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USGS2016

Ecological resilience

Resilience is the capacity of complex systems of people and nature to withstand disturbance without shifting into an alternate regime, or a different type of system organized around different processes and structures (Holling, 1973). Resilience theory was developed to explain the non-linear dynamics of complex adaptive systems, like social-ecological systems (SES) (Walker & Salt, 2006). It is often apparent when the resilience of a SES has been exceeded as the system discernibly changes, such as when a thriving city shifts into a poverty trap, but it is difficult to predict when that shift might occur because of the non-linear dynamics of complex systems. Ecological resilience should not be confused with engineering resilience (Angeler & Allen, 2016), which emphasizes the ability of a SES to perform a specific task consistently and predictably, and to re-establish performance quickly should a disturbance occur. Engineering resilience assumes that complex systems are characterized by a single equilibrium state, and this assumption is not appropriate for complex adaptive systems such as SES. In the risk governance context this means that compounded perturbations derived from hazards or global change can have unexpected and highly uncertain effects on natural resources, humans and societies. These effects can manifest in regime shifts, potentially spurring environmental degradation that might lock SES in an undesirable system state that can be difficult to reverse, and as a consequence economic crises, conflict, human health problems.

Book chapter↗

USGS2023

Rivers of Arctic North America

This chapter describes the geomorphology, hydrology, chemistry, biodiversity, and ecology of rivers in the North American Arctic. The history, physiography, climate, and land use of the Arctic regions are also described. The chapter includes details on the Kobuk and Colville rivers in Alaska, the Thelon and Kazan rivers in the central Canadian Arctic, Koroc River and Nakvak Brook in the eastern Canadian low Arctic, Thomsen River on Banks Island in the western Canadian Arctic Archipelago, and Ruggles River on Ellesmere Island in the Canadian high Arctic. The rivers are characteristic of the major ecoregions of the North American Arctic, covering a range of geomorphological and physiographic conditions. The history of use of the rivers by Inuit and Dene First Nations Peoples of the north provides the foundation to understand the social, cultural, and economic importance of the river systems, and potential threats to the rivers from climate change are outlined.

Book chapter↗

USGS2018

Southeast

The Southeast includes vast expanses of coastal and inland low-lying areas, the southern portion of the Appalachian Mountains, numerous high-growth metropolitan areas, and large rural expanses. These beaches and bayous, fields and forests, and cities and small towns are all at risk from a changing climate. While some climate change impacts, such as sea level rise and extreme downpours, are being acutely felt now, others, like increasing exposure to dangerous high temperatures, humidity, and new local diseases, are expected to become more significant in the coming decades. While all regional residents and communities are potentially at risk for some impacts, some communities or populations are at greater risk due to their locations, services available to them, and economic situations. Observed warming since the mid-20th century has been uneven in the Southeast region, with average daily minimum temperatures increasing three times faster than average daily maximum temperatures. The number of extreme rainfall events is increasing. Climate model simulations of future conditions project increases in both temperature and extreme precipitation. Trends towards a more urbanized and denser Southeast are expected to continue, creating new climate vulnerabilities. Cities across the Southeast are experiencing more and longer summer heat waves. Vector-borne diseases pose a greater risk in cities than in rural areas because of higher population densities and other human factors, and the major urban centers in the Southeast are already impacted by poor air quality during warmer months. Increasing precipitation and extreme weather events will likely impact roads, freight rail, and passenger rail, which will likely have cascading effects across the region. Infrastructure related to drinking water and wastewater treatment also has the potential to be compromised by climate-related events. Increases in extreme rainfall events and high tide coastal floods due to future climate change will impact the quality of life of permanent residents as well as tourists visiting the low-lying and coastal regions of the Southeast. Sea level rise is contributing to increased coastal flooding in the Southeast, and high tide flooding already poses daily risks to businesses, neighborhoods, infrastructure, transportation, and ecosystems in the region. There have been numerous instances of intense rainfall events that have had devastating impacts on inland communities in recent years. The ecological resources that people depend on for livelihoods, protection, and well-being are increasingly at risk from the impacts of climate change. Sea level rise will result in the rapid conversion of coastal, terrestrial, and freshwater ecosystems to tidal saline habitats. Reductions in the frequency and intensity of cold winter temperature extremes are already allowing tropical and subtropical species to move northward and replace more temperate species. Warmer winter temperatures are also expected to facilitate the northward movement of problematic invasive species, which could transform natural systems north of their current distribution. In the future, rising temperatures and increases in the duration and intensity of drought are expected to increase wildfire occurrence and also reduce the effectiveness of prescribed fire practices. Many in rural communities are maintaining connections to traditional livelihoods and relying on natural resources that are inherently vulnerable to climate changes. Climate trends and possible climate futures show patterns that are already impacting—and are projected to further impact—rural sectors, from agriculture and forestry to human health and labor productivity. Future temperature increases are projected to pose challenges to human health. Increases in temperatures, water stress , freeze-free days, drought, and wildfire risks, together with changing conditions for invasive species and the movement of diseases, create a number of potential risks for existing agricultural systems. Rural communities tend to be more vulnerable to these changes due to factors such as demography, occupations, earnings, literacy, and poverty incidence. In fact, a recent economic study using a higher scenario (RCP8.5) suggests that the southern and midwestern populations are likely to suffer the largest losses from future climate changes in the United States. Climate change tends to compound existing vulnerabilities and exacerbate existing inequities. Already poor regions, including those found in the Southeast, are expected to continue incurring greater losses than elsewhere in the United States.

Report↗

USGS2023

Toxicological effects assessment for wildlife in the 21st Century: Review of current methods and recommendations for a path forward

Model species (e.g., granivorous gamebirds, waterfowl, passerines, domesticated rodents) have been used for decades in guideline laboratory tests to generate survival, growth and reproductive data for prospective Ecological Risk Assessments (ERAs) for birds and mammals, while officially adopted risk assessment schemes for amphibians and reptiles do not exist. There are recognized shortcomings of current in vivo methods as well as uncertainty around the extent to which species with different life histories (e.g., terrestrial amphibians, reptiles, bats) than these commonly used models are protected by existing ERA frameworks. Approaches other than validating additional animal models for testing are being developed, but incorporation of such new approach methodologies (NAMs) into risk assessment frameworks will require robust validations against in vivo responses. This takes time, and the ability to extrapolate findings from non-animal studies to organism- and population-level effects in terrestrial wildlife remains weak. Failure to adequately anticipate and predict hazards could have economic and potentially even legal consequences for regulators and product registrants. In order to be able to use fewer animals or replace them altogether in the long-term, vertebrate use and whole organism data will be needed to provide data for NAMs validation in the short term. Therefore, it is worth investing resources for potential updates to existing standard test guidelines used in the laboratory as well as addressing the need for clear guidance on conduct of field studies. Herein we review the potential for improving standard in vivo test methods and for advancing the use of field studies in wildlife risk assessment, as these tools will be needed into the foreseeable future.

Integrated Environmental Assessment and Management↗

USGS1966

Contamination of the freshwater ecosystem by pesticides

A large part of our disquieting present-day pesticide problem is intimately tied to the freshwater ecosystem. Economic poisons are used in so many types of terrain to control so many kinds of organisms that almost all lakes and streams are likely to be contaminated. In addition to accidental contamination many pesticides are deliberately applied directly to fresh waters for suppression of aquatic animals or plants. The problem is intensified because of the extreme susceptibility of freshwater organisms. The complexity of freshwater environments and their variety makes it difficult to comprehend the total effect of pesticides.

Journal of Applied Ecology↗

USGS2019

Invasive plant species

Invasive species may be one of the worts environmental problems facing the conservation of natural areas, because of their role in changing ecosystem function. At the same time, invasive species cause much human suffering and economic loss. The approach to eliminating invasive species can be improved by a better understanding of the various types of invasive species, and the scientific hypotheses surrounding their ability to invade novel environments. Despite the billions of dollars spent each year, invasive species are difficult if not impossible to eliminate after they have established. Various methods of eliminating plant species from natural communities are described in this review. An increased understanding of the nature of invasive species including their genetic relationship to their progenitors, hypotheses regarding their invasive qualities, and effective approaches for their removal from ecosystems are all sorely needed. Volunteers can help in the invasive species effort by working on local plant/animal removal projects, reporting invasive species sightings to appropriate officials, or working with scientists to collect basic data for ecological research.

Book chapter↗

USGS1973

Review of wastewater problems and wastewater-management planning in the San Francisco Bay region, California

The San Francisco Bay region has suffered adverse environmental effects related to the discharge of municipal-, industrial-, and agricultural- wastewater and storm-water runoff. Specific pollutional properties of theses discharges are not well understood in all cases although the toxic materials and aquatic-plant nutrients (biostimulants) found in municipal and industrial waterwater are considered to be a major cause of regional water-quality problems. Other water-quality problems in the region are commonly attributed to pesticides found in agricultural wastewater and potentially pathogenic bacteria in municipal-wastewater discharges and in storm-water runoff. The geographical distribution and magnitude of wastewater discharges in the bay region, particularly those from municipalities and industries, is largely a function of population, economic growth, and urban development. As might be expected, the total volume of wastewater has increased in a trend paralleling this growth and development. More significant, perhaps, is the fact that the total volume parameters such as BOD (biochemical oxygen demand), biostimulant concentrations, and toxicity, has increased despite large expenditures on new and improved municipal- and industrial-wastewater-treatment plants. Also, pollutant loadings from other major source, such as agriculture and storm-water runoff, have increased. At the time of writing (1972), many Federal, State, regional, and local agencies are engaged in a comprehensive wastewater-management-planning effort for the entire bay region. Initial objectives of this planning effort are: (1) the consolidation and coordination of loosely integrated wastewater-management facilities and (2) the elimination of wastewater discharges to ecologically sensitive areas, such as fresh-water streams and shallow extremities of San Francisco Bay. There has been some investigation of potential long-range wastewater-management alternatives based upon disposal in deep water in the bay, in the Pacific Ocean, or on land. Also, wastewater-reclamation and water-reuse concepts seem to be growing in favor with the public and should become and important part of future wastewater-management plans. Because most wastewater-reclamation and water-reuse systems would involve the use of land (that is agricultural irrigation, ground-water recharge, recreational reservoirs) local and regional lang-use planners can ass much to wastewater-management planning by identifying local and subregional waterwater-reclamation and water-reuse possibilities within their jurisdictions and integrating them with future land-use plans. The timely participation of planner is essential because Federal and State planning and funding deadlines for a regional wastewater-management system become effective in July 1973 and 1974, respectively.

California↗

USGS2025

Density dependence and weather drive dabbling duck spatiotemporal distributions and intercontinental migration

Understanding migratory waterfowl spatiotemporal distributions is important because, in addition to their economic and cultural value, wild waterfowl can be infectious reservoirs of highly pathogenic avian influenza virus (HPAIV). Waterfowl migration has been implicated in regional and intercontinental HPAIV dispersal, and predictive capabilities of where and when HPAIV may be introduced to susceptible spillover hosts would facilitate biosecurity and mitigation efforts. To develop forecasts for HPAIV dispersal, an improved understanding of how individual birds interact with their environment and move on a landscape scale is required. Using an agent-based modeling approach, we integrated individual-scale energetics, species-specific morphology and behavior, and landscape-scale weather and habitat data in a mechanistic stochastic framework to simulate Mallard ( Anas platyrhynchos ) and Northern Pintail ( Anas acuta ) annual migration across the Northern Hemisphere. Our model recreated biologically realistic migratory patterns using a first principles approach to waterfowl ecology, behavior, and physiology. Conducting a limited structural sensitivity analysis comparing reduced models to eBird Status and Trends in reference to the full model, we identified density dependence as the main factor influencing spring migration and breeding distributions, and wind as the main factor influencing fall migration and overwintering distributions. We show evidence of weather patterns in Northeast Asia causing significant intercontinental pintail migration to North America. By linking individual energetics to landscape-scale processes, we identify key drivers of waterfowl migration while developing a predictive model responsive to daily weather patterns. This model paves the way for future waterfowl migration research predicting HPAIV transmission, climate change impacts, and oil spill effects.

Avian Research↗

USGS2018

Biology and impacts of Pacific Islands invasive species. 14. Sus scrofa the feral pig (Artiodactyla: Suidae)

Feral pigs ( Sus scrofa L.) are perhaps the most abundant, widespread, and economically significant large introduced vertebrate across the Pacific island region. Unlike many other nonnative invasive species, feral pigs have both cultural and recreational importance in the region, complicating their management. Today, Pacific island feral pigs are a mixture of several strains of domestic swine, Asiatic wild boar, and European wild boar. Due to their generalist diet and rooting behavior, feral pigs alter soils and watersheds and negatively impact native and nonnative flora and fauna. As a result, feral pigs have played a role in the extinction of several species of plants and animals on Pacific islands and have negative effects on both ecotourism and agricultural industries in the region. Despite numerous published studies on feral pigs in the Pacific island region, of which the majority include systematic analyses of original empirical data, some fundamental aspects of feral pig ecology remain poorly characterized, at least partly due to the remote and inaccessible environments that they often inhabit. To address these knowledge gaps, effort should be made to integrate research conducted outside the Pacific island region into local management strategies. This review summarizes the origins, history, ecology, environmental effects, and current management of feral pigs in the Pacific island region; integrates regional scientific findings with those of other insular and continental systems; and identifies current knowledge gaps requiring further research to inform the ecology and management of this impactful invasive species.

Hawai'i↗

USGS2024

Potential use of poultry farms by wild waterfowl in California's Central Valley varies across space, times of day, and species: implications for influenza transmission risk

Interactions between wildlife and livestock can lead to cross-species disease transmission, which incurs economic costs and threatens wildlife conservation. Wild waterfowl are natural hosts of avian influenza viruses (AIVs), are often abundant near poultry farms, and have been linked to outbreaks of AIVs in poultry. Interspecific and seasonal variation in waterfowl movement and habitat use means that the risk of disease transmission between wild birds and poultry inevitably varies across species, space, and time. Here, we used GPS telemetry data from 10 waterfowl species in and near California's Central Valley, a region where both wild waterfowl and domestic poultry are abundant, to study selection of poultry farms by waterfowl across diel, seasonal, and annual cycles. We found that waterfowl selected for wetlands, open water, protected areas, and croplands, which meant that they generally avoided habitats that were likely to be used for poultry farming. These selection patterns were linked to species' ecology and diel behavioral patterns, such that avoidance of poultry habitats was stronger for local or partial migrants than for long-distance migrants, and stronger during daytime than at night. We then combined these habitat selection results with data on poultry farm locations to map risk of waterfowl–poultry contact across the Central Valley. Average selection strength at poultry farms was low, suggesting that current placement of poultry farms is generally effective for limiting risk of contact with wild birds. When we combined these habitat selection results with data on species' abundances and AIV infection prevalence, we found dramatic variation in potential AIV transmission risk among species. These results could be used to prioritize surveillance and biosecurity efforts for regions and times of relatively high risk. More generally, these results highlight that fine-scale movement data can help identify interspecific, seasonal, and diel patterns in animal behaviors that affect wildlife and poultry health.

California↗

USGS2023

California State waters map series—Benthic habitat characterization in the region offshore of Morro Bay, California

Coastal and Marine Ecological Classification Standard geoform, substrate, and biotic component geographic information system products were developed for the California State waters of south-central California in the region offshore of Morro Bay. The study was motivated by interest in development of offshore wind-energy capacity and infrastructure in Federal waters offshore. The Bureau of Ocean Energy Management, in coordination with the State of California and many other members of the California Intergovernmental Renewable Energy Task Force, issued calls for information in 2018 for the study area offshore of Morro Bay, California. The study area is adjacent to a nuclear power plant (currently scheduled for decommissioning) with a developed electric grid connection, and in an area of high wind resource potential. The Bureau of Ocean Energy Management is the lead agency responsible for planning and leasing in the U.S. Exclusive Economic Zone and funded this project to assess baseline conditions of, and the potential effects on, the seafloor environment. This project, carried out by the U.S. Geological Survey, resulted in three data releases for individual map blocks that are part of the California State Waters Map Series: (1) Offshore of Point Estero, (2) Offshore of Morro Bay, and (3) Offshore of Point Buchon. The study area consists of 341 square kilometers (km 2 ) of multibeam echo sounder (MBES) data acquired by Fugro, Inc., in 2010. Towed camera-sled video was acquired in 2012 to supervise the classification of the MBES data into habitats. There were 935 annotations of organisms and habitat made from 22 video transects. Using video observations of habitat as ground truth, derivatives of the MBES data were classified into 3 seafloor character types (hard-rugged, hard-flat, and soft-flat), 25 modifier groups, and 9 geoforms. The study area substrate is predominantly soft-flat sediment (mud and fine sand) covering 191.3 km 2 (56.1 percent) of the area. Hard-flat substrate areas, predominantly coarse sediment in scour depressions, cover 52.2 km 2 (15.3 percent) of the study area. The hard-rugged substrate areas are primarily outcrops of layered sedimentary bedrock and constitute 97.5 km 2 of the study area (28.6 percent). After classification of bathymetry and backscatter raster images according to substrate, false-positive hard areas produced by noise artifacts were removed by manual editing. Nine geoforms were then identified in the analysis. The predominant geoforms mirror the seafloor character results, shelf geoforms (flat areas covered in soft sediment), rock outcrop geoforms (hard, rugged areas), and scour depression geoforms (flat areas covered in coarse sediment formed by bottom currents).

California↗

USGS2012

Spatially explicit land-use and land-cover scenarios for the Great Plains of the United States

The Great Plains of the United States has undergone extensive land-use and land-cover change in the past 150 years, with much of the once vast native grasslands and wetlands converted to agricultural crops, and much of the unbroken prairie now heavily grazed. Future land-use change in the region could have dramatic impacts on ecological resources and processes. A scenario-based modeling framework is needed to support the analysis of potential land-use change in an uncertain future, and to mitigate potentially negative future impacts on ecosystem processes. We developed a scenario-based modeling framework to analyze potential future land-use change in the Great Plains. A unique scenario construction process, using an integrated modeling framework, historical data, workshops, and expert knowledge, was used to develop quantitative demand for future land-use change for four IPCC scenarios at the ecoregion level. The FORE-SCE model ingested the scenario information and produced spatially explicit land-use maps for the region at relatively fine spatial and thematic resolutions. Spatial modeling of the four scenarios provided spatial patterns of land-use change consistent with underlying assumptions and processes associated with each scenario. Economically oriented scenarios were characterized by significant loss of natural land covers and expansion of agricultural and urban land uses. Environmentally oriented scenarios experienced modest declines in natural land covers to slight increases. Model results were assessed for quantity and allocation disagreement between each scenario pair. In conjunction with the U.S. Geological Survey's Biological Carbon Sequestration project, the scenario-based modeling framework used for the Great Plains is now being applied to the entire United States.

Great Plains↗

USGS2015

Effects of Hydrocarbon Extraction on Landscapes of the Appalachian Basin

An important and sometimes overlooked aspect of contemporary natural gas exploration, development, and delivery activities is the geographic profile and spatial footprint that these activities have on the land surface. The function of many ecosystems and the goods and services they provide, in large part, are the result of their natural spatial arrangement on the landscape. Shale-gas development can create alterations to the pattern of land use and land cover, and represents a specific form of land use and land cover change that can substantially impact critical aspects of the spatial pattern, form, and function of landscape interactions, including many biological responses. The need for energy resources has created numerous economic opportunities for hydrocarbon extraction in the Appalachian basin. The development of alternative energy natural gas resources from deep-shale drilling techniques, along with conventional natural gas extraction methods, has created a flurry of wells, roads, pipelines, and related infrastructure across many parts of the region. An unintended and sometimes overlooked consequence of these activities is their effect on the structure and function of the landscape and ecosystems. The collective effect of over 100,000 hydrocarbon extraction permits for oil, coal bed methane, Marcellus and Utica Shale natural gas wells, and other types of hydrocarbon gases and their associated infrastructure has saturated much of the landscape and disturbed the natural environment in the Appalachian basin. The disturbance created by the sheer magnitude of the development of these collective wells and infrastructure directly affects how the landscape and ecosystems function and how they provide ecological goods and services.

New York, Ohio, Pennsylvania, Virginia, West Virgi↗

USGS2003

Surveillance strategies for detecting Chronic Wasting Disease in free-ranging deer and elk: Results of a CWD surveillance workshop

Executive Summary Chronic Wasting Disease (CWD), a fatal brain disease of North American deer and elk, has recently emerged as an important wildlife management issue. Interest and concern over the spread of this disease and its potential impact on free-ranging cervid populations has increased with discovery of the disease in numerous states and provinces. Current studies suggest that CWD may adversely affect of these highly visible, socially desirable, and economically valuable species. Despite the lack of evidence that CWD affects humans or livestock, a significant concern has been the perceived risk to humans and livestock. Uncertainty about whether CWD poses a health risk to hunters and their families who consume venison has resulted in testing of free-ranging cervids for CWD. In response to many of these concerns, wildlife management agencies across the nation have undertaken surveillance programs to detect CWD in their cervid populations. The nation-wide costs for an extensive CWD surveillance program have been estimated at several million dollars. This document provides guidance on the development and conduct of scientifically sound surveillance programs to detect CWD in free-ranging deer and elk populations. These guidelines will not apply equally to all jurisdictions. In many cases local circumstances, resources, area(s) of concern, disease risk, animal and landscape ecology, political, social, and many other factors will influence the objectives, design, and conduct of CWD surveillance programs. Part I of this report discusses the importance of management goals, strategies, and disease risks in developing a surveillance program. Part II describes surveillance methods, steps in designing a sampling strategy to detect CWD, alternative collection methods, and statistical considerations. Part III describes costs (personnel, time, and money) associated with implementation of these plans that will influence program design. Part IV outlines research that is needed to further development of CWD surveillance methods. Unfortunately in dealing with CWD, many important biological facts are still unknown and further research will be required to answer these questions. In most situations surveillance strategies suggested may require several years to complete, will require careful consideration of management objectives, and extensive operational planning in order to be meaningful and to be scientifically based.

Book↗

USGS2021

Multi‐constrained catchment scale optimization of groundwater abstraction using linear programming

Due to increasing water demands globally, freshwater ecosystems are under constant pressure. Groundwater resources, as the main source of accessible freshwater, are crucially important for irrigation worldwide. Over‐abstraction of groundwater leads to declines in groundwater levels; consequently, the groundwater inflow to streams decreases. The reduction in base flow and alteration of the stream flow regime can potentially have an adverse impact on groundwater‐dependent ecosystems. A spatially distributed, coupled groundwater‐surface water model can simulate the impacts of groundwater abstraction on aquatic ecosystems. A constrained optimization algorithm and a simulation model in combination can provide an objective tool for the water practitioner to evaluate the interplay between economic benefits of groundwater abstractions and requirements to environmental flow. In this study, a holistic catchment‐scale groundwater abstraction optimization framework has been developed that allows for a spatially explicit optimization of groundwater abstraction, while fulfilling a pre‐defined maximum allowed reduction of stream flow (base flow (Q95) or median flow (Q50)) as constraint criteria for 1484 stream locations across the catchment. A balanced K‐Means clustering method was implemented to reduce the computational burden of the optimization. The model parameters and observation uncertainties calculated based on Bayesian linear theory allow for a risk assessment on the optimized groundwater abstraction values. The results from different optimization scenarios indicated that using the linear programming optimization algorithm in conjunction with integrated models provides valuable information for guiding the water practitioners in designing an effective groundwater abstraction plan with the consideration of environmental flow criteria important for the ecological status of the entire system.

Groundwater↗

USGS2001

Cruise Report; RV Moana Wave cruise M1-01-GM; the bathymetry and acoustic backscatter of the mid shelf to upper slope off Panama City, Florida, northeastern Gulf of Mexico; September 3, through October 12, 2001, Panama City, FL to Panama City, FL

A zone of deep-water reefs is thought to extend from the mid and outer shelf south of Mississippi and Alabama to at least the northwestern Florida shelf off Panama City, Florida (Figure 1, 67kb). The reefs off Mississippi and Alabama are found in water depths of 60 to 120 m (Ludwick and Walton, 1957; Gardner et al., in press) and were the focus of a multibeam echosounder (MBES) mapping survey by the U.S. Geological Survey (USGS) in 2000 (Gardner et al., 2000; in press). If this deep-water-reef trend does exist along the northwestern Florida shelf, then it is critical to determine the accurate geomorphology and type of the reefs that occur because of their importance as benthic habitats for fisheries. Precisely georeferenced high-resolution mapping of bathymetry is a fundamental first step in the study of areas suspected to be critical habitats. Morphology is thought to be critical to defining the distribution of dominant demersal plankton/planktivores communities. Fish faunas of shallow hermatypic reefs have been well studied, but those of deep ahermatypic reefs have been relatively ignored. The ecology of deep-water ahermatypic reefs is fundamentally different from hermatypic reefs because autochthonous intracellular symbiotic zooxanthellae (the carbon source for hermatypic corals) do not form the base of the trophic web in ahermatypic reefs. Instead, exogenous plankton, transported to the reef by currents, serves as the primary carbon source. Thus, one of the principle uses of the morphology data will be to identify whether any reefs found are hermatypic or ahermatypic in origin. Community structure and trophodynamics of demersal fishes of the outer continental of the northeastern Gulf of Mexico presently are the focus of a major USGS reseach project. A goal of the project is to answer questions concerning the relative roles played by morphology and surficial geology in controling biological differentiation. Deep-water reefs are important because they are fish havens, key spawning sites, and are critical early larval and juvenile habitats for economically important sport/food fishes. It is known that deep-water reefs function as a key source for re-population (via seasonal and ontogenetic migration) of heavily impacted inshore reefs. The deep-water reefs south of Mississippi and Alabama support a lush fauna of ahermatypic hard corals, soft corals, black corals, sessile crinoids and sponges, that together form a living habitat for a well-developed fish fauna. The fish fauna comprises typical Caribbean reef fishes and Carolinian shelf fishes, plus epipelagic fishes, and a few deep-sea fishes. The base of the megafaunal invertebrate food web is plankton, borne by essentially continuous semi-laminar currents generated by eddies, spawned off the Loop Current, that periodically travel across the shelf edge. A few, sidescan-sonar surveys have been made of areas locally identified as Destin Pinnacles, Steamboat Lumps Marine Reserve (Koenig et al., 2000; Scanlon, et al., 2000; 2001), Twin Ridges (Briere, et al., 2000; Scanlon, et al., 2000), and Madison-Swanson Marine Reserve (Koenig et al., 2000; Scanlon, et al., 2000; 2001). However, no quantitative and little qualitative information about the geomorphology and surficial geology can be gained from these data. Existing bathymetry along the northwestern Florida shelf suggests the existence of areas of possible isolated deep-water reefs. NOAA bathymetric maps NOS NH16-9 and NG16-12 show geomorphic expressions that hint of the presence of reefs in isolated areas rather than in a continuous zone. There has been no systematic, high-resolution bathymetry collected in this area, prior to this cruise. After the successful mapping of the deep-water reefs on the Mississippi and Alabama shelf (Gardner et al., 2000; in press), a partnership composed of the USGS, Minerals Management Service, and NOAA was formed to continue the deep-reef mapping to the northwest Florida mid shelf and upper slope. This cruise is the first fruit of that partnership.

Florida↗

USGS2000

Cruise report RV Ocean Surveyor cruise O-1-00-GM the bathymetry and acoustic backscatter of the Pinnacles area, northern Gulf of Mexico May 23, through June 10, 2000 Venice, LA to Venice, LA

An extensive deep (~100 m) reef tract occurs on the Mississippi-Alabama outer continental shelf (OCS). The tract, known as "The Pinnacles", is apparently part of a sequence of drowned reef complexes along the "40-fathom" shelf edge of the northern Gulf of Mexico (Ludwick and Walton, 1957). It is critical to determine the accurate geomorphology of deep-reefs because of their importance as benthic habitats for fisheries. The Pinnacles were mapped by Ludwick and Walton (1957) using a single-beam echo sounder but the spatial extent and morphology were interpreted from a series of widely separated, poorly navigated bathymetric profiles. Other recent studies, supported by Minerals Management Service (MMS), used towed sidescan sonars and single-channel seismic-reflection profiling. None of the existing studies provide the quality of geomorphic data necessary for reasonable habitat studies. The fish faunas of shallow hermatypic reefs have been well studied, but those of deep ahermatypic reefs have relatively ignored. The ecology of deep ahermatypic reefs is fundamentally different from hermatipic reefs because autochthonous intracellular symbiotic zooxanthellae (the carbon source for hermatypic corals) do not form the base of the trophic web. Instead, exogenous plankton, transported to the reef by currents, serves as the primary carbon source. Deep OCS reefs also lie below the practical working depths for SCUBA; consequently, remote investigations from a ship or in situ investigations using submersibles or ROVs are required. Community structure and trophodynamics of demersal fishes of the Pinnacles are presently the focus of USGS reseach. A goal of the research is to answer questions concerning the relataive roles played by geomorphology and surficial geology in the interaction with and control of biological differentiation. OCS reefs are important because we now know that such areas are important coral reef fish havens, key spawning 2 sites, and a critical early larval and juvenile habitats for economically important sport/food fishes. Also, deep-reef ecosystems as well as the fish populations they sustain are impacted by intensive oil-field development. It is now known that deep OCS reefs function as a key source of re-population (via seasonal and ontogenetic migration) of already heavily impacted inshore reefs. A reflection of this realization is the recent closure by the Gulf States Fisheries Management Council of a 600 mi 2 area of the Florida Middle Grounds (another unmapped major "40-fathom" OCS reef complex) to commercial fishing to preserve grouper spawning aggregations. It is known that the Pinnacles reefs support a lush fauna of ahermatypic hard corals, soft corals, black corals, sessile crinoids and sponges—together forming a living habitat for a well-developed fish fauna. The fish fauna comprises typical Caribbean reef fishes and Carolinian shelf fishes, plus epipelagic fishes, and a few deep-sea fishes. The base of the megafaunal invertebrate food web is plankton, borne by essentially continuous semi-laminar currents flowing predominantly out of the SW, up, along and across the shelf edge. These currents are intercepted by pinnacles reefs, which lie roughly in two linear tracts, parallel to the coastline (see fig. 1 in report). USGS research initiated in 1997 (Sulak et al., in progress) has demonstrated that the Pinnacles reef fish fauna is dominated by planktivorous fishes. Ongoing food habits, trophic web and stable isotope analyses by the USGS are reinforcing a basic picture of deep OCS reefs as ecosystems based on exogenous current-borne plankton. Long-term current meter deployments have demonstrated that the >3 m, <16m relief of the Pinnacles reefs disrupts the prevailing currents, inducing local complexity (F. Kelly, Texas A&M Univ., pers. comm.) favorable to plankton and planktivores. Geodetically accurate bathymetry maps, coregistered with calibrated acoustic backscatter maps, are critical to delineate benthic biotopes, and are essential to correlate biological community differentiation with the physical environment. Previous mapping of the Pinnacles area using the TAMU towed single-beam sidescan system (Anonymous., 1999) employed technology with inherent deficiencies in backscatter calibration, bathymetric precision, and geo-referencing. The resulting bathymetric interpretations of TAMU data are further degraded by ship-track-parallel artifacts that obliterate geomorphology rendering them inadequate to provide high-resolution mapping of individual target reefs (typical maximum relief 15 m, diameter 200-500 m). The sidescan-sonar surveys of the area (Laswell et al., 1990) suffer many of the same deficiencies as the TAMU data so they add no quantitative and little qualitative information about the geomorphology and surficial geology.

Gulf of Mexico, the Pinnacles area↗

USGS2004

Chapter 11 The phosphoria formation: A model for forecasting global selenium sources to the environment

Mining of the Permian Phosphoria Formation — a marine, oil-generating, phosphatic shale — provided the selenium (Se) source implicated in the recent deaths of livestock in southeast Idaho. Field studies and the geohydrologic balance of Se in southeast Idaho confirm risk to animals from exposure to Se through leaching of mined waste shale into streams, discharge of regional drainage, and impoundment of drainage in wetland areas. Forage grown to stabilize waste rock contoured into hills or used as cross-valley fill provides an additional mechanism of Se exposure for the environment (Mackowiak et al., Chapter 19). The average Se concentration of the Meade Peak Member of the Phosphoria Formation is an order of magnitude higher than those of other exploited marine shales that have been linked to incidences of Se toxicosis via oil refining and irrigation in the western United States. The Phosphoria Formation accumulated in an environment that preserved organic matter and contributed to the formation of economic-grade phosphate and oil deposits. The addition of this phosphate-mining case study enables a comprehensive approach to the identification of marine sedimentary Se sources and a more complete range of ecotoxic field studies on which to establish the conditions and anthropogenic connections that determine uptake, release, and recycling of Se in food webs. A constructed conceptual model of Se pollution indicates that ancient organic-rich depositional marine basins, unre- stricted by age, are linked to the contemporary global distribution of Se source rocks. A global plot shows (a) the areal association of major basins hosting phosphate deposits and petroleum source rocks and (b) the importance of paleo-latitudinal setting in influencing the composition of the deposits. Given the geographic patterns, Se emerges as a contami- nant within specific regions of the globe that may limit phosphate mining, oil refining, and drainage of agricultural lands because of potential ecological risks to vulnerable food webs. Selenium also may serve as a geochemical exploration tool that signals an ancient productive biological environment.

Handbook of Exploration and Environmental Geochemi↗