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At least 397 records · Page 22Linked to original sources
USGS2025

Land application of drill waste: A scope analysis

Drilling fluid waste land application, a process where drilling wastes are spread and tilled into the land surface, has become common in some petroleum-producing states, however, the potential benefits and risks of this practice are not well studied. Drilling fluids can be water- or oil-based and can have high concentrations of total soluble salts and total petroleum hydrocarbons. Comprehensive chemical characterization of these fluids is not well documented in the literature, and the extent of land application is largely unknown. We hypothesized that the land application of drill waste would fluctuate over time due to economic factors. To begin to understand the extent of historical and potential future land application, we analyzed data from over 5,800 drilling fluid land application permits collected by the Oklahoma Corporation Commission for years 2000, 2005, 2010, and 2015–2020. During the years studied, drilling fluid wastes were applied to more than 250,000 acres in Oklahoma, with over 54,000 thousand barrels (Mbbl) of liquids and nearly 21,000 Mbbl of solids applied. Land application is widespread (occurring in 59/77 counties), however recent drilling activity, land availability, and the economics of transportation have created conditions favorable for land application specifically in the Anadarko Basin. Land application can co-occur with sensitive areas, such as important groundwater and surface-water drinking sources and agricultural fields used for subsistence or feed crop production. Our approach for quantifying the extent of land application, along with further chemical characterization studies, can aid operators and land managers who are considering this practice in assessing the associated benefits and risks.

Oklahoma↗
USGS2010

Evaluation of a portable automated serum chemistry analyzer for field assessment of harlequin ducks, Histrionicus histrionicus

A portable analytical chemistry analyzer was used to make field assessments of wild harlequin ducks ( Histrionicus histrionicus ) in association with telemetry studies of winter survival in Prince William Sound, Alaska. We compared serum chemistry results obtained on-site with results from a traditional laboratory. Particular attention was paid to serum glucose and potassium concentrations as potential indicators of high-risk surgical candidates based on evaluation of the field data. The median differential for glucose values ( 𝑁 = 8 2 ) between methods was 0.6 mmol/L (quartiles 0.3 and 0.9 mmol/L) with the median value higher when assayed on site. Analysis of potassium on site returned a median of 2.7 mmol/L ( 𝑁 = 8 8 ; quartiles 2.4 and 3.0 mmol/L). Serum potassium values were too low for quantitation by the traditional laboratory. Changes in several serum chemistry values following a three-day storm during the study support the value of on site evaluation of serum potassium to identify presurgical patients with increased anesthetic risk.

Alaska↗
USGS2012

Climate change and human health: Spatial modeling of water availability, malnutrition, and livelihoods in Mali, Africa

This study develops a novel approach for projecting climate trends in the Sahel in relation to shifting livelihood zones and health outcomes. Focusing on Mali, we explore baseline relationships between temperature, precipitation, livelihood, and malnutrition in 407 Demographic and Health Survey (DHS) clusters with a total of 14,238 children, resulting in a thorough spatial analysis of coupled climate-health dynamics. Results suggest links between livelihoods and each measure of malnutrition, as well as a link between climate and stunting. A ‘front-line’ of vulnerability, related to the transition between agricultural and pastoral livelihoods, is identified as an area where mitigation efforts might be usefully targeted. Additionally, climate is projected to 2025 for the Sahel, and demographic trends are introduced to explore how the intersection of climate and demographics may shift the vulnerability ‘front-line’, potentially exposing an additional 6 million people in Mali, up to a million of them children, to heightened risk of malnutrition from climate and livelihood changes. Results indicate that, holding constant morbidity levels, approximately one quarter of a million children will suffer stunting, nearly two hundred thousand will be malnourished, and over one hundred thousand will become anemic in this expanding arid zone by 2025. Climate and health research conducted at finer spatial scales and within shorter projected time lines can identify vulnerability hot spots that are of the highest priority for adaptation interventions; such an analysis can also identify areas with similar characteristics that may be at heightened risk. Such meso-scale coupled human-environment research may facilitate appropriate policy interventions strategically located beyond today’s vulnerability front-line.

Applied Geography↗
USGS2019

Evaluation of Potential Translocation Sites for an Imperiled Cyprinid, theHornyhead Chub

Translocation of isolated species into suitable habitats may help secure vulnerable, geographically limited species. Due to the decline of Wyoming Hornyhead Chub Nocomis biguttatus , conservation actions such as translocation of populations within the plausible historical range are being considered to improve population redundancy and resiliency to disturbance events. Translocation of Wyoming Hornyhead Chub must be rigorously evaluated because a hatchery stock does not exist, so all fish used in translocations will come from the wild population. We present an approach to identify best available translocation sites prior to translocation efforts taking place. We evaluated fish community composition and habitat conditions at 54 potential translocation sites for Hornyhead Chub within 12 streams of the North Platte River Basin of Wyoming. We used two analyses to identify translocation sites most similar to currently occupied Hornyhead Chub sites on the Laramie River: hurdle models to predict hypothetical abundance of Hornyhead Chub at translocation sites and non-metric multidimensional scaling (NMDS) with fish community and habitat conditions. Presence and abundance of Hornyhead Chub was related to lack of nonnative predators and habitat features characteristic of backwater and velocity refuge habitats. We used a rank scoring system to weight the outcomes of each analysis and the highest ranking translocation sites occurred at a historical locality, the Sweetwater River. Our approach may be appropriate for other at-risk species with isolated distributions and little historical data.

Wyoming↗
USGS2022

Examining landowners’ preferences for a chronic wasting disease management program

Private landowners are key partners in chronic wasting disease (CWD) management, especially in landscapes where there is limited public ownership. In this study, we evaluated landowners' preferences for alternative hypothetical CWD management programs using a stated choice experiment. We were particularly interested in understanding preferences for the use of financial incentives to motivate white-tailed deer harvest and facilitate hunter access to private lands as potential CWD management tools. We used latent class analysis to characterize preference heterogeneity among landowners stemming from patterns of choice. We compared means and distributions of auxiliary variables related to landowners' perceived risks, trust, attitudes toward management, and sociodemographics across latent classes stemming from choice model results. The pooled model demonstrated that reducing deer population density, providing payments to landowners for CWD-positive deer taken from their property, the form of incentives for public access, and banning recreational deer feeding had a small positive effect on respondents' choice of CWD management program. However, providing financial payments to hunters for harvesting CWD-positive deer and the use of targeted culling had the opposite effect on choice. Latent class models revealed that a majority of respondents exhibited a pattern of preference where all forms of incentives exerted a negative effect on choice, but smaller subsets of landowners positively evaluate the use of some incentives. Post-hoc contrasts revealed relationships between patterns of preferences and trust, risk, and attitudes toward CWD management with small to medium effects. Results demonstrated limited support for the use of financial incentives as a tool to manage access and harvest in the southeast Minnesota CWD management zone

Minnesota↗
USGS2016

Fine‐resolution conservation planning with limited climate‐change information

Climate‐change induced uncertainties in future spatial patterns of conservation‐related outcomes make it difficult to implement standard conservation‐planning paradigms. A recent study translates Markowitz's risk‐diversification strategy from finance to conservation settings, enabling conservation agents to use this diversification strategy for allocating conservation and restoration investments across space to minimize the risk associated with such uncertainty. However, this method is information intensive and requires a large number of forecasts of ecological outcomes associated with possible climate‐change scenarios for carrying out fine‐resolution conservation planning. We developed a technique for iterative, spatial portfolio analysis that can be used to allocate scarce conservation resources across a desired level of subregions in a planning landscape in the absence of a sufficient number of ecological forecasts. We applied our technique to the Prairie Pothole Region in central North America. A lack of sufficient future climate information prevented attainment of the most efficient risk‐return conservation outcomes in the Prairie Pothole Region. The difference in expected conservation returns between conservation planning with limited climate‐change information and full climate‐change information was as large as 30% for the Prairie Pothole Region even when the most efficient iterative approach was used. However, our iterative approach allowed finer resolution portfolio allocation with limited climate‐change forecasts such that the best possible risk‐return combinations were obtained. With our most efficient iterative approach, the expected loss in conservation outcomes owing to limited climate‐change information could be reduced by 17% relative to other iterative approaches.

Conservation Biology↗
USGS2021

Improving species status assessments under the U.S. Endangered Species Act and implications for multispecies conservation challenges worldwide

Despite its successes, the U.S. Endangered Species Act (ESA) has proven challenging to implement due to funding limitations, workload backlog, and other problems. As threats to species survival intensify and as more species come under threat, the need for the ESA and similar conservation laws and policies in other countries to function efficiently has grown. Attempts by the U.S. Fish and Wildlife Service (USFWS) to streamline ESA decisions include multispecies recovery plans and habitat conservation plans. We address species status assessment (SSA), a USFWS process to inform ESA decisions from listing to recovery, within the context of multispecies and ecosystem planning. Although existing SSAs have a single-species focus, ecosystem-based research can efficiently inform multiple SSAs within a region and provide a foundation for transition to multispecies SSAs in the future. We considered at-risk grassland species and ecosystems within the southeastern United States, where a disproportionate number of rare and endemic species are associated with grasslands. To initiate our ecosystem-based approach, we used a combined literature-based and structured World Café workshop format to identify science needs for SSAs. Discussions concentrated on 5 categories of threats to grassland species and ecosystems, consistent with recommendations to make shared threats a focus of planning under the ESA: (1) habitat loss, fragmentation, and disruption of functional connectivity; (2) climate change; (3) altered disturbance regimes; (4) invasive species; and (5) localized impacts. For each threat, workshop participants identified science and information needs, including database availability, research priorities, and modeling and mapping needs. Grouping species by habitat and shared threats can make the SSA process and other planning processes for conservation of at-risk species worldwide more efficient and useful. We found a combination of literature review and structured discussion effective for identifying the scientific information and analysis needed to support the development of multiple SSAs.

Conservation Biology↗
USGS1982

An application of a vulnerability index to oil spill modeling in the Gulf of Mexico

An analysis was made of the relative impact to the shoreline of the Gulf of Mexico from proposed Federal Outer Continental Shelf oil and gas leasing activity. An oil spill trajectory model was coupled with a land segment vulnerability characterization to predict the risks to the shoreline. Such a technique allows spatial and temporal variability in oil spill sensitivity to be represented and combined with the likelihood of oil spill contact to specific coastal segments in the study area. Predicted relative impact was greatest along the coastlines of Louisiana, Mississippi, and Alabama. Useful information is provided for environmental impact analysis, as well as oil spill response planning.

Open-File Report↗
USGS1992

Sampling and analysis for radon-222 dissolved in ground water and surface water

Radon-222 is a naturally occurring radioactive gas in the uranium-238 decay series that has traditionally been called, simply, radon. The lung cancer risks associated with the inhalation of radon decay products have been well documented by epidemiological studies on populations of uranium miners. The realization that radon is a public health hazard has raised the need for sampling and analytical guidelines for field personnel. Several sampling and analytical methods are being used to document radon concentrations in ground water and surface water worldwide but no convenient, single set of guidelines is available. Three different sampling and analytical methods-bubbler, liquid scintillation, and field screening-are discussed in this paper. The bubbler and liquid scintillation methods have high accuracy and precision, and small analytical method detection limits of 0.2 and 10 pCi/l (picocuries per liter), respectively. The field screening method generally is used as a qualitative reconnaissance tool.

Environmental Monitoring and Assessment↗
USGS2012

Economic analysis of the proposed rule to prevent arrival of new genetic strains of the rust fungus Puccinia psidii in Hawai'i.

Since its first documented introduction to Hawai‘i in 2005, the rust fungus P. psidii has already severely damaged Syzygium jambos (Indian rose apple) trees and the federally endangered Eugenia koolauensis (nioi). Fortunately, the particular strain has yet to cause serious damage to ‘ōhi‘a, which comprises roughly 80% of the state’s native forests and covers 400,000 ha. Although the rust has affected less than 5% of Hawaii’s ‘ōhi‘a trees thus far, the introduction of more virulent strains and the genetic evolution of the current strain are still possible. Since the primary pathway of introduction is Myrtaceae plant material imported from outside the state, potential damage to ‘ohi‘a can be minimized by regulating those high-risk imports. We discuss the economic impact on the state’s florist, nursery, landscaping, and forest plantation industries of a proposed rule that would ban the import of non-seed Myrtaceae plant material and require a one-year quarantine of seeds. Our analysis suggests that the benefits to the forest plantation industry of a complete ban on non-seed material would likely outweigh the costs to other affected sectors, even without considering the reduction in risk to ‘ōhi‘a. Incorporating the value of ‘ōhi‘a protection would further increase the benefit-cost ratio in favor of an import ban.

Hawaii↗
USGS1992

Modeling metapopulation dynamics for single species of seabirds

Seabirds share many characteristics setting them apart from other birds. Importantly, they breed more or less obligatorily in local clusters of colonies that can move regularly from site to site, and they routinely exchange breeders. The properties of such metapopulations have only recently begun to be examined, often with models that are occupancy-based (using only colony presence or absence data) and deterministic (using single, empirically determined values for each of several population biology parameters). Some recent models are now frequency-based (using actual population sizes at each site), as well as stochastic (randomly varying critical parameters between biologically realistic limits), yielding better estimates of the behavior of future populations. Using two such models designed to quantify relative risks of population changes under different future scenarios (RAMAS/stage and RAMAS/space), we have examined probable future populations dynamics for three hypothetical seabirds -- an albatross, a cormorant, and a tern. With real parameters and ranges of values we alternatively modelled each species with and without density dependence, as well as with their numbers in a single, large colony, or in many smaller ones, distributed evenly or lognormally. We produced a series of species-typical lines for different population risks over the 50 years we simulated. We call these curves Instantaneous Threat Assessments (ITAs), and their shapes mirror the varying life history characteristics of our three species. We also demonstrated (by a process known as sensitivity analysis) that the most important parameters determining future population fates of all three species were correlation of mean growth rate among colonies; dispersal rate of present and future breeders; subadult survivorship; and the number of subpopulations (=colonies) - in roughly that descending order of importance. In addition, density dependence was found to markedly alter ITA line shape and position, dramatically in the tern. Finally, we show that for each of our three seabirds, a substantial reduction in the risk of the entire population's going to extinction was provided by a metapopulation (i.e. colonial) breeding structure -- thus comfortably confirming what avian ecologists have long known but about which population modellers are somtimes still unsure.

Book chapter↗
USGS2022

Phylogenetic risk assessment is robust for forecasting the impact of European insects on North American conifers

Some introduced species cause severe damage, although the majority have little impact. Robust predictions of which species are most likely to cause substantial impacts could focus efforts to mitigate those impacts or prevent certain invasions entirely. Introduced herbivorous insects can reduce crop yield, fundamentally alter natural and managed forest ecosystems, and are unique among invasive species in that they require certain host plants to succeed. Recent studies have demonstrated that understanding the evolutionary history of introduced herbivores and their host plants can provide robust predictions of impact. Specifically, divergence times between hosts in the native and introduced ranges of a nonnative insect can be used to predict the potential impact of the insect should it establish in a novel ecosystem. However, divergence time estimates vary among published phylogenetic datasets, making it crucial to understand if and how the choice of phylogeny affects prediction of impact. Here, we tested the robustness of impact prediction to variation in host phylogeny by using insects that feed on conifers and predicting the likelihood of high impact using four different published phylogenies. Our analyses ranked 62 insects that are not established in North America and 47 North American conifer species according to overall risk and vulnerability, respectively. We found that results were robust to the choice of phylogeny. Although published vascular plant phylogenies continue to be refined, our analysis indicates that those differences are not substantial enough to alter the predictions of invader impact. Our results can assist in focusing biosecurity programs for conifer pests and can be more generally applied to nonnative insects and their potential hosts by prioritizing surveillance for those insects most likely to be damaging invaders.

Ecological Applications↗
USGS2021

Contrasting patterns of demography and population viability among gopher tortoise (Gopherus polyphemus) populations at the species’ northern range edge

Population viability analyses are useful tools to predict abundance and extinction risk for imperiled species. In southeastern North America, the federally threatened gopher tortoise ( Gopherus polyphemus ) is a keystone species in the diverse and imperiled longleaf pine ( Pinus palustris ) ecosystem, and researchers have suggested that tortoise populations are declining and characterized by high extinction risk. We report results from a 30-year demographic study of gopher tortoises in southern Alabama (1991–2020), where 3 populations have been stable and 3 others have declined. To better understand the demographic vital rates associated with stable and declining tortoise populations, we used a multi-state hierarchical mark-recapture model to estimate sex- and stage-specific patterns of demographic vital rates at each population. We then built a predictive population model to project population dynamics and evaluate extinction risk in a population viability context. Population structure did not change significantly in stable populations, but juveniles became less abundant in declining populations over 30 years. Apparent survival varied by age, sex, and site; adults had higher survival than juveniles, but female survival was substantially lower in declining populations than in stable ones. Using simulations, we predicted that stable populations with high female survival would persist over the next 100 years but sites with lower female survival would decline, become male-biased, and be at high risk of extirpation. Stable populations were most sensitive to changes in apparent survival of adult females. Because local populations varied greatly in vital rates, our analysis improves upon previous demographic models for northern populations of gopher tortoises by accounting for population-level variation in demographic patterns and, counter to previous model predictions, suggests that small tortoise populations can persist when habitat is managed effectively. © 2021 The Wildlife Society.

Alabama↗
USGS2003

Arsenic in Illinois ground water — Community and private supplies

Assessing the distribution of arsenic in ground water from community-water supplies, private supplies, or monitoring wells is part of the process of determining the risk of arsenic contamination of drinking water in Illinois. Lifestyle, genetic, and environmental factors make certain members of the population more susceptible to adverse health effects from repeated exposure to drinking water with high arsenic concentrations (Ryker, 2001). In addition, such factors may have geographic distribution patterns that complicate the analysis of the relation between arsenic in drinking water and health effects. For example, arsenic may not be the only constituent affecting the quality of drinking water in a region (Ryker, 2001); however, determining the extent and distribution of arsenic in ground water is a starting place to assess the potential risk for persons drinking from a community or private supply. Understanding the potential sources and pathways that mobilize arsenic in ground water is a necessary step in protecting the drinking-water supply in Illinois.

Illinios↗
USGS1999

Relative effects of plumage coloration and vegetation density on nest success

Many passerine species are highly dichromatic with brightly-colored males and cryptically-colored females. Bright plumage in males is commonly thought to arise as a result of sexual selection by females such that males with bright coloration possess high fitness. However, bright plumage potentially could expose males to increased predation risk. Consistent with this idea, males of many highly dichromatic passerine species do not incubate. I tested whether brightly-colored males avoid incubation to reduce the probability of visual predators locating their nest. This hypothesis predicts greater hatching success for clutches incubated by cryptically-colored individuals than by brightly-colored individuals. The Northern Cardinal (Cardinalis cardinalis) is a common dichromatic species that breeds throughout the eastern U.S. I placed two button-quail (Turnix st).) eggs in each of 203 simulated cardinal nests. Dull brown cardboard, simulating a female cardinal, was placed over about half of all clutches. Bright red cardboard, simulating a male cardinal, was placed over the other clutches. Nest success was highest for well-concealed nests (87%) and lowest for nests in open habitat (54%). Nests containing red cardboard did not have significantly lower success than nests with brown cardboard, nor did I detect a significant color X vegetation-density interaction. My analysis may have had insufficient power to detect an effect of color on nest success; alternatively, brightly-colored males that do not incubate may achieve benefits unrelated to predation risk.

Condor↗
USGS2024

Transdisciplinary research supports the sustainability of barrier island systems threatened by climate change

The management of developed barrier islands is often piece-meal and reactionary despite the complex, dynamic nature of these systems, and sustainable practices will become increasingly difficult due to heightened pressures of climate change. Adaptation actions, including nature-based solutions, need to be thoroughly evaluated prior to implementation to understand system-wide impacts and avoid maladaptation. Anarde et al. (2024a), ( https://doi.org/10.1029/2023ef003672 ), Anarde et al. (2024b), ( https://doi.org/10.1029/2023ef004200 ) is the latest important contribution in a growing body of transdisciplinary research that more robustly evaluates the complex physical process-and-response relationship of barrier systems via sophisticated numerical modeling approaches that also interface with socioeconomic models to inform coastal management actions in response to mitigating coastal risk. This new research indicates the importance of coordinated system-scale barrier island management, as strategies to reduce coastal hazard risk in one location will directly affect adjacent communities. Further, this work demonstrates that reducing barrier management interventions may actually promote barrier recovery and sustainability in the face of sea level rise. In addition, recent advances in the analysis and application of remotely sensed data from satellites and oblique aerial photography provide scientists an unprecedented opportunity to track coastal evolution over a wide range of spatial and temporal scales at minimal cost. As sea level rise and changing storm patterns challenge the sustainable management of barrier island systems, integrating these advanced, transdisciplinary tools will enable scientists and coastal practitioners to more thoroughly evaluate coastal adaptation options, efficiently invest limited resources to mitigate coastal hazard risk for communities, support healthy ecosystems, and reduce system-wide impacts.

Earth's Future↗
USGS2004

Economic and health risk trade-offs of swim closures at a Lake Michigan beach

This paper presents a framework for analyzing the economic, health, and recreation implications of swim closures related to high fecal indicator bacteria (FIB) levels. The framework utilizes benefit transfer policy analysis to provide a practical procedure for estimating the effectiveness of recreational water quality policies. Evaluation criteria include the rates of intended and unintended management outcomes, whether the chosen protocols generate closures with positive net economic benefits to swimmers, and the number of predicted illnesses the policy is able to prevent. We demonstrate the framework through a case study of a Lake Michigan freshwater beach using existing water quality and visitor data from 1998 to 2001. We find that a typical closure causes a net economic loss among would-be swimmers totaling $1274-37 030/ day, depending on the value assumptions used. Unnecessary closures, caused by high indicator variability and a 24-h time delay between when samples are taken and the management decision can be made, occurred on 14 (12%) out of 118 monitored summer days. Days with high FIB levels when the swim area is open are also common but do relatively little economic harm in comparison. Also, even if the closure policy could be implemented daily and perfectly without error, only about 42% of predicted illnesses would be avoided. These conclusions were sensitive to the relative values and risk preferences that swimmers have for recreation access and avoiding health effects, suggesting a need for further study of the impacts of recreational water quality policies on individuals.

Environmental Science & Technology↗
USGS2021

Optimal allocation of law enforcement patrol effort to mitigate poaching activities

Poaching is a global problem causing the decline of species worldwide. Optimizing the efficiency of ranger patrols to deter poaching activity at the lowest possible cost is crucial for protecting species with limited resources. We applied decision analysis and spatial optimization algorithms to allocate efforts of ranger patrols throughout a national park. Our objective was to mitigate poaching activity at or below management risk targets for the lowest monetary cost. We examined this trade‐off by constructing a Pareto efficiency frontier using integer linear programming. We used data from a ranger‐based monitoring program in Nyungwe National Park, Rwanda. Our measure of poaching risk is based on dynamic occupancy models that account for imperfect detection of poaching activities. We found that in order to achieve a 5% reduction in poaching risk, 622 ranger patrol events (each corresponding to patrolling 1‐km 2 sites) were needed within a year at a cost of US$49,760. In order to attain a 60% reduction in poaching risk, 15,560 patrol events were needed at a cost of US \$ 1,244,800. We evaluated the trade‐off between patrol cost and poaching risk based on our model by constructing a Pareto efficiency frontier and park managers found the solution for a 50% risk reduction to be a practical trade‐off based on funding constraints (comparable to recent years) and the diminishing returns between risk mitigation and cost. This expected reduction in risk required 8,558 patrol events per year at a cost of US \$ 684,640. Our results suggest that optimal solutions could increase efficiency compared to the actual effort allocations from 2006 to 2016 in Nyungwe National Park (e.g., risk reductions of ~30% under recent budgets compared to ~50% reduction in risk under the optimal strategy). The modeling framework in this study took into account imperfect detection of poaching risk as well as the directional and conditional nature of ranger patrol events given the spatial adjacency relationships of neighboring sites and access points. Our analyses can help to improve the efficiency of ranger patrols, and the modeling framework can be broadly applied to other spatial conservation planning problems with conditional, multilevel, site selection.

Nyungwe National Park↗