Digital Commons Network^™

Nitrate Levels In The Tap Water Of Several Northeast Iowa Communities In 2026, Kamyar Enshayan

Faculty Publications

Tap water samples were taken from numerous sites in several northeast Iowa communities along the Cedar River to learn what levels of nitrate people are actually drinking over a several-months period in 2026, with the hope of inspiring public conversations, understanding and action. Samples were taken from February to June 2026.  None of the tap water samples violated the current outdated nitrate limit of 10 mg/l set 35 years ago. However, published public health studies in the past 15 years reveal that consuming nitrate in drinking water at levels as low as 5mg/l for a long time can increase the …

Upper Mora River Corridor Plan. Path To Social And Economic Recovery. A Working Paper, José A. Rivera Ph.D

Faculty Publications

The Working Paper outlines a plan for the Upper Mora River Corridor as a path to the social and economic recovery of the watershed and its communities in the Mora Valley of New Mexico in the aftermath of the year 2022 wildfires. The first section of the plan includes an historical overview of the traditional gristmills of northern New Mexico and places where a few of them are preserved and still standing. The next section goes into detail as to the early commercial mills situated along the upper Mora River Corridor with a focus on the four remaining mills: the …

Climate Change And The Reconfiguration Of Arctic Access, Charles H. Norchi, Amanda H. Lynch

Faculty Publications

The Arctic is warming faster than any other region on Earth, with surface air temperatures increasing at a rate nearly four times the global average.1 This amplification of global change has been reshaping the Arctic for decades, altering sea ice extent and thickness, snow regimes, permafrost stability, and hydrological systems. Against this backdrop, a persistent narrative has taken hold that the diminishing cryosphere2 is setting the table for opportunity: opening the Arctic to navigation, development, and exploitation. But this thaw renders the Arctic neither benign nor uniformly accessible. The region remains frozen for most of the year, dark for months …

The Sortee Guidelines For Data And Code Quality Control In Ecology And Evolutionary Biology, Joel L. Pick, Bethany J. Allen, Benedicte Bachelot, Kevin R. Bairos-Novak, Jack A. Brand, Barbara Class, Tad Dallas, Pietro B. D'Amelio, Erola Fenollosa, Esteban Fernández-Juricic, Dylan G. Gomes, Matthew J. Grainger, Thomas Guillemaud, John Christian, Ruby Krasnow, Malgorzata Lagisz, Sebastian Lequime, Daniel S. Maynard, Shinichi Nakagawa, Rose E. O'Dea, Et. Al.

Faculty Publications

Open data and code are crucial to increasing transparency and reproducibility, and in building trust in scientific research. However, despite an increasing number of journals in ecology and evolutionary biology mandating for data and code to be archived alongside published articles, the amount and quality of archived data and code, and subsequent reproducibility of results, has remained worryingly low. As a result, a handful of journals have recruited dedicated data editors, whose role is to help authors increase the overall quality of archived data and code. There is, however, a general lack of consensus around what a data editor should …

Potential Impacts Of Climate Interventions On Marine Ecosystems, Kelsey E. Roberts, Tyler Rohr, Morgan R. Raven, Michael S. Diamond, Daniele Visioni, Ben Kravitz, Ryan Heneghan, Colleen M. Petrik, Daniele Bianchi, Kelly Ortega-Cisneros, Monica A. Morrison, Vanessa Van Heerden, Nicola A. Wiseman, Gouri Anil, Zachary J. Cannizzo, Marta Coll, Joshua Coupe, Ryan Freedman, Kristen Krumhardt, Lester Kwiatkowski, Nicole S. Lovenduski, Jessica Y. Luo, Holly C. Olivarez, Alan Robock, Jeroen Steenbeek, Cheryl S. Harrison

Faculty Publications

Rising global temperatures pose significant risks to marine ecosystems, biodiversity, and fisheries. Recent comprehensive assessments suggest that large-scale mitigation efforts to limit warming are falling short, and all feasible future climate projections, including those that represent optimistic emissions reductions, exceed the Paris Agreement's 1.5°C or 2° warming targets during this century. While avoiding further CO2 emissions remains the most effective way to prevent environmental destabilization, interest is growing in climate interventions—deliberate, large-scale manipulations of the environment aimed at reducing global warming. These include carbon dioxide removal (CDR) to reduce atmospheric CO2 concentrations over time, and solar radiation modification (SRM), which …

Ecologic Factors Contributing To West Nile Virus Hyperendemicity In Central South Carolina: An Integrated Vector–Human–Environmental Study, Elba S. Fridriksson, Ahayla Muraleedharan, Kyndall C. Dye-Braumuller, Madeleine M. Meyer, Kia Zellars, Hiuxuan Li, Melissa S. Nolan Ph.D., Mph

Faculty Publications

West Nile virus (WNV) is an endemic arboviral infection in the United States that has undergone phyloge-netic evolution since its introduction 25 years ago. An integrated vector–human–pathogen study was conducted in the summer of 2023 to unearth contemporary Culex quinquefasciatus habitat patterns and human transmission spillover foci in South Carolina, a state with historically little WNV data. A serosurvey revealed WNV seroprevalence 10 times the national average (22% versus 2%, respectively), with unusual epidemiologic risk factors. Female Culex quinquefas-ciatus WNV positivity was low (2.7%), with viral phylogenetics 100% homologous to the WN02 clade. Mosquito vectors clustered in affluent urban neighborhoods …

Research Initiative For Northeast Grazing Soils (Rings) Soil Carbon Data Report, Karla M. Jarecke, Joseph P. Amsili, Alexandra Contosta, Caitlin Hicks Pries, Kelsey H. Jensen, Morgan Mcclure, Alexander Steiner, Eric Von Wettberg, Mojtaba Zeraatpisheh

Faculty Publications

The Research Initiative for Northeast Grazing Soils (RINGS) is a multi-institutional collaboration with a mission to advance the understanding of soil organic carbon (SOC) dynamics in grazing systems across the northeastern United States. RINGS distributed a survey between October 2025 and June 2026 to researchers and practitioners across the Northeast to identify where SOC data has been collected and the basic field and lab methods used. The survey asked participants to describe existing soil datasets collected on land directly or indirectly impacted by grazing livestock. The survey was distributed to colleagues of RINGS researchers that work at university, corporate and …

Understanding Landowner Perceptions: Enhancing Conservation Easement Adoption In Missouri's Priority Landscapes, Mckenna N. Thompson, Jennah I. Klein, Robin M. Rotman, Sonja A. Wilhelm Stanis, Gus C. Raeker, Michele D. Baumer

Faculty Publications

Conservation of private lands is essential for protecting open space, supporting ecosystems and species, preserving resources, and facilitating outdoor recreation. One tool for private land conservation is a conservation easement – a voluntary legal agreement where a landowner surrenders certain rights to use or develop their property. This study explores landowner perceptions of perpetual conservation easements in areas of high conservation value in Missouri, focusing on landowners without existing easements. Through interviews, four themes emerge containing both motivations and constraints: prior knowledge, land protection, regulations, and finance. Many landowners were unfamiliar with conservation easements or had misconceptions or misunderstandings. The …

Esg Performance Evolution In Retail: A Systematic Review And Meta-Analysis, Jiyeon Kim Ph.D., Wooyoung Yang

Faculty Publications

Environmental, social, and governance (ESG) practices have transformed from peripheral corporate social responsibility initiatives into core strategic imperatives in retail. Despite growing interest, the literature remains fragmented across disciplines and geographic contexts, with no comprehensive sector-specific analysis examining the evolution of ESG performance in retail contexts. Following the PRISMA 2020 guidelines, we conducted a systematic review and meta-analysis of 127 empirical studies published between 1988 and 2024 across major databases. Random-effects models assessed ESG-performance relationships, while stakeholder theory, the resource-based view, and Consumer Behavior frameworks explained the underlying mechanisms through temporal and subsectoral analysis. ESG practices demonstrate significant positive correlations …

On Good Terms: Pathways To Decolonizing Science-Appropriated Indigenous Terminologies In Arctic Research, Stanislav Saas Ksenofontov, Vera Kuklina, Alexander Kholodov, Andrey Petrov

Faculty Publications

Many western scientific disciplines adopted Indigenous Knowledge and terminology without deference to or understanding of the original meanings and values attached to Indigenous terms and concepts. This form of scientific appropriation has become a serious barrier to efforts of decolonizing Arctic research. The notion of Alaas is an example of such appropriation by the western science-based system of Indigenous knowledge about human–nature relations. This paper aims to discuss the term Alaas as it is conceptualized in both western science and Indigenous knowledge. The paper will explore the development of “alas” as an international permafrost science term and Alaas as an …

Novel Sequential Modeling Framework Improves Phytoplankton Biomass Predictions In Response To Multiple Environmental Stressors, Zhuyin Tong, Jiayu Guo, Yikai Liu, Lizhen Lin, Jixin Chen, Xin Liu, Bangqin Huang, Edward A. Laws, Wupeng Xiao

Faculty Publications

Understanding the impacts of multiple environmental stressors on phytoplankton biomass is crucial for predicting marine ecosystem responses under global climate change. This study employed a sequential modeling framework integrating principal component analysis, generalized additive models, and artificial neural networks to improve predictions of phytoplankton chlorophyll a concentrations in the Taiwan Strait. Analyzing a decadal dataset, we found that a 2°C rise in sea surface temperature and a 0.2 pH decline will each lead to an 11.3% reduction in chlorophyll a biomass, whereas nitrogen enrichment is expected to increase it by only 2.8%. The combined effects of these stressors will result …

Prescribed Fire Leads A Pine Flatwoods Specialist Tree Frog To Seek Local Refugia, Ian Biazzo, Pedro F. Quintana-Ascencio

Faculty Publications

Pine savannas of the southeastern United States evolved with frequent low-intensity wildfires. Today, land managers use prescribed fires to restore this ecological process while also controlling vegetative fuel accumulation. Given the ubiquitous application of this management tool, studies should consider impacts on target and nontarget taxa in these systems. During fires, animal populations persist in the landscape when individuals emigrate to unburned areas or seek refugia within the burn zone; otherwise, they experience local extirpation. We examined the effect of prescribed fires on a pine flatwoods specialist frog, the pinewoods treefrog Dryophytes femoralis, in a frequently burned pine landscape. …

Special Delivery Of Proteinaceous Matter To Deep-Sea Microbes, Yuan Shen, Ronald Benner, Taylor A.B. Broek, Brett D. Walker, Matthew D. Mccarthy

Faculty Publications

Earth’s deep ocean holds a vast reservoir of dissolved organic carbon, traditionally considered old and resistant to microbial degradation. Radiocarbon analyses indicate the hidden occurrence of younger dissolved organic carbon components, assumed to be accessible to deep-sea microorganisms but not yet demonstrated. Using compound-class radiocarbon analysis, molecular characterization, and bioassay experiments, we provide direct evidence for rapid microbial utilization of young, labile, high–molecular weight proteinaceous material in bathypelagic waters. The abundance of labile proteinaceous material diminishes from epipelagic to mesopelagic waters but notably increases in bathypelagic waters, where it exhibits a short turnover time (days) and resembles surface plankton in …

Teaching Archival Silences With The New Hampshire Maps Collection, Kai H. Uchida

Faculty Publications

This conference presentation was given at the Annual Spring 2025 Meeting for New England Archivists.

For the past two years, the University Archivist at Milne Special Collections and Archives at the University of New Hampshire has partnered with an instructor in the Natural Resources and Environmental Studies Department to teach about its historic map collections. This presentation will discuss the planning, execution, and lessons learned from using a historic state maps collection to educate students on the concept of "archival silence," and to advocate for the use of historical map collections to develop critical archival and data literacies.

Flood Risk And Mitigation Calculator Tool To Support Decision-Making For Enhancing Community Resilience: A Case Study Of The U.S.A. Gulf Coastal Region, Rubayet Bin Mostafiz, Ayat Al Assi, Arash Taghinezhad, Carol J. Friedland, Robert V. Rohli, Md Adilur Rahim, Christopher T. Emrich, Melanie Gall, Eric Johnson

Faculty Publications

Real-estate websites make it easy to find and access information about a home. Information on property value, square footage, number of rooms, quality of schools, crime rates, and more is readily available. Some of these platforms have begun integrating climate-related risks in generic ways. However, this information provides limited if any actionable value and is unlikely to guide people’s decision-making on buying or renting a home, deciding where to vacation, or investing in a property. Making residents aware of the natural hazard risks to which their homes may be exposed is an important component of making communities more resilient. Both …

Sars-Cov-2 Detection And Persistence In A Remote Amazonian Settlement, Glauco M. Silva, Roberto C. Ilacqua, Franciely G. Gonçalves, Carla M. Santana, Felipe T. Jordão, Paula R. Prist, Melissa S. Nolan Ph.D., Mph, Andreia F. Brilhante, Marcia A. Sperança, Gabriel Z. Laporta

Faculty Publications

Background: COVID-19 continues to pose a major global health challenge. Despite its geographic distance from Brazil’s major urban centers, Acre state has experienced notable outbreaks. This study assessed the detection and persistence of SARS-CoV-2 in the rural settlement of Santa Luzia, located in the remote municipality of Cruzeiro do Sul, Acre state, Brazil. Methods: In July 2022, a cross-sectional survey was conducted at 40 sites from an ongoing environmental study, selected by deforestation patterns and proximity to health posts. Saliva samples were collected from residents aged 5–90 years, followed by nucleic acid extraction and multiplex RT-qPCR for SARS-CoV-2 detection. Results: …

Net Evaporation-Induced Mangrove Area Loss Across Low-Lying Caribbean Islands, Isamar M. Cortés, Jorge Lorenzo-Trueba, Andre S. Rovai, Robert R. Twilley, Mark Chopping, Temilola Fatoyinbo

Faculty Publications

Although mangroves provide many beneficial ecosystem services, such as blue carbon storage and coastal protection, they are currently under threat due to changes in climate conditions, such as prolonged drought exposure. Under drought conditions, evaporation exceeds precipitation and high soil salinities can lead to stunted growth and die-back. To quantify this interplay, we developed a database for low-lying and uninhabited mangrove islands in the Caribbean under various evaporation and precipitation regimes. We extracted physical and biological information from each island using remote sensing techniques and coupled it with a process-based model. We used this database to develop a model that …

Research Overview On Urban Heat Islands Driven By Computational Intelligence, Chao Liu, Siyu Lu, Jiawei Tian, Lirong Yin, Lei Wang, Wenfeng Zheng

Faculty Publications

In recent years, the intensification of the urban heat island (UHI) effect has become a significant concern as urbanization accelerates. This survey comprehensively explores the current status of surface UHI research, emphasizing the role of land use and land cover changes (LULC) in urban environments. We conducted a systematic review of 8260 journal articles from the Web of Science database, employing bibliometric analysis and keyword co-occurrence analysis using CiteSpace to identify research hotspots and trends. Our investigation reveals that vegetation cover and land use types are the two most critical factors influencing UHI intensity. We analyze various computational intelligence techniques, …

Integrative Highway Rights-Of-Way Management To Reduce Stormwater Run-Off And Enhance Habitat, Madeline M. Showers, Robin M. Rotman

Faculty Publications

Nature-based management along highway rights-of-way (ROW) has been a focus in several states to benefit pollinators through supporting diverse and native vegetative communities. There is the potential to enhance the ecological benefits of this practice by integrating stormwater management into restoration plans and incorporating other complex, multidisciplinary factors. Historically, lack of technical assistance and limited resources has led managers to use unsustainable roadside practices that reduce the potential ecological services of the ROW; however, integrative management can aid in the prioritization of management efforts and link objectives of various resource agencies. In this literature review, we address the ecological impacts …

Macroevolution Of The Plant–Hummingbird Pollination System, Elisa Barreto, Mannfred M.A. Boehm, Ezgi Ogutcen, Stefan Abrahamczyk, Michael Kessler, Jordi Bascompte, Agnes S. Dellinger, Carolina Bello, D. Matthias Dehling, François Duchenne, Miriam Kaehler, Laura P. Lagomarsino, Lúcia G. Lohmann, María A. Maglianesi, Hélène Morlon, Nathan Muchhala, Juan Francisco Ornelas, Mathieu Perret, Nelson R. Salinas, Stacey D. Smith, Jana C. Vamosi, Isabela G. Varassin, Catherine H. Graham

Faculty Publications

Plant–hummingbird interactions are considered a classic example of coevolution, a process in which mutually dependent species influence each other's evolution. Plants depend on hummingbirds for pollination, whereas hummingbirds rely on nectar for food. As a step towards understanding coevolution, this review focuses on the macroevolutionary consequences of plant–hummingbird interactions, a relatively underexplored area in the current literature. We synthesize prior studies, illustrating the origins and dynamics of hummingbird pollination across different angiosperm clades previously pollinated by insects (mostly bees), bats, and passerine birds. In some cases, the crown age of hummingbirds pre-dates the plants they pollinate. In other cases, plant …

Conducting Structure-From-Motion (Sfm) Modeling Of Freshwater Environments Using Unpiloted Aerial Systems (Uas): Challenges And Lessons Learned, Benjamin T. Fraser, Christine L. Bunyon, Russell G. Congalton

Faculty Publications

The pairing of Unpiloted Aerial Systems (UAS) and Structure from Motion (SfM) has provided new capabilities for modeling freshwater environments. Applications of UAS-SfM range from water quality monitoring to the mapping of aquatic vegetation. The models produced provide users with the ability to analyze features at ultra-high-resolutions and across scales not easily achieved through in situ sampling. Despite the demonstrated benefits of UAS-SfM in freshwater and other natural resource disciplines, there remain fundamental technical challenges in the modeling of environments with homogenous surfaces (e.g., water). In this research, the effectiveness of several image collection and processing approaches for the modelling …

Snapshots Of Coastal Ecology Using Multiproxy Analysis Reveals Insights Into The Preservation Of Swamp And Marsh Environments Since The Late Pleistocene, Kendall Fontenot, Kristine L. Delong, Brian A. Schubert, Sophie Warny, Davin J. Wallace, Carrie M. Miller, Erin Culver-Miller, Michael J. Polito, Carl A. Reese, Kathryn Garretson, Kehui Xu, Grant L. Harley, Jeffrey Obelcz, Kelli L. Moran, Julian Traphagan, Douglas Jones, Alicia Caporaso

Faculty Publications

The southeastern United States Coastal Plain ecosystem contains baldcypress (Taxodium distichum) swamps and grass-dominated marshes. These ecosystems also occurred on the exposed continental shelf during lower sea levels but are rarely preserved due to the mechanically erosive nature of transgression and regression. Two presently marine sites on the northeastern Gulf of Mexico's continental shelf contain well-preserved woody terrestrial sediments that were the subject of previous studies. This study continues the investigation using geochemical (δ13C, δ15N, δ34S) and palynological characteristics of these formerly terrestrial sediments to determine if swamps and/or marshes existed at the time of deposition. The first site is …

Employing Digital Pcr For Enhanced Detection Of Perinatal Toxoplasma Gondii Infection: A Cross-Sectional Surveillance And Maternal-Infant Outcomes Study In El Salvador, Mary K. Lynn, Marvin Stanley Rodriguez Aquino, Pamela Michelle Cornejo Rivas, Xiomara Miranda, David F. Torres-Romero, Hanson Cowan, Madeleine M. Meyer, Willber D. Castro-Godoy, Mufaro Kanyangarara Ph.D., Stella Coker Watson Self Ph.D., Ms, Berry A. Campbell, Melissa Nolan Ph.D., Mph

Faculty Publications

Toxoplasma gondii is a parasitic infection that can be transmitted in utero, resulting in fetal chorioretinitis and other long-term neurological outcomes. If diagnosed early, pregnancy-safe chemotherapeutics can prevent vertical transmission. Unfortunately, diagnosis of acute, primary infection among pregnant women remains neglected, particularly in low-and-middle-income countries. Clinically actionable diagnosis is complex due to the commonality of infection during childhood and early adulthood which spawn long-last antibody titers and historically unreliable direct molecular diagnostics. The current study employed a cross-sectional T. gondii perinatal surveillance study using digital PCR, a next generation molecular diagnostic platform, and a maternal-fetal outcomes survey to ascertain …

A Sensor-Based Simulation Method For Spatiotemporal Event Detection, Yuqin Jiang, Andrey A. Popov, Zhenlong Li, Michael E. Hodgson, Binghu Huang

Faculty Publications

Human movements in urban areas are essential to understand human–environment interactions. However, activities and associated movements are full of uncertainties due to the complexity of a city. In this paper, we propose a novel sensor-based approach for spatiotemporal event detection based on the Discrete Empirical Interpolation Method. Specifically, we first identify the key locations, defined as “sensors”, which have the strongest correlation with the whole dataset. We then simulate a regular uneventful scenario with the observation data points from those key locations. By comparing the simulated and observation scenarios, events are extracted both spatially and temporally. We apply this method …

Employing Digital Pcr For Enhanced Detection Of Perinatal Toxoplasma Gondii Infection: A Cross-Sectional Surveillance And Maternalinfant Outcomes Study In El Salvador, Mary K. Lynn, Marvin Stanley Rodriguez Aquino, Pamela Michelle Cornejo Rivas, Xiomara Miranda, David F. Torres-Romero, Hanson Cowan, Madeleine M. Meyer, Willber D. Castro-Godoy, Mufaro Kanyangarara Ph.D., Stella C.W. Self Ph.D., Ms, Berry A. Campbell, Melissa S. Nolan Ph.D., Mph

Faculty Publications

Toxoplasma gondii is a parasitic infection that can be transmitted in utero, resulting in fetal chorioretinitis and other long-term neurological outcomes. If diagnosed early, pregnancysafe chemotherapeutics can prevent vertical transmission. Unfortunately, diagnosis of acute, primary infection among pregnant women remains neglected, particularly in low-andmiddle-income countries. Clinically actionable diagnosis is complex due to the commonality of infection during childhood and early adulthood which spawn long-last antibody titers and historically unreliable direct molecular diagnostics. The current study employed a cross-sectional T. gondii perinatal surveillance study using digital PCR, a next generation molecular diagnostic platform, and a maternal-fetal outcomes survey to ascertain the …

Indigenous Peoples And Local Communities Report Ongoing And Widespread Climate Change Impacts On Local Social-Ecological Systems, Victoria Sharakhmatova, Victoria Reyes-García, David García-Del-Amo, Santiago Álvarez-Fernández, Petra Benyei, Laura Calvet-Mir, André B. Junqueira, Vanesse Labeyrie, Xiaoyue Li, Sara Miñarro, Vincent Porcher, Anna Porcuna-Ferrer, Anna Schlingmann, Christoph Schunko, Ramin Soleymani, Adrien Tofighi-Niaki, Mariam Abazeri, Emmanuel M.N.A.N. Attoh, Ayansina Ayanlade, Julia Vieira Da Cunha Ávila, Daniel Babai, Rodrigo C. Bulamah, Joao Campos-Silva, Rosario Carmona, Julián Caviedes, Rumbidzayi Chakauya, Mouna Chambon, Zhuo Chen, Fasco Chengula, Esther Conde, Aida Cuní-Sanchez

Faculty Publications

The effects of climate change depend on specific local circumstances, posing a challenge for worldwide research to comprehensively encompass the diverse impacts on various local social-ecological systems. Here we use a place-specific but cross-culturally comparable protocol to document climate change indicators and impacts as locally experienced and analyze their distribution. We collected first-hand data in 48 sites inhabited by Indigenous Peoples and local communities and covering all climate zones and nature-dependent livelihoods. We documented 1,661 site-agreed reports of change corresponding to 369 indicators. Reports of change vary according to climate zone and livelihood activity. We provide compelling evidence that climate …

Migration And Erosion In Tidal And River Channels In Bangladesh, Katharine M. Donato, Leslie Valentine, Amanda Carrico, Carol A. Wilson, Kimberly G. Rogers, Timo Tonassi

Faculty Publications

Environmental stressors and natural disasters are changing the physical landscapes in many countries worldwide. In this paper, we ask whether and how erosion affects internal and international migration in Bangladesh. Building on prior studies, we use data from 3, 600 households in 18 research sites to investigate how erosion in tidal and river channels is related to the risk of making a first internal or international trip, net of extreme weather conditions and other relevant attributes. Findings reveal that the relationship between erosion and the likelihood of making a first domestic or international trip is moderated by livelihood type and …

Soil Legacy Nutrients Contribute To The Decreasing Stoichiometric Ratio Of N And P Loading From The Mississippi River Basin, Zihao Bian, Hanqin Tian, Shufen Pan, Hao Shi, Chaoqun Lu, Christopher Anderson, Wei Jun Cai, Charles S. Hopkinson, Dubravko Justic, Latif Kalin, Steven Lohrenz, Steven Mcnulty, Naiqing Pan, Ge Sun, Zhuonan Wang, Yuanzhi Yao, Yongfa You

Faculty Publications

Human-induced nitrogen–phosphorus (N, P) imbalance in terrestrial ecosystems can lead to disproportionate N and P loading to aquatic ecosystems, subsequently shifting the elemental ratio in estuaries and coastal oceans and impacting both the structure and functioning of aquatic ecosystems. The N:P ratio of nutrient loading to the Gulf of Mexico from the Mississippi River Basin increased before the late 1980s driven by the enhanced usage of N fertilizer over P fertilizer, whereafter the N:P loading ratio started to decrease although the N:P ratio of fertilizer application did not exhibit a similar trend. Here, we hypothesize that different release rates of …

Single-Cell Analysis In Hypersaline Brines Predicts A Water-Activity Limit Of Microbial Anabolic Activity, Emily R. Paris, Nestor Arandia-Gorostidi, Benjamin Klempay, Jeff S. Bowman, Alexandra Pontefract, Claire E. Elbon, Jennifer B. Glass, Ellery D. Ingall, Peter T. Doran, Sanjoy M. Som, Britney E. Schmidt, Anne E. Dekas

Faculty Publications

Hypersaline brines provide excellent opportunities to study extreme microbial life. Here, we investigated anabolic activity in nearly 6000 individual cells from solar saltern sites with water activities (aw) ranging from 0.982 to 0.409 (seawater to extreme brine). Average anabolic activity decreased exponentially with aw, with nuanced trends evident at the single-cell level: The proportion of active cells remained high (>50%) even after NaCl saturation, and subsets of cells spiked in activity as aw decreased. Intracommunity heterogeneity in activity increased as seawater transitioned to brine, suggesting increased phenotypic heterogeneity with increased physiological stress. No microbial activity was detected in the …

Responses Of Phytoplankton Communities To The Effect Of Both River Plume And Coastal Upwelling, Zhuyin Tong, Lingqi Ma, Shujie Cai, Lei Wang, Wupeng Xiao, Bangqin Huang, Edward A. Laws

Faculty Publications

River plumes and coastal upwelling systems are both nutrient-abundant habitats compared to the open ocean, and the mechanisms that structure the phytoplankton community when these occur together are unclear. In this study we investigated the dynamics and drivers of phytoplankton biomass and community composition in the Pearl River plume-coastal upwelling system on the northern South China Sea shelf during summer. We found that phytoplankton biomass was lower in the plume than in upwelled water. Diatoms were the only dominant group in the upwelled water. In contrast, diatoms and Synechococcus were co-dominant in the plume, and the negative correlation between the …