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At least 217 records · Page 12Linked to original sources
USGS2022

Democratizing macroecology: Integrating unoccupied aerial systems with the National Ecological Observatory Network

Macroecology research seeks to understand ecological phenomena with causes and consequences that accumulate, interact, and emerge across scales spanning several orders of magnitude. Broad-extent, fine-grain information (i.e., high spatial resolution data over large areas) is needed to adequately capture these cross-scale phenomena, but these data have historically been costly to acquire and process. Unoccupied aerial systems (UAS or drones carrying a sensor payload) and the National Ecological Observatory Network (NEON) make the broad-extent, fine-grain observational domain more accessible to researchers by lowering costs and reducing the need for highly specialized equipment. Integration of these tools can further democratize macroecological research, as their strengths and weaknesses are complementary. However, using these tools for macroecology can be challenging because mental models are lacking, thus requiring large up-front investments in time, energy, and creativity to become proficient. This challenge inspired a working group of UAS-using academic ecologists, NEON professionals, imaging scientists, remote sensing specialists, and aeronautical engineers at the 2019 NEON Science Summit in Boulder, Colorado, to synthesize current knowledge on how to use UAS with NEON in a mental model for an intended audience of ecologists new to these tools. Specifically, we provide (1) a collection of core principles for collecting high-quality UAS data for NEON integration and (2) a case study illustrating a sample workflow for processing UAS data into meaningful ecological information and integrating it with NEON data collected on the ground—with the Terrestrial Observation System—and remotely—from the Airborne Observation Platform. With this mental model, we advance the democratization of macroecology by making a key observational domain—the broad-extent, fine-grain domain—more accessible via NEON/UAS integration.

Ecosphere↗
USGS2008

Using an ecological ethics framework to make decisions about the relocation of wildlife

Relocation is an increasingly prominent conservation tool for a variety of wildlife, but the technique also is controversial, even among conservation practitioners. An organized framework for addressing the moral dilemmas often accompanying conservation actions such as relocation has been lacking. Ecological ethics may provide such a framework and appears to be an important step forward in aiding ecological researchers and biodiversity managers to make difficult moral choices. A specific application of this framework can make the reasoning process more transparent and give more emphasis to the strong sentiments about non-human organisms held by many potential users. Providing an example of the application of the framework may also increase the appeal of the reasoning process to ecological researchers and biodiversity managers. Relocation as a conservation action can be accompanied by a variety of moral dilemmas that reflect the interconnection of values, ethical positions, and conservation decisions. A model that is designed to address moral dilemmas arising from relocation of humans provides/demonstrates/illustrates a possible way to apply the ecological ethics framework and to involve practicing conservationists in the overall decision-making process. ?? 2008 Springer Science+Business Media B.V.

Science and Engineering Ethics↗
USGS2019

Water priorities for the nation—The U.S. Geological Survey next generation water observing system

The challenges of providing safe and sustainable water supplies for human and ecological uses and protecting lives and property during water emergencies are well recognized. The U.S. Geological Survey (USGS) plays an essential role in meeting these challenges through its observational networks and renowned water science and research activities (National Academies of Science, Engineering, and Medicine, 2018). Substantial advances in water science, together with emerging breakthroughs in technical and computational capabilities, have led the USGS to develop a Next Generation Water Observing System (NGWOS) . The NGWOS will provide real-time data on water quantity and quality in more affordable and rapid ways than previously possible, and in more locations. The data will be served through a modernized USGS National Water Information System that will be coupled to advanced modeling tools to inform daily water operations, decision-making during water emergencies (like floods, droughts, and contaminant spills), assessments of past trends in water quantity and quality, and forecasts of future water availability.

Fact Sheet↗
USGS2016

Development of working hypotheses linking management of the Missouri River to population dynamics of Scaphirhynchus albus (pallid sturgeon)

This report documents a process of filtering of hypotheses that relate Missouri River Scaphirhynchus albus (pallid sturgeon) population dynamics to management actions including flow alterations, channel reconfigurations, and pallid sturgeon population augmentation. The filtering process was a partnership among U.S. Geological Survey, U.S. Army Corps of Engineers, and U.S. Fish and Wildlife Service to contribute to the Missouri River Recovery Management Plan process. The objective of the filtering process was to produce a set of hypotheses with high relevance to pallid sturgeon population dynamics and decision making on the Missouri River. The Missouri River Pallid Sturgeon Effects Analysis team filtered hundreds of potential hypotheses implicit in conceptual ecological models to develop a set of 40 candidate dominant hypotheses that were identified by experts as being important in pallid sturgeon population dynamics. Using a modified Delphi process and additional expert opinion, the team reduced this set of hypotheses to 23 working dominant hypotheses. We then matched the 23 hypotheses with management actions that could influence the biotic outcomes, resulting in as many as 176 potential effects between management actions and pallid sturgeon in the Missouri River. This number was consolidated to a candidate set of 53 working management hypotheses because some management actions applied to multiple life stages of the pallid sturgeon. We used an additional round of expert surveys to identify a set of 30 working management hypotheses. Finally, the set of working management hypotheses was filtered by the U.S. Army Corps of Engineers, Missouri River Recovery Program for actions that were within the agency’s authority and jurisdiction. This round resulted in a set of 21 hypotheses for initial modeling of linkages from management to pallid sturgeon population responses. The initial set of candidate hypotheses provides a useful starting point for quantitative modeling and adaptive management of the river and species. We anticipate that hypotheses will change from the set of working management hypotheses as adaptive management progresses. More importantly, hypotheses that have been filtered out of our multistep process are still being considered. These filtered hypotheses are archived and if existing hypotheses are determined to be inadequate to explain observed population dynamics, new hypotheses can be created or filtered hypotheses can be reinstated.

Missouri River Basin↗
USGS2009

Science-Based Strategies for Sustaining Coral Ecosystems

Coral ecosystems and their natural capital are at risk. Greenhouse gas emissions, overfishing, and harmful land-use practices are damaging our coral reefs. Overwhelming scientific evidence indicates that the threats are serious, and if they are left unchecked, the ecological and social consequences will be significant and widespread. Although the primary stressors to coral ecosystems are known, science-based strategies are needed to more accurately explain natural processes and forecast human-induced change. Collaborations among managers and scientists and enhanced mapping, monitoring, research, and modeling can lead to effective mitigation plans. U.S. Geological Survey scientists and their partners assess coral ecosystem history, ecology, vulnerability, and resiliency and provide study results to decisionmakers who may devise policies to sustain coral resources and the essential goods and services they provide.

Fact Sheet↗
USGS2017

Biological and ecological science for Florida—The Sunshine State

Florida is rich in sunshine and other natural resources essential to the State's economy. More than 100 million tourists visit Florida's beaches, wetlands, forests, oceans, lakes, and streams where they generate billions of dollars and sustain more than a million jobs. Florida also provides habitat for several thousand freshwater and marine fish, mammals, birds, and other wildlife that are viewed, hunted, or fished, or that provide valuable ecological services. Fertile soils and freshwater supplies support agriculture and forest industries and generate more than $8 billion of revenue annually and sustain thousands of jobs.

Florida↗
USGS2009

Sediment regime constraints on river restoration - An example from the lower Missouri river

Dammed rivers are subject to changes in their flow, water-quality, and sediment regimes. Each of these changes may contribute to diminished aquatic habitat quality and quantity. Of the three factors, an altered sediment regime is a particularly unyielding challenge on many dammed rivers. The magnitude of the challenge is illustrated on the Lower Missouri River, where the largest water storage system in North America has decreased the downriver suspended-sediment load to 0.2%–17% of pre-dam loads. In response to the altered sediment regime, the Lower Missouri River channel has incised as much as 3.5 m just downstream of Gavins Point Dam, although the bed has been stable to slightly aggrading at other locations farther downstream. Effects of channel engineering and commercial dredging are superimposed on the broad-scale adjustments to the altered sediment regime. The altered sediment regime and geomorphic adjustments constrain restoration and management opportunities. Incision and aggradation limit some objectives of flow-regime management: In incising river segments, ecologically desirable reconnection of the floodplain requires discharges that are beyond operational limits, whereas in aggrading river segments, small spring pulses may inundate or saturate low-lying farmlands. Lack of sediment in the incising river segment downstream of Gavins Point Dam also limits sustainable restoration of sand-bar habitat for bird species listed under the Endangered Species Act. Creation of new shallow-water habitat for native fishes involves taking sediment out of floodplain storage and reintroducing most or all of it to the river, raising concerns about increased sediment, nutrient, and contaminant loads. Calculations indicate that effects of individual restoration projects are small relative to background loads, but cumulative effects may depend on sequence and locations of projects. An understanding of current and historical sediment fluxes, and how they vary along the river, provides a quantitative basis for defining management constraints and identifying opportunities.

Special Paper of the Geological Society of America↗
USGS2013

Topobathymetric model of Mobile Bay, Alabama

Topobathymetric Digital Elevation Models (DEMs) are a merged rendering of both topography (land elevation) and bathymetry (water depth) that provides a seamless elevation product useful for inundation mapping, as well as for other earth science applications, such as the development of sediment-transport, sea-level rise, and storm-surge models. This 1/9-arc-second (approximately 3 meters) resolution model of Mobile Bay, Alabama was developed using multiple topographic and bathymetric datasets, collected on different dates. The topographic data were obtained primarily from the U.S. Geological Survey (USGS) National Elevation Dataset (NED) (http://ned.usgs.gov/) at 1/9-arc-second resolution; USGS Experimental Advanced Airborne Research Lidar (EAARL) data (2 meters) (http://pubs.usgs.gov/ds/400/); and topographic lidar data (2 meters) and Compact Hydrographic Airborne Rapid Total Survey (CHARTS) lidar data (2 meters) from the U.S. Army Corps of Engineers (USACE) (http://www.csc.noaa.gov/digitalcoast/data/coastallidar/). Bathymetry was derived from digital soundings obtained from the National Oceanic and Atmospheric Administration’s (NOAA) National Geophysical Data Center (NGDC) (http://www.ngdc.noaa.gov/mgg/geodas/geodas.html) and from water-penetrating lidar sources, such as EAARL and CHARTS. Mobile Bay is ecologically important as it is the fourth largest estuary in the United States. The Mobile and Tensaw Rivers drain into the bay at the northern end with the bay emptying into the Gulf of Mexico at the southern end. Dauphin Island (a barrier island) and the Fort Morgan Peninsula form the mouth of Mobile Bay. Mobile Bay is 31 miles (50 kilometers) long by a maximum width of 24 miles (39 kilometers) with a total area of 413 square miles (1,070 square kilometers). The vertical datum of the Mobile Bay topobathymetric model is the North American Vertical Datum of 1988 (NAVD 88). All the topographic datasets were originally referenced to NAVD 88 and no transformations were made to these input data. The NGDC hydrographic, multibeam, and trackline surveys were transformed from mean low water (MLW) or mean lower low water (MLLW) to NAVD 88 using VDatum (http://vdatum.noaa.gov). VDatum is a tool developed by the National Geodetic Survey (NGS) that performs transformations among tidal, ellipsoid-based, geoid-based, and orthometric datums using calibrated hydrodynamic models. The vertical accuracy of the input topographic data varied depending on the input source. Because the input elevation data were derived primarily from lidar, the vertical accuracy ranges from 6 to 20 centimeters in root mean square error (RMSE). he horizontal datum of the Mobile Bay topobathymetric model is the North American Datum of 1983 (NAD 83), geographic coordinates. All the topographic and bathymetric datasets were originally referenced to NAD 83, and no transformations were made to the input data. The bathymetric surveys were downloaded referenced to NAD 83 geographic, and therefore no horizontal transformations were required. The topbathymetric model of Mobile Bay and detailed metadata can be obtained from the USGS Web sites: http://nationalmap.gov/.

Alabama↗
USGS2020

Direct and indirect effects of a keystone engineer on a shrubland-prairie food web

Keystone engineers are critical drivers of biodiversity throughout ecosystems worldwide. Within the North American Great Plains, the black‐tailed prairie dog is an imperiled ecosystem engineer and keystone species with well‐documented impacts on the flora and fauna of rangeland systems. However, because this species affects ecosystem structure and function in myriad ways (i.e., as a consumer, a prey resource, and a disturbance vector), it is unclear which effects are most impactful for any given prairie dog associate. We applied structural equation models (SEM) to disentangle direct and indirect effects of prairie dogs on multiple trophic levels (vegetation, arthropods, and birds) in the Thunder Basin National Grassland. Arthropods did not show any direct response to prairie dog occupation, but multiple bird species and vegetation parameters were directly affected. Surprisingly, the direct impact of prairie dogs on colony‐associated avifauna (Horned Lark [ Eremophila alpestris ] and Mountain Plover [ Charadrius montanus ]) had greater support than a mediated effect via vegetation structure, indicating that prairie dog disturbance may be greater than the sum of its parts in terms of impacts on localized vegetation structure. Overall, our models point to a combination of direct and indirect impacts of prairie dogs on associated vegetation, arthropods, and avifauna. The variation in these impacts highlights the importance of examining the various impacts of keystone engineers, as well as highlighting the diverse ways that black‐tailed prairie dogs are critical for the conservation of associated species.

Wyoming↗
USGS2012

Ecosystem engineering varies spatially: a test of the vegetation modification paradigm for prairie dogs

Colonial, burrowing herbivores can be engineers of grassland and shrubland ecosystems worldwide. Spatial variation in landscapes suggests caution when extrapolating single-place studies of single species, but lack of data and the need to generalize often leads to ‘model system’ thinking and application of results beyond appropriate statistical inference. Generalizations about the engineering effects of prairie dogs ( Cynomys sp.) developed largely from intensive study at a single complex of black-tailed prairie dogs C. ludovicianus in northern mixed prairie, but have been extrapolated to other ecoregions and prairie dog species in North America, and other colonial, burrowing herbivores. We tested the paradigm that prairie dogs decrease vegetation volume and the cover of grasses and tall shrubs, and increase bare ground and forb cover. We sampled vegetation on and off 279 colonies at 13 complexes of 3 prairie dog species widely distributed across 5 ecoregions in North America. The paradigm was generally supported at 7 black-tailed prairie dog complexes in northern mixed prairie, where vegetation volume, grass cover, and tall shrub cover were lower, and bare ground and forb cover were higher, on colonies than at paired off-colony sites. Outside the northern mixed prairie, all 3 prairie dog species consistently reduced vegetation volume, but their effects on cover of plant functional groups varied with prairie dog species and the grazing tolerance of dominant perennial grasses. White-tailed prairie dogs C. leucurus in sagebrush steppe did not reduce shrub cover, whereas black-tailed prairie dogs suppressed shrub cover at all complexes with tall shrubs in the surrounding habitat matrix. Black-tailed prairie dogs in shortgrass steppe and Gunnison's prairie dogs C. gunnisoni in Colorado Plateau grassland both had relatively minor effects on grass cover, which may reflect the dominance of grazing-tolerant shortgrasses at both complexes. Variation in modification of vegetation structure may be understood in terms of the responses of different dominant perennial grasses to intense defoliation and differences in foraging behavior among prairie dog species. Spatial variation in the engineering role of prairie dogs suggests spatial variation in their keystone role, and spatial variation in the roles of other ecosystem engineers. Thus, ecosystem engineering can have a spatial component not evident from single-place studies.

Ecography: Pattern and Diversity in Ecology↗
USGS2007

Hydrostratigraphic Framework and Selection and Correlation of Geophysical Log Markers in the Surficial Aquifer System, Palm Beach County, Florida

The surficial aquifer system is the major source of freshwater for public water supply in Palm Beach County, Florida, yet many previous studies of the hydrogeology of this aquifer system have focused only on the eastern one-half to one-third of the county in the more densely populated coastal area (Land and others, 1973; Swayze and others, 1980; Swayze and Miller, 1984; Shine and others, 1989). Population growth in the county has resulted in the westward expansion of urbanized areas into agricultural areas and has created new demands on the water resources of the county. Additionally, interest in surface-water resources of central and western areas of the county has increased. In these areas, plans for additional surface-water storage reservoirs are being made under the Comprehensive Everglades Restoration Plan originally proposed by the U.S. Army Corps of Engineers and the South Florida Water Management District (1999), and stormwater treatment areas have been constructed by the South Florida Water Management District. Surface-water and ground-water interactions in the Everglades are thought to be important to water budgets, water quality, and ecology (Harvey and others, 2002). Most of the previous hydrogeologic and ground-water flow simulation studies of the surficial aquifer system have not utilized a hydrostratigraphic framework, in which stratigraphic or sequence stratigraphic units, such as those proposed in Cunningham and others (2001), are delineated in this stratigraphically complex aquifer system. A thick zone of secondary permeability mapped by Swayze and Miller (1984) was not subdivided and was identified as only being within the Anastasia Formation of Pleistocene age. Miller (1987) published 11 geologic sections of the surficial aquifer system, but did not delineate any named stratigraphic units in these sections. This limited interpretation has resulted, in part, from the complex facies changes within rocks and sediments of the surficial aquifer system and the seemingly indistinct and repetitious nature of the most common lithologies, which include sand, shell, sandstone, and limestone. Model construction and layer definition in a simulation of ground-water flow within the surficial aquifer system of Palm Beach County utilized only the boundaries of one or two major hydrogeologic zones, such as the Biscayne aquifer and surficial aquifer system; otherwise layers were defined by average elevations rather than geologic structure or stratigraphy (Shine and others, 1989). Additionally, each major permeable zone layer in the model was assumed to have constant hydraulic conductivity with no allowance for the possibility of discrete (thin) flow zones within the zone. The key to understanding the spatial distribution and hydraulic connectivity of permeable zones in the surficial aquifer system beneath Palm Beach County is the development of a stratigraphic framework based on a consistent method of county-wide correlation. Variability in hydraulic properties in the system needs to be linked to the stratigraphic units delineated in this framework, and proper delineation of the hydrostratigraphic framework should provide a better understanding and simulation of the ground-water flow system. In 2004, the U.S. Geological Survey, in cooperation with the South Florida Water Management District, initiated an investigation to develop a hydrostratigraphic framework for the surficial aquifer system in Palm Beach County.

Scientific Investigations Map↗
USGS2015

Sea-level rise modeling handbook: Resource guide for coastal land managers, engineers, and scientists

Global sea level is rising and may accelerate with continued fossil fuel consumption from industrial and population growth. In 2012, the U.S. Geological Survey conducted more than 30 training and feedback sessions with Federal, State, and nongovernmental organization (NGO) coastal managers and planners across the northern Gulf of Mexico coast to evaluate user needs, potential benefits, current scientific understanding, and utilization of resource aids and modeling tools focused on sea-level rise. In response to the findings from the sessions, this sea-level rise modeling handbook has been designed as a guide to the science and simulation models for understanding the dynamics and impacts of sea-level rise on coastal ecosystems. The review herein of decision-support tools and predictive models was compiled from the training sessions, from online research, and from publications. The purpose of this guide is to describe and categorize the suite of data, methods, and models and their design, structure, and application for hindcasting and forecasting the potential impacts of sea-level rise in coastal ecosystems. The data and models cover a broad spectrum of disciplines involving different designs and scales of spatial and temporal complexity for predicting environmental change and ecosystem response. These data and models have not heretofore been synthesized, nor have appraisals been made of their utility or limitations. Some models are demonstration tools for non-experts, whereas others require more expert capacity to apply for any given park, refuge, or regional application. A simplified tabular context has been developed to list and contrast a host of decision-support tools and models from the ecological, geological, and hydrological perspectives. Criteria were established to distinguish the source, scale, and quality of information input and geographic datasets; physical and biological constraints and relations; datum characteristics of water and land components; utility options for setting sea-level rise and climate change scenarios; and ease or difficulty of storing, displaying, or interpreting model output. Coastal land managers, engineers, and scientists can benefit from this synthesis of tools and models that have been developed for projecting causes and consequences of sea-level change on the landscape and seascape.

Professional Paper↗
USGS2008

Faunal impact on vegetation structure and ecosystem function in mangrove forests: A review

The last 20 years witnessed a real paradigm shift concerning the impact of biotic factors on ecosystem functions as well as on vegetation structure of mangrove forests. Before this small scientific revolution took place, structural aspects of mangrove forests were viewed to be the result of abiotic processes acting from the bottom-up, while, at ecosystem level, the outwelling hypothesis stated that mangroves primary production was removed via tidal action and carried to adjacent nearshore ecosystems where it fuelled detrital based food-webs. The sesarmid crabs were the first macrofaunal taxon to be considered a main actor in mangrove structuring processes, thanks to a number of studies carried out in the Indo-Pacific forests in the late 1970s and early 1980s. Following these classical papers, a number of studies on Sesarmidae feeding and burrowing ecology were carried out, which leave no doubts about the great importance of these herbivorous crabs in structuring and functioning Old world ecosystems. Although Sesarmidae are still considered very important in shaping mangrove structure and functioning, recent literature emphasizes the significance of other invertebrates. The Ocypodidae have now been shown to have the same role as Sesarmidae in terms of retention of forest products and organic matter processing in New world mangroves. In both New and Old world mangroves, crabs process large amounts of algal primary production, contribute consistently to retention of mangrove production and as ecosystem engineers, change particle size distribution and enhance soil aeration. Our understanding of the strong impact of gastropods, by means of high intake rates of mangrove products and differential consumption of propagules, has changed only recently. The role of insects must also be stressed. It is now clear that older techniques used to assess herbivory rates by insects strongly underestimate their impact, both in case of leaf eating and wood boring species and that herbivorous insects can potentially play a strong role in many aspects of mangrove ecology. Moreover, researchers only recently realized that ant–plant interactions may form an important contribution to our understanding of insect–plant dynamics in these habitats. Ants seem to be able to relieve mangroves from important herbivores such as many insects and sesarmid crabs. It thus seems likely that ants have positive effects on mangrove performance.

Aquatic Botany↗
USGS2008

Ecology in the information age: Patterns of use and attrition rates of internet-based citations in ESA journals, 1997–2005

As the amount of information available on the internet has increased, so too has the number of citations to network-accessible information in scholarly research. We searched all papers in four Ecological Society of America journals from 1997 to 2005 for articles containing a citation to material on the internet. We then tested the links to determine whether the information cited in the paper was still accessible. We identified 877 articles that contained at least one link to information on the internet and a total of 2100 unique links. The majority of these citations were based on an object's location (Uniform Resource Locator; 77%), whereas the rest were based on an object's identity (eg Digital Object Identifier, GenBank Accession number). We found that 19–30% of the location-based links were unavailable and that there was a positive relationship between the age of an article and the probability of the link being inactive. Using an internet search engine, we recovered 72–84% of the lost information, leaving a total of 6.2% of the total citations unavailable. Our results highlight the problem of persistence of information stored on the world wide web and we include recommendations for minimizing this problem.

Frontiers in Ecology and the Environment↗
USGS2019

Marshes are the new beaches: Integrating sediment transport into restoration planning

Recent coastal storms and associated recovery efforts have led to increased investment in nature-based coastal protection, including restoration of salt marshes and construction of living shorelines. In particular, many of these efforts focus on increasing vertical elevation through sediment nourishment, where sediment is removed from the tidal channel and placed on the marsh plain, or preventing lateral erosion through shoreline protection. In the USA alone, millions of dollars have been allocated or spent on these coastal protection solutions over the last few decades because of their perceived sustainability and ecologically positive co-benefits including habitat provision and carbon sequestration. These projects would benefit from integration of sediment transport pathways, budgets, and metrics during planning and modeling of restoration outcomes, in order to evaluate sustainability before investment. This is analogous to the decades of experience with coastal management and engineering on the open coast. Salt marshes are geomorphic features that rely partially on external sediment supply to maintain their network of tidal channels, intertidal flats, and marsh plain. Removing sediment from one component of the overall system to nourish another component may be counterproductive, given that the net sediment budget is unchanged. For example, dredging a tidal channel beyond its equilibrium condition will cause it to fill with sediment from the tidal flat or elsewhere in the system. This may cause slumping of the marsh edge, or over-deepening of other sections of the channel to compensate. Similarly, shoreline protection that prevents edge erosion hampers the marsh plain’s ability to accrete on the levee and naturally transgress landward or it starves other components of the system of regularly supplied sediment. A limited vertical or lateral-only perspective, instead of a three-dimensional perspective, during project planning and evaluation may lead to suboptimal decision-making regarding restoration priorities, approaches, and outcomes. I contend that before significant investments are made in marsh restoration through sediment nourishment or shoreline protection, sediment transport measurements and models that consider sediment dynamics should be integrated into the early phases of restoration planning. This will help identify where and under what conditions marsh restoration will most likely be successful and economically justified. Triaging and prioritizing is then possible, which is a sustainable approach for restoration, given the persistent vulnerability of marshes to sea-level rise, storms, and sediment deficits.

Estuaries and Coasts↗
USGS2023

Bedform distributions and dynamics in a large, channelized river: Implications for benthic ecological processes

Sand bedforms are fundamental habitat elements for benthic fish in large, sand-bedded rivers and are hypothesized to provide flow refugia, food transport, and ecological disturbance. We explored bedform distributions and dynamics in the Lower Missouri River, Missouri, with the objective of understanding the implications of these features for benthic fish habitat, particularly for the endangered pallid sturgeon (Scaphirhynchus albus) and shovelnose sturgeon (Scaphirhynchus platorynchus) during their early life stages. We mapped bathymetry in a 3-kilometer-long reach of the highly engineered Lower Missouri River 22 times over a three-year period from 2019-2021 using a multibeam echosounder. Surveys included precise water surface and bed elevations over discharges ranging from 1,360-8,550 cubic meters per second. This included weekly surveys during a large flood event with a peak of 9,290 cubic meters per second in the spring and summer of 2019. Velocity was mapped with an acoustic Doppler current profiler during 11 of the 22 multibeam surveys. The dataset illustrates how bedforms are distributed in a typical Missouri River reach and how they evolve with changes in discharge. We measured a variety of bedform characteristics, including height, length, lee-slope angle, and crest orientation, and examined their relationship to larval sturgeon catch in the reach in 2020 and 2021. Bedform shapes are controlled by depositional environment and discharge and range in size from less than a meter in wavelength and amplitude to greater than 4 meters high and 75 meters long and generally have low angle lee-slopes. Small dunes were located in lower velocity regions on the inside of a bend and behind wing-dikes, as well as superimposed on larger dunes. Larger dunes were generally located in the channel thalweg and were associated with higher flow velocities. However, bedform size did not necessarily scale with discharge over the course of the 2019 flood, possibly due to sediment supply limitations and hysteresis effects. Changes in bedform size over the course of the flood event were most pronounced in the thalweg; less change in bedform size occurred behind wing dikes on the inside of channel bends, indicating some degree of habitat stability. Despite rarely getting caught in the thalweg, larval sturgeon drift in the thalweg until they are intercepted into off-channel habitats in wing dike fields, where they are caught in much higher numbers. Bedform orientations were affected by flow expansion around wing dikes, indicative of the role of wing dikes in influencing exchange of material between the thalweg and channel margins. Increased understanding of bedform distributions and dynamics will inform future sampling and habitat restoration designs for larval pallid sturgeon and contribute to increased understanding of their influence on benthic ecological processes.

Conference Paper↗
USGS2009

Feeding ecology of long-tailed ducks Clangula hyemalis wintering on the Nantucket Shoals

A substantial proportion, perhaps 30%, of the North American breeding population of Long-tailed Ducks ( Clangula hyemalis ) winter in the vicinity of Nantucket Island, Massachusetts. These birds spend the night on Nantucket Sound and commute during daylight hours to the Nantucket Shoals, which extend about 65 km offshore from the southeastern corner of Nantucket. Strip transects done from a single-engine plane in 1997 and 1998 indicated that Long-tailed Ducks foraged over the shallower (≤ 20 m depth) portions of the Nantucket Shoals, up to 70 km offshore. Diet analyses of ten birds collected in February 1999 and five in December 2006 showed that they fed principally (106.6 /- 42.0 individuals per crop) on Gammarus annulatus , a pelagic amphipod that often forms large aggregations, and is consumed by several species of fish and marine mammals. Our findings emphasize the importance of conservation of the Nantucket Shoals and the prevention of oil spills or other potentially harmful accidents.

Massachusetts↗
USGS2013

Benthic substrate classification map: Gulf Islands National Seashore

The 2005 hurricane season was devastating for the Mississippi Gulf Coast. Hurricane Katrina caused significant degradation of the barrier islands that compose the Gulf Islands National Seashore (GUIS). Because of the ability of coastal barrier islands to help mitigate hurricane damage to the mainland, restoring these habitats prior to the onset of future storms will help protect the islands themselves and the surrounding habitats. During Hurricane Katrina, coastal barrier islands reduced storm surge by approximately 10 percent and moderated wave heights (Wamsley and others, 2009). Islands protected the mainland by preventing ocean waves from maintaining their size as they approached the mainland. In addition to storm protection, it is advantageous to restore these islands to preserve the cultural heritage present there (for example, Fort Massachusetts) and because of the influence that these islands have on marine ecology. For example, these islands help maintain a salinity regime favorable to oysters in the Mississippi Sound and provide critical habitats for many migratory birds and endangered species such as sea turtles (Chelonia mydas, Caretta caretta, and Dermochelys coriacea), Gulf sturgeon (Acipenser oxyrinchus desotoi), and piping plovers (Charadrius melodus) (U.S. Army Corps of Engineers, 2009a). As land manager for the GUIS, the National Park Service (NPS) has been working with the State of Mississippi and the Mobile District of the U.S. Army Corps of Engineers to provide a set of recommendations to the Mississippi Coastal Improvements Program (MsCIP) that will guide restoration planning. The final set of recommendations includes directly renourishing both West Ship Island (to protect Fort Massachusetts) and East Ship Island (to restore the French Warehouse archaeological site); filling Camille Cut to recreate a continuous Ship Island; and restoring natural regional sediment transport processes by placing sand in the littoral zone just east of Petit Bois Island. Prevailing sediment transport processes will provide natural renourishment of the westward islands in the barrier system (U.S. Army Corps of Engineers, 2009b). One difficulty in developing the final recommendations is that few data are available to incorporate into restoration plans related to bathymetry, sediment type, and biota. For example, the most recent bathymetry available dates to when East and West Ship Islands were a single continuous island (1917). As a result, the MsCIP program has encouraged post-hurricane bathymetric data collection for future reference. Furthermore, managing a complex environment such as this barrier island system for habitat conservation and best resource usage requires significant knowledge about those habitats and resources. To effectively address these issues, a complete and comprehensive understanding of the type, geographic extent, and condition of marine resources included within the GUIS is required. However, the data related to the GUIS marine resources are limited either spatially or temporally. Specifically, there is limited knowledge and information about the distribution of benthic habitats and the characteristics of the offshore region of the GUIS, even though these are the habitats that will be most affected by habitat restoration. The goal of this project is to develop a comprehensive map of the benthic marine habitats within the GUIS to give park managers the ability to develop strategies for coastal and ocean-resource management and to aid decisionmakers in evaluating conservation priorities.

Mississippi↗