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USGS2012

Developing a broader scientific foundation for river restoration: Columbia River food webs

Well-functioning food webs are fundamental for sustaining rivers as ecosystems and maintaining associated aquatic and terrestrial communities. The current emphasis on restoring habitat structure—without explicitly considering food webs—has been less successful than hoped in terms of enhancing the status of targeted species and often overlooks important constraints on ecologically effective restoration. We identify three priority food web-related issues that potentially impede successful river restoration: uncertainty about habitat carrying capacity, proliferation of chemicals and contaminants, and emergence of hybrid food webs containing a mixture of native and invasive species. Additionally, there is the need to place these food web considerations in a broad temporal and spatial framework by understanding the consequences of altered nutrient, organic matter (energy), water, and thermal sources and flows, reconnecting critical habitats and their food webs, and restoring for changing environments. As an illustration, we discuss how the Columbia River Basin, site of one of the largest aquatic/riparian restoration programs in the United States, would benefit from implementing a food web perspective. A food web perspective for the Columbia River would complement ongoing approaches and enhance the ability to meet the vision and legal obligations of the US Endangered Species Act, the Northwest Power Act (Fish and Wildlife Program), and federal treaties with Northwest Indian Tribes while meeting fundamental needs for improved river management.

Proceedings of the National Academy of Sciences of↗

USGS2012

Linking soil moisture balance and source-responsive models to estimate diffuse and preferential components of groundwater recharge

Results are presented of a detailed study into the vadose zone and shallow water table hydrodynamics of a field site in Shropshire, UK. A conceptual model is developed and tested using a range of numerical models, including a modified soil moisture balance model (SMBM) for estimating groundwater recharge in the presence of both diffuse and preferential flow components. Tensiometry reveals that the loamy sand topsoil wets up via macropore flow and subsequent redistribution of moisture into the soil matrix. Recharge does not occur until near-positive pressures are achieved at the top of the sandy glaciofluvial outwash material that underlies the topsoil, about 1 m above the water table. Once this occurs, very rapid water table rises follow. This threshold behaviour is attributed to the vertical discontinuity in the macropore system due to seasonal ploughing of the topsoil, and a lower permeability plough/iron pan restricting matrix flow between the topsoil and the lower outwash deposits. Although the wetting process in the topsoil is complex, a SMBM is shown to be effective in predicting the initiation of preferential flow from the base of the topsoil into the lower outwash horizon. The rapidity of the response at the water table and a water table rise during the summer period while flow gradients in the unsaturated profile were upward suggest that preferential flow is also occurring within the outwash deposits below the topsoil. A variation of the source-responsive model proposed by Nimmo (2010) is shown to reproduce the observed water table dynamics well in the lower outwash horizon when linked to a SMBM that quantifies the potential recharge from the topsoil. The results reveal new insights into preferential flow processes in cultivated soils and provide a useful and practical approach to accounting for preferential flow in studies of groundwater recharge estimation.

Shropshire County↗

USGS2002

U.S. Geological Survey Activities Related to American Indians and Alaska Natives Fiscal Year 2002

Information is a resource for Native American governments, communities, organizations, and people. The U.S. Geological Survey (USGS) provides technical expertise, reports, and other impartial information sources that benefit Native Americans interested in subsistence issues, water, land use, and the health of many parts of the environment. Native self-sufficiency, economic development, and conservation are cultivated through Native decisions informed with USGS data and analyses. The USGS works in cooperation with American Indian and Alaska Native governments, conducting research on water and mineral resources, animals and plants of environmental, economic, or subsistence importance, natural hazards, and geologic resources. Digital data on cartography, mineral resources, streamflow, biota, and other topics are available to American Indian and Alaska Native individuals and institutions. The USGS recognizes the need to learn from and share knowledge with Native peoples. This report describes most of the activities that the USGS conducted with American Indian and Alaska Native governments, educational institutions, and individuals during Federal Fiscal Year 2002. Some of these USGS activities were carried out in concert with the Bureau of Indian Affairs (BIA). Others were conducted by Tribes, Tribal organizations, professional societies, and the USGS. A growing number of Tribal governments, educational institutions, and other Tribal organizations have begun using geographic information systems and other digital technologies in recent years. As Tribes become more interested in and more adept at managing digital information, they are seeking relevant data from the USGS more frequently. Using digital technologies provides Tribal governments with additional means of managing lands and resources for the benefit of current and future generations. The USGS recognizes the need to make its information available to Tribal governments, and to work with those governments and other institutions to advance data management capabilities. The USGS also recognizes that Tribal institutions have varying needs, interests, and capacities. The USGS strives to be sensitive to the unique circumstances of each of these institutions while supporting their self-driven evolution. The USGS is responding to these needs by increasing the transfer of scientific information to American Indian and Alaska Native governments and by training employees of those governments to conduct scientific studies and improve scientific data management. The USGS is also encouraging American Indians and Alaska Natives to pursue careers in science and seeking ways to hire Indian and Native students. By identifying, improving, and disseminating information about available hiring mechanisms, the USGS is working to make hiring such students easier, and, therefore, more likely, for USGS managers. The U.S. Geological Survey is the Federal science bureau within the Department of the Interior (DoI). The USGS is non-regulatory and is not a significant manager of Federal or Trust lands or assets. However, as described in this report, there are several types of USGS activities that involve American Indians, Alaska Natives, and their lands. One type of activity is the course of formal studies, conducted through existing USGS programs, that involves collection of specific types of data as well as investigative and research projects. These projects typically last 2 or 3 years, although a few are parts of longer-term activities. Some projects are funded through cooperative agreements, from monies provided to the USGS by individual Tribal governments, or by the BIA. The USGS provides matching funds for cooperative projects. These formal projects may also receive funding from the U.S. Environmental Protection Agency, the Indian Health Service (part of the Department of Health and Human Services), or other Federal agencies. The USGS routinely works with its sister bureaus in the Department of the Interior to provide the scientific information and expertise needed to meet the Department's science priorities. Within this context, the USGS and the BIA are cooperating to use USGS information resources to benefit American Indian and Alaska Native peoples and their lands. The second type of USGS activity is less formal, based on initiatives designed and conducted by USGS employees. Frequently involving educational activities, these endeavors are prompted by employee interests, often as collateral issues, that result from one or more USGS employees identifying and responding to an observed need. In these activities, USGS employees help fulfill a mission of the USGS--to prove scientific relevance--while helping their fellow citizens. Increasingly, some of the educational activities are becoming parts of formal USGS projects. USGS employees have also taken the initiative in assisting American Indians and Alaska Natives through participation in several organizations that were created to foster awareness of science among Native peoples and to help build support and communication networks. One such group is the American Indian Science and Engineering Society (AISES). This group sponsors an annual national meeting in which USGS employees participate. USGS employees join this organization on a voluntary basis, bringing the benefits of this expanded network to the USGS, as many employees do with other professional organizations. Each part of the USGS has identified an American Indian/Alaska Native liaison. The USGS has a regional organizational structure, with Western, Central, and Eastern Regions. The regions work in concert with specific scientific disciplines to conduct the scientific mission of the USGS. The regional structure is intended to bring us closer to our customers; we hope that Native Americans and Alaska Natives will use the contacts listed at the end of this report.

Report↗

USGS2025

A geospatial analysis of water-quality threats from orphan wells in principal and secondary aquifers of the United States

Throughout the history of oil and gas production in the United States, millions of wells have been drilled for exploration and energy production. Hundreds of thousands of unplugged wells are no longer actively producing and are currently under orphan status, with no responsible party obligated for plugging. Orphan wells can pose threats to water resources by providing pathways for contaminants such as hydrocarbons and brines to migrate into water-supply aquifers. In this study, we investigate the potential threats to groundwater resources posed by orphan wells at the national scale. Water-quality data is extremely sparse in relation to orphan wells nationally and may not be suitable for identifying contamination from oil and gas development. We used geospatial and statistical methods to evaluate which principal and secondary aquifer systems may be most susceptible to contamination from orphan wells. Analysis involved three sets of susceptibility factors including: 1) factors related to the number and density of orphan wells; 2) factors that can threaten well integrity and contribute to transport of contaminants; and 3) factors related to groundwater withdrawal rates and the affected populations/communities in the event of water quality disturbances. From a dataset of 117,672 documented orphan wells, 64,203 fall within a principal aquifer system, while the remainder fall within a secondary aquifer system. By assessing the combination of well integrity and hydrogeologic factors within these aquifer systems, five groupings of principal aquifers were identified, where groups ranged from aquifer systems with high numbers of orphan wells, multiple well integrity threats and high withdrawals, to aquifers with a relatively low number of orphan wells, limited well integrity threats and minimal water use. Three regions of the country emerge containing aquifers with higher susceptibility to contamination from orphan oil and gas wells. These regions include 1) The Appalachian Basin (including the Pennsylvanian Aquifer System), 2) The Gulf Coast Aquifers (including the Coastal Lowlands Aquifer system) and 3) The California Aquifers (including the California Coastal Basin Aquifer system). This work is the first multivariate geospatial investigation of orphan wells and groundwater resources on a national scale, and sheds light on which aquifers are most susceptible to groundwater contamination from orphan wells.

Science of the Total Environment↗

USGS2011

Quantification of a male sea lamprey pheromone in tributaries of Laurentian Great Lakes by liquid chromatography-tandem mass spectrometry

We developed an assay for measuring 7α,12α,24-trihydroxy-5a-cholan-3-one-24-sulfate (3kPZS), a mating pheromone released by male sea lampreys (Petromyzon marinus), at low picomolar concentrations in natural waters to assess the presence of invasive populations. 3kPZS was extracted from streamwater at a rate of recovery up to 90% using a single cation-exchange and reversed-phase mixed-mode cartridge, along with [ 2 H 5 ]3kPZS as an internal standard, and quantified using ultrahigh performance liquid chromatography-tandem mass spectrometry. The limit of detection was below 0.1 ng L –1 (210 fM), which was the lowest concentration tested. Intra- and interday coefficients of variation were between 0.3–11.6% and 4.8–9.8%, respectively, at 1 ng 3kPZS L –1 and 5 ng 3kPZS L –1 . This assay was validated by repeat measurements of water samples from a stream spiked with synthesized 3kPZS to reach 4.74 ng L –1 or 0.24 ng L –1 . We further verified the utility of this assay to detect spawning populations of lampreys; in the seven tributaries to the Laurentian Great Lakes sampled, 3kPZS concentrations were found to range between 0.15 and 2.85 ng L –1 during the spawning season in known sea lamprey infested segments and were not detectable in uninfested segments. The 3kPZS assay may be useful for the integrated management of sea lamprey, an invasive species in the Great Lakes where pheromone-based control and assessment techniques are desired.

Environmental Science & Technology↗

USGS2025

Interrogating process deficiencies in large-scale hydrologic models with interpretable machine learning

Large-scale hydrologic models are increasingly being developed for operational use in the forecasting and planning of water resources. However, the predictive strength of such models depends on how well they resolve various functions of catchment hydrology, which are influenced by gradients in climate, topography, soils, and land use. Most assessments of hydrologic model uncertainty have been limited to traditional statistical methods. Here, we present a proof-of-concept approach that uses interpretable machine learning techniques to provide post hoc assessment of model sensitivity and process deficiency in hydrologic models. We train a random forest model to predict the Kling–Gupta efficiency (KGE) of National Water Model (NWM) and National Hydrologic Model (NHM) streamflow predictions for 4383 stream gauges in the conterminous United States. Thereafter, we explain the local and global controls that 48 catchment attributes exert on KGE prediction using interpretable Shapley values. Overall, we find that soil water content is the most impactful feature controlling successful model performance, suggesting that soil water storage is difficult for hydrologic models to resolve, particularly for arid locations. We identify nonlinear thresholds beyond which predictive performance decreases for NWM and NHM. For example, soil water content less than 210 mm, precipitation less than 900 mm yr −1 , road density greater than 5 km km −2 , and lake area percent greater than 10 % contributed to lower KGE values. These results suggest that improvements in how these influential processes are represented could result in the largest increases in NWM and NHM predictive performance. This study demonstrates the utility of interrogating process-based models using data-driven techniques, which has broad applicability and potential for improving the next generation of large-scale hydrologic models.

conterminous United States↗

USGS2023

One byte at a time: Gathering best practices, guidelines, and resources for data standards to support ocean exploration and characterization

Initiated through Presidential direction and now codified, the National Ocean Mapping, Exploration, and Characterization (NOMEC) Council comprises leaders from U.S. federal agencies with a shared goal of mapping all waters of the United States and exploring and characterizing priority areas. The NOMEC Council’s two Interagency Working Groups, Ocean and Coastal Mapping (IWG-OCM) and Ocean Exploration and Characterization (IWG-OEC), both achieved major milestones recently with the 2023 release of the Draft Standard Ocean Mapping Protocols (SOMP) and the 2022 publication of the National Priorities for Ocean Exploration and Characterization. Building on this groundwork, the IWG-OEC is now looking to define and share best practices, guidelines, and resources for ocean exploration and characterization with the long-term goal of increasing community wide standardization to help achieve consistent common practices. First, the IWG-OEC plans to compile federal agency resources and share them in a newly developed online resource repository. The next phase is for the IWG-OEC to create opportunities for non-federal sectors to provide input on developing and populating this repository with additional content (existing standards and protocols, best practice and guidelines documents, etc.). After experts representing multiple sectors are identified, a series of results-oriented workshops are planned to provide input on all aspects of the data, products, and services from exploration and characterization. Finally, the IWG-OEC plans to widely share the online repository of best practices and standard operating procedures. A systematic, transparent, and collaborative process to share standards and protocols can help to enhance the interoperability of data and inform new lines of inquiry, discovery, research, and innovation.

Frontiers in Marine Science↗

USGS2022

A Central Asia hydrologic monitoring dataset for food and water security applications in Afghanistan

From the Hindu Kush mountains to the Registan Desert, Afghanistan is a diverse landscape where droughts, floods, conflict, and economic market accessibility pose challenges for agricultural livelihoods and food security. The ability to remotely monitor environmental conditions is critical to support decision making for humanitarian assistance. The Famine Early Warning Systems Network (FEWS NET) Land Data Assimilation System (FLDAS) global and Central Asia data streams provide information on hydrologic states for routine integrated food security analysis. While developed for a specific project, these data are publicly available and useful for other applications that require hydrologic estimates of the water and energy balance. These two data streams are unique because of their suitability for routine monitoring, as well as for being a historical record for computing relative indicators of water availability. The global stream is available at ∼ 1-month latency, and monthly average outputs are on a 10 km grid from 1982–present. The second data stream, Central Asia (21–56 ∘ N, 30–100 ∘ E), at ∼ 1 d latency, provides daily average outputs on a 1 km grid from 2000–present. This paper describes the configuration of the two FLDAS data streams, background on the software modeling framework, selected meteorological inputs and parameters, and results from previous evaluation studies. We also provide additional analysis of precipitation and snow cover over Afghanistan. We conclude with an example of how these data are used in integrated food security analysis. For use in new and innovative studies that will improve understanding of this region, these data are hosted by U.S. Geological Survey data portals and the National Aeronautics and Space Administration (NASA). The Central Asia data described in this paper can be accessed via the NASA repository at https://doi.org/10.5067/VQ4CD3Y9YC0R (Jacob and Slinski, 2021), and the global data described in this paper can be accessed via the NASA repository at https://doi.org/10.5067/5NHC22T9375G (McNally, 2018).

Earth System Science Data↗

USGS2018

Inferring watershed hydraulics and cold-water habitat persistence using multi-year air and stream temperature signals

Streams strongly influenced by groundwater discharge may serve as “climate refugia” for sensitive species in regions of increasingly marginal thermal conditions. The main goal of this study is to develop paired air and stream water annual temperature signal analysis techniques to elucidate the relative groundwater contribution to stream water and the effective groundwater flowpath depth. Groundwater discharge to streams attenuates surface water temperature signals, and this attenuation can be diagnostic of groundwater gaining systems. Additionally, discharge from shallow groundwater flowpaths can theoretically transfer lagged annual temperature signals from aquifer to stream water. Here we explore this concept using multi-year temperature records from 120 stream sites located across 18 mountain watersheds of Shenandoah National Park, VA, USA and a coastal watershed in Massachusetts, USA. Both areas constitute important cold-water habitat for native brook trout ( Salvelinus fontinalis ). Observed annual temperature signals indicate a dominance of shallow groundwater discharge to streams in the National Park, in contrast to the coastal watershed that has strong, apparently deeper, groundwater influence. The average phase lag from air to stream signals in Shenandoah National Park is 11 d; however, extended lags of approximately 1 month were observed in a subset of streams. In contrast, the coastal stream has pronounced attenuation of annual temperature signals without notable phase lag. To better understand these observed differences in signal characteristics, analytical and numerical models are used to quantify mixing of the annual temperature signals of surface and groundwater. Simulations using a total heat budget numerical model indicate groundwater-induced annual temperature signal phase lags are likely to show greater downstream propagation than the related signal amplitude attenuation. The measurement of multi-seasonal paired air and water temperatures offers great promise toward understanding catchment processes and informing current cold-water habitat management at ecologically-relevant scales.

Virginia↗

USGS2020

Time-dependent accumulation of Cd, Co, Cu, Ni, and Zn in mayfly and caddisfly larvae in experimental streams: Metal sensitivity, uptake pathways, and mixture toxicity

Conceptual and quantitative models were developed to assess time-dependent processes in four sequential experimental stream studies that determined abundances of natural communities of mayfly and caddisfly larvae dosed with single metals (Cd, Co, Cu, Ni, Zn) or multiple metals (Cd+Zn, Co+Cu, Cu+Ni, Cu+Zn, Ni+Zn, Cd+Cu+Zn, Co+Cu+Ni, Cu+Ni+Zn). Metal mixtures contained environmentally relevant metal ratios found in mine drainage. Free metal ion concentrations, accumulation of metals by periphyton, and metal uptake by four families of aquatic insect larvae were either measured (Brachycentridae) or predicted (Ephemerellidae, Heptageniidae, Hydropsychidae) using equilibrium and biodynamic models. Toxicity functions, which included metal accumulations by larvae and metal potencies, were linked to abundances of the insect families. Model results indicated that mayflies accumulated more metal than caddisflies and the relative importance of metal uptake by larvae via dissolved or dietary pathways highly depended on metal uptake rate constants for each insect family and concentrations of metals in food and water. For solution compositions in the experimental streams, accumulations of Cd, Cu, and Zn in larvae occurred primarily through dietary uptake, whereas uptake of dissolved metal was more important for Co and Ni accumulations. Cd, Cu, and Ni were major contributors to toxicity in metal mixtures and for metal ratios examined. Our conceptual approach and quantitative results should aid in designing laboratory experiments and field studies that evaluate metal uptake pathways and metal mixture toxicity to aquatic biota.

Science of the Total Environment↗

USGS2026

Predicting reach-scale macroinvertebrate community changes due to declining flows in an aridland river

Understanding the connection between streamflow and macroinvertebrate community structure is critical for managing river ecosystems under scenarios of change caused by human activities and drought. Streamflow influences physical habitat characteristics, including depth, water velocity, and substrate composition, which structure macroinvertebrate communities. Although strong empirical evidence has linked macroinvertebrates to these variables, most studies are correlative, and predictive approaches that link altered streamflow to changes in habitat availability and community structure remain limited. To address this gap, we coupled benthic macroinvertebrate surveys with reach-scale, 2-dimensional hydraulic models to quantify changes in community structure in response to altered streamflows. We characterized macroinvertebrate communities and physical habitat conditions in riffle, run, and pool mesohabitats across 3 reaches of a free-flowing section of the Verde River (Arizona, USA) over 3 y and developed hydraulic models using overflight data, ground surveys, and streamflow monitoring. Macroinvertebrate communities differed among mesohabitats, with riffles supporting higher macroinvertebrate densities and pools exhibiting higher taxonomic richness. The 2-dimensional hydraulic models indicated that declining streamflows could reduce the area of suitable habitat in riffles and runs relative to pools, potentially shifting the distribution of mesohabitats and altering community composition. These changes may lead to declines in overall macroinvertebrate diversity and abundance under reduced flow conditions. By explicitly linking streamflow to habitat availability and community structure, this study demonstrates how integrating hydraulic modeling with biological surveys can improve predictions of ecological response to flow alteration. This framework provides a basis for flow management strategies aimed at maintaining habitat heterogeneity and supporting biodiversity in river networks.

Arizona↗

USGS2019

An assessment of plant species differences on cellulose oxygen isotopes from two Kenai Peninsula, Alaska peatlands: Implications for hydroclimatic reconstructions

Peat cores are valuable archives of past environmental change because they accumulate plant organic matter over millennia. While studies have primarily focused on physical, ecological, and some biogeochemical proxies, cores from peatlands have increasingly been used to interpret hydroclimatic change using stable isotope analyses of cellulose preserved in plant remains. Previous studies indicate that the stable oxygen isotope compositions (δ 18 O) preserved in alpha cellulose extracted from specific plant macrofossils reflect the δ 18 O values of past peatland water and thereby provide information on long-term changes in hydrology in response to climate. Oxygen isotope analyses of peat cellulose (δ 18 O cellulose ) have been successfully developed from peat cores that accumulate the same species for millennia. However, to fully exploit the potential of this proxy in species-diverse fens, studies are needed that account for the isotopic variations caused by changes in dominant species composition. This study assesses variation in δ 18 O values among peatland plant species and how they relate to environmental waters in two fens informally named Horse Trail and Goldfin, located on the leeward (dry) and windward (wet) side, respectively, of the climatic gradient across the Kenai Peninsula, Alaska. Environmental water δ 18 O values at both fens reflect unmodified δ 18 O values of mean annual precipitation, although at Goldfin standing pools were slightly influenced by evaporation. Modern plant [mosses and Carex spp. (sedges)] δ 18 O cellulose values indicate that all Carex spp. are higher (~2.5‰) than those of mosses, likely driven by their vascular structure and ecophysiological difference from non-vascular mosses. Moss δ 18 O cellulose values within each peatland are similar among the species, and differences appear related to evaporation effects on environmental waters within hummocks and hollows. The plant taxa-environmental water δ 18 O differences are applied to the previously determined Horse Trail Fen untreated bulk δ 18 O record. Results include significant changes to inferred millennial-to-centennial scale hydroclimatic trends where dominant taxa shift from moss to Carex spp., indicating that modern calibration datasets are necessary for interpreting stable isotopes from fens, containing a mix of vascular and nonvascular plants. Accounting for isotopic offsets through macrofossil analysis and modern plant-water isotope measurements opens new opportunities for hydroclimatic reconstructions from fen peatlands.

Alaska↗

USGS2013

Assessing winter cover crop nutrient uptake efficiency using a water quality simulation model

Winter cover crops are an effective conservation management practice with potential to improve water quality. Throughout the Chesapeake Bay Watershed (CBW), which is located in the Mid-Atlantic US, winter cover crop use has been emphasized and federal and state cost-share programs are available to farmers to subsidize the cost of winter cover crop establishment. The objective of this study was to assess the long-term effect of planting winter cover crops at the watershed scale and to identify critical source areas of high nitrate export. A physically-based watershed simulation model, Soil and Water Assessment Tool (SWAT), was calibrated and validated using water quality monitoring data and satellite-based estimates of winter cover crop species performance to simulate hydrological processes and nutrient cycling over the period of 1991–2000. Multiple scenarios were developed to obtain baseline information on nitrate loading without winter cover crops planted and to investigate how nitrate loading could change with different winter cover crop planting scenarios, including different species, planting times, and implementation areas. The results indicate that winter cover crops had a negligible impact on water budget, but significantly reduced nitrate leaching to groundwater and delivery to the waterways. Without winter cover crops, annual nitrate loading was approximately 14 kg ha −1 , but it decreased to 4.6–10.1 kg ha −1 with winter cover crops resulting in a reduction rate of 27–67% at the watershed scale. Rye was most effective, with a potential to reduce nitrate leaching by up to 93% with early planting at the field scale. Early planting of winter cover crops (~30 days of additional growing days) was crucial, as it lowered nitrate export by an additional ~2 kg ha −1 when compared to late planting scenarios. The effectiveness of cover cropping increased with increasing extent of winter cover crop implementation. Agricultural fields with well-drained soils and those that were more frequently used to grow corn had a higher potential for nitrate leaching and export to the waterways. This study supports the effective implement of winter cover crop programs, in part by helping to target critical pollution source areas for winter cover crop implementation.

Chesapeake Bay Watershed↗

USGS2023

Two centuries of southwest Iceland annually-resolved marine temperature reconstructed from Arctica islandica shells

Iceland's exposure to major ocean current pathways of the central North Atlantic makes it a useful location for developing long-term proxy records of past marine climate. Such records provide more detailed understanding of the full range of past variability which is necessary to improve predictions of future changes. We constructed a 225-year (1791–2015 CE) master shell growth chronology from 29 shells of Arctica islandica collected at 100 m water depth in southwest Iceland (Faxaflói). The growth chronology provides a robust age model for shell oxygen isotope (δ 18 O shell ) data produced at annual resolution for 251 years (1765–2015 CE). The temperature reconstruction derived from δ 18 O shell shows coherence with May–October local surface temperature records and sea surface temperatures in the North Atlantic region, suggesting it is a useful proxy indicator of water temperature variability at 100 m depth within Faxaflói. Field correlations between the shell-based records and gridded sea surface temperature data reveal strong positive correlations between the 1-year lagged shell growth and temperatures within the subpolar gyre post-1972, suggesting a delayed influence of subpolar gyre dynamics on ecological indicators in southwest Iceland in recent decades. However, the shell growth chronology and δ 18 O shell record generally show relatively weak and insignificant correlations with larger region climate indices including the Atlantic Multidecadal Variability, North Atlantic Oscillation, and East Atlantic pattern. Therefore the interannual variations in the newly produced shell-based records appear to reflect more local to regional dynamics around southwest Iceland than large-scale modes of climate variability.

Estuarine, Coastal and Shelf Science↗

USGS2012

Development and evaluation of a boat-mounted RFID antenna for monitoring freshwater mussels

Development of radio frequency identification (RFID) technology and passive integrated transponder (PIT) tags has substantially increased the ability of researchers and managers to monitor populations of aquatic organisms. However, use of transportable RFID antenna systems (i.e., backpack-mounted) is currently limited to wadeable aquatic environments (<1.4 m water depth). We describe the design, construction, and evaluation of a boat-mounted RFID antenna to detect individually PIT-tagged benthic aquatic organisms (mussels). We evaluated the effects of tag orientation on detection distances in water with a 32-mm half-duplex PIT tag. Detection distances up to 50 cm from the antenna coils were obtained, but detection distance was dependent on tag orientation. We also evaluated detection distance of PIT tags beneath the sediment to simulate detection of burrowing mussels with 23- and 32-mm tags. In sand substrate, the maximum detection distance varied from 3.5 cm and 4.5 cm (vertical tag orientation) to 24.7 cm and 39.4 cm (45° tag orientation) for the 23- and 32-mm PIT tags, respectively. Our results suggest a 1.4-m total detection width for tagged mussels on the substrate surface by the boat-mounted antenna system regardless of tag orientation. However, burrowed mussels may require multiple passes to increase detection that would be influenced by depth, tag orientation, and tag size. Construction of the boat-mounted antenna was relatively low in cost (<500 USD) and had several advantages (less labor and time intensive, increased safety) over traditional mussel sampling techniques (diving, snorkeling) in nonwadeable habitats.

Freshwater Science↗

USGS2005

Geologic and geophysical maps of the Las Vegas 30' x 60' quadrangle, Clark and Nye counties, Nevada, and Inyo County, California

Las Vegas and Pahrump are two of the fastest growing cities in the US, and the shortage of water looms as among the greatest future problems for these cities. These new maps of the Las Vegas 30 x 60-minute quadrangle provide a geologic and geophysical framework and fundamental earth science database needed to address societal issues such as ground water supply and contamination, surface flood, landslide, and seismic hazards, and soil properties and their changing impact by and on urbanization. The mountain ranges surrounding Las Vegas and Pahrump consist of Mesozoic, Paleozoic and Proterozoic rocks. A majority of these rocks are Paleozoic carbonate rocks that are part of Nevada's carbonate rock aquifer province. The Spring Mountains represent a major recharge site in the province, where maximum altitude is 3,632 m (Charleston Peak) above sea level. Rocks in the Sheep and Las Vegas Ranges and Spring Mountains contain correlative, northeast-striking, southeast-verging thrust faults that are part of the Cretaceous, Sevier orogenic belt. These thrusts were offset during the Miocene by the Las Vegas Valley shear system (LVVSZ). We conducted new mapping in the Blue Diamond area, highlighting refined work on the Bird Spring thrust, newly studied ancient landslides, and gravity-slide blocks. We conducted new mapping in the Las Vegas Range and mapped previously unrecognized structures such as the Valley thrust and fold belt; recognition of these structures has led to a refined correlation of Mesozoic thrust faults across the LVVSZ. New contributions in the quadrangle also include a greatly refined stratigraphy of Paleozoic bedrock units based on conodont biostragraphy. We collected over 200 conodont samples in the quadrangle and established stratigraphic reference sections used to correlate units across the major Mesozoic thrust faults. Quaternary deposits cover about half of the map area and underlie most of the present urbanized area. Deposits consist of large coalescing alluvial fans that grade downslope to extensive areas of fine-grained sediment indicative of groundwater-discharge during the Pleistocene. In the central areas of Las Vegas and Pahrump valleys, Quaternary fault scarps associated with past ground-water discharge deposits suggest a genetic relationship. In collaboration with NBMG and University of Nevada, a variety of ages of gravelly alluvium are newly mapped using surficial characteristics and soil development, along with reassessment of previously published mapping during compilation. Reconnaissance geochronology (thermoluminescence and U-series) of eolian and authigenic components of surficial and buried soils and spring deposits is applied to test hypotheses of geomorphic and hydrologic response to climate change over the past 100 k.y.). The major structure in the Las Vegas quadrangle is the LVVSZ. Because the LVVSZ is concealed by thick basin-fill deposits of Quaternary and Tertiary age, it was characterized primarily based on geophysics. Likewise, the newly described State line fault system in Pahrump Valley has also been characterized by geophysics, where geophysically inferred structures correlate remarkably with surface structures defined by our new geologic mapping in the Mound Spring and Hidden Hills Ranch 7.5-minute quadrangles.

Scientific Investigations Map↗

USGS2016

Predictive mapping of seabirds, pinnipeds and cetaceans off the Pacific Coast of Washington

About this report This report supports Washington-led marine spatial planning and responsible stewardship of natural and cultural resources by the Olympic Coast National Marine Sanctuary. Washington state agencies and the sanctuary continually seek the best available science to improve management of marine uses and stewardship of resources (Etheridge et al., 2010; Washington Department of Fish and Wildlife, 2015a). This report and associated data provide new, state- and sanctuary-requested information on seabird, pinniped, and cetacean distributions. Through spatial planning, information on species distributions can help to identify high-value conservation areas, minimize adverse effects of ocean uses and mitigate impacts of coastal hazards. Correspondingly, the Washington Department of Fish and Wildlife has already begun to use the maps of predicted relative density presented in this report to identify ecologically important areas off the Pacific Coast of Washington and apply this information to plan for offshore renewable energy development. This is the culmination of three years of work to compile information on seabirds, pinnipeds, and cetaceans, and advance a modeling framework that can integrate data sets and develop accurate predictions of relative density for important species off the Pacific Coast of Washington. Previous reports, which evaluated existing datasets of at-sea observations (Menza et al., 2014; Kracker and Menza, 2015) and presented superseded versions of seabird models (Menza et al., 2015), provided base information for this report. In addition to the maps in this published report, all new seabird, pinniped and cetacean predictions will be made publicly available as digital geospatial data through the National Centers for Environmental Information. This research supports the National Oceanic and Atmospheric Administration (NOAA) Coastal Zone Management Program, a voluntary partnership between the federal government and U.S. coastal and Great Lakes states and territories authorized by the Coastal Zone Management Act (CZMA) of 1972 to address national coastal issues. The act provides the basis for protecting, restoring, and responsibly developing our nation’s diverse coastal communities and resources. To meet the goals of the CZMA, the national program takes a comprehensive approach to coastal resource management – balancing the often competing and occasionally conflicting demands of coastal resource use, economic development, and conservation. A wide range of issues are addressed through the program, including coastal development, water quality, public access, habitat protection, energy facility siting, ocean governance and planning, coastal hazards, and climate change. Accurate maps of seabird and marine mammal distributions are an important tool for making informed management decisions that affect all of these issues.

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USGS2025

Fisheries research and monitoring activities of the Lake Erie Biological Station, 2024

A comprehensive understanding of fish populations and their interactions is the cornerstone of modern fishery management and the basis for Lake Erie’s Fish Community Objectives (FCOs) developed in 2020 (Francis et al. 2020). The 2024 U.S. Geological Survey (USGS) Lake Erie Biological Station Annual Report is responsive to these FCOs and the USGS obligations via a Memorandum of Understanding (MOU 2017) with the Great Lakes Fishery Commission (GLFC) Council of Lake Committees (CLC) to provide scientific information in support of fishery management. Goals for the USGS Great Lakes Deepwater Fish Assessment and Ecological Studies were to monitor long-term changes in the fish community and track population dynamics of key fishes of interest to management agencies. Specific to Lake Erie, expectations were sustained investigations of native percids, prey fish populations, and Lake Trout. All work was conducted as part of the Deepwater Science Program under the authority of the Great Lakes Fishery Research Authorization Act of 2019 (16 USC §941h). The USGS 2024 Deepwater Science Program fieldwork began in Lake Erie in March and concluded in December, using trawl, gill net, hydroacoustic, lower trophic sampling devices, and telemetry methods. This work resulted in 44 bottom trawls covering 41 ha of lake bottom and catching 48,936 fish totaling 995 kg in the West Basin of Lake Erie, with detailed results described below. Overnight gill net sets (n=25) for coldwater species were performed in the East Basin of Lake Erie. A total of 8 km of gillnet was deployed during these surveys, which caught 106 fish, 92 of which were native coldwater species: Lake Trout, Burbot, and Lake Whitefish. Results from coldwater species assessments will be reported in the Coldwater Task Group report to the GLFC and the CLC (CTG 2025). These reports are used to inform Lake Trout stocking decisions and direct lamprey control measures (16 USC §939a). USGS hydroacoustic sampling included twenty-six 5-km transects (130 km total) in the Central Basin as part of a collaborative lake-wide survey with details and results reported by the Forage Task Group (FTG 2025). Lower trophic sampling provided data from zooplankton samples (n=12) and water quality profiles (n=12) to populate a database maintained by the Michigan Department of Natural Resources (MDNR), Ontario Ministry of Natural Resources (OMNR), Ohio Department of Natural Resources (ODNR), Pennsylvania Fish and Boat Commission (PFBC), and New York State Department of Environmental Conservation (NYSDEC). USGS also assisted CLC member agencies with deployment and maintenance of Great Lakes Acoustic Telemetry Observation System (GLATOS) infrastructure throughout all three Lake Erie basins and tributaries, supporting multiple coordinated telemetry investigations. This report presents biomass-based summaries of fish communities in western Lake Erie derived from USGS bottom trawl surveys conducted from 2013 to 2024 during June and September. The survey design compliments the August ODNR- OMNRF effort by reinforcing stock assessments with more robust data. Analyses herein evaluated trends in total biomass, abundance of dominant predator and forage species, non-native species composition, biodiversity, and community structure. Data from this effort are accessible for download (Keretz et al. 2025)

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