Digital Commons Network^™

Seasonal And Geologic Controls On Submarine Groundwater Discharge-Derived Nutrient Fluxes To Two Coastal Embayments, Moira Taylor, Joseph J. Tamborski, Aaron Alorda-Kleinglass, Nathaniel Maynard

OES Faculty Publications

Submarine groundwater discharge and porewater exchange are critical but often overlooked sources of nutrients to coastal systems. This study investigates how sediment permeability and summer-winter seasonal dynamics influence the magnitude and biogeochemistry of nutrient fluxes from submarine groundwater discharge and porewater exchange. Reaction rates in the subterranean estuary were used to identify the transformations and drivers of nutrient loading in two geologically distinct embayments in the U.S. East Coast: the highly permeable Peconic Bay estuary (NY), and the surficially fine-grained coastal embayments of the southern Delmarva Peninsula (VA). We applied radium isotope mass balances to distinguish total submarine groundwater discharge …

Characterizing The Unique Chemical Imprint Of On-Axis, Lower-Temperature Hydrothermal Flow To The Deep Ocean (Southern East Pacific Rise, 16.5°-18.0°S), Laura E. Moore, Randelle M. Bundy, Joseph A. Resing, Scott White, Tamara Baumberger, Peter N. Sedwick, Nathaniel J. Buck, Anson M. Antriasian, Isaac Keohane, Bettina M. Sohst, Sharon L. Walker, Christopher R. German

OES Faculty Publications

In addition to high-temperature vents, lower-temperature flow (LTF) (< 300°C) is abundant along mid-ocean ridges and contributes globally-important fluxes of heat and water along with largely-unconstrained geochemical influences on the ocean. We examined the impact of on-axis LTF on the chemical composition of the overlying water column (< 40 m above seafloor) along the 16.5°-18.0°S sector of the ultrafast-spreading southern East Pacific Rise using autonomous underwater vehicle Sentry surveys and conductivity-temperature-depth rosette casts. LTF sites were typically spatially isolated from high-temperature systems and imparted unique chemical signatures to the overlying ocean. Water column samples impacted by LTF exhibited low particulate iron:sulfur ratios and high methane: total-dissolvable manganese ratios, whereas samples influenced by high-temperature venting exhibited opposite trends. We confirmed that LTF imparts a distinct and measurable chemical signature to the water column, independent from high-temperature vents. Isolated, on-axis LTF will be important to consider when assessing hydrothermal circulation impacts upon ocean biogeochemistry.

Testing The Limits Of Provenance Analysis From Basaltic Fluvial Sediment Near Sandvatn, Iceland, As A Mars Analog, Audrey R. Putnam, Kirsten L. Siebach, Michael T. Thorpe, Valerie M. Tu, Elizabeth B. Rampe, Candice C. Bedford, Gelu Costin, Joseph J. Tamborski

OES Faculty Publications

Detrital sediments that accumulate downstream and are preserved in sedimentary rocks can allow characterization of geologic formations that are inaccessible for spatial or temporal reasons. However, mixing, sorting, and alteration of sediment during transport may complicate reconstruction of protolith characteristics. We test the preservation of three key provenance signals in coarse fluvial sand at a Mars analog watershed in Iceland to determine whether detrital sediments capture (a) watershed magmatic chemical variation, (b) textural indicators of lava-water interaction during eruption and cooling, and (c) hydrothermal alteration. Specifically, we tested whether diagnostic variations in rock mineralogy, chemistry, and texture can be recovered …

Contribution Of Non-Linear Internal Waves To Marine Net Primary Production Has Been Underestimated, Xiaoju Pan, Tung-Yuan Ho, George T. F. Wong, Jen-Hua Tai, Shoude Guan, Fuh-Kuo Shiah

OES Faculty Publications

Field observations in the northern South China Sea (NSCS) indicate that elevated concentrations of chlorophyll a (Chl_a) associated with non-linear internal waves (NIWs) were more pronounced in the subsurface than at the sea-surface. At a given surface Chl_a, the vertically integrated Chl_a in an NIW-active area was 45% higher than that in an area where the NIW activities were minimal. As a result, net primary production (PP_eu) estimated from surface Chl_a from remote sensing by using the current Chl_a-based PP_eu model (e.g. VGPM) would have underestimated the true value by the same amount. If this correction is …

Autonomous Float Data Reveal Decoupled Trends In Chlorophyll And Stratification In The Indian Ocean, Marufa Ishaque, Sophie Clayton, John Klinck

OES Faculty Publications

Recent studies have shown that the Indian Ocean is warming significantly, but how this warming impacts primary production is largely unresolved due to a relative lack of depth-resolved biological observations. In this study, we have used Biogeochemical-Argo data from 2013 to 2022, comprising over 9,000 individual profiles, to examine regional patterns and trends in depth-integrated chlorophyll, depth-integrated net primary production and stratification in the northern and Equatorial Indian Ocean. Our analysis shows that water column stratification is increasing in the majority of the study area, with the highest rate of increase observed in the western Bay of Bengal. At the …

Recirculated Submarine Groundwater Discharge Dominates Nutrient Inputs And Enhances Eutrophication Risk In A Coastal Lagoon, Júlia Rodriguez-Puig, Clara Ruiz-González, Marc Diego-Feliu, Irene Alorda-Montiel, Aaron Alorda-Kleinglass, Daniel Romano-Gude, Andrea G. Bravo, Júlia Dordal-Soriano, Javier Gilabert, Sophia Bergeler, Celine Lavergne, Gemma Casas, Marisol Manzano, Jordi Garcia-Orellana, Valentí Rodellas

OES Faculty Publications

Submarine groundwater discharge (SGD) is a widely recognized pathway for nutrient transport to coastal systems. Prior studies overlook the unique biogeochemical signatures of different SGD pathways, neglecting their differences in biogeochemical transformations and spatiotemporal factors. Here, we present an integrated assessment of nutrient delivery through three SGD pathways (fresh SGD, long‐scale recirculated SGD, and short‐scale porewater exchange), alongside surface water inputs, to evaluate their seasonality and impact on nutrient dynamics in a coastal lagoon. We conducted five field surveys in March, July, and November 2021, July 2024, and March 2025 in the Mar Menor lagoon, an ecosystem facing severe ecological …

Microbial Mats In Dinosaur Ichnocoenoses, Nora Noffke, Paul C. Murphy, Roger C. Buntin, Martin G. Lockley

OES Faculty Publications

Until now, the significance of microbial mats in preservation of dinosaur tracks and in reconstructing the palaeoenvironment in which dinosaurs roamed was rarely studied. Dinosaur tracks are commonly found close to ancient aquatic bodies where moist sediment had once allowed footstep registration. At such sites, epibenthic or endobenthic microbial mats may have developed as well and may have led to exquisite track preservation. Microbial mats in coastal, lacustrine or flood plain environments cause 'microbially induced sedimentary structures—MISS', which are micobialites found in sandy or evaporitic settings. The microbial structures record environmental parameters including meteorological conditions that existed at the time …

Unintended Consequences Of Estuarine Management Within The Trajectory Of Recovery: Examples From The Chesapeake Bay, Jessica S. Turner, Fei Da, Molly M. Mitchell

OES Faculty Publications

Estuaries are vital ecosystems that support biodiversity, human populations, and economic activities such as fisheries, aquaculture, and tourism. Managing estuarine systems often involves interventions to regulate sediment and nutrient inputs with the goal of improving water quality, and subsequently the economic values of the estuary. However, these management strategies can produce unintended consequences. The Chesapeake Bay is an estuary recovering from eutrophication which provides clear case studies for these patterns. In the Chesapeake Bay, decreased sediment inputs, resulting from shoreline stabilization and watershed modifications, can impair marsh resilience to sea level rise and disrupt sediment-light-algal interactions affecting water clarity. Likewise, …

Aquatic Macrophytes As Nature-Based Solutions: Challenges And Opportunities Across Inland And Coastal Waters, Morgan Botrel, Roxane Maranger, Lindsay L. Trottier, Mathieu Cusson, Lars L. Iverson, Fanny Noisette, Christian Nozais, Katrine Turgeon, Andrea Bertolo, Thibaud André-Alphonse, Simon Bélanger, Arthur De Grandpré, Jean-Olivier Goyette, Sabine Hilt, Ladd Johnson, Valérie Langlois, Martin Laporte, Félix Lauzon, Brigitte Légaré, Anne Ola, Marie-Pomme Presne-Poissant, Matthieu Prugne, Caroline Susini, Richard Zimmerman

OES Faculty Publications

Macrophytes are foundation species whose use as nature-based solution (NbS) in aquatic ecosystems can help reduce climate change impacts while mitigating biodiversity loss. The discrepancy in research and application of macrophytes as NbS across inland and marine coastal ecosystems is an opportunity to expand the concept and learn from different approaches. We report on an initiative uniting marine and freshwater scientists that compared knowledge on macrophytes as NbS across realms, identified advances and gaps in their use, and synthesized challenges and opportunities for application. We conducted a bibliometric analysis and an expert participatory exercise around recent review papers. We reveal …

The Effects Of A Microplate On Plume-Ridge Interactions: Constraints From Comparing Easter And Juan Fernandez Microplates In The Eastern Pacific Ocean, Katherine Ames, Jennifer Georgen

OES Faculty Publications

This study investigates the nature of plume-ridge interactions near a tectonic microplate using mantle Bouguer anomaly (MBA) gravity calculations. The focus of this investigation is a comparison of the Easter and Juan Fernandez microplates, which are located in the eastern Pacific Ocean along the Pacific, Nazca, and Antarctic plate boundaries. The microplates have several similar characteristics, including general size, time of formation, and clockwise rotation within the larger bounding mid-ocean ridge systems. Unlike the Juan Fernandez microplate, however, the Easter microplate is located near a mantle plume (Easter/Salas y Gomez). Previously published geochemical data suggest that material from this plume …

Regional Oceanographic Controls On Water Column Nitrogen Fixation In Northern Australian Waters, Douglas G. Capone, Ajit Subramaniam, Yubin Raut, Joseph P. Montoya, Margaret R. Mulholland, Rachel Ann Foster, Miles Furnas, Edward J. Carpenter

OES Faculty Publications

Large blooms of the diazotrophic cyanobacteria, Trichodesmium, have been re-ported along the north coast of Australia and are readily evident in remote sensing images. During a research cruise in November 1999, we sampled from Townsville to Broome, examined Trichodesmium population densities and their rates of carbon and N₂ fixation alongside microscopy-based cell counts of them and other cyanobacte-rial diazotrophs. Additionally, we also enumerated the picophytoplankton community using flow-cytometry, measured bulk chlorophyll concentrations, carbon and N₂ fixation rates, and water column hydrography, enabling comparison of diazotrophic and picophytoplankton functional groups across the system. Agglomerative hierarchical clustering analysis of physicochemical oceanographic …

Efficient Preservation Of Old Methane-Derived Organic Carbon In Deep-Sea Surface Sediments, Rui Bao, Yangli Che, Mingzhi Liu, Naiyu Zhang, Yang Zhou, Lihua Dong, Shen Li, Owen A. Sherwood, Min Yu, Zongheng Chen, Shengxiong Yang, Nan Wang, Longhai Zhu, Jiawang Chen, Mutai Bao, Haoshuai Li, Luonan Chen, Weifeng Wu, Haiyue Ma, David J. Burdige

OES Faculty Publications

Methane released from the subseafloor is significantly attenuated during upward migration, yet the preservation of methane-derived organic carbon (OC) in global deep-sea sediments remains poorly understood. Here, we measured carbon isotopes coupled with temperature-ramped analyses on various methane seepage sediments. Our results reveal a correlation between the radiocarbon (¹⁴)C) content in deep-sea surface sediments and sulfate-methane transition depth. Notably, our findings suggest that a substantial amount of (¹⁴)C-depleted OC may originate from deep-seated methane and is efficiently preserved in surface seepage sediments. We propose that the efficient OC preservation is related to microbial-mediated aggregate formation at the seawater-sediment interface, where …

Revisiting The Life Cycle Of Margalefidinium Polykrikoides Group Iii, Eduardo Pérez-Vega, Kenneth N. Mertens, Pjotr Meyvisch, Margaret R. Mulholland

OES Faculty Publications

Dinoflagellates produce cysts as a strategy to withstand environmental stressors, with nutrient depletion generally considered a key trigger for cyst production. Resting cysts are thick-walled, typically composed of one to several layers, and characterized by a prolonged dormancy period. In contrast, pellicle cysts possess a thin, single wall and exhibit no dormancy or a markedly shorter dormancy than resting cysts of the same species. Margalefidinium polykrikoides produces pellicle and resting cysts, whereas its congener, M. fulvescens, has been shown to produce pumpkin-like structures. Using phase-contrast microscopy, time-lapse microscopy, FlowCam, and attenuated total reflection Fourier transform infrared microspectroscopy (ATR μ-FTIR), …

Microplastics Suppress Copepod Grazing Of The Harmful Algal Bloom-Forming Dinoflagellate, Alexandrium Catenella, Megan Ladds, Christopher Gobler

OES Faculty Publications

While harmful algal blooms (HABs) are prominent occurrences in coastal zones where microplastic concentrations are maximal, the manner in which microplastics may influence food webs and HABs is poorly understood. This study explored how polystyrene microplastics affected copepod grazing of the saxitoxin-synthesizing harmful dinoflagellate, Alexandrium catenella, as well as a non-toxic dinoflagellate, Gymnodinium aureolum. Experiments were performed using multiple densities of microplastics (250 – 10,000 mL^–¹) of differing sizes (4 and 10 µm), as well as multiple densities of microalgae in microplates. The addition of 10 µm microplastics at densities of 1000 – 10,000 beads mL^{– …}

Visualizing The Barely Detectable: Particle Characteristics Of The Elusive Aquatic Gel Phase In The Northeastern Subtropical Atlantic, Huanqing Huang, María Couret, Santiago Hernández-León, Alexander B. Bochdansky

OES Faculty Publications

Marine gels constitute a large yet poorly explored ocean carbon pool. Shadow imaging was tuned to detect particles at two sensitivity levels: high–optical density particles (HODP), resembling the particles captured by most imaging systems, and low–optical density particles (LODP), representing a vastly more abundant and gel-dominated pool. This method enabled us to map and characterize a portion of oceanic gels without filtration and staining. In the subtropical northeast Atlantic, LODP outnumbered HODP of the same size by one or two orders of magnitude. Morphology and particle number spectra differed greatly between the two pools, with LODP showing greater morphological homogeneity …

Differences In Sideerophore Production During The Growth Of Phytoplankton In Southern Ocean Incubation Experiments Under High- And Low-Iron Conditions, Randelle M. Bundy, Kristen N. Buck, Bethany D. Jenkins, P. Dreux Chappell, Daniel J. Repeta, Alexa Sterling, Shannon M. Yang, Laura Holland, Léo Mahieu, Laura E. Moore

OES Faculty Publications

Iron is an important micronutrient required by marine microorganisms. The Southern Ocean is an ecosystem where primary production is limited by the availability of iron, but how microorganisms in this region adapt to low-iron conditions or respond to episodic iron inputs is understudied. We tested how external iron additions would impact bacterial production of siderophores during phytoplankton growth using shipboard incubation experiments under a range of iron conditions. Similar heterotrophic bacteria communities and phytoplankton biomass were observed whether iron was added from the continental margin or as inorganic iron. Under both high- and low-iron conditions, the heterotrophic bacteria community remained …

Remote Sensing Of Particulate Organic Carbon And Phytoplankton Carbon In The Northern South China Sea, Xiaoju Pan, Tung-Yuan Ho, George T. F. Wong, Jen-Hua Tai, Lijuan Nie

OES Faculty Publications

Surface concentrations of particulate organic carbon (POC) and phytoplankton carbon (C_phy) in the northern South China Sea (NSCS) have been assessed successfully by remote sensing with appropriate regional tuning. Match-up comparisons between satellite derivations and field observations showed uncertainties of ± 28.5% for POC and ± 37.0% for C_phy. The satellite-derived climatological distributions are consistent with previous reports. In the open NSCS where phytoplankton growth is controlled primarily by the convective overturn, both POC and C_phy are higher in winter, associating with the effect of stronger northeast monsoons and surface cooling, than in summer, when …

Different Last Millennium El Niño Southern Oscillation Sea Surface Temperature Patterns Drive Disparate North Atlantic Tropical Cyclone Characteristics, Elizabeth Wallace, Sylvia Dee, Andrew Bierbower, Xinyue Luo, Richard Sullivan, Wenchang Yang, Gabe Vecchi, Kerry Emanuel

OES Faculty Publications

Understanding the relationship between the El Niño-Southern Oscillation (ENSO) phenomenon and North Atlantic tropical cyclone (TC) activity is critical for both seasonal predictions and future projections of TCs. Unfortunately, the satellite observational era (1970-present) captures too few El Niño events to fully characterize the response of TC activity to this multivariate, multi-scalar, and non-linear climate phenomenon. Here we explore ENSO-TC teleconnections using large data sets (>100 k) of synthetic North Atlantic tropical cyclones simulated for the past millennium using three different climate reconstructions - two earth system models (Max Planck Institute, Community Earth System Model) and one paleoclimate data …

Water Mass Dynamics Drive Nitrogen Fixation Rates And Diazotroph Community Composition In The Coastal Region, Katherine E. Crider, Corday R. Selden, Kimberly Powell, Sing-How Tuo, Michael Muglia, Patterson Taylor, Margaret R. Mulholland, P. Dreux Chappell

OES Faculty Publications

Although significant N₂ fixation rates (NFRs) have been observed throughout mid-Atlantic coastal waters, studies have been limited in their temporal coverage, and the methods used to detect nitrogen fixers (diazotrophs) and their findings have varied. This study investigated NFRs and diazotroph communities in a dynamic coastal setting between Nags Head and Pea Island, North Carolina, USA, during a monthly time series from June 2019 to August 2020, and an August 2019 cruise. We observed movement of the Cape Hatteras Front and distinct NFRs and diazotroph communities in the Mid-Atlantic Bight, South-Atlantic Bight, Chesapeake Bay and Oregon Inlet plume waters, and …

Effect Of Density Irregularities On Radio Frequency Wave Propagation In Ionospheric Plasmas, Eun-Hwa Kim, Jay Johnson, Syun'ichi Shiraiwa, Nicola Bertelli, Masayuki Ono, Simon Wing

Faculty Publications

No abstract provided.

Effects Of Density Turbulence On Helicon Wave Propagation In The Core Plasmas, Eun-Hwa Kim, Syun'ichi Shiraiwa, Seung-Hoe Ku, A. Bortolon, Masayuki Ono, Nicola Bertelli, Robert I. Pinsker

Faculty Publications

No abstract provided.

Existence, Nonexistence And Uniqueness Of Positive Solution To A General Elliptic System With Fixed Or Perturbed Growth Rates, Joon Hyuk Kang, Noah Koliadko

Faculty Publications

No abstract provided.

Investigation Of Causal Relationships Of The Cross-Scale Wave Coupling Through Information Theoretical Approach, Elmer Rivera, J. Johnson, Simon Wing, Eun-Hwa Kim, Khan-Hyuk Kim, Katariina Nykyri

Faculty Publications

No abstract provided.

The Study Of The Quasi-Periodicity Observed On Plasma Density And Magnetic Field On Saturn's Magnetosphere: An Information Theory Approach, B. R. Neupane, J. R. Johnson, P. A. Delamere, Simon Wing, A. Sciola, K. Sorathia, Joe Caggiano, B. Mino, Colby Maxim

Faculty Publications

No abstract provided.

A Predator-Prey Biological Model Of Multiple Species With Linear Growth Rates, Joon Hyuk Kang

Faculty Publications

No abstract provided.

Impact Of Job Demands On Performance, Satisfaction, And Environment, Michelle Chin Loy

Theses and Dissertations

This applied dissertation examined the relationships between job resources, job demands, work engagement, perceived stress, and job satisfaction among university employees. The target participants for the study were employees at an academic institution in the South Florida area. The researcher e-mailed two surveys to the employees, and a response rate of 20% was achieved. One survey was conducted to assess the psychosocial work environment factors, and the impact on the employees’ well-being. The sub-scales used were Job Resources, Job Demands, Well-being outcomes, and Stress. The other survey measured the work engagement, the employees’ well-being, and how they experience enthusiasm, commitment, …

Usage Behavior Of Hispanic English Learners With Bilingual Homework Resources In Developmental Mathematics At Community College, Debra Krieg

Theses and Dissertations

This applied dissertation, grounded in the theoretical framework of metalinguistic awareness, was designed to understand how six Hispanic English learners (ELs) were utilizing homework help resources when offered in both English and Spanish. Specifically, the study was conducted at a mid-Atlantic community college with students enrolled in a developmental mathematics course. Homework has long been established as a tool that increases the probability of academic success. The shift to web-based assignments in developmental mathematics from traditional pencil and paper homework has yielded positive results yet little is known regarding how learners utilize bilingual digital assessment tools to achieve mastery of …

The Effectiveness Of Behavioral Skills Training In Enhancing Teachers’ Ability To Write Specific, Measurable, And Individualized Iep Goals Targeting Quality-Of-Life Skills, Emilia Endean

Theses and Dissertations

This applied dissertation sought to assess the effectiveness of a behavior skills training (BST) protocol in improving teacher behaviors for writing high-quality individualized education plan (IEP) goals that target quality-of-life (QoL) domains. High-quality IEP goals that target both academic and functional repertoires are required by the Individuals with Disabilities Education Act (2004) and are essential for students with disabilities to achieve meaningful outcomes. BST is an effective intervention for teaching a variety of skills. No prior research has explicitly examined the application of BST for teacher professional development in writing IEP goals.

This single-subject study used a time-lagged multiple probe …

Does Integrating Parental Involvement In Therapy Improve Behavior In Children With Attention Deficit Hyperactivity Disorder?, Pamela Lassiter

Theses and Dissertations

The research problem was the lower success rate of interventions for children with attention deficit hyperactivity disorder (ADHD) because of the exclusion of parents in the counseling process. The purpose of the research was to explore if integrating parent involvement in therapy improved the behaviors in children with ADHD. The study occurred at a private mental health facility that used cognitive behavior therapy and behavior interventions with the children.

The study was guided by the phenomenological qualitative research design. Ten single parents of male children, ages 4 to 10 with ADHD, participated in this study. Parents were selected using a …

Fairness: Examining Support And Resources Available To Respondents In Title Ix Cases, Emanuel Jerome Oliver

Theses and Dissertations

This phenomenological study explored how higher education institutions develop Title IX procedures to ensure respondents receive fair treatment from the outset of the adjudication process. It also examined how colleges and universities provide resources and support to respondents throughout the Title IX process. The study used semi structured interviews with Title IX Coordinators at various higher education institutions to understand how they have developed practices to support respondents.

Findings revealed that higher education institutions have developed various methods to support respondents in the Title IX process. The goal of the Title IX process is to ensure that respondents receive the …