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Vision for a worldwide fluvial-sediment information network

The nations of the world suffer both from the deleterious effects of some natural and human-altered fluxes of fluvial sediment and a lack of consistent and reliable information on the temporal and spatial occurrence of fluvial sediments. Decades ago, this difficulty was unavoidable due to a lack of understanding of the magnitude and scope of environmental influences exerted by fluvial sediment coupled with a dearth of tools for monitoring and studying the data. Such is no longer the case. Fluvial sediment has a broad influence on the environment and humanity. Data needs that were once limited primarily to reservoir and channel maintenance now include issues associated with public water supply; contaminated sediment management; productivity of agricultural lands; stream restoration and watershed health; in-stream biotic stability; post-wildfire channel morphology; dam decommissioning, rehabilitation, or removal; and legal requirements for sediment management (Gray and Glysson, 2005). The adverse effects of poorly managed or unmanaged sediment movement related to these and other issues are well-known qualitatively, and in some cases quantitatively. For example, physical, chemical, and biological damages attributable to fluvial sediment in North America alone are now estimated to range between $20 billion and $50 billion annually (Pimental and others, 1995; Osterkamp and others, 1998; 2004). Capabilities for monitoring, analyzing, storing, and sharing fluvial-sediment data have been developed and, in many cases, are sufficiently mature for consideration for global utilization. Hence, there is not only a strong and expanding need for a global effort to gauge and understand fluvial-sediment characteristics and processes better, but the knowledge and tools to achieve these ends are largely available and ready for their applicability to be evaluated. Given the increasing importance of erosion and sediment processes for water-resources management, an International Sedimentation Initiative (ISI, 2007a), under the United Nations Educational, Scientific, and Cultural Organization’s International Hydrologic Programme (IHP, 2007) was adopted in 2004. The ISI, the focus of which is on sustainable water-resources management on the global scale, features six major activities and projects, which are listed as part of the section entitled, “Relation of the WoFSIN concept to the thrusts of the International Sedimentation Initiative,” that precedes the “Conclusions” section of this paper. Based on the need for more, and more consistent and reliable fluvial-sediment information and on the existence of the ISI and other international and national sediment programs, we envision the need for a Worldwide Fluvial Sediment-Information Network (WoFSIN) with a focus on data acquisition, storage, and dissemination globally. Envisioned components of a WoFSIN, administered largely via the Internet and relying mostly on the benefits derived from existing resources and programs, follow that summary. The goal of the WoFSIN is to maximize the availability and usefulness of the world’s historical and current fluvial-sediment and ancillary data through collaboration with existing programs so as to require few additional resources in the long-term. Thus, the WoFSIN concept was developed recognizing that informed resource management is predicated on the availability of adequate and reliable information. The WoFSIN is described in the ensuing sections in stand-alone fashion, followed by a section that describes the complementary aspects of the WoFSIN and the International Sediment Initiative. Thus, our first objective is to describe the fundamental components of a WoFSIN. Our second objective is to identify overlap or gaps between the WoFSIN and ISI concepts that might be useful in refining the ISI’s ability to meet its global mission to develop decision support for sediment management at the global scale more fully, cost-effectively, and (or) with enhanced quality.

Conference Paper↗

Geochemical Survey of Missouri: Plans and progress for second six-month period (January-June 1970)

This is the second six-month progress report on studies in environmental geochemistry in the State of Missouri initiated on behalf of the Environmental Health Surveillance Project in July, 1969. The studies are being made in support of epidemiological investigations of the Surveillance Project to provide general information pertaining to the occurrence and distribution of chemical elements in rocks, soils, plants, and water throughout the State. Emphasis is placed on the occurrence and distribution of elements in the natural environment, though studies of the effects of some types of chemical pollution are necessarily included. The objectives and plans for the three phases of the Survey that are directed at the rocks, soils, and vegetation are described in the progress report for the first six-month period; those for the phase of the project concerned with the water are described by Gerald L. Feder in a later section of the present report. The addition of this latter phase significantly expands the scope of our study and increases its relevance to studies of human and animal health. Mr. Feder has a valuable background in the geology and hydrology of Missouri, and we are most pleased that he has joined us in this effort.

Missouri↗

When synthetic chemicals degrade in the environment: What are the absolute fate, effects, and potential risks to humans and the ecosystem?

Various processes degrade synthetic chemicals—pesticides, pharmaceuticals, biocides, and industrials—in the environment ( 1 , 2 ). Consequently, the environment may be exposed to a mixture of the parent compounds and any resulting degradation products (degradates). Recent advances in analytical methodology and greater access to analytical standards have advanced degradates research ( 3 , 4 ). Specifically, research on pesticides has found degradates in surface water ( 5 – 10 ), groundwater ( 11 – 13 ), precipitation ( 14 – 16 ), air ( 17 , 18 ), and sediment ( 19 , 20 ). Pharmaceuticals and detergent degradates also exist in the environment ( 21 – 23 ). Figure 1 shows that degradates were detected as often as or more frequently than the parent compound. Although some regulatory schemes require information about the impacts of degradates on human and environmental health, that information does not exist for many compounds ( 25 , 26 ). Pesticides are the exception. In this article, we bring together the available data to address the environmental behavior of degradates and their effects on organisms and discuss how to identify substances of potential concern. In addition, we cite gaps in the current knowledge and make recommendations for future research requirements. While the article focuses on pesticides, we believe these observations can be extended to biologically active compounds and some industrial substances.

Environmental Science & Technology↗

PCB concentrations in Pere Marquette River and Muskegon River watersheds, 2002

Polychlorinated biphenyl compounds (PCBs) are a class of209 individual compounds (known as congeners) for which there are no known natural sources. PCBs are carcinogenic and bioaccumulative compounds. For over 40 years, PCBs were manufactured in the United States. The flame resistant property of PCBs made them ideal chemicals for use as flame-retardants, and as coolants and lubricants in transformers and other electrical equipment. PCBs were also used in heating coils, carbonless paper, degreasers, varnishes, lacquers, waterproofing material, and cereal boxes. In addition, they were frequently used in the manufacturing of plastics, adhesives, and paints. During the manufacturing period of PCBs, these chemicals entered the environment though atmospheric release during manufacturing and burning of PCB products, leaks and spills, and improper disposal. Although PCB manufacturing was banned over 20 years ago, PCBs still enter the environment from hazardous waste sites, improper disposals of PCB-containing products, weathering of asphalt and other substances containing PCBs, burning of PCB containing products, leakage from old equipment, leaching from landfills, and release from contaminated sediments. PCBs do not readily break down in the environment, thus remain there for long periods of time. A small amount may remain dissolved in water but most adhere to organic particles and bottom sediments. In sufficient concentrations, PCBs affect human, wildlife, and aquatic health. PCBs accumulate in fatty tissues of animals and fish and are passed on to those that eat them. PCBs are animal teratogens and potentially carcinogenic. They can cause death of animals, fish, and birds; death or low growth rate of plants; shortened lifespan; reproductive problems; and lower fertility. Women who are exposed to high levels of PCBs may have babies with slightly lower birth weights and transfer the PCBs through the breast milk, which may affect the immune system and motor development of the child. Rule 323.1057 (Toxic Substances) of the Part 4. Water Quality Standards gives procedure for calculating water-quality values to protect human, wildlife and aquatic life. For total PCB, the applicable Rule 57 water-quality value is the human cancer value (HCV=0.26 ng/L), In 2002, U. S. Geological Survey (USGS) and Michigan Department of Environmental Quality (MDEQ) cooperatively planned and executed a monitoring program for PCBs in water and sediment from the Pere Marquette River and Muskegon River watersheds. The Pere Marquette and Muskegon River are in the west central part of Michigan's Lower Peninsula (fig. 1). The Pere Marquette River watershed is about 750 square miles, and the Muskegon River is about 2700 square miles. Both rivers are popular recreational waters, and the Pere Marquette River is a Michigan designated Natural River (Part 305 of the Natural Rivers and Environmental Protection Act 451 of 1994).

Michigan↗

Prevalence of pelagic diatoms and harmful algae in tellinid bivalve diets during record low sea ice in the Pacific Arctic determined by DNA metabarcoding

Understanding changes at the base of the marine food web in the rapidly transforming Arctic is essential for predicting and evaluating ecosystem dynamics. The northern Bering Sea experienced record low sea ice in 2018, followed by the second lowest in 2019, highlighting the urgency of the issue for this region. In this study, we investigated the diet of the clam Macoma calcarea in the Pacific Arctic using DNA metabarcoding, employing 18S and rbcL markers to identify dietary components. Our findings revealed a strong dependence on pelagic diatoms, particularly Chaetoceros sp., with a near absence of ice algae in the clam diet. This pattern reflects the lack of lipid-rich ice algal production during these low sea ice events. Additionally, our analysis detected algae capable of producing harmful toxins, notably Alexandrium dinoflagellates, in the clam diet, underscoring the need for increased monitoring due to potential ecosystem and human health risks. This study demonstrates the utility of DNA metabarcoding in unraveling the complex dynamics of Arctic marine food webs and pelagic-benthic coupling, providing a glimpse of future conditions in a rapidly changing environment.

Bering Sea, Chukchi Sea↗

Anthropogenic organic compounds in source water of select community water systems in the United States, 2002-10

Drinking water delivered by community water systems (CWSs) comes from one or both of two sources: surface water and groundwater. Source water is raw, untreated water used by CWSs and is usually treated before distribution to consumers. Beginning in 2002, the U.S. Geological Survey’s (USGS) National Water-Quality Assessment Program initiated Source Water-Quality Assessments (SWQAs) at select CWSs across the United States, primarily to characterize the occurrence of a large number of anthropogenic organic compounds that are predominantly unregulated by the U.S. Environmental Protection Agency. Source-water samples from CWSs were collected during 2002–10 from 20 surface-water sites (river intakes) and during 2002–09 from 448 groundwater sites (supply wells). River intakes were sampled approximately 16 times during a 1-year sampling period, and supply wells were sampled once. Samples were monitored for 265 anthropogenic organic compounds. An additional 3 herbicides and 16 herbicide degradates were monitored in samples collected from 8 river intakes and 118 supply wells in areas where these compounds likely have been used. Thirty-seven compounds have an established U.S. Environmental Protection Agency (EPA) Maximum Contaminant Level (MCL) for drinking water, 123 have USGS Health-Based Screening Levels (HBSLs), and 29 are included on the EPA Contaminant Candidate List 3. All compounds detected in source water were evaluated both with and without an assessment level and were grouped into 13 categories (hereafter termed as “use groups”) based on their primary use or source. The CWS sites were characterized in a national context using an extract of the EPA Safe Drinking Water Information System to develop spatially derived and system-specific ancillary data. Community water system information is contained in the EPA Public Supply Database, which includes 2,016 active river intakes and 112,099 active supply wells. Ancillary variables including population served, watershed size, land use, population density, and recharge were characterized for each of the watersheds for river intakes and contributing areas for supply wells. A total of 313 samples were collected from 20 river intakes. Between the years of 2002 through 2010, samples were collected approximately 16 times over the course of a year. Seventy-one compounds from 12 of the 13 use groups commonly occurred (detected in greater than or equal to 1 percent of samples using an assessment level of 0.05 microgram per liter or when a compound was detected in greater than or equal to 10 percent of samples without an assessment level) indicating a wide variety of sources and pathways to these rivers and highlighting the importance of source-water protection strategies. A total of 448 supply wells were sampled once during 2002–10 as part of 30 independent groundwater studies. About 15 CWS supply wells were sampled for each independent groundwater study. Twenty-eight compounds from 7 of the 13 use groups commonly occurred indicating a wide variety of sources and pathways exist for these compounds to reach these wells and highlighting the importance of wellhead protection strategies. About one-half the 265 compounds monitored (122) were detected in both surface water and groundwater samples. A more diverse suite of compounds were detected in surface water in comparison to groundwater. However, herbicides and herbicide degradates were the most frequent group of compounds detected in both surface water and groundwater. Sixty-five of the most commonly occurring compounds were detected in one or more samples from both surface water and groundwater. Human-health benchmarks (MCLs for regulated compounds and HBSLs for unregulated compounds) were available for more than one-half the compounds (160 of the 265) monitored in this study. Fifty-eight percent (41 of 71) of the commonly occurring compounds in surface water have a human-health benchmark to which concentrations can be compared; 19 have MCLs and 22 have HBSLs. Eighty-three percent (24 of 28) of the most commonly occurring compounds in groundwater have a human-health benchmark for which concentrations can be compared; 14 have MCLs and 10 have HBSLs. To put results from this study into context with the national distribution of river intakes and supply wells used by CWSs, sites were grouped into the respective national population of land-use quartiles. The increase in compound occurrence with increasing urban and agricultural land use in the watershed or contributing area was more evident for rivers than for supply wells. The increase in detection frequency of herbicides and herbicide degradates with increasing agricultural land use was more evident for rivers than for supply wells. The occurrence of solvents did not change substantially with increasing urban land use for rivers or supply wells. Basic co-occurrence analyses were completed with and without an assessment level. Considering all detections in surface water without an assessment level, approximately 86 percent of source-water samples contained 2 or more compounds, and 50 percent of samples contained at least 14 compounds. Considering all detections in groundwater without an assessment level, 50 percent of samples contained at least three compounds. For the most part, the compounds detected most frequently as individual compounds in the environment often composed the most frequent unique mixtures. Five of the 10 most frequently co-occurring unique mixtures in both surface water and groundwater were the same: atrazine and deethylatrazine; atrazine and chloroform; deethylatrazine and simazine; atrazine and simazine; and deethylatrazine, atrazine, and simazine. Because similar mixtures were identified in both surface water and groundwater without an assessment level, future studies could be directed toward better understanding the toxicological importance of these unique mixtures. Summed concentrations of herbicide degradates were compared to concentrations of the parent herbicides in surface-water and groundwater samples collected from 8 river intakes and 118 CWS wells, from which samples were analyzed for an additional 3 herbicides and 16 degradates. The toxicity to humans for many of these degradate products is largely unknown and thus points to the importance of monitoring these compounds (both the parent and degradate) in the environment. This study highlights the importance of anthropogenic organic compounds in source water of select CWSs in the United States by characterizing their occurrence in surface-water and groundwater samples. Compound concentrations and occurrence are summarized and evaluated in a human-health context, when possible. Additionally, compounds found to co-occur as mixtures for both surface water and groundwater highlight the significance of low-level compound co-occurrence.

Scientific Investigations Report↗

Ecotoxicological profile of a high prevalence marine disease area in Florida's Gulf coast

Pervasive marine pollution can have devastating effects on ocean health. Polychlorinated Biphenyls (PCB), Polycyclic Aromatic Hydrocarbons (PAH), and Organochlorine Pesticides (OCP) are of particular concern given their high level of toxicity and carcinogenicity. These compounds originate from anthropogenic activity, therefore are often ubiquitous in coastal environments close to human sources. Marine turtles in coastal Florida (USA) are affected by fibropapillomatosis, a tumor-causing panzootic with highly debilitating symptoms. Despite repeated associations between fibropapillomatosis occurrence and carcinogenic pollution, the ecotoxicological status of high disease areas in the Florida Gulf has been unknown. Our study deployed passive sampling devices along a structured inshore-to-offshore coastal grid to generate the first comprehensive dataset on the concentration and diversity of oncogenic pollutants in Crystal River, Florida, where juvenile green turtles exhibit a fibropapillomatosis prevalence of 74%. Multiple OCP, PAH, and PCB compounds were detected for a total chemical concentration of 16,086.98 pg/L (Σ OCP 45.51 pg/L + Σ PAH 16,014.53 pg/L + Σ PCB 26.94 pg/L). Density and composition of carcinogenic pollution was found to be significantly lower in offshore green turtle habitats compared to inshore habitats (p=0.02), suggesting multiple potential contamination sources along the coastline. The carcinogenic compounds detected have been shown to have associations with fibropapillomatosis in other parts of the world, as well as having wider ecosystem implications. Our work contributes to the body of knowledge correlating the emerging threat of harmful ocean pollution and marine wildlife diseases.

Florida↗

Tissue distribution and immunomodulation in channel catfish (Ictalurus punctatus) following dietary exposure to polychlorinated biphenyl Aroclors and food deprivation

Although most countries banned manufacturing of polychlorinated biphenyls (PCBs) over 40 years ago, PCBs remain a global concern for wildlife and human health due to high bioaccumulation and biopersistance. PCB uptake mechanisms have been well studied in many taxa; however, less is known about depuration rates and how post-exposure diet can influence PCB concentrations and immune response in fish and wildlife populations. In a controlled laboratory environment, we investigated the influence of subchronic dietary exposure to two PCB Aroclors and food deprivation on tissue-specific concentrations of total PCBs and PCB homologs and innate immune function in channel catfish ( Ictalurus punctatus ). Overall, we found that the concentration of total PCBs and PCB homologs measured in whole body, fillet, and liver tissues declined more slowly in food-deprived fish, with slowest depuration observed in the liver. Additionally, fish that were exposed to PCBs had lower plasma cortisol concentrations, reduced phagocytic oxidative burst activity, and lower cytotoxic activity, suggesting that PCBs can influence stress and immune responses. However, for most measures of immune function, the effects of food deprivation had a larger effect on immune response than did PCB exposure. Taken together, these results suggest that short-term dietary exposure to PCBs can increase toxicity of consumable fish tissues for several weeks, and that PCB mixtures modulate immune and stress responses via multiple pathways. These results may inform development of human consumption advisories and can help predict and understand the influence of PCBs on fish health.

International Journal of Environmental Research an↗

Global trends in emerging viral diseases of wildlife origin

Fifty years ago, infectious diseases were rarely considered threats to wildlife populations, and the study of wildlife diseases was largely a neglected endeavor. Furthermore, public health leaders at that time had declared that “it is time to close the book on infectious diseases and the war against pestilence won,” a quote attributed to Dr. William H. Stewart in 1967. There is some debate whether he actually said these words; however, they reflect the widespread belief at that time (Spellberg, 2008). Leap forward to today, and the book on infectious diseases has been dusted off. There is general consensus that the global environment favors the emergence of infectious diseases, and in particular, diseases of wildlife origin (Taylor et al., 2001). Examples of drivers of these infectious diseases include climate and landscape changes, human demographic and behavior changes, global travel and trade, microbial adaptation, and lack of appropriate infrastructure for wildlife disease control and prevention (Daszak et al., 2001). The consequences of these emerging diseases are global and profound with increased burden on the public health system, negative impacts on the global economy and food security, declines and extinctions of wildlife species, and subsequent loss of ecosystem integrity. For example, 35 million people are currently living with HIV infection globally (http://www.who.int/gho/hiv/en); 400 million poultry have been culled since 2003 as a result of efforts to control highly pathogenic H5N1 avian influenza (http://www.fao.org/avianflu/en/index.html), and there are increasing biological and ecological consequences. Examples of health threats to biodiversity include the “spillover” of human diseases to great ape populations (Köndgen et al., 2008), the near-extirpation of the black-footed ferret from canine distemper and sylvatic plague (for a review see Abbott et al., 2012), and threats to Hawaiian forest birds from introduced pathogens such as avian malaria and avian pox (van Riper et al., 1986, 2002). There are also newly discovered pathogens or diseases that have resulted in population declines, and global extinctions of several species. Examples include Batrachochytrium dendrobatidis, which causes a cutaneous fungal infection of amphibians and is linked to declines of amphibians globally (Kriger and Hero, 2009); and recently discovered Pseudogymnoascus (Geomyces) destructans, the etiologic agent of white-nose syndrome (WNS), which has caused precipitous declines of North American bat species (Blehert et al., 2009). Furthermore, there is increasing evidence of the subsequent impacts on human and ecosystem health; for example, increasing risk of exposure to Lyme disease as a consequence of decreased biodiversity (LoGiudice et al., 2003) as well as the economic cost of the loss of bats due to decreased insect control services (Boyles et al., 2011). Figure A12-1 is a timeline of important diseases investigated by the U.S. Geological Survey since the 1970s, which illustrates three factors: 1. The unprecedented emergence of new pathogens and geographic spread of known pathogens since the 1990s; 2. Diseases are increasingly causing large-scale, negative impacts on wildlife populations and spreading over larger geographic areas rather than remaining localized; and 3. Diseases are increasingly of concern for multiple sectors, including public health, agriculture and wildlife management agencies. Of increasing concern are these novel diseases such as WNS as they are hard to anticipate, particularly devastating to human health or wildlife populations, challenging to manage, spread over large geographic areas in short time periods, and may result in ecological ripple effects that are difficult to predict. The following article provides examples of recently emerged viral diseases of wildlife origin. The examples have been selected to illustrate the drivers of emerging viral diseases, both novel pathogens and previously known diseases, the impacts of these diseases, as well as the role of wildlife both as “villains” or reservoirs as well as “victims” of these viral diseases. The article also discusses potential management strategies for emerging viral diseases in wildlife populations and future science directions in wildlife health to prevent, prepare, respond to, and recover from these disease events. Finally, the concept of One Health and its potential role in developing solutions to these issues of mutual concern is discussed.

Conference Paper↗

Impacts of saltwater intrusion on wetland prey production and composition in a historically freshwater marsh

Sea level rise is a fundamental driver of ecosystem change and has the potential to shift the spatial distributions of habitats more rapidly than species can adapt. Rapid sea level rise and associated saltwater intrusion have negative impacts on coastal environments, including loss of habitat for species such as sea turtles and shorebirds. In Florida’s largest wetland, the Everglades, the availability of small fishes that are prey for wading birds serve as an indicator of ecosystem health. In the southwestern part of the ecosystem, sea level rise and a reduction in freshwater flow have converted formerly freshwater marsh into an estuarine mangrove-dominated landscape. In this study, we sampled fish communities in this southwest portion of the Everglades exposed to a range of saline conditions. Biomass of native fishes was highest at a salinity value of approximately 25 parts per thousand, while non-native biomass decreased with increasing salinity. Applying salinity change scenarios, we determined that a 10% reduction from the salinity levels recorded in this study would be optimal for biomass of native fishes. The baseline data we collected on non-native fishes at the site will be useful for monitoring as restoration progresses and for managers working on invasive species control. This region has been actively undergoing ecosystem restoration for the last decade, but restored freshwater flow closer to historical conditions is still years away. Without increased freshwater inflow from hydrologic restoration, rising sea levels and saltwater intrusion may provide conservation challenges for wading birds and their prey-base fishes.

Florida↗

Accounting for missing ticks: Use (or lack thereof) of hierarchical models in tick ecology studies

Ixodid (hard) ticks play important ecosystem roles and have significant impacts on animal and human health via tick-borne diseases and physiological stress from parasitism. Tick occurrence, abundance, activity, and key life-history traits are highly influenced by host availability, weather, microclimate, and landscape features. As such, changes in the environment can have profound impacts on ticks, their hosts, and the spread of diseases. Researchers recognize that spatial and temporal factors influence activity and abundance and attempt to account for both by conducting replicate sampling bouts spread over the tick questing period. However, common field methods notoriously underestimate abundance, and it is unclear how (or if) tick studies model the confounding effects of factors influencing activity and abundance. This step is critical as unaccounted variance in detection can lead to biased estimates of occurrence and abundance. We performed a descriptive review to evaluate the extent to which studies account for the detection process while modeling tick data. We also categorized the types of analyses that are commonly used to model tick data. We used hierarchical models (HMs) that account for imperfect detection to analyze simulated and empirical tick data, demonstrating that inference is muddled when detection probability is not accounted for in the modeling process. Our review indicates that only 5 of 412 (1 %) papers explicitly accounted for imperfect detection while modeling ticks. By comparing HMs with the most common approaches used for modeling tick data (e.g., ANOVA), we show that population estimates are biased low for simulated and empirical data when using non-HMs, and that confounding occurs due to not explicitly modeling factors that influenced both detection and abundance. Our review and analysis of simulated and empirical data shows that it is important to account for our ability to detect ticks using field methods with imperfect detection. Not doing so leads to biased estimates of occurrence and abundance which could complicate our understanding of parasite-host relationships and the spread of tick-borne diseases. We highlight the resources available for learning HM approaches and applying them to analyzing tick data.

Maine↗

Assessing time-integrated dissolved concentrations and predicting toxicity of metals during diel cycling in streams

Evaluating water quality and the health of aquatic organisms is challenging in systems with systematic diel (24 hour) or less predictable runoff-induced changes in water composition. To advance our understanding of how to evaluate environmental health in these dynamic systems, field studies of diel cycling were conducted in two streams (Silver Bow Creek and High Ore Creek) affected by historical mining activities in southwestern Montana. A combination of sampling and modeling tools were used to assess the toxicity of metals in these systems. Diffusive Gradients in Thin Films (DGT) samplers were deployed at multiple time intervals during diel sampling to confirm that DGT integrates time-varying concentrations of dissolved metals. Thermodynamic speciation calculations using site specific water compositions, including time-integrated dissolved metal concentrations determined from DGT, and a competitive, multiple-metal biotic ligand model incorporated into the Windemere Humic Aqueous Model Version 6.0 (WHAM VI) were used to determine the chemical speciation of dissolved metals and biotic ligands. The model results were combined with previously collected toxicity data on cutthroat trout to derive a relationship that predicts the relative survivability of these fish at a given site. This integrative approach may prove useful for assessing water quality and toxicity of metals to aquatic organisms in dynamic systems and evaluating whether potential changes in environmental health of aquatic systems are due to anthropogenic activities or natural variability.

Science of the Total Environment↗

Highlighting the complexities of a groundwater pilot study during an avian influenza outbreak: Methods, lessons learned, and select contaminant results

The highly pathogenic avian influenza (H5N2) outbreak in the Midwestern United States (US) in 2015 was historic due to the number of birds and poultry operations impacted and the corresponding economic loss to the poultry industry and was the largest animal health emergency in US history. The U.S. Geological Survey (USGS), with the assistance of several state and federal agencies, aided the response to the outbreak by developing a study to determine the extent of virus transport in the environment. The study goals were to: develop the appropriate sampling methods and protocols for measuring avian influenza virus (AIV) in groundwater, provide the first baseline data on AIV and outbreak- and poultry-related contaminant occurrence and movement into groundwater, and document climatological factors that may have affected both survival and transport of AIV to groundwater during the months of the 2015 outbreak. While site selection was expedient, there were often delays in sample response times due to both relationship building between agencies, groups, and producers and logistical time constraints. This study's design and sampling process highlights the unpredictable nature of disease outbreaks and the corresponding difficulty in environmental sampling of such events. The lessons learned, including field protocols and approaches, can be used to improve future research on AIV in the environment.

Iowa↗

Fathead minnow and bluegill sunfish life-stage responses to 17β-estradiol exposure in outdoor mesocosms

Developmental and reproductive effects of 17β-estradiol (E2) exposure on two generations of fathead minnows and one generation of bluegill sunfish were assessed. Fish were exposed to E2 for six continuous weeks in outdoor mesocosms simulating natural lake environments. First generation fish were exposed while sexually mature. Second generation fathead minnows were exposed either during early development, sexual maturity, or both stages. Multiple endpoints were measured to assess effects of E2 exposure on fecundity and fish health and development. Plasma vitellogenin concentrations were highly variable in all fish. Differences in egg production timing for both species indicate differences in fecundity between females exposed to E2 and controls. First generation fathead minnows exposed to E2 had lower body condition factors and reduced secondary sexual characteristic expression by males. Only a difference in relative liver weight was observed in second generation fathead minnows. First generation bluegill males exposed to E2 had significantly smaller testes compared to controls. Although fish response was highly variable, results indicate that exposure to E2 at environmentally relevant concentrations affect fathead minnow and bluegill sunfish health and development, which may have implications for the health and sustainability of fish populations. Furthermore, exposure timing and environmental factors affect fish response to E2 exposure.

Journal of the American Water Resources Associatio↗

Desert tortoises in the Mojave and Colorado deserts

The desert tortoise ( Gopherus agassizii ) is a widespread species of the southwestern United States and Mexico. Within the United States, desert tortoises live in the Mojave, Colorado, and Sonoran deserts of southeastern California, southern Nevada, southwestern Utah, and western Arizona (Fig. 1). A substantial portion of the habitat is on lands administered by the U.S. Department of the Interior. The U.S. government treats the desert tortoise as an indicator or umbrella species to measure the health and well-being of the ecosystems it inhabits. The tortoise functions well as an indicator because it is long-lived, takes 12-20 years to reach reproductive maturity, and is sensitive to changes in the environment. In 1990 the U.S. Fish and Wildlife Service listed the species as threatened in the northern and western parts of its geographic range (Fig. 1) because of widespread population declines and overall habitat loss, deterioration, and fragmentation. Because some populations exhibit significant genetic, morphologic (see glossary), and behavioral differences, the Desert Tortoise Recovery Team identified six distinctive population segments (Fig. 1) for critical habitat protection and long-term conservation within the Mojave and Colorado deserts (e.g., Lamb et al. 1989; USFWS 1994). The population segments are representative of distinctive climatic, floristic, and geographic regions.

Arizona, California, Nevada, Utah↗

Profiling lunar dust dissolution in aqueous environments: The design concept

Published studies and internal NASA reports indicate that when native lunar dust is suspended in an aqueous solution a variety of metal and other ions are released. This release has implications for future lunar missions, ranging from effects on mission hardware, effects on life support systems, possible direct effects on human health, and effects on research experiments such as plant growth experiments, space biology experiments and any activities that may involve the use of water sourced from the lunar poles. Furthermore, such contaminants could become concentrated or chemically altered to a more hazardous form during a variety of lunar mission activities, including everything from space suit cleaning to lunar industrial materials extraction. The exact profile of the release of ions from lunar dust and the nature of the partially dissolved particles has not been explored. Any model of this dissolution must be based on an understanding of the unique micromorphology of lunar dust, including its glassy nature, agglutinate features, high surface area and the presence of small deposits of elemental iron (nanophase iron) located near the surface of the grain particles. Dust has a very high surface area available for interaction with water. For this reason, on first exposure to water, an immediate pulsed release of ions could occur, with more prolonged release taking place over months or years. The few studies that have been conducted previously have been limited in both the time scales examined and in the selection of ions that were measured. The proposed investigation is a comprehensive materials science investigation, using the most modern analytical tools to catalogue all metals given off from lunar dust in various aqueous solutions and their time profiles of release from the very short term to the very long term. The product of the proposed study will be a comprehensive database determined from NASA curated samples collected from the Apollo landing sites that can be applied to research in both living systems and non-living systems on the moon. The methods developed in the proposed study will also establish standards for analysis of lunar dust samples returned from future manned missions (Artemis and others) and future robotic missions. The knowledge gained from this basic materials science investigation will have broad impact on the design of engineered human safety and health systems.

Acta Astronautica↗

Notable decomposition products of senescing Lake Michigan Cladophora glomerata

Massive accumulations of Cladophora , a ubiquitous, filamentous green alga, have been increasingly reported along Great Lakes shorelines, negatively affecting beach aesthetics, recreational activities, public health and beachfront property values. Previously, the decomposition byproducts of decaying algae have not been thoroughly examined. To better understand the negative consequences and potential merit of the stranded Cladophora , a three month mesocosm study of the dynamic chemical environment of the alga was conducted using fresh samples collected from southern Lake Michigan beaches. Typical fermentation products, such as organic acids, sulfide compounds, and alcohols were detected in the oxygen–deprived algae. Short chain carboxylic acids peaked on day seven, in correspondence with the lowest pH value. Most low molecular mass carbon compounds were eventually consumed, but 4-methylphenol, indole, and 3-methylindole were detected throughout the incubation period. Natural oils were detected in fresh and decomposing algae, indicating the stable nature of these compounds. The mesocosm experiment was validated by directly sampling the fluid within decomposing Cladophora mats in the field; many of the same compounds were found. This study suggests that the problematic Cladophora accumulations may be harvested for useful byproducts, thereby reducing the odiferous and potentially harmful mats stranded along the shorelines.

Lake Michigan↗

Occurrence and attempted mitigation of carbon dioxide in a home constructed on reclaimed coal-mine spoil, Pike County, Indiana

In recent years carbon dioxide intrusion has become recognized as a potentially serious health threat where homes are constructed on or near reclaimed surface coal mines. When carbon dioxide invades the living space of a home, it can collect near the floor, displace the oxygen there, and produce an oxygen-deficient environment. In this investigation, several lines of inquiry were pursued to determine the environmental factors that most influence carbon dioxide intrusion at a Pike County, Ind., home where this phenomenon is known to occur. It was found that carbon dioxide intrusion events at the home are most closely tied to rapid drops in barometric pressure and rainfall. Other researchers have shown that windy conditions and periods of cold weather also can contribute to soil-gas intrusion to structures. From this, a conceptual model was developed to illustrate the influence of these four meteorological conditions. Additionally, three mitigation methods-block-wall depressurization, block-wall and sub-slab depressurization, and block-wall and sub-slab pressurization-were applied successively to the study-site home, and environmental data were collected to evaluate the effectiveness of each mitigation method. In each case, it was found that these methods did not ensure a safe environment when meteorological conditions were favorable for carbon dioxide intrusion.

Scientific Investigations Report↗