that simply identifying the H-P boundary may not be adequate for defining the shoreface reservoir. Further, sediment flux from the lower shoreface to the beach may be reduced by geologically limited cross-shore sediment distribution and shoreface steepening mediated by human modifications to the shoreline. Finally, the geologic limit of the shoreface is often shallower than a wave-based estimate of shoreface extent, implying that the geologic shoreface extent at our study site can be mobilized over short time scales (years-decades) and that the wave-based shoreface extent may be inaccurate when estimating shoreline response to sea-level rise. Our results demonstrate that the combination of hydrodynamics, humans, and geology on shoreface sediment fluxes impact how barrier islands respond to future changes in sediment supply and climate.

      Relative contributions of  suspended sediment between the upper Suiattle River Basin and a non-glacial tributary, Washington, May 2016–September 2017

      Released July 19, 2022 12:01 EST

      2022, Open-File Report 2022-1056

      Kristin L. Jaeger, Scott W. Anderson, Craig A. Senter, Christopher A. Curran, Scott Morris

      Concentrations of suspended sediment were measured in discrete samples and turbidity was continuously monitored at four U.S. Geological Survey streamgages in western Washington State, including one gage on the Sauk River; two gages on the Suiattle River, a tributary to the Sauk River; and one gage on Downey Creek, a tributary to the Suiattle River. The Suiattle River is a sediment-rich stream with headwaters on Glacier Peak, a glaciated volcano in the northern Cascade Range.

      Contributions of suspended sediment to the Suiattle River from unglaciated tributaries, represented by Downey Creek, were compared to the contributions from Glacier Peak in the upper Suiattle River watershed. During summer 2017, a period for which complete records of discharge and sediment data were available for all three streamgages in the Suiattle River Basin, the suspended-sediment load from Downey Creek (drainage area [DA] 93 square kilometers [km2]) was 1,400 metric tons, which is equivalent to a sediment yield of about 15 metric tons per km2. During the same period, the suspended-sediment load from the upper Suiattle River (DA 176 km2) was 142,000 metric tons, or a sediment yield of about 800 metric tons per km2; and the suspended-sediment load from the lower Suiattle River (DA 733 km2) was 230,000 metric tons, or a sediment yield of about 300 metric tons per km2. The Downey Creek Basin accounts for 13 percent of the drainage area of the Suiattle River watershed but contributed only 0.6 percent of the suspended-sediment load over the summer of 2017 and water year 2017 (October 1, 2016–September 30, 2017). In contrast, the upper Suiattle River Basin, which accounts for 24 percent of the entire Suiattle River watershed, contributed 62 percent of the suspended-sediment load during the summer of 2017.

      Given the short period for which data were collected, it cannot be known with certainty whether the above values are representative of long-term means. The relatively minor contribution of suspended sediment from Downey Creek, however, is consistent with the expectation that the upper Suiattle River, which drains Glacier Peak, is the dominant contemporary source of suspended sediment to the Sauk River. During summer 2016, the suspended-sediment load in the upper Siuattle River (180,000 metric tons) was more than double the estimated load in the lower Sauk River (80,000 metric tons), even though the upper Suiattle River represents only 10 percent of the total contributing area to the lower Sauk River Basin. This ratio of relative contribution is interpreted as an indication of transient storage of sediment along the Suiattle and Sauk Rivers between the two streamgaging stations. In the glaciated upper Suiattle River Basin, sediment is transported by annual glacial-melt processes in spring and summer months, deposited during the summer base-flow period, and then remobilized by fall and winter floods for delivery to the lower Sauk River.

      New Jersey and Landsat

      Released July 19, 2022 09:20 EST

      2022, Fact Sheet 2022-3054

      U.S. Geological Survey

      New Jersey ranks among the smallest of States but packs a lot within its borders. Of course, that includes the more than 9 million people who make it the most densely populated State, but it also includes diverse landscapes. Ranging from Atlantic Ocean barrier islands and beaches to the Appalachian Mountains, and Pine Barrens forests to swampland, the “Garden State” retains remnants of an agricultural past with produce, horse, and dairy farms and plant nurseries.

      The third State to join the Union has had a strong geographic presence in U.S. history. More than 200 American Revolution battles and skirmishes were fought in New Jersey—more than in any other State. Manufacturing, tourism, and fishing have each had a significant effect on New Jersey’s industrial history. Today, many residents commute from this strategic location to work in New York City, just across the Hudson River to the northeast, or in Philadelphia, just across the Delaware River to the west.

      A dense population and climate change can increase risks for residents and the natural resources around them. Landsat helps officials monitor and plan for resilient cities and landscapes. Here are a few specific ways Landsat benefits New Jersey.

      Gull plumages are, and are not, what they appear to human vision

      Released July 19, 2022 09:13 EST

      2022, Annales Zoologici Fennici (59) 187-203

      Muir D Eaton, Pilar Benites, Luke Campillo, Robert E. Wilson, Sarah A. Sonsthagen

      Clear correlations between human and bird visual assessments of color have been documented, and are often assumed, despite fundamental differences in human and avian visual physiology and morphology. Analyses of plumage colors with avian perceptual models have shown widespread hidden inter-sexual and inter-specific color variation among passerines perceived as monochromatic to humans, highlighting the uncertainty of human vision to predict potentially relevant variation in color. Herein, we use reflectance data from 13 Larus gull species as an exemplar data set to study concordance between human vision and avian visual modeling of feather colors near, or below, the human threshold for discrimination. We found little evidence among gulls for sexual dichromatism hidden from human vision, but did find inter-specific color variation among gulls that is not seen by humans. Neither of these results were predictable a priori, and we reassert that reflectance measurements of actual feather colors, analyzed with avian relevant visual models, represent best practice when studying bird coloration.

      Comprehensive pressure core analysis for hydrate-bearing sediments from Gulf of Mexico Green Canyon Block 955, including assessments of geomechanical viscous behavior and nuclear magnetic resonance permeability

      Released July 19, 2022 09:08 EST

      2022, AAPG Bulletin (106) 1143-1177

      Jun Yoneda, Yusuke Jin, Michihiro Muraoka, Motoi Oshima, Kiyofumi Suzuki, William F. Waite, Peter Flemings

      Quantifying the petrophysical and geomechanical properties of gas hydrate reservoirs is essential for understanding the natural hydrate system and predicting gas production behavior for future resource development. Pressure-core analysis tools were used to characterize methane hydrate–bearing sediments recovered from the Gulf of Mexico Green Canyon Block 955, under an international collaboration with The University of Texas and the National Institute of Advanced Industrial Science and Technology. Pressure-core samples were successfully transferred from Austin, Texas to Sapporo, Japan. Index property measurements (grain size, grain density, hydration number, gas composition, thermal conductivity), along with triaxial compression, consolidation, and permeability tests with a nuclear magnetic resonance (NMR) analyzer were conducted. Compression tests at different strain rates confirmed a strain rate dependence for hydrate-bearing sediment, and an equation for predicting strength as a function of hydrate saturation and strain rate is proposed. Compression and swelling indices were obtained from high-effective stress consolidation tests. Furthermore, secondary compression coefficients for hydrate-bearing sediments were obtained, suggesting that hydrate exhibits creeping behavior on timescales of minutes to hours. A relatively high initial permeability of a few millidarcys was confirmed. In addition, the first NMR signal measurement was performed on a hydrate-bearing pressure core to acquire the NMR transverse or spin-spin (T2) distribution. Results confirm that the Schlumberger Doll Research model and Timur-Coates model predictions underestimate permeability measured directly via fluid flow. Permeability estimated using specific surface values derived from NMR T2 distributions is in good agreement with flow test results. Finally, an extended Timur-Coates model was proposed and predicts intrinsic permeability with high accuracy.

      Evidence of increased mussel abundance related to the Pacific marine heatwave and sea star wasting

      Released July 19, 2022 09:01 EST

      2022, Marine Ecology

      Sarah Beth Traiger, James L. Bodkin, Heather Coletti, Brenda Ballachey, Dean Thomas, Daniel Esler, Katrin Iken, Brenda Konar, Mandy Lindeberg, Daniel Monson, Brian H. Robinson, Robert M. Suryan, Ben Weitzman

      Mussels occupy a key middle trophic position in nearshore food webs linking primary producers to predators. Climate-related environmental changes may synergistically combine with changes in predator abundance to affect intertidal ecosystems. We examined the influence of two major events on mussel (Mytilus trossulus) abundance in the northern Gulf of Alaska: the recent Pacific marine heatwave (PMH, 2014–2016) and an outbreak of sea star wasting (SSW). We investigated how mussel abundance changed since the onset of SSW and whether the density of predatory sea stars or PMH-related temperature metrics explain variation in mussel abundance. Sea stars and mussels were surveyed since 2005 approximately annually in four regions of the northern Gulf of Alaska: Katmai (KATM), Kachemak Bay (KBAY), Kenai Fjords (KEFJ) and western Prince William Sound (WPWS). Mussel percent cover in the mid-intertidal increased 1–3 years after declines in sea stars at all regions and in the low-intertidal at KATM, KBAY, and KEFJ, but not at WPWS. After the onset of SSW, large (≥20 mm length) mussel density and mussel bed width increased at KATM but not the other regions. Total mussel densities, including recruits, did not differ before and after the onset of SSW. The total number of sea stars significantly explained variation in mussel metrics, but the proportions of the three sea star species examined did not. We did not find strong evidence for direct effects of temperature on mussels. The effects of the PMH and the SSW outbreak appear to have combined, with increased temperatures indirectly benefiting mussels in concert with relaxed top-down pressure from sea stars, allowing for increased mussel abundance. Changing mussel abundance may affect intertidal local productivity and the abundance or performance of other nearshore consumers of mussels.

      Relocated beaver can increase water storage and decrease stream temperature in headwater streams

      Released July 19, 2022 09:01 EST

      2022, Ecosphere (13)

      Benjamin J. Dittbrenner, Jason W. Schilling, Christian E. Torgersen, Joshua J. Lawler

      Many areas are experiencing increasing stream temperatures due to climate change, and some are experiencing reduced summer stream flows and water availability. Because dam building and pond formation by beaver can increase water storage, stream cooling, and riparian ecosystem resilience, beaver have been proposed as a potential climate adaption tool. Despite the large number of studies that have evaluated how beaver activity may affect hydrology and water temperature, few experimental studies have quantified these outcomes following beaver relocation. We evaluated changes in temperature and water storage following the relocation of 69 beaver into 13 headwater stream reaches of the Skykomish River watershed within the Snohomish River basin, Washington, USA. We evaluated how beaver dams affected surface and groundwater storage and stream temperature. Successful relocations created 243 m3 of surface water storage per 100 m of stream in the first year following relocation. Dams raised water table elevations by up to 0.33 m and stored approximately 2.4 times as much groundwater as surface water per relocation reach. Stream reaches downstream of dams exhibited an average decrease of 2.3°C during summer base-flow conditions. We also assessed how dam age, condition, maintenance frequency, and pond morphology influenced stream temperature at naturally colonized wetland complexes. Our findings demonstrate that dam building can increase water storage and reduce stream temperatures in the first year following successful beaver relocation. Fluvial and floodplain morphology of candidate reaches for relocation is an important consideration because it determines the type and magnitude of response. Relocation to reaches with existing small, abandoned ponds may address thermal criteria by conversion from warming to cooling reaches, whereas relocation within large, abandoned complexes or vacant habitat may result in greater water storage. Although beaver relocation can be an effective climate adaptation strategy to retain more stable hydrologic regimes and water quality in our study area, there appear to be regionally specific environmental and geomorphic factors that influence how beaver affect water storage and temperature. More research is needed to investigate how and why these regional differences affect water storage and stream temperature response in beaver-influenced systems.

      A phylogeny based on cytochrome-c oxidase gene sequences identifies sympatric Ichthyophonus genotypes in the NE Pacific Ocean

      Released July 19, 2022 08:57 EST

      2022, Diseases of Aquatic Organisms (150) 61-67

      Jacob L. Gregg, Paul Hershberger, Abigail S. Neat, Hiruni T. Jayasekera, Jayde A. Ferguson, Rachel L. Powers, Maureen K. Purcell

      ABSTRACT: In recent decades, evidence has accumulated to suggest that the widespread and highly variable parasite Ichthyophonus hoferi is actually a species complex. Highly plastic morphology and a general lack of defining structures has contributed to the likely underestimate of biodiversity within this group. Molecular methods are a logical next step in the description of these parasites, but markers used to date have been too conserved to resolve species boundaries. Here we use mitochondrial encoded cytochrome-c oxidase (MTCO1) gene sequences and phylogenic analysis to compare Ichthyophonus spp. isolates from several marine and anadromous fish hosts. The resulting phylogeny displays lineage separation among isolates and possible host/niche segregation not previously described. The parasite type that infects Pacific herring Clupea pallasii, Atlantic herring C. harengus, Atlantic salmon Salmo salar, and Pacific staghorn sculpin Oligocottus maculosus (Clade A) is different from that which infects Chinook salmon Oncorhynchus tshawytscha, walleye pollock Gadus chalcogrammus, Greenland halibut Reinhardtius hippoglossoides, and Pacific halibut Hippoglossus stenolepsis (Clade B). MTCO1 sequences confirmed the presence of a more divergent Ichthyophonus sp. isolated from American shad Alosa sapidissima in rivers of eastern North America (Clade C), while American shad introduced to the Pacific Ocean are infected with the same parasite that infects Pacific herring (Clade A). Currently there are no consensus criteria for delimiting species within Ichthyophonidae, but MTCO1 sequences hold promise as a potential species identifying marker and useful epizootiological tool.

      Ten-year ecological responses to fuel treatments within semiarid Wyoming big sagebrush ecosystems

      Released July 19, 2022 08:55 EST

      2022, Ecosphere (13)

      David A. Pyke, Scott Shaff, Jeanne C. Chambers, Eugene W. Schupp, Beth A. Newingham, Margaret L Gray, Lisa M. Ellsworth

      Sagebrush ecosystems of western North America are threatened by invasive annual grasses and wildfires that can remove fire-intolerant shrubs for decades. Fuel reduction treatments are used ostensibly to aid in fire suppression, conserve wildlife habitat, and restore historical fire regimes, but long-term ecological impacts of these treatments are not clear. In 2006, we initiated fuel reduction treatments (prescribed fire, mowing, and herbicide applications [tebuthiuron and imazapic]) in six Artemisia tridentata ssp. wyomingensis communities. We evaluated long-term effects of these fuel treatments on: (1) magnitude and longevity of fuel reduction; (2) Greater Sage-grouse habitat characteristics; and (3) ecological resilience and resistance to invasive annual grasses. Responses were analyzed using repeated-measures linear mixed models. Response variables included plant biomass, cover, density and height, distances between perennial plants, and exposed soil cover. Prescribed fire produced the greatest reduction in woody fuel over time. Mowing initially reduced woody biomass, which recovered by year 10. Tebuthiuron did not significantly reduce woody biomass compared to controls. All woody fuel treatments reduced sagebrush cover to below 15% (recommended minimum for Greater Sage-grouse habitat), but only prescribed fire reduced cover to below controls. Median mowed sagebrush height remained above the recommended 30 cm. Cheatgrass (Bromus tectorum) cover increased to above the recommended maximum of 10% across all treatments and controls. Ecological resilience to woody fuel treatments was lowest with fire and greatest with mowing. Low resilience over the 10 posttreatment years was identified by: (1) poor perennial plant recovery posttreatment with sustained reductions in cover and density of some perennial plant species; (2) sustained reductions in lichen and moss cover; and (3) increases in cheatgrass cover. Although 10 years is insufficient to conclusively describe final ecological responses to fuel treatments, mowing woody fuels has the greatest potential to reduce woody fuel, minimize shrub mortality and soil disturbance, maintain lichens and mosses, and minimize long-term negative impacts on Greater Sage-grouse habitat. However, maintaining ecological resilience and resistance to invasion may be threatened by increases in cheatgrass cover, which are occurring regionally.

      Fibropapillomatosis dynamics in green sea turtles Chelonia mydas over 15 years of monitoring in Akumal Bay, Quintana Roo, Mexico

      Released July 19, 2022 08:49 EST

      2022, Diseases of Aquatic Organisms (149) 133-143

      Fernando A. Muñoz Tenería, Vanessa Labrada-Martagón, Roberto Herrera-Pavón, Thierry M. Work, Erik González Ballesteros, Ana Negrete-Philippe, Gisela Maldonado-Saldaña

      ABSTRACT: Fibropapillomatosis (FP) is a tumor disease that affects all sea turtle species but is mainly seen in green turtles Chelonia mydas. The pathology of FP has been described extensively, but its dynamics in populations over time have been less studied. We analyzed the dynamics of FP in a population of green turtles in Akumal Bay on the central coast of the Mexican Caribbean. A total of 475 green turtles were captured over 15 yr (2004-2018). The highest prevalence of FP was found in the largest turtles, and there was a positive relationship between FP prevalence and size of turtles. FP was first detected in 2008 at a prevalence of 1.6%, and annual prevalence increased markedly from 17.9% in 2015 to 54% by 2018. Likewise, severity of FP increased over time, with most turtles falling into moderately to severely diseased categories (tumor score 2). The average size of turtles with FP was significantly larger than the size of individuals without FP. Regression of tumors was seen in 21% of turtles, tumor score was higher in smaller individuals, and only tumor score 2 was present in the largest sea turtles. An increase in the prevalence and tumor score of FP coincided with the massive arrival of Sargassum in 2015, suggesting that altered environmental conditions may have played a role. The increased prevalence of FP in Akumal Bay prompts the need to explain what might be driving this phenomenon and how widespread it is in the Caribbean.

      North Dakota and Landsat

      Released July 19, 2022 05:41 EST

      2022, Fact Sheet 2022-3053

      U.S. Geological Survey

      The State of North Dakota once did not figure prominently in the Nation’s economy. The sparsely populated State supported food production, and hunters and anglers were drawn to its lakes, rivers, and wide-open spaces, but its economy was overshadowed by that of other States. However, the State and its prairie expanses recently rocketed from an economic afterthought to a national energy leader with the soaring production of oil and natural gas in the Bakken oil patch.

      The Bakken development has been transformative for North Dakota’s landscapes in myriad ways. It has boosted economic output, drawn thousands of new residents to cities like Williston and Watford City, and led to a proliferation of oil and gas pads.

      In the past two decades, North Dakota experienced other major changes, such as the expansion of the depressional wetlands of the Prairie Pothole Region on the eastern side of the State. These critical breeding areas for waterfowl, which stretch across Minnesota, South Dakota, North Dakota, and Canada, are home to more than 50 percent of North America’s migratory birds.

      Changes from oil and gas production, urban development, and wetland resurgence can all be tracked over time using the unparalleled Earth observation record of the U.S. Geological Survey Landsat data archive. Its 50-year record of repeat imagery also aids in the monitoring, cataloging, and management of cropland, invasive insect species, and natural or human-made disaster recovery. Here are just a few examples of the benefits offered to North Dakota by the Landsat Program.

      Indiana and Landsat

      Released July 18, 2022 16:34 EST

      2022, Fact Sheet 2022-3049

      U.S. Geological Survey

      Natural resources have always been a strength for Indiana. Once largely covered by forest, the State now includes a mix of forest, farmland, wetlands, and small lakes. In fact, farms and forested areas make up more than 80 percent of the land. The Ohio River forms the southern border, and the south shore of Lake Michigan contrasts with urban development in the northwestern corner. Indiana Dunes National and State Parks reside just east of the Chicago metropolitan area.

      Agriculture adds more than $30 billion to the economy in Indiana, which placed eighth in the country for agricultural exports at $4.6 billion in 2017. Indiana ranks in the top five States nationally for the production of corn and soybeans. The “Hoosier State” also grows sizable crops of popcorn, spearmint, peppermint, pumpkins, tomatoes, and watermelon. Additionally, hogs, cattle, dairy, and poultry contribute to the agricultural economy. Other industries important to Indiana include manufacturing, medicine, energy, and mining. Mineral sources vary from coal, building stone, and gypsum to sand, gravel, and shale.

      Landsat can help monitor the condition of natural resources and the effects of extreme weather events. Here are several ways Landsat has benefited Indiana.

      Expert perspectives on global biodiversity loss and its drivers and impacts on people

      Released July 18, 2022 08:10 EST

      2022, Frontiers in Ecology and the Environment

      Forest Isbell, Patricia Balvanera, Akira S. Mori, Jin-Sheng He, James M. Bullock, Ganga Ram Regmi, Eric W. Seabloom, Simon Ferrier, Osvaldo E. Sala, Nathaly R. Guerrero-Ramírez, Julia Tavella, Daniel J. Larkin, Bernhard Schmid, Charlotte L. Outhwaite, Pairot Pramua, Elizabeth T. Borer, Michel Loreau, Taiwo Crossby Omotoriogun, David O. Obura, Maggie Anderson, Cristina Portales-Reyes, Kevin Kirkman, Pablo M Vergara, Adam Thomas Clark, Kimberly J Komatsu, Owen L. Petchey, Sarah R. Weiskopf, Laura J. Williams, Scott L. Collins, Nico Eisenhauer, Christopher H Trisos, Delphine Renard, Alexandra J. Wright, Poonam Tripathi, Jane Cowles, Jarrett E. K. Byrnes, Peter B. Reich, Andy Purvis, Zati Sharip, Mary I. O'Connor, Clare E. Kazanski, Nick M. Haddad, Eulogio H. Soto, Laura E. Dee, Sandra Díaz, Chad R. Zirbel, Meghan L. Avolio, Shaopeng Wang, Zhiyuan Ma, Jingjing Liang, Hanan C. Farah, Justin Andrew Johnson, Brian W. Miller, Yann Hautier, Melinda D. Smith, Johannes M. H. Knops, Bonnie Myers, Zuzana Harmáčková, Jorge Cortés, Mike Harfoot, Andrew Gonzalez, Tim Newbold, Jacqueline Oehri, Marina Mazón, Cynnamon Dobbs, Meredith S. Palmer

      Despite substantial progress in understanding global biodiversity loss, major taxonomic and geographic knowledge gaps remain. Decision makers often rely on expert judgement to fill knowledge gaps, but are rarely able to engage with sufficiently large and diverse groups of specialists. To improve understanding of the perspectives of thousands of biodiversity experts worldwide, we conducted a survey and asked experts to focus on the taxa and freshwater, terrestrial, or marine ecosystem with which they are most familiar. We found several points of overwhelming consensus (for instance, multiple drivers of biodiversity loss interact synergistically) and important demographic and geographic differences in specialists’ perspectives and estimates. Experts from groups that are underrepresented in biodiversity science, including women and those from the Global South, recommended different priorities for conservation solutions, with less emphasis on acquiring new protected areas, and provided higher estimates of biodiversity loss and its impacts. This may in part be because they disproportionately study the most highly threatened taxa and habitats.

      Assessing spatial transferability of a random forest metamodel for predicting drainage fraction

      Released July 16, 2022 06:59 EST

      2022, Journal of Hydrology (612)

      Elisa Bjerre, Michael N. Fienen, Raphael Schneider, Julian Koch, Anker L. Højberg

      Fully distributed hydrological models are widely used in groundwater management, but model speed and data requirements impede their use for decision support purposes. Metamodels provide a simpler and faster model which emulates the underlying complex model using machine learning techniques. However, metamodel predictions beyond the ranges, in space and/or time, of training data are highly uncertain, and thus it is important to assess the predictive model performance to ranges outside the training data, i.e., model transferability. We present a novel methodology for evaluating model transferability to areas not contained in the training data set, based on various metrics that quantify the differences in covariate distributions between training and testing data. The transferability method can be employed as a screening tool to assess the suitability of a metamodel for spatial prediction beyond its training domain. We evaluated this transferability approach on a Random Forest metamodel of a 1000 km2 fully distributed coupled groundwater model for predicting drainage fraction, the partitioning of infiltrating water between drains and groundwater. We conducted spatial cross-validation on 9 holdout sub-basins to assess metamodel transferability beyond sampling locations and compared this estimate with a random split-sample validation test. Using mappable covariates only, the metamodel showed high performance (R2 = 0.79) tested on a 20% randomly sampled holdout. Conversely, metamodel performance significantly decreased for the 9 spatial holdouts (R2 ranging from 0.13 to 0.61). We document that the proposed transferability metric correlates with metamodel predictive performance, and demonstrate its use to assess model transferability to datasets outside the training data spatial domain.

      Riparian buffers provide refugia during secondary forest succession

      Released July 16, 2022 06:37 EST

      2022, Diversity and Distributions

      Michelle E. Thompson, Brian J. Halstead, Maureen A. Donnelly


      Secondary forests regenerating from human disturbance are increasingly becoming a predominant forest type in many regions, and they play a significant role in forest community dynamics. Understanding the factors that underlie the variation in species responses during secondary succession is important for understanding community assembly and biodiversity monitoring and management. Because species vary in ecology and behaviour, responses to ecosystem change should vary among species. Here, we show that habitat type (riparian, upland), phylogeny, and species traits mediate anuran and lizard probability of occurrence and species richness in pasture and secondary forest.


      Sarapiquí and Osa Peninsula, Costa Rica.


      We used phylogenetic occupancy models to estimate assemblage-level and species-specific responses to forest succession in 30 chronosequence sites that include pasture, secondary forest regenerating from pasture, and mature forest sites.


      For the majority of species, we found increasing probability of occurrence in upland habitats as forest regenerated from pasture to secondary forest and similar probability of occurrence in riparian habitats across pasture, secondary forest, and mature forest sites. Species' responses to forest stage were phylogenetically correlated, and the trend was especially strong for anuran response to pasture sites. Anurans with lentic larval habitat had a positive occupancy response to pasture upland habitat, and anurans with lotic larval habitat had a variable response to different forest stages compared to mature forest.

      Main Conclusions

      Our study, which focuses on sites that are minimally isolated from mature forest reference sites, indicated that anuran and lizard occupancy rapidly recovered to a level similar to mature forest in a relatively short time span (approximately 20 years). Riparian habitats are key ecosystem features in our system and provide refugia for organisms in early successional stages. Maintenance of vegetation along streams shows that we can mitigate forest conversion by maintaining riparian buffers.