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At least 397 records · Page 22Linked to original sources

Photogrammetry of the deep seafloor from archived unmanned submersible exploration dives

Large amounts of video images have been collected for decades by scientific and governmental organizations in deep (>1000 m) water using manned and unmanned submersibles and towed cameras. The collected images were analyzed individually or were mosaiced in small areas with great effort. Here, we provide a workflow for utilizing modern photogrammetry to construct virtual geological outcrops hundreds or thousands of meters in length from these archived video images. The photogrammetry further allows quantitative measurements of these outcrops, which were previously unavailable. Although photogrammetry had been carried out in recent years in the deep sea, it had been limited to small areas with pre-defined overlapping dive paths. Here, we propose a workflow for constructing virtual outcrops from archived exploration dives, which addresses the complicating factors posed by single non-linear and variable-speed vehicle paths. These factors include poor navigation, variable lighting, differential color attenuation due to variable distance from the seafloor, and variable camera orientation with respect to the vehicle. In particular, the lack of accurate navigation necessitates reliance on image quality and the establishment of pseudo-ground-control points to build the photogrammetry model. Our workflow offers an inexpensive method for analyzing deep-sea geological environments from existing video images, particularly when coupled with rock samples.

Journal of Marine Science and Engineering

The saturated zone at Yucca Mountain: An overview of the characterization and assessment of the saturated zone as a barrier to potential radionuclide migration

The US Department of Energy is pursuing Yucca Mountain, Nevada, for the development of a geologic repository for the disposal of spent nuclear fuel and high-level radioactive waste, if the repository is able to meet applicable radiation protection standards established by the US Nuclear Regulatory Commission and the US Environmental Protection Agency (EPA). Effective performance of such a repository would rely on a number of natural and engineered barriers to isolate radioactive waste from the accessible environment. Groundwater beneath Yucca Mountain is the primary medium through which most radionuclides might move away from the potential repository. The saturated zone (SZ) system is expected to act as a natural barrier to this possible movement of radionuclides both by delaying their transport and by reducing their concentration before they reach the accessible environment. Information obtained from Yucca Mountain Site Characterization Project activities is used to estimate groundwater flow rates through the site-scale SZ flow and transport model area and to constrain general conceptual models of groundwater flow in the site-scale area. The site-scale conceptual model is a synthesis of what is known about flow and transport processes at the scale required for total system performance assessment of the site. This knowledge builds on and is consistent with knowledge that has accumulated at the regional scale but is more detailed because more data are available at the site-scale level. The mathematical basis of the site-scale model and the associated numerical approaches are designed to assist in quantifying the uncertainty in the permeability of rocks in the geologic framework model and to represent accurately the flow and transport processes included in the site-scale conceptual model. Confidence in the results of the mathematical model was obtained by comparing calculated to observed hydraulic heads, estimated to measured permeabilities, and lateral flow rates calculated by the site-scale model to those calculated by the regional-scale flow model. In addition, it was confirmed that the flow paths leaving the region of the potential repository are consistent with those inferred from gradients of measured head and those independently inferred from water-chemistry data. The general approach of the site-scale SZ flow and transport model analysis is to calculate unit breakthrough curves for radionuclides at the interface between the SZ and the biosphere using the three-dimensional site-scale SZ flow and transport model. Uncertainties are explicitly incorporated into the site-scale SZ flow and transport abstractions through key parameters and conceptual models. ?? 2002 Elsevier Science B.V. All rights reserved.

Journal of Contaminant Hydrology

Flood-inundation maps for the Pawtuxet River in West Warwick, Warwick, and Cranston, Rhode Island

A series of 15 digital flood-inundation maps was developed for a 10.2-mile reach of the Pawtuxet River in the municipalities of West Warwick, Warwick, and Cranston, Rhode Island, by the U.S. Geological Survey (USGS), in cooperation with the Rhode Island Emergency Management Agency and the U.S. Army Corps of Engineers. The coverage of the maps extends downstream from Natick Pond dam near State Route 33/Providence Street bridge in West Warwick to the mouth of the river at Pawtuxet Cove (Broad Street bridge) on the border between Cranston and Warwick, R.I. A one-dimensional step-backwater hydraulic model created and calibrated for the Federal Emergency Management Agency Flood Insurance Studies for Kent and Providence Counties in 2015 was updated for this study. The updated hydraulic model reflects the removal of the Pawtuxet Falls dam during 2011 and the raised elevation of a levee surrounding the Warwick Sewer Authority wastewater treatment facility during 2014–17. The hydraulic model was calibrated by using the current (2018) stage-discharge relation at the USGS Pawtuxet River at Cranston, Rhode Island, streamgage (01116500) and documented high-water marks from the March 31, 2010, flood, which had a peak flow greater than the estimated 0.2-percent annual exceedance probability floodflow. The hydraulic model was used to compute water-surface profiles for 15 flood stages at 1-foot (ft) intervals referenced to the USGS Pawtuxet River at Cranston, Rhode Island, streamgage (01116500) and ranging from 8.0 ft (15.2 ft, North American Vertical Datum of 1988), which is the National Weather Service Advanced Hydrologic Prediction Service flood category “action stage,” to 22.0 ft (29.2 ft, North American Vertical Datum of 1988), which is the maximum stage of the stage-discharge relation at the streamgage and exceeds the National Weather Service Advanced Hydrologic Prediction Service flood category “major flood stage” of 13.0 ft. The simulated water-surface profiles were combined with a geographic information system digital elevation model derived from light detection and ranging (lidar) data with a 1.0-ft vertical accuracy to create flood-inundation maps. The flood-inundation maps depict estimates of the areal extent and depth of flooding corresponding to 15 selected flood stages at the streamgage. The flood-inundation maps depict only riverine flooding and do not depict any tidal backwater or coastal storm surge that might occur in the lower part of the river reach. The flood-inundation maps can be accessed through the USGS Flood Inundation Mapping Science website at https://water.usgs.gov/osw/flood_inundation . Near-real-time stages and discharges at the Pawtuxet River streamgage can be obtained from the USGS National Water Information System at https://waterdata.usgs.gov/ . The National Weather Service Advanced Hydrologic Prediction Service provides flood forecasts of stage for this site (CRAR1) at https:/water.weather.gov/ahps/ . The availability of flood-inundation maps referenced to current and forecasted water levels at the USGS Pawtuxet River at Cranston, Rhode Island, streamgage (01116500) can provide emergency management personnel and residents with information that is critical for flood response activities, such as evacuations and road closures, and postflood recovery efforts. The flood-inundation maps are nonregulatory but provide Federal, State, and local agencies and the public with estimates of the potential extent of flooding during flood events.

Rhode Island

Effects of tidally varying river flow on entrainment of juvenile salmon into Sutter and Steamboat Sloughs

Survival of juvenile salmonids in the Sacramento–San Joaquin Delta (Delta) varies by migration route, and thus the proportion of fish that use each route affects overall survival through the Delta. Understanding factors that drive routing at channel junctions along the Sacramento River is therefore critical to devising management strategies that maximize survival. Here, we examine entrainment of acoustically tagged juvenile Chinook Salmon into Sutter and Steamboat sloughs from the Sacramento River. Because these sloughs divert fish away from the downstream entrances of the Delta Cross Channel and Georgiana Slough (where fish access the low-survival region of the interior Delta), management actions to increase fish entrainment into Sutter and Steamboat sloughs are being investigated to increase through-Delta survival. Previous studies suggest that fish generally “go with the flow”—as net flow into a divergence increases, the proportion of fish that enter that divergence correspondingly increases. However, complex tidal hydrodynamics at sub-daily time-scales may be decoupled from net flow. Therefore, we modeled routing of acoustic tagged juvenile salmon as a function of tidally varying hydrodynamic data, which was collected using temporary gaging stations deployed between March and May of 2014. Our results indicate that discharge, the proportion of flow that entered the slough, and the rate of change of flow were good predictors of an individual’s probability of being entrained. In addition, interactions between discharge and the proportion of flow revealed a non-linear relationship between flow and entrainment probability. We found that the highest proportions of fish are likely to be entrained into Steamboat Slough and Sutter Slough on the ascending and descending limbs of the tidal cycle, when flow changes from positive to negative. Our findings characterize how patterns of entrainment vary with tidal flow fluctuations, providing information critical for understanding the potential effect of management actions (e.g., fish guidance structures) to modify routing probabilities at this location. Main Content View Larger 1 Sponsored by the Delta Science Program and the UC Davis Muir Institute ABSTRACT Survival of juvenile salmonids in the Sacramento–San Joaquin Delta (Delta) varies by migration route, and thus the proportion of fish that use each route affects overall survival through the Delta. Understanding factors that drive routing at channel junctions along the Sacramento River is therefore critical to devising management strategies that maximize survival. Here, we examine entrainment of acoustically tagged juvenile Chinook Salmon into Sutter and Steamboat sloughs from the Sacramento River. Because these sloughs divert fish away from the downstream entrances of the Delta Cross Channel and Georgiana Slough (where fish access SFEWS Volume 19 | Issue 2 | Article 4 https://doi.org/10.15447/sfews.2021v19iss2art4 * Corresponding author: rperry@usgs.gov 1 Western Fisheries Research Center US Geological Survey Cook, WA 98605 USA 2 California Water Science Center US Geological Survey Sacramento, CA 95819 USA 3 Current address: Mid-Columbia Fish and Wildlife Conservation Office Yakima Basin Program US Fish and Wildlife Service Yakima, WA 98903 USA the low-survival region of the interior Delta), management actions to increase fish entrainment into Sutter and Steamboat sloughs are being investigated to increase through-Delta survival. Previous studies suggest that fish generally “go with the flow”—as net flow into a divergence increases, the proportion of fish that enter that divergence correspondingly increases. However, complex tidal hydrodynamics at sub-daily time-scales may be decoupled from net flow. Therefore, we modeled routing of acoustic tagged juvenile salmon as a function of tidally varying hydrodynamic data, which was collected using temporary gaging stations deployed between March and May of 2014. Our results indicate that discharge, the proportion of flow that entered the slough, and the rate of change of flow were good predictors of an individual’s probability of being entrained. In addition, interactions between discharge and the proportion of flow revealed a non-linear relationship between flow and entrainment probability. We found that the highest proportions of fish are likely to be entrained into Steamboat Slough and Sutter Slough on the ascending and descending limbs of the tidal cycle, when flow changes from positive to negative. Our findings characterize how patterns of entrainment vary with tidal flow fluctuations, providing information critical for understanding the potential effect of management RESEARCH Effects of Tidally Varying River Flow on Entrainment of Juvenile Salmon into Sutter and Steamboat Sloughs Jason G. Romine 1,3 , Russell W. Perry* 1 , Paul R. Stumpner 2 , Aaron R. Blake 2 , Jon R. Burau 2 2 VOLUME 19, ISSUE 2, ARTICLE 4 actions (e.g., fish guidance structures) to modify routing probabilities at this location. KEY WORDS Telemetry, juvenile salmon, migration routing, survival INTRODUCTION The Sacramento–San Joaquin River Delta (hereafter referred to as “the Delta”) is a complex series of channels and embayments in west central California of the United States. The Delta has undergone drastic transformation through construction of dikes, levees, reclaimed land, dredged canals and cuts, and water export projects (Nichols et al. 1986). The loss of habitat coupled with introduction of non-native piscivorous fishes has led to the decline of several salmonid stocks that utilize the Delta (Lindley 2009; National Marine Fisheries Service 2014). The physical complexity of the Delta poses significant challenges for understanding how juvenile salmon negotiate the complex channel network and survive in different migration routes. Yet such information is critical for understanding how water-management actions, such as operation of water diversions, influence survival of juvenile salmon. Through-Delta survival of juvenile Chinook Salmon that emigrate from the Sacramento River ranges from 10% to 80%, depending on river flow and migration route (Perry et al. 2018). The Delta can be broken down into four primary routes: (1) Sacramento River, (2) Steamboat and Sutter sloughs, (3) Georgiana Slough, and (4) Delta Cross Channel (DCC). Fish that remain in the Sacramento River consistently have the highest survival (Perry et al. 2010, 2013, 2018). However, fish that enter the interior Delta—the region to the south of the Sacramento River (Figure 1)—have the lowest survival among all routes and survive at less than half the rate of fish in the Sacramento River, likely as a result of longer migration times and exposure to non-native predators (Newman and Brandes 2010; Perry et al. 2018). On average, fish that migrate through Steamboat and Sutter sloughs exhibit survival similar to fish that remain in the Sacramento River at high flows but have lower survival at low flows (Perry et al. 2018). Because of differences in survival among migration routes, the proportion of fish that use each route affects the total survival of the population. Therefore, understanding the drivers behind fish routing in the Delta is imperative to inform management actions that help in the recovery of imperiled salmonid populations in the Central Valley. For example, Perry et al. (2013) found that total survival through the Delta could be increased by up to 7 percentage points by eliminating entrainment into Georgiana Slough and the DCC. These findings led to investigation of management actions to reduce entrainment into the DCC (Plumb et al. 2016) and Georgiana Slough (Perry et al. 2014). Both physical and non-physical barriers have been tested at the entrance to Georgiana Slough divergence (Perry et al. 2014; Romine et al. 2016). A non-physical barrier was able to reduce entrainment to the interior Delta through Georgiana Slough (Perry et al. 2014), but a floating fish-guidance structure reduced entrainment to a lesser extent (Romine et al. 2016). Research and engineering solutions to minimize entrainment have focused on the Georgiana Slough divergence, the DCC divergence, and the Old River divergence in the San Joaquin River (Buchanan et al. 2013; SJRG 2013). However, there has been little focus on understanding fish routing dynamics at other primary river junctions in the Delta, such as Sutter and Steamboat sloughs. Sutter and Steamboat sloughs diverge from the Sacramento about 10 km upstream from the DCC and Georgiana slough, and represent the first major junction that juvenile salmon encounter as they enter the Delta from the Sacramento River ( Figure 1 ). Because Sutter and Steamboat sloughs are upstream of the entrance to the interior Delta via the DCC and Georgiana Slough (Figure 1), juvenile salmon that enter Sutter and Steamboat sloughs avoid entrainment into the interior Delta where survival is low. Thus, management actions to increase entrainment could increase overall.

Sacramento–San Joaquin Delta

Trends in concentrations of polychlorinated biphenyls in fish tissue from selected sites in the Delaware River basin in New Jersey, New York, and Pennsylvania, 1969-98

Polychlorinated biphenyl (PCB) concentrations in fish tissue collected during the 1990's from selected sites in the Delaware River Basin were compared with concentrations in fish tissue collected during 1969-88. Data collected by State and Federal agencies on concentrations in whole-body common carp ( Cyprinus carpio ) and white sucker ( Catostomus commersoni ), and edible portions of American eel ( Anguilla rostrata ), smallmouth bass ( Micropterus dolomieu ), and channel catfish ( Ictalurus punctatus ) during 1969-98 were compiled to define temporal trends in concentrations of PCBs in fish tissue from selected segments of the Delaware River, Lehigh River, Schuylkill River, and Brandywine Creek. The Delaware River in the vicinity of Trenton, New Jersey and Yardley, Pennsylvania (above the tidal influence) had the largest long-term data set among the sites considered for this study and was the only site with sufficient data for statistical analysis. A general pattern of decline in PCB concentrations during 1969-98 was apparent for this river segment. PCB concentrations in whole-body white sucker from this lower Delaware River segment declined during 1969-98 from a highest concentration of 7 micrograms per gram ( μ g/g, wet weight) in a sample collected during 1972 to 0.26 μ g/g (wet weight) in a sample collected during 1998. PCB concentration was negatively correlated with year (Spearman rank correlation -0.46, p < 0.08, n = 15); especially after removal of a sample from 1977 with an unusually low concentration (Spearman rank correlation -0.53, p = 0.05, n = 14). PCB concentrations in edible flesh of American eel declined during 1975-95, from a highest concentration of 3.8 μ g/g (wet weight) in a sample collected during 1976 to less than the reporting limit of 0.26 μ g/g (wet weight) in samples collected during 1993 and 1995. PCB concentrations in most samples (for species considered in this study) collected from the lower Delaware River exceeded the National Academy of Sciences and National Academy of Engineering (NAS/NAE) wildlife guideline level of 0.5 μ g/g during the 1970's and 1980's, and decreased to below this level during the 1990's. No samples of edible portions of game fish exceeded the U.S. Food and Drug Administration (FDA) tolerance level by the mid 1980's. However, the PCB concentration in a smallmouth bass fillet sample that was collected during 1998 (0.37 μ g/g) exceeded the Pennsylvania fish-consumption advisory level of 0.06 μ g/g, and the concentrations in whole-body common carp and white sucker collected during 1998 (1.10 μ g/g and 0.26 μ g/g, respectively) exceeded the New York State Department of Environmental Conservation wildlife criterion concentration of 0.11 μ g/g. (The concentration in carp also exceeded the 1973 NAS/NAE wildlife guideline concentration of 0.5 μ g/g.) Graphical analysis of PCB concentrations in whole white sucker and (or) edible portions of American eel from the upper Delaware River, lower Delaware River, middle Schuylkill River, and Brandywine Creek indicate a decline from the 1970's and (or) 1980's to the middle to late 1990's. Temporal trends in PCB concentrations in white sucker samples from the lower Lehigh and Schuylkill Rivers during 1979-98 are less clear; the PCB concentration (wet-weight basis) from a sample collected in 1998 from the lower Lehigh River was similar to that from a sample collected in 1979, and concentrations actually increased during 1982-98. Similarly, PCB concentrations in samples of white sucker and American eel from the lower Schuylkill River were highly variable over time.

New Jersey, New York, Pennsylvania

Contaminants of emerging concern in the Great Lakes: Science to inform management practices for protecting the health and integrity of wildlife populations from adverse effects: GLRI action plan I, focus area 1, goal 5

Executive Summary: Under Action Plan I (2010-2014) of the Great Lakes Restoration Initiative (GLRI), Federal and Academic partners began an investigation of the presence and distribution of contaminants of emerging concern (CECs) in the Great Lakes and potential impacts on fish and wildlife. The term CECs is applied to a broad range of chemicals that are currently in use but for which we currently lack good understanding of whether fish, wildlife, or humans are being exposed and/or whether negative health or environmental effects are expected if exposure occurs. Pharmaceuticals, personal care products, flame retardants, many current use pesticides, and poly- and perfluorinated chemicals are some well-known groups of CECs, but there is no definitive or comprehensive list that can be used to support the management of CECs to reduce impacts on the Great Lakes ecosystem. Four overarching goals were identified for this collaborative investigation: 1. Evaluate the sources, occurrence, and distribution of CECs across the Great Lakes Basin. 2. Examine associations between the distribution of CECs and land-use patterns. 3. Review both scientific literature and field-generated data to determine the potential for CECs to cause adverse effects on Great Lakes fish and wildlife populations. 4. Develop efficient strategies to survey and/or monitor for threats that CECs may pose in order to take effective management actions before those threats evolve into large scale impacts on Great Lakes ecosystems or the services they provide. Achievement of these goals ensures progress towards Focus Area 1: Toxic Substances and Areas of Concern from GLRI Action Plan I, Goal 5: “ The health and integrity of wildlife populations and habitat are protected from adverse chemical and biological effects associated with the presence of toxic substances in the Great Lakes Basin ”. This large-scale research effort was comprised of individual and collaborative projects from multiple federal agencies and academic institutions, involving over 85 investigators, and overseen by the U.S. Environmental Protection Agency (EPA) Region 5, Great Lakes National Program Office. Partners include the United States Geological Survey, the National Oceanic and Atmospheric Administration, U.S. Fish and Wildlife Service, Saint Cloud State University, the U.S. EPA Office of Research and Development, and the U.S. Army Corps of Engineers. Key findings: 1. Contaminants of emerging concern were found throughout the monitored Great Lakes tributaries, but types and concentrations vary in association with regional land use. CECs were detected in nearly all samples collected. The type and concentration of the specific contaminants detected varied considerably among field sites and in association with land use type, such as urban, agricultural, wetland, 2 or forest. Contaminants were detected in the water column, sediment, and tissues of all species surveyed in the current work (mussels, aquatic insects, fish, and insect-eating birds). 2. There were over 20 contaminants for which CEC concentrations approached or exceeded those reported to cause toxicity in laboratory experiments. This was based on detection in water, sediments and or biota at one or more field sites. These contaminants represent compounds that warrant further investigation and monitoring with respect to potential impacts in certain areas of the Great Lakes basin. Based on the present investigation, compounds of greatest concern include: polycyclic aromatic hydrocarbons, associated with oil-based products and combustion of organic matter; atrazine, an herbicide; dichlorvos, an insecticide; and ibuprofen and venlafaxine, both pharmaceuticals. 3. Results suggest that mixtures of CECs presently found in most Great Lakes tributary locations surveyed may elicit subtle biological effects, but likely are not, alone, causing obvious detriment to current communities of fish and wildlife. CECs detected in the Great Lakes were associated with subtle biological effects like changes in gene expression, altered circulating glucose, etc. in both wild-caught and laboratory-reared organisms. These effects were generally not indicative of reproductive failure or mortality. However, the effects may have more serious implications when combined with other sources of stress like habitat degradation, changing climate conditions, and competition with invasive species. Due to limited historical data, it is unknown whether severe CEC-related impacts have already affected aquatic communities in waterbodies that have received long-term inputs of these contaminants. Likewise, under Action Plan I, biological effects were not necessarily evaluated at the sites where CEC concentrations exceeding laboratory toxicity thresholds were detected. As a result, strategic, ongoing surveillance and monitoring of CECs is warranted. This collaborative investigation resulted in new tools, approaches, and data that can be used to inform and support the management of CECs to reduce their impacts on Great Lakes natural resources. The following products of this research effort are available through https://communities.geoplatform.gov/glri/ or by contacting the investigators (see technical chapters found in Appendices A-F): 1. Database of CEC occurrence and concentrations in US tributary streams. The database includes CEC detections in water, sediment, and fish and wildlife tissues, and represents the most comprehensive survey of CECs in the Great Lakes Region. 2. Synopses of results and key findings. Integrated summaries of results, conclusions, and management implications of the CEC research are available through reports, topical fact sheets, and presentations. 3. Technical publications: This collaborative research effort has resulted in over 50 peer-reviewed publications, agency reports, and data releases that can be of use to resource managers, the scientific community, and members of the public. 4. Innovative tools. Innovative monitoring devices, sampling equipment, conceptual frameworks, and software applications were developed over the course of this 3 research. These tools are transferable to stakeholders via internet accessibility or via specifications, instructions, and demonstration detailed in technical publications. Hypotheses to guide CECs research under Action Plan II. Findings from 2010-2014 were used to guide further research in 2015-2018 for basin-wide surveillance of CECs and for sites warranting further study of potential biological impacts of CECs. Additional surveillance included both evaluation of additional classes of contaminants and expanded lists for chemical classes shown to be of greatest concern. Mixtures of some of the most frequently detected contaminants were also tested in laboratory studies to understand whether long term exposures to multiple contaminants may result in effects not evident from uncontrolled, short-term field experiments.

Great Lakes

Shoaling wave shape estimates from field observations and derived bedload sediment rates

The shoaling transformation from generally linear deep-water waves to asymmetric shallow-water waves modifies wave shapes and causes near-bed orbital velocities to become asymmetrical, contributing to net sediment transport. In this work, we used two methods to estimate the asymmetric wave shape from data at three sites. The first method converted wave measurements made at the surface to idealized near-bottom wave-orbital velocities using a set of empirical equations: the “parameterized” waveforms. The second method involved direct measurements of velocities and pressure made near the seabed: the “direct” waveforms. Estimates from the two methods were well correlated at all three sites (Pearson’s correlation coefficient greater than 0.85). Both methods were used to drive bedload-transport calculations that accounted for asymmetric waves, and the results were compared with a traditional excess-stress formulation and field estimates of bedload transport derived from ripple migration rates based on sonar imagery. The cumulative bedload transport from the parameterized waveform was 25% greater than the direct waveform, mainly because the parameterized waveform did not account for negative skewness. Calculated transport rates were comparable to rates estimated from ripple migration except during the largest event, when calculated rates were as much as 100 times greater, which occurred during high period waves.

Florida, Massachusetts, New York

Return flows from beaver ponds enhance floodplain-to-river metals exchange in alluvial mountain catchments

River to floodplain hydrologic connectivity is strongly enhanced by beaver- ( Castor canadensis ) engineered channel water diversions. The hydroecological impacts are wide ranging and generally positive, however, the hydrogeochemical characteristics of beaver-induced flowpaths have not been thoroughly examined. Using a suite of complementary ground- and drone-based heat tracing and remote sensing methodology we characterized the physical template of beaver-induced floodplain exchange for two alluvial mountain streams near Crested Butte, Colorado, USA. A flowpath-oriented perspective to water quality sampling allowed characterization of the chemical evolution of channel water diverted through floodplain beaver ponds and ultimately back to the channel in ‘beaver pond return flows’. Subsurface return flow seepages were universally suboxic, while ponds and surface return flows showed a range of oxygen concentration due to in-situ photosynthesis and atmospheric mixing. Median concentrations of reduced metals: manganese (Mn), iron (Fe), aluminum (Al), and arsenic (As) were substantially higher along beaver-induced flowpaths than in geologically controlled seepages and upstream main channel locations. The areal footprint of reduced return seepage flowpaths were imaged with surface electromagnetic methods, indicating extensive zones of high-conductivity shallow groundwater flowing back toward the main channels and emerging at relatively warm bank seepage zones observed with infrared. Multiple-depth redox dynamics within one focused seepage zone showed coupled variation over time, likely driven by observed changes in seepage rate that may be controlled by pond stage. High-resolution times series of dissolved Mn and Fe collected downstream of the beaver-impacted reaches demonstrated seasonal dynamics in mixed river metal concentrations. Al time series concentrations showed proportional change to Fe at the smaller stream location, indicating chemically reduced flowpaths were sourcing Al to the channel. Overall our results indicated beaver-induced floodplain exchanges create important, and perhaps dominant, transport pathways for floodplain metals by expanding chemically-reduced zones paired with strong advective exchange.

Colorado

Ecological Requirements for Pallid Sturgeon Reproduction and Recruitment in the Lower Missouri River: A Research Synthesis 2005-08

This report provides a synthesis of results obtained between 2005 and 2008 from the Comprehensive Sturgeon Research Program, an interagency collaboration between the U.S. Geological Survey, Nebraska Game and Parks Commission, U.S. Fish and Wildlife Service, and the U.S. Army Corps of Engineers' Missouri River Recovery - Integrated Science Program. The goal of the Comprehensive Sturgeon Research Program is to improve fundamental understanding of reproductive ecology of the pallid sturgeon with the intent that improved understanding will inform river and species management decisions. Specific objectives include: *Determining movement, habitat-use, and reproductive behavior of pallid sturgeon; *Understanding reproductive physiology of pallid sturgeon and relations to environmental conditions; *Determining origin, transport, and fate of drifting pallid sturgeon larvae, and evaluating bottlenecks for recruitment of early life stages; *Quantifying availability and dynamics of aquatic habitats needed by pallid sturgeon for all life stages; and *Managing databases, integrating understanding, and publishing relevant information into the public domain. Management actions to increase reproductive success and survival of pallid sturgeon in the Lower Missouri River have been focused on flow regime, channel morphology, and propagation. Integration of 2005-08 Comprehensive Sturgeon Research Program research provides insight into linkages among flow regime, re-engineered channel morphology, and pallid sturgeon reproduction and survival. The research approach of the Comprehensive Sturgeon Research Program integrates opportunistic field studies, field-based experiments, and controlled laboratory studies. The field study plan is designed to explore the role of flow regime and associated environmental cues using two complementary approaches. An upstream-downstream approach compares sturgeon reproductive behavior between an upstream section of the Lower Missouri River with highly altered flow regime to a downstream section that maintains much of its pre-regulation flow variability. The upstream section also has the potential for an experimental approach to compare reproductive behavior in years with pulsed flow modifications ('spring rises') to years without. The reproductive cycle of the female sturgeon requires several years to progress through gonadal development, oocyte maturation, and spawning. Converging lines of evidence support the hypothesis that maturation and readiness to spawn in female sturgeon is cued many months before spawning. Information on reproductive readiness of shovelnose sturgeon indicates that sturgeon at different locations along the Lower Missouri River between St. Louis and Gavins Point Dam are all responding to the same early cue. Although not a perfect surrogate, the more abundant shovelnose sturgeon is morphologically, physiologically, and genetically similar to pallid sturgeon, and thereby provides a useful comparative model for the rarer species. Day length is the likely candidate to define a temporal spawning window. Within the spawning window, one or more additional, short-term, and specific cues may serve to signal ovulation and release of gametes. Of three potential spawning cues - water temperature, water discharge, and day of year - water temperature is the most likely proximate cue because of the fundamental physiological role temperature plays in sturgeon embryo development and survival, and the sensitivity of many fish hormones to temperature change. It also is possible that neither temperature nor discharge is cueing spawning; instead, reproductive behavior may result from the biological clock advancing an individual fish's readiness to spawn day after day through the spawning period until the right moment, independent of local environmental conditions. Separation of the individual effects of discharge events, water temperature, and other possible factors, such as proximity to male

Scientific Investigations Report

Concentrations and distributions of metals associated with dissolved organic matter from the Suwannee River (GA, USA)

Concentrations and distributions of metals in Suwannee River (SR) raw filtered surface water (RFSW) and dissolved organic matter (DOM) processed by reverse osmosis (RO), XAD-8 resin (for humic and fulvic acids [FA]), and XAD-4 resin (for “transphilic” acids) were analyzed by asymmetrical flow field-flow fractionation (AsFlFFF). SR samples were compared with DOM samples from Nelson's Creek (NLC), a wetland-draining stream in northern Michigan; previous International Humic Substances Society (IHSS) FA and RO samples from the SR; and an XAD-8 sample from Lake Fryxell (LF), Antarctica. Despite application of cation exchange during sample processing, all XAD and RO samples contained substantial metal concentrations. AsFlFFF fractograms allowed metal distributions to be characterized as a function of DOM component molecular weight (MW). In SR RFSW, Fe, Al, and Cu were primarily associated with intermediate to higher than average MW DOM components. SR RO, XAD-8, and XAD-4 samples from May 2012 showed similar MW trends for Fe and Al but Cu tended to associate more with lower MW DOM. LF DOM had abundant Cu and Zn, perhaps due to amine groups that should be present due to its primarily algal origins. None of the fractograms showed obvious evidence for mineral nanoparticles, although some very small mineral nanoparticles might have been present at trace concentrations. This research suggests that AsFlFFF is important for understanding how metals are distributed in different DOM samples (including IHSS samples), which may be key to metal reactivity and bioavailability.

Georgia

Seismic hazards and land-use planning

Basic earth-science data are necessary for a realistic assessment of seismic hazards and as a basis for limiting corrective land-use controls only to those areas of greatest hazard. For example, the location, character, and amount of likely displacement and activity of surface faulting can be predicted if detailed geologic maps and seismic data are available and are augmented by field studies at critical localities. Because few structures can withstand displacement of their foundations, they should be located off active fault traces, the distance varying with the character of faulting, the certainty with which fault traces are known, and the importance of the structure. Recreational activities and other nonoccupancy land uses should be considered for fault zone areas where land is under pressure for development; elsewhere, such areas should remain as open space. Two methods of predicting ground shaking effects have applications to land-use decisions: (1) Relative earthquake effects can be related to firmness of the ground and can be used in a gross way to allocate population density in the absence of more sophisticated analyses; and (2) intensity maps, based on, (a) damage from former earthquakes, or (b) a qualitative analyses of geologic units added to a design earthquake, can be helpful both for general and specific plans. Theoretical models are used with caution to predict ground motion for critical structures to be located at specific sites with unique foundation conditions. Fully adequate methods of assessing possible shaking remain to be developed. Where land-use decisions do not reflect likely ground shaking effects, stringent building codes are needed, particularly for important structures. Ground failure (landsliding, ground cracking and lurching, differential settlement, sand boils, and subsidence) commonly results from liquefaction, loss of soil strength, or compaction. Areas suspected of being most likely to fail should not be developed unless detailed site studies can demonstrate the hazard does not exist or can be overcome. Various methods can be used to reduce the high, long-term public costs that follow development of unstable ground. However, areas subject to tectonic deformation generally cannot be predicted nor can effects of such deformation be minimized. Large water waves, such as produced by tsunamis, seiches, and dam failure or overtopping, can be anticipated in many places. Their effects can be lessened by land-use regulations similar to flood-plain zoning, restrictions on location of critical structures, and appropriate warning systems. Many local, state, and federal government agencies, universities, and private consultants may be able to assist planners by advising them of pertinent data and where those data can be obtained. Interpretation of the data for an evaluation of seismic risk commonly requires a team of planners, geologists, and soil and structural engineers.

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Upriver migrating sea lamprey exhibit similar responses to hydrodynamic features as other up and downriver-moving species

Identifying commonalities in how fish navigate rivers near infrastructure will enhance water operations and design by improving our ability to predict engineering outcomes (e.g., barrier construction/removal, fish passage installation) in novel settings before the cost of real-world implementation. Evidence from intermediate-scale computer models (time scales of minutes to days and spatial scales <2 km) suggests that fish movement behavior in rivers is frequently governed by responses to one or more of the following hydrodynamic features: (1) flow direction (i.e., rheotaxis), (2) flow velocity magnitude, (3) turbulence, and (4) depth, plus (5) the integration of information over recent time periods (i.e., memory/experience). However, the lack of consistent modeling approaches, infrequent assessment of each response in isolation and combination, and a focus on a limited number of species means the generality of these responses is uncertain. We use a computer model, specifically a pattern-oriented modeling approach incorporating individual based models (IBMs), to apply responses to the four hydrodynamic features plus memory/experience in different combinations to study their value for reproducing the movement of an infrequently modeled species and lifestage, upriver migrating adult sea lamprey, Petromyzon marinus . The study site was the region downstream of the Sault Ste. Marie lock and dam complex located between Canada and the U.S.A on the St. Marys River joining Lake Superior and Lake Huron. Our analysis indicates that rheotaxis and a response to velocity magnitude as well as recent past experience improve sea lamprey spatio-temporal movement prediction compared to other, simpler forms of modeled behavior. Sea lamprey movement is also biased toward lower levels of turbulence (e.g., turbulent kinetic energy) or its precursor (i.e., the spatial gradient in water speed). A response to water depth was not found to be important, but the modeled domain was two-dimensional which limited our assessment. As similar responses to hydrodynamic features are found in very different fish, commonalities appear to underlie river navigation across a range of species and life stages that share the goal-oriented behavior of upriver and downriver movement. The systematic approach of our analysis highlights the accuracy trade-offs of each response, individually and in combination, that often accompany alternative behavioral formulations in a computer model of fish movement. The model structure provides a framework to which future findings from the analyses of additional species in different contexts can be added.

Sault Ste. Marie lock and dam complex in the St. M

Categorizing active marine acoustic sources based on their potential to affect marine animals

Marine acoustic sources are widely used for geophysical imaging, oceanographic sensing, and communicating with and tracking objects or robotic vehicles in the water column. Under the U.S. Marine Mammal Protection Act and similar regulations in several other countries, the impact of controlled acoustic sources is assessed based on whether the sound levels received by marine mammals meet the criteria for harassment that causes certain behavioral responses. This study describes quantitative factors beyond received sound levels that could be used to assess how marine species are affected by many commonly deployed marine acoustic sources, including airguns, high-resolution geophysical sources (e.g., multibeam echosounders, sidescan sonars, subbottom profilers, boomers, and sparkers), oceanographic instrumentation (e.g., acoustic doppler current profilers, split-beam fisheries sonars), and communication/tracking sources (e.g., acoustic releases and locators, navigational transponders). Using physical criteria about the sources, such as source level, transmission frequency, directionality, beamwidth, and pulse repetition rate, we divide marine acoustic sources into four tiers that could inform regulatory evaluation. Tier 1 refers to high-energy airgun surveys with a total volume larger than 1500 in 3 (24.5 L) or arrays with more than 12 airguns, while Tier 2 covers the remaining low/intermediate energy airgun surveys. Tier 4 includes most high-resolution geophysical, oceanographic, and communication/tracking sources, which are considered unlikely to result in incidental take of marine mammals and therefore termed de minimis . Tier 3 covers most non-airgun seismic sources, which either have characteristics that do not meet the de minimis category (e.g., some sparkers) or could not be fully evaluated here (e.g., bubble guns, some boomers). We also consider the simultaneous use of multiple acoustic sources, discuss marine mammal field observations that are consistent with the de minimis designation for some acoustic sources, and suggest how to evaluate acoustic sources that are not explicitly considered here.

Journal of Marine Science and Engineering

Scoping of flood hazard mapping needs for Cumberland County, Maine

This report was prepared by the U.S. Geological Survey (USGS) Maine Water Science Center as the deliverable for scoping of flood hazard mapping needs for Cumberland County, Maine, under Federal Emergency Management Agency (FEMA) Inter-Agency Agreement Number HSFE01-05-X-0018. This section of the report explains the objective of the task and the purpose of the report. The Federal Emergency Management Agency (FEMA) developed a plan in 1997 to modernize the FEMA flood mapping program. FEMA flood maps delineate flood hazard areas in support of the National Flood Insurance Program (NFIP). FEMA's plan outlined the steps necessary to update FEMA's flood maps for the nation to a seamless digital format and streamline FEMA's operations in raising public awareness of the importance of the maps and responding to requests to revise them. The modernization of flood maps involves conversion of existing information to digital format and integration of improved flood hazard data as needed. To determine flood mapping modernization needs, FEMA has established specific scoping activities to be done on a county-by-county basis for identifying and prioritizing requisite flood-mapping activities for map modernization. The U.S. Geological Survey (USGS), in cooperation with FEMA and the Maine State Planning Office Floodplain Management Program, began scoping work in 2005 for Cumberland County. Scoping activities included assembling existing data and map needs information for communities in Cumberland County, documentation of data, contacts, community meetings, and prioritized mapping needs in a final scoping report (this document), and updating the Mapping Needs Update Support System (MNUSS) Database or its successor with information gathered during the scoping process. The average age of the FEMA floodplain maps in Cumberland County, Maine is 21 years. Most of these studies were in the early to mid 1980s. However, in the ensuing 20-25 years, development has occurred in many of the watersheds, and the characteristics of the watersheds have changed with time. Therefore, many of the older studies may not depict current conditions nor accurately estimate risk in terms of flood heights. The following is the scope of work as defined in the FEMA/USGS Statement of Work: Task 1: Collect data from a variety of sources including community surveys, other Federal and State Agencies, National Flood Insurance Program (NFIP) State Coordinators, Community Assistance Visits (CAVs) and FEMA archives. Lists of mapping needs will be obtained from the MNUSS database, community surveys, and CAVs, if available. FEMA archives will be inventoried for effective FIRM panels, FIS reports, and other flood-hazard data or existing study data. Best available base map information, topographic data, flood-hazard data, and hydrologic and hydraulic data will be identified. Data from the Maine Floodplain Management Program database also will be utilized. Task 2: Contact communities in Cumberland County to notify them that FEMA and the State have selected them for a map update, and that a project scope will be developed with their input. Topics to be reviewed with the communities include (1) Purpose of the Flood Map Project (for example, the update needs that have prompted the map update); (2) The community's mapping needs; (3) The community's available mapping, hydrologic, hydraulic, and flooding information; (4) target schedule for completing the project; and (5) The community's engineering, planning, and geographic information system (GIS) capabilities. On the basis of the collected information from Task 1 and community contacts/meetings in Task 2, the USGS will develop a Draft Project Scope for the identified mapping needs of the communities in Cumberland County. The following items will be addressed in the Draft Project Scope: review of available information, determine if and how effective FIS data can be used in new project, and identify other data needed to

Open-File Report

Scoping of flood hazard mapping needs for Kennebec County, Maine

This report was prepared by the U.S. Geological Survey (USGS) Maine Water Science Center as the deliverable for scoping of flood hazard mapping needs for Kennebec County, Maine, under Federal Emergency Management Agency (FEMA) Inter-Agency Agreement Number HSFE01-05-X-0018. This section of the report explains the objective of the task and the purpose of the report. The Federal Emergency Management Agency (FEMA) developed a plan in 1997 to modernize the FEMA flood mapping program. FEMA flood maps delineate flood hazard areas in support of the National Flood Insurance Program (NFIP). FEMA's plan outlined the steps necessary to update FEMA's flood maps for the nation to a seamless digital format and streamline FEMA's operations in raising public awareness of the importance of the maps and responding to requests to revise them. The modernization of flood maps involves conversion of existing information to digital format and integration of improved flood hazard data as needed. To determine flood mapping modernization needs, FEMA has established specific scoping activities to be done on a county-by-county basis for identifying and prioritizing requisite flood-mapping activities for map modernization. The U.S. Geological Survey (USGS), in cooperation with FEMA and the Maine State Planning Office Floodplain Management Program, began scoping work in 2005 for Kennebec County. Scoping activities included assembling existing data and map needs information for communities in Kennebec County (efforts were made to not duplicate those of pre-scoping completed in March 2005), documentation of data, contacts, community meetings, and prioritized mapping needs in a final scoping report (this document), and updating the Mapping Needs Update Support System (MNUSS) Database or its successor with information gathered during the scoping process. The average age of the FEMA floodplain maps in Kennebec County, Maine is 16 years. Most of these studies were in the late 1970's to the mid 1980s. However, in the ensuing 20-30 years, development has occurred in many of the watersheds, and the characteristics of the watersheds have changed with time. Therefore, many of the older studies may not depict current conditions nor accurately estimate risk in terms of flood heights. The following is the scope of work as defined in the FEMA/USGS Statement of Work: Task 1: Collect data from a variety of sources including community surveys, other Federal and State Agencies, National Flood Insurance Program (NFIP) State Coordinators, Community Assistance Visits (CAVs) and FEMA archives. Lists of mapping needs will be obtained from the MNUSS database, community surveys, and CAVs, if available. FEMA archives will be inventoried for effective FIRM panels, FIS reports, and other flood-hazard data or existing study data. Best available base map information, topographic data, flood-hazard data, and hydrologic and hydraulic data will be identified. Data from the Maine Floodplain Management Program database also will be utilized. Task 2: Contact communities in Kennebec County to notify them that FEMA and the State have selected them for a map update, and that a project scope will be developed with their input. Topics to be reviewed with the communities include (1) Purpose of the Flood Map Project (for example, the update needs that have prompted the map update); (2) The community's mapping needs; (3) The community's available mapping, hydrologic, hydraulic, and flooding information; (4) target schedule for completing the project; and (5) The community's engineering, planning, and geographic information system (GIS) capabilities. On the basis of the collected information from Task 1 and community contacts/meetings in Task 2, the USGS will develop a Draft Project Scope for the identified mapping needs of the communities in Kennebec County. The following items will be addressed in the Draft Project Scope: review of available information, determine if and how e

Open-File Report

Scoping of flood hazard mapping needs for Somerset County, Maine

This report was prepared by the U.S. Geological Survey (USGS) Maine Water Science Center as the deliverable for scoping of flood hazard mapping needs for Somerset County, Maine, under Federal Emergency Management Agency (FEMA) Inter-Agency Agreement Number HSFE01-05-X-0018. This section of the report explains the objective of the task and the purpose of the report. The Federal Emergency Management Agency (FEMA) developed a plan in 1997 to modernize the FEMA flood mapping program. FEMA flood maps delineate flood hazard areas in support of the National Flood Insurance Program (NFIP). FEMA's plan outlined the steps necessary to update FEMA's flood maps for the nation to a seamless digital format and streamline FEMA's operations in raising public awareness of the importance of the maps and responding to requests to revise them. The modernization of flood maps involves conversion of existing information to digital format and integration of improved flood hazard data as needed. To determine flood mapping modernization needs, FEMA has established specific scoping activities to be done on a county-by-county basis for identifying and prioritizing requisite flood-mapping activities for map modernization. The U.S. Geological Survey (USGS), in cooperation with FEMA and the Maine State Planning Office Floodplain Management Program, began scoping work in 2005 for Somerset County. Scoping activities included assembling existing data and map needs information for communities in Somerset County (efforts were made to not duplicate those of pre-scoping completed in March 2005), documentation of data, contacts, community meetings, and prioritized mapping needs in a final scoping report (this document), and updating the Mapping Needs Update Support System (MNUSS) Database or its successor with information gathered during the scoping process. The average age of the FEMA floodplain maps in Somerset County, Maine is 18.1 years. Most of these studies were in the late 1970's to the mid 1980s. However, in the ensuing 20-30 years, development has occurred in many of the watersheds, and the characteristics of the watersheds have changed with time. Therefore, many of the older studies may not depict current conditions nor accurately estimate risk in terms of flood heights. The following is the scope of work as defined in the FEMA/USGS Statement of Work: Task 1: Collect data from a variety of sources including community surveys, other Federal and State Agencies, National Flood Insurance Program (NFIP) State Coordinators, Community Assistance Visits (CAVs) and FEMA archives. Lists of mapping needs will be obtained from the MNUSS database, community surveys, and CAVs, if available. FEMA archives will be inventoried for effective FIRM panels, FIS reports, and other flood-hazard data or existing study data. Best available base map information, topographic data, flood-hazard data, and hydrologic and hydraulic data will be identified. Data from the Maine Floodplain Management Program database also will be utilized. Task 2: Contact communities in Somerset County to notify them that FEMA and the State have selected them for a map update, and that a project scope will be developed with their input. Topics to be reviewed with the communities include (1) Purpose of the Flood Map Project (for example, the update needs that have prompted the map update); (2) The community's mapping needs; (3) The community's available mapping, hydrologic, hydraulic, and flooding information; (4) target schedule for completing the project; and (5) The community's engineering, planning, and geographic information system (GIS) capabilities. On the basis of the collected information from Task 1 and community contacts/meetings in Task 2, the USGS will develop a Draft Project Scope for the identified mapping needs of the communities in Somerset County. The following items will be addressed in the Draft Project Scope: review of available information, determine if and ho

Open-File Report

Anthropocene streams and base-level controls from historic dams in the unglaciated mid-Atlantic region, USA

Recently, widespread valley-bottom damming for water power was identified as a primary control on valley sedimentation in the mid-Atlantic US during the late seventeenth to early twentieth century. The timing of damming coincided with that of accelerated upland erosion during post-European settlement land-use change. In this paper, we examine the impact of local drops in base level on incision into historic reservoir sediment as thousands of ageing dams breach. Analysis of lidar and field data indicates that historic milldam building led to local base-level rises of 2–5 m (typical milldam height) and reduced valley slopes by half. Subsequent base-level fall with dam breaching led to an approximate doubling in slope, a significant base-level forcing. Case studies in forested, rural as well as agricultural and urban areas demonstrate that a breached dam can lead to stream incision, bank erosion and increased loads of suspended sediment, even with no change in land use. After dam breaching, key predictors of stream bank erosion include number of years since dam breach, proximity to a dam and dam height. One implication of this work is that conceptual models linking channel condition and sediment yield exclusively with modern upland land use are incomplete for valleys impacted by milldams. With no equivalent in the Holocene or late Pleistocene sedimentary record, modern incised stream-channel forms in the mid-Atlantic region represent a transient response to both base-level forcing and major changes in land use beginning centuries ago. Similar channel forms might also exist in other locales where historic milling was prevalent.

Delaware, Maryland, Newe Jersey, New York, Pennsyl

Strategic Plan for the North American Breeding Bird Survey: 2006-2010

Executive Summary The mission of the North American Breeding Bird Survey (BBS) is to provide scientifically credible measures of the status and trends of North American bird populations at continental and regional scales to inform biologically sound conservation and management actions. Determining population trends, relative abundance, and distributions of North American avifauna is critical for identifying conservation priorities, determining appropriate conservation actions, and evaluating those actions. The BBS program, jointly coordinated by the U.S. Geological Survey and Environment Canada’s Canadian Wildlife Service, provides the U.S. and Canadian Federal governments, state and provincial agencies, other conservation practitioners, and the general public with science-based avian population trend estimates and other information for regional and national species’ population assessments. Despite the demonstrated value of the BBS for furthering avian conservation across North America, its importance is often underappreciated, and it is underfunded compared with many other government-supported programs that report on status of the environment. Today, BBS resources, adjusted for inflation, are below the amount allocated in the 1970s and are still only sufficient to support two biologists. Yet the number of routes, participants, data, and data requests has quadrupled. Data and information management and delivery requirements and security concerns, non-existent in 1966, impose further demands on BBS resources. In addition, the Mexican expansion of the BBS offers new hope for a truly continental approach to avian conservation, but also brings additional challenges. Meeting the goals of this plan will take cooperation among myriad stakeholders; yet, even with collaboration, most objectives of this plan will be unattainable if BBS program support is not increased. The BBS developed this strategic plan to help set priorities and identify resources required for the program to continue to meet the evolving needs of the conservation community for information on bird population change. By setting clear goals, strategies, and measures of success, this plan provides a cohesive framework and vision for maintenance and development of the BBS. The plan identifies two major goals for the BBS, with a number of strategies and objectives to achieve these goals. Over the next 5 years, progress made in addressing each long-term goal and its associated 5-year strategies and objectives will gage the plan’s success. Specific actions, projected outcomes, and measures of success related to accomplishing these are outlined in Table 1, with a timeline in Table 2. The two main goals for the program, with a summary of the strategies to achieve them, are: Goal 1: Collect scientifically credible measures of the status and trends of North American bird populations at continental and regional scales. The North American Breeding Bird Survey will continue to support North American natural resource conservation through the collection of scientifically credible measures of the status and trends of continental bird populations. While doing this, the BBS will work to improve the science behind the program to better meet its mission and the changing needs of the avian conservation community. In partnership with collaborators, the BBS will address detection probability bias and habitat bias, improve analytical methods, and more fully assess and account for observer quality. Moreover, the BBS will improve the quality and breadth of avian population data through strategic increases in route density and the establishment of a Mexican BBS program. Goal 2: Ensure BBS data and analytical results are widely available and easily accessible for use by the avian conservation and management communities. At the heart of the BBS lies a four-million-record database containing more than 40 years of data on more than 600 bird species. These data are of no value if not well maintained, appropriately analyzed, and widely and easily accessible. The USGS has greatly improved data management and accessibility in recent years. Trend estimates were first made available via the Internet in the mid-1990s, followed closely by the raw data with baseline metadata and standard operating procedures. Nevertheless, numerous enhancements to data management and the usability of BBS results will greatly improve the ability of the BBS to serve avian conservation goals. The BBS needs to ensure that BBS data and results presented on the web site use the best data-management practices and statistical methods, with adequate documentation for users to understand them and any differences between different trend estimates. Moreover, the BBS needs to increase communication with BBS partners and stakeholders to ensure that it continues to meet the avian population status and trends needs of the conservation community and to encourage the development of new products. Working with collaborators, the BBS will develop tools for integrating environmental parameters like habitat change into the analyses, and for integrating BBS data with other avian survey results. In addition, the BBS will continue to improve data and database management through the incorporation of additional data and data fields, such as georeferenced stop locations and more complete metadata for the raw data and results, thus enhancing the uses that can be made of the data.

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