Open Access Publications

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Open access publications related to sustainability research.

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3D Computational Model for an Electrochemical Gas Separation and Inerting System
(Journal of The Electrochemical Society, 2022-04-25) Aryal, Utsav Raj; Aziz, Majid; Prasad, Ajay K.
Aircraft fuel tank inerting is employed to reduce the flammability of the fuel vapor in the ullage (air volume above the fuel) by restricting its oxygen concentration to a safe value—12% for commercial aircraft and 9% for military aircraft. Inerting is typically accomplished by displacing oxygen in the ullage with an inert gas like nitrogen. Electrochemical gas separation and inerting system (EGSIS) is an on-board method to generate and supply nitrogen-enriched air (NEA) to the fuel tank. EGSIS combines a polymer electrolyte membrane (PEM) electrolyzer anode which dissociates water to evolve oxygen, and a PEM fuel cell cathode which reduces oxygen from atmospheric air to produce NEA at its outlet. This paper represents the first attempt to model and simulate EGSIS using a three-dimensional, steady state, isothermal model. Various EGSIS performance indicators such as current density, reactant concentration distribution, and polarization curves are studied as a function of operating conditions and design parameters. The results from the computational model are validated against our previous experimental results for various operating conditions. The simulation results reveal the effects of temperature, reactant flowrates, and material property optimization on EGSIS performance. Different operating strategies are explored with the goal of improving system performance.
A Bacillus velezensis strain shows antimicrobial activity against soilborne and foliar fungi and oomycetes
(Frontiers in Fungal Biology, 2024-02-23) Wockenfuss, Anna; Chan, Kevin; Cooper, Jessica G.; Chaya, Timothy; Mauriello, Megan A.; Yannarell, Sarah M.; Maresca, Julia A.; Donofrio, Nicole M.
Biological control uses naturally occurring antagonists such as bacteria or fungi for environmentally friendly control of plant pathogens. Bacillus spp. have been used for biocontrol of numerous plant and insect pests and are well-known to synthesize a variety of bioactive secondary metabolites. We hypothesized that bacteria isolated from agricultural soil would be effective antagonists of soilborne fungal pathogens. Here, we show that the Delaware soil isolate Bacillus velezensis strain S4 has in vitro activity against soilborne and foliar plant pathogenic fungi, including two with a large host range, and one oomycete. Further, this strain shows putative protease and cellulase activity, consistent with our prior finding that the genome of this organism is highly enriched in antifungal and antimicrobial biosynthetic gene clusters. We demonstrate that this bacterium causes changes to the fungal and oomycete hyphae at the inhibition zone, with some of the hyphae forming bubble-like structures and irregular branching. We tested strain S4 against Magnaporthe oryzae spores, which typically form germ tubes and penetration structures called appressoria, on the surface of the leaf. Our results suggest that after 12 hours of incubation with the bacterium, fungal spores form germ tubes, but instead of producing appressoria, they appear to form rounded, bubble-like structures. Future work will investigate whether a single antifungal molecule induces all these effects, or if they are the result of a combination of bacterially produced antimicrobials.
A Benign Synthesis Route to Terephthalic Acid via Two-Step Electrochemical Oxidation of P-xylene
(Journal of The Electrochemical Society, 2024-05-31) Ding, Haoran; Orazov, Marat; Oliveira, Nicholas; Yan, Yushan
Terephthalic acid is conventionally synthesized through the AMOCO process under harsh conditions, making milder electrosynthesis routes desirable. Electrooxidation of p-xylene has been demonstrated but the degree of oxidation is limited, resulting in low terephthalic acid yields. Here, we demonstrate a process with two electrochemical steps enabling the complete oxidation of p-xylene into terephthalic acid. The first electrochemical step achieves C-H activation of p-xylene using electrochemically generated bromine as a mediator, while the second electrochemical step does alcohol oxidation of 1,4-benzenedimethanol into terephthalate on NiOOH. The divided cell in the first step simultaneously generates acid and base that are utilized subsequently, negating the need of external acid and base addition and thus offering a cost competitive synthesis route. The competing bromide oxidation in the second step is suppressed by using constant voltage electrolysis at 0.50 V, where an optimal yield of terephthalic acid of 81% is achieved.
A comparative assessment of household power failure coping strategies in three American cities
(Energy Research and Social Science, 2024-05-19) Andresen, Adam X.; Kurtz, Liza C.; Chakalian, Paul M.; Hondula, David M.; Meerow, Sara; Gall, Melanie
Household power outage experiences vary based on outage characteristics and the household's ability to cope with a disruption. While disaster management scholarship has produced methods to predict where the most significant impacts of a hazard may occur, these methods do not anticipate secondary effects, such as those from power outages. This research is necessary as the expected risks associated with power outages will increase in the United States due to climate change, increasing electricity demand, and aging infrastructure. To understand households' power outage experiences, we collected 896 surveys from three cities in the United States: Detroit, MI; Miami, FL; and Phoenix, AZ. Participants were recruited through Amazon's Mechanical Turk (MTurk) service to complete a survey. We hypothesized that racial/ethnic minority groups, specifically non-white households and lower-income households experienced more frequent and prolonged power outages. We also hypothesized that the same groups were more likely to have experienced more significant adverse effects, such as throwing away perishable food and not receiving assistance. We found that non-white households in Phoenix and Detroit were more likely to experience longer outages than white households; however, this association was not present in Miami and was not statistically significant in any city. Income was not a major factor in predicting food waste or assistance received during the longest self-reported outage. Further assessments in varying geographical contexts and more generalizable samples are necessary to increase understanding of how households experience power outages.
A comparison of raptor densities and habitat use in Kansas cropland and rangeland ecosystems
(Journal of Raptor Research, 2000-09) Williams, Christopher K.; Applegate, Roger D.; Lutz, R. Scott; Rusch, Donald H.
We counted raptors on line transects along roads to assess densities, species diversity, and habitat selection of winter raptors between cropland and rangeland habitats in eastern Kansas. We conducted counts every 2 wk between September-March 1994-98. Species diversity indices did not differ between the two habitats (P -- 0.15). We calculated density estimates and cover type selection for Red- tailed Hawks (Buteojamaicensis), Northern Harriers (Circus cyaneus), and American Kestrels (Falco sparv- erius). Red-tailed Hawks and Northern Harrier densities were higher in cropland, while kestrel densities did not differ between the two habitats. All three species across both habitats had a general preference for idleland habitat. We believe three factors could explain the higher raptor densities in cropland: increased prey abundance, increased visibility of prey associated with harvested agriculture fields, and/ or a higher relative amount of preferred hunting habitat.
A Consideration of Wildlife in the Benefit-Costs of Hydraulic Fracturing: Expanding to an E3 Analysis
(Sustainability, 2022-04-17) Caldwell, Jennifer A.; Williams, Christopher K.; Brittingham, Margaret C.; Maier, Thomas J.
High-volume hydraulic fracturing (“fracking”) for natural gas in the Marcellus Shale (underlying about 24 mil ha in New York, Pennsylvania, Maryland, West Virginia, Ohio, and Virginia) has become a politically charged issue, primarily because of concerns about drinking water safety and human health. This paper examines fracking in the Marcellus region, and the tradeoffs between the energy and economic potential of natural gas extraction and the environmental impacts on wildlife. Therefore, we introduce a new E3 analysis that combines the costs and benefits as regards energy, economics, and the environment. The Marcellus Shale has the most proven reserves of natural gas of any basin in the United States, at 129 trillion cubic feet. Income from natural gas development comes primarily from direct and indirect jobs, and induced jobs (those created when direct workers spend their earnings in a community), taxes and fees, and royalty and lease payments to rights holders. Fracking, however, has detrimental effects on wildlife and wildlife habitats. Terrestrial habitat effects are primarily due to landscape fragmentation from the clearing of land for pipeline and well pad development, which often removes mature forest and creates open corridors and edge habitats. An increase in forest edge and open corridors is associated with shifts in the bird community, as generalist species that do well around people increase in abundance, while forest specialists decline. Invasive plants associated with disturbance further degrade forest habitats. Aquatic habitats are also affected, both directly and indirectly. Hydraulic fracturing requires up to 20 mil L of water per well fracture, most of which comes from surface water sources in the Marcellus region. The removal of water, especially in smaller headwaters, can increase sedimentation, alter water temperature and change its chemistry, resulting in reductions in aquatic biodiversity. Given the reality that hydraulic fracturing will continue, there is a need to develop practices that best minimize negative impacts on terrestrial and aquatic habitats, as well as policies and the resolve to enforce these practices. To achieve a more sustainable balance between economic, energy, and environmental costs and benefits, we recommend that industry, scientists, non-governmental organizations, mineral rights holders, landowners, and regulators work together to develop a set of best management practices that represent the best knowledge available.
A Mid-Atlantic and a National Population Model of Northern Bobwhite Demographic Sensitivity
(National Quail Symposium Proceedings, 2012) Williams, Christopher K.; Sandercock, Brett K.; Lohr, Michael; Castelli, Paul M.
Numerous field studies have estimated fecundity and survival rates for northern bobwhites (Colinus virginianus), but a synthetic population model based on life-stage simulation analysis (LSA) was only recently developed to examine demographic sensitivity of the finite rate of population change. We compare local demographic parameters of bobwhite versus a national compilation to identify limiting demographic factors for improved regional habitat planning and management. The national compilation provided a useful overview but combined parameters across populations at different latitudes and under different management regimes. We parameterized our LSA model to examine the sensitivity of the finite rate of growth (k) to simulated variation in 9 demographic parameters primarily estimated from field studies for one population in regional decline in New Jersey. Our model results predicted population declines in New Jersey (k 1⁄4 0.55) comparable to the national estimate (k 1⁄4 0.54), but notable differences occurred in sensitivity of demographic variables. The national model predicted winter survival of adults made the greatest contribution to variance of k (r2 1⁄4 0.42) followed by summer survival of adults (r2 1⁄4 0.13), and survival of chicks (r2 1⁄4 0.11). Our regional model for New Jersey also predicted winter and summer survival of adults would make the greatest contribution to variance of k (r2 1⁄4 0.33 and r2 1⁄4 0.13). The New Jersey model, in contrast to the national model, showed that annual variation in components of fecundity had a large effect on Var(k): including clutch size (r2 1⁄4 0.18 vs. national r2 1⁄4 0.01), nest success (r2 1⁄4 0.20 vs. national r2 1⁄4 0.06), and the number of young produced per nest that survived 30 days (r2 1⁄4 0.53 vs. national r2 1⁄4 0.16). Slopes of linear regression between simulated variation in each demographic variable against k were similar between the national and regional models. The slope for number of young produced per nest that survived 30 days with one exception was lower in the New Jersey data indicating more young are required to realize a stationary population. Our simulation results suggest management practices that improve winter survival or the number of young surviving 30 days will have the greatest potential to increase bobwhite population growth rate in New Jersey. Future linkage of models of demographic performance to experimental habitat manipulations will aid regional scientific planning to improve necessary habitat management.
A population model for management of Atlantic flyway resident population Canada geese
(Wildlife Society Bulletin, 2016-03-28) Beston, Julie A.; Williams, Christopher K.; Nichols, Theodore C.; Castelli, Paul M.
Highly abundant resident Canada geese (Branta canadensis) cause property damage throughout their range. Effective reduction and management of these populations requires knowledge of their population dynamics and responses to management actions. We used data from New Jersey, USA, and other resident Canada goose populations to produce stage-structured matrix models for resident Canada geese from both urban and rural landscapes. We ran stochastic simulations to assess 3 management activities for Atlantic Flyway Resident Population Canada geese: harvest, nest treatment, and cull. Unrealistic harvest rates, in excess of 10% for urban geese, would be needed to reduce the urban population to target levels within 10 years in the absence of other management activities. Nest treatment to prevent hatching is less controversial than culling adults, but as many as 62% of eggs in urban areas would need to be treated annually to sufficiently reduce the mean stochastic population growth rate. Cull would be the most effective way to achieve the population goal, but current cull rates are insufficient to reduce the urban population. Although reduction of urban geese was a challenge, current management activities in rural populations appeared to be sufficient to reduce populations. We also provide a simple spreadsheet tool for managers who want to explore management options for other resident Canada goose populations by inserting relevant vital rate estimates for their populations and manipulating management activities. © 2016 The Wildlife Society.
A portable aviary for field observations of behavior
(Journal of Field Ornithology, 2002-01-01) Van Why, Kyle R.; Williams, Christopher K.; Applegate, Roger D.; Flock, Brian E.
We describe a lightweight, portable, and inexpensive field aviary that was designed for observing Northern Bobwhite (Colinus virginianus) vigilance and feeding behavior. The general construction details of this aviary are easily modified to accommodate a variety of bird species and research objectives. SINOPSIS. Aviario portatil para hacer observaciones en el campo sobre la conducta de aves Describimos un aviario porta´til, liviano y de bajo costo disen˜ado para hacer estudios sobre la conducta alimentaria de Colinus virginianus. Los detalles en generales de construccio´n de este aviario se puede modificar fa´cilmente para acomodar una gran variedad de aves y diferentes objetivos de investigacio´n.
A qualitative study of healthcare providers’ attitudes toward assisted partner notification for people with HIV in Indonesia
(BMC Health Services Research, 2023-01-24) Levy, Judith A.; Earnshaw, Valerie A.; Milanti, Ariesta; Waluyo, Agung; Culbert, Gabriel J.
Background Assisted partner notification (APN) is recommended as a public health strategy to increase HIV testing in people exposed to HIV. Yet its adoption in many countries remains at an early stage. This qualitative study sought the opinions of HIV health service providers regarding the appropriateness and feasibility of implementing APN in Indonesia where such services are on the cusp of adoption. Methods Four focus group discussions totaling 40 health service providers were held in Jakarta, Indonesia to consider APN as an innovative concept and to share their reactions regarding its potential implementation in Indonesia. Voice-recorded discussions were conducted in Bahasa, transcribed verbatim, and analyzed. Results Participants recognized APN’s potential in contacting and informing the partners of HIV-positive clients of possible viral exposure. They also perceived APN’s value as a client-driven service permitting clients to select which of three partner notification methods would work best for them across differing partner relationships and settings. Nonetheless, participants also identified personal and health system challenges that could impede successful APN adoption including medical and human resource limitations, the need for specialized APN training, ethical and equity considerations, and lack of sufficient clarity concerning laws and government policies regulating 3rd party disclosures. They also pointed to the job-overload, stress, personal discomfort, and the ethical uncertainty that providers might experience in delivering APN. Conclusion Overall, providers of HIV services embraced the concept of APN but forecast practical difficulties in key service areas where investments in resources and system change appeared necessary to ensure effective and equitable implementation.
A Quantitative Summary of Attitudes toward Wolves and Their Reintroduction (1972-2000)
(Wildlife Society Bulletin, 2002) Williams, Christopher K.; Ericsson, Göran; Heberlein, Thomas A.
This paper reports an analysis of support for wolves (Canis spp.) reported in 38 quantitative surveys conducted between 1972 and 2000. Of 109 records reported in these surveys, a majority (51 %) showed positive attitudes toward wolves and 60% supported wolf restoration. Attitudes toward wolves had a negative correlation with age, rural residence, and ranching and farming occupations, and positive correlation with education and income. Thirty-five percent of ranchers and farmers surveyed had positive attitudes toward wolves. Among surveys of the general population samples, 61 % expressed positive attitudes. Surveys of environmental and wildlife groups showed an average of 69% support. Surveys in the lower 48 states showed higher proportions of positive attitudes than surveys in Scandinavia and Western Europe, where a majority did not support wolves. Among all surveys, 25% of respondents had neutral attitudes toward wolves. Positive attitudes toward wolves did not appear to be increasing over time. Because attitudes toward wolves are often not strong among the general public, they have the potential to change rapidly if linked to other, stronger attitudes and beliefs. We expect that progress in education and urbanization will lead to increasingly positive attitudes over time. Negative attitudes associated with age are probably a cohort effect, and we should not expect the aging populations in the United States and Europe to lead to more negative wolf attitudes. Paradoxically, successful wolf reintroductions are likely to reduce general positive sentiment, since the presence of wolves gives people a more balanced experience with the animals. Traditionally, people with the most positive attitudes toward wolves have been those with the least experience.
A recreation demand model for warmwater fishing in Delaware with welfare effects for improvements in catch rates, species diversity, and water clarity
(Agricultural and Resource Economics Review, 2024-03-18) Dalvand, Kaveh; Parsons, George
We estimate a recreation demand model for warmwater fishing in Delaware and then use it to measure welfare gains associated with improved fishing quality as measured by catch rate of fish, diversity of species, and clarity of water. We use a “linked” site choice – trip frequency model with data gathered by the Delaware Division of Fish and Wildlife. Our site choice model includes 118 rivers and lakes in the state with detailed characteristics of each. We develop hypothetical scenarios of fishing quality improvement involving combinations of fish catch, fish diversity, and water clarity and apply it to individual water bodies, water basins, selected water body groupings, and statewide. Values are reported in seasonal per angler and aggregate terms.
A Reflection on the Relationship Between Place and Health: Understanding Undergraduate Student Experiences and Priorities During the COVID-19 Pandemic
(Delaware Journal of Public Health, 2022-08) Rao, Abhigna; Hoffman, Lindsay; Bleakley, Amy; Karpyn, Allison
Environment and setting have a large influence on matters of population health, and college is a critical place for students, shaping both health and education. College students across the nation were impacted by the COVID-19 pandemic, and changes at universities left many anxious, isolated, and coping with social, emotional, and educational impacts. Objective: To perform a data analysis of the qualitative responses garnered through the Student Return to Campus Survey administered at the University of Delaware (UD) in Spring 2020, and to identify common themes of student experiences and priorities during the pandemic years to inform future recommendations for health crisis management. Methods: The study utilized secondary data analysis from an online student experience survey of 2,941 Freshman, Sophomore, and Junior students from the 2020-2021 academic year. Results: Qualitative analysis revealed a set of common outstanding themes influencing the college pandemic experience, including: Quality and Accessibility of Education in a Virtual Learning Environment; Quality of Student Life; Mental Health During the Pandemic; Thoughts and Attitudes About Vaccination Policies, Masking, Testing, and COVID Guidelines; Priorities and Considerations About the Return to Campus; and Overall Feelings About the Pandemic at UD. Conclusions: Student experiences were influenced by academic, social, emotional, and financial factors, which were often described with great intensity, and were at times contradictory. Students emphasized struggles with transitioning to and with virtual learning, the quality of campus resources, financial responsibilities, family health, and personal health. The results also shed light on the importance of communication with the campus community and the desire for students to express opinions during a crisis. Health Policy Implications: The results of this study have implications for crisis management for college campuses and planning for future responses to unanticipated events and ongoing COVID-19 mitigation efforts.
A satellite-based mobile warning system to reduce interactions with an endangered species
(Ecological Applications, 2021-05-30) Breece, Matthew W.; Oliver, Matthew J.; Fox, Dewayne A.; Hale, Edward A.; Haulsee, Danielle E.; Shatley, Matthew; Bograd, Steven J.; Hazen, Elliott L.; Welch, Heather
Earth-observing satellites are a major research tool for spatially explicit ecosystem nowcasting and forecasting. However, there are practical challenges when integrating satellite data into usable real-time products for stakeholders. The need of forecast immediacy and accuracy means that forecast systems must account for missing data and data latency while delivering a timely, accurate, and actionable product to stakeholders. This is especially true for species that have legal protection. Acipenser oxyrinchus oxyrinchus (Atlantic sturgeon) were listed under the United States Endangered Species Act in 2012, which triggered immediate management action to foster population recovery and increase conservation measures. Building upon an existing research occurrence model, we developed an Atlantic sturgeon forecast system in the Delaware Bay, USA. To overcome missing satellite data due to clouds and produce a 3-d forecast of ocean conditions, we implemented data interpolating empirical orthogonal functions (DINEOF) on daily observed satellite data. We applied the Atlantic sturgeon research model to the DINEOF output and found that it correctly predicted Atlantic sturgeon telemetry occurrences over 90% of the time within a 3-d forecast. A similar framework has been utilized to forecast harmful algal blooms, but to our knowledge, this is the first time a species distribution model has been applied to DINEOF gap-filled data to produce a forecast product for fishes. To implement this product into an applied management setting, we worked with state and federal organizations to develop real-time and forecasted risk maps in the Delaware River Estuary for both state-level managers and commercial fishers. An automated system creates and distributes these risk maps to subscribers’ mobile devices, highlighting areas that should be avoided to reduce interactions. Additionally, an interactive web interface allows users to plot historic, current, future, and climatological risk maps as well as the underlying model output of Atlantic sturgeon occurrence. The mobile system and web tool provide both stakeholders and managers real-time access to estimated occurrences of Atlantic sturgeon, enabling conservation planning and informing fisher behavior to reduce interactions with this endangered species while minimizing impacts to fisheries and other projects.
A suite of agronomic factors can offset the effects of climate variability on rainfed maize production in Kenya
(Scientific Reports, 2022-10-03) Oluoch, Kevin Ong'are; De Groote, Hugo; Gitonga, Zachary M.; Jin, Zhenong; Davis, Kyle Frankel
Achieving food security in sub-Saharan Africa (SSA) is a multidimensional challenge. SSA reliance on food imports is expected to grow in the coming decades to meet the population's demand, projected to double to over 2 billion people by 2050. In addition, climate change is already affecting food production and supply chains across the region. Addressing these multiple food security challenges will necessitate rapid enhancements in agricultural productivity, which is influenced by a host of demographic, agronomic, and climatic factors. We use statistical approaches to examine rainfed maize in Kenya, where maize cultivation and consumption are widespread and central to livelihoods and national food security. We find that improving a suite of agronomic factors, such as applying fertilizer, planting certified seeds, and extension services, will have a greater effect on rainfed maize productivity than demographics and can offset the effects of climate change. These findings could also offer insights into similar challenges for other crops in Kenya and other SSA countries.
Adaptation to compound climate risks: A systematic global stocktake
(iScience, 2023-02-17) Simpson, Nicholas P.; Williams, Portia Adade; Mach, Katharine J.; Berrang-Ford, Lea; Biesbroek, Robbert; Haasnoot, Marjolijn; Segnon, Alcade C.; Campbell, Donovan; Musah-Surugu, Justice Issah; Joe, Elphin Tom; Nunbogu, Abraham Marshall; Sabour, Salma; Meyer, Andreas L.S.; Andrews, Talbot M.; Singh, Chandni; Siders, A.R.; Lawrence, Judy; van Aalst, Maarten; Trisos, Christopher H.; The Global Adaptation Mapping Initiative Team
Highlights: • Compound climate impacts are particularly hard to adapt to • Compound vulnerabilities and exposures constrain adaptation capabilities • Inappropriate responses to climate change can lead to maladaptation • Compound impacts can have cascading effects on response options Summary: This article provides a stocktake of the adaptation literature between 2013 and 2019 to better understand how adaptation responses affect risk under the particularly challenging conditions of compound climate events. Across 39 countries, 45 response types to compound hazards display anticipatory (9%), reactive (33%), and maladaptive (41%) characteristics, as well as hard (18%) and soft (68%) limits to adaptation. Low income, food insecurity, and access to institutional resources and finance are the most prominent of 23 vulnerabilities observed to negatively affect responses. Risk for food security, health, livelihoods, and economic outputs are commonly associated risks driving responses. Narrow geographical and sectoral foci of the literature highlight important conceptual, sectoral, and geographic areas for future research to better understand the way responses shape risk. When responses are integrated within climate risk assessment and management, there is greater potential to advance the urgency of response and safeguards for the most vulnerable. Graphical abstract at: https://doi.org/10.1016/j.isci.2023.105926
Adaptive Thermal Control of Cell Groups to Extend Cycle Life of Lithium-Ion Battery Packs
(Applied Sciences, 2023-04-07) Connor, Wesley D.; Advani, Suresh G.; Prasad, Ajay K.
We present a novel approach for a battery management system in which adaptive thermal control is employed to balance the capacities of individual groups of cells within a lithium-ion battery pack. Maintaining capacity balance within the battery pack in this manner can significantly extend its cycle life. We explore the physical implementation of this concept and demonstrate that it is a viable way to extend the life of battery packs. The experimental setup consists of three pairs of cells connected electrically in series and supplied with coolant flow from a chiller. All cells are initially in capacity balance and are cooled uniformly for the first 50 fast charge/discharge cycles. Subsequently, cooling is halted to specific cell pairs to deliberately unbalance their capacities. Finally, cooling is selectively restored to correct the capacity imbalance between the cell groups by the end of 100 charge/discharge cycles. These results suggest that adaptive thermal control can be used effectively to maintain capacity balance within the battery pack.
Addressing variability in estuarine food density for American black ducks
(Wildlife Society Bulletin, 2016-07-08) Goldstein, Marissa; Williams, Christopher K.; Castelli, Paul. M.; Duren, Kenneth R.
Habitat limitation and availability of food energy may be the cause of decline in American black duck (Anas rubripes) populations. Estimating food availability is a critical step in developing winter carrying-capacity estimates for black ducks. Recent research has estimated the biomass and energy supply of winter black duck foods in coastal marshes using a single-core sampling method, but estimates had large variability. We tested whether taking bulk core samples (i.e., homogenizing multiple core samples and subsampling a single core from it) at the same location (vs. a single core sample) would alter the mean and variance in food estimates in 7 different landscape–vegetation types (hereafter, habitat types: mudflat, subtidal, low marsh, high marsh, quasi-tidal pools, a tidal impoundment, and a freshwater impoundment) in coastal New Jersey, USA, during 2011. In all but one habitat type, there were no differences in the mean biomass or the mean energy density estimates for the single core samples and the bulk core samples, across all food types. Variance was reduced in subtidal and quasi-tidal pool habitats, but variance increased in tidal impoundments. Assessing time and cost-efficiency of bulk samples over single samples, cost per sample increased 4–12%/core. Because we observed little difference in food biomass, energy, and their respective variance estimates between single and bulk methods, while recording a slightly greater cost, we recommend researchers use the single-core sampling method to save both time and money. Further reductions in variance will likely need to be achieved through increased sample sizes. © 2016 The Wildlife Society.
Advancing Wildlife Policy of Eastern Timber Wolves and Lake Sturgeon through Traditional Ecological Knowledge
(Sustainability, 2022-03-24) Schley, Hannah L.; West, Ilene F.; Williams, Christopher K.
Traditional Ecological Knowledge (TEK) is becoming more prominent in wildlife management decisions and policy making. The cooperation of TEK and Western science paradigms have been beneficial for conserving our natural resources and wildlife populations. However, there are still concerns with accepting TEK as part of wildlife management, policy, and regulations. With increasing challenges to wildlife conservation, it is vital to implement Indigenous TEK to form more robust and holistic approaches to wildlife management. Here, we present two case studies in the upper Midwest region of the United States involving the Ojibwe tribe that show the importance of TEK collaboration and how that knowledge can be used for the betterment of ecologically sensitive species—lake sturgeon and eastern timber wolves.
Aggregation and Degradation of Dispersants and Oil by Microbial Exopolymers (ADDOMEx): Toward a Synthesis of Processes and Pathways of Marine Oil Snow Formation in Determining the Fate of Hydrocarbons
(Frontiers in Marine Science, 2021-07-19) Quigg, Antonietta; Santschi, Peter H.; Xu, Chen; Ziervogel, Kai; Kamalanathan, Manoj; Chin, Wei-Chun; Burd, Adrian B.; Wozniak, Andrew; Hatcher, Patrick G.
Microbes (bacteria, phytoplankton) in the ocean are responsible for the copious production of exopolymeric substances (EPS) that include transparent exopolymeric particles. These materials act as a matrix to form marine snow. After the Deepwater Horizon oil spill, marine oil snow (MOS) formed in massive quantities and influenced the fate and transport of oil in the ocean. The processes and pathways of MOS formation require further elucidation to be better understood, in particular we need to better understand how dispersants affect aggregation and degradation of oil. Toward that end, recent work has characterized EPS as a function of microbial community and environmental conditions. We present a conceptual model that incorporates recent findings in our understanding of the driving forces of MOS sedimentation and flocculent accumulation (MOSSFA) including factors that influence the scavenging of oil into MOS and the routes that promote decomposition of the oil post MOS formation. In particular, the model incorporates advances in our understanding of processes that control interactions between oil, dispersant, and EPS in producing either MOS that can sink or dispersed gels promoting microbial degradation of oil compounds. A critical element is the role of protein to carbohydrate ratios (P/C ratios) of EPS in the aggregation process of colloid and particle formation. The P/C ratio of EPS provides a chemical basis for the “stickiness” factor that is used in analytical or numerical simulations of the aggregation process. This factor also provides a relative measure for the strength of attachment of EPS to particle surfaces. Results from recent laboratory experiments demonstrate (i) the rapid formation of microbial assemblages, including their EPS, on oil droplets that is enhanced in the presence of Corexit-dispersed oil, and (ii) the subsequent rapid oil oxidation and microbial degradation in water. These findings, combined with the conceptual model, further improve our understanding of the fate of the sinking MOS (e.g., subsequent sedimentation and preservation/degradation) and expand our ability to predict the behavior and transport of spilled oil in the ocean, and the potential effects of Corexit application, specifically with respect to MOS processes (i.e., formation, fate, and half-lives) and Marine Oil Snow Sedimentation and Flocculent Accumulation.

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