Open Access. Powered by Scholars. Published by Universities.®

Oceanography

Institution
Keyword
Publication Year
Publication
Publication Type

Articles 331 - 360 of 401

Full-Text Articles in Fresh Water Studies

Thermoelectric Generation And Thermophysical Properties Of Metal Oxide Nanofluids, Xinran Hou, Rong-Tsu Wang, Shaowen Huang, Jung-Chang Wang Mar 2021

Thermoelectric Generation And Thermophysical Properties Of Metal Oxide Nanofluids, Xinran Hou, Rong-Tsu Wang, Shaowen Huang, Jung-Chang Wang

Journal of Marine Science and Technology–Taiwan

This study describes the comprehensive characterization of the diverse water-based nanofluids involving aluminum oxide, titanium dioxide, and zinc oxide nanoparticles, which were prepared through the two-step synthesis method assisted by a microemulsion ultrasound skill with effects of both weight-percent concentration (wt.%) in the range of 1.0% and 5.0% and between 20 oC and 40 0C. The mean cluster size, zeta potential, pH value, viscosity, thermal conductivity, absorbance, light absorption, and electrical charge density of the various nanofluids were surveyed by relative experiments. The results showed that the 2 wt.% Al2O3, 2 wt.% TiO2 …


Wireless Sensor Network-Based Monitoring Of Bridge Pile Foundations For Detecting Scouring Depth, Han-Tang Huang, H. Ping Tserng, Ruei-Yu Hou, Mirosław Skibniewski Mar 2021

Wireless Sensor Network-Based Monitoring Of Bridge Pile Foundations For Detecting Scouring Depth, Han-Tang Huang, H. Ping Tserng, Ruei-Yu Hou, Mirosław Skibniewski

Journal of Marine Science and Technology–Taiwan

Climate change brings about unprecedented increases in the occurrence of storms and flooding. In response to increased risk of bridge pier scouring, there is a need for increased safety monitoring of bridges. This paper presents a wireless sensor network (WSN) - based solution developed to measure micro-vibrations of a bridge pier. Test measurement values are converted with the use of the Fast Fourier Transform (FFT) method to obtain natural frequencies. Scouring depth of the pier is estimated with the use of a Finite Element Method model. WSN is used to collect the signal and to test data transmission stability in …


A New Fuzzy Dea Model For Solving The Mcdm Problems In Supplier Selection, Chi-Mao Tsai, Hsuan-Shih Lee, Guo-Ya Gan Mar 2021

A New Fuzzy Dea Model For Solving The Mcdm Problems In Supplier Selection, Chi-Mao Tsai, Hsuan-Shih Lee, Guo-Ya Gan

Journal of Marine Science and Technology–Taiwan

Supplier selection is a crucial task in supply chain management, and good supply chain management is essential to a company's ability to develop sustainably and gain the trust and satisfaction of its customers. In modern supply chain management, supplier selection often takes the form of a multi-criteria decision-making (MCDM) problem. Thus, to solve this problem, this study formulated a novel fuzzy MCDM model, which is based on the fuzzy data envelopment analysis model. This novel approach can transform the linguistic variables of assessment criteria into well-founded quantitative data for calculation. Moreover, our approach can effectively discriminate between decision-making units (both …


Evaluation Of The Human Discomfort Caused By Ship Vibrations, Laurentiu Picu, Eugen Rusu Mar 2021

Evaluation Of The Human Discomfort Caused By Ship Vibrations, Laurentiu Picu, Eugen Rusu

Journal of Marine Science and Technology–Taiwan

The present work analyzes the subjective responses of people exposed to transient vibrations caused by systems with a single degree of freedom. In this context, the main objective of the research was to identify the main effect of vibrations on people's well-being at work (in particular on vessels crew) and to discover those frequencies that lead to the greatest discomfort. In order to achieve this goal, 12 laboratory experiments were carried out involving ten male subjects in good health, aged between 28 and 42. The variables of the vibratory system considered are: acceleration (4.8 ÷ 8.6 m/s¡2), amplitude (1 ÷ …


Application Of Physically Based Semi-Distributed Hec-Hms Model For Flow Simulation In Tributary Catchments Of Kaohsiung Area Taiwan, Fiaz Hussain, Ray-Shyan Wu, Kai-Chun Yu Mar 2021

Application Of Physically Based Semi-Distributed Hec-Hms Model For Flow Simulation In Tributary Catchments Of Kaohsiung Area Taiwan, Fiaz Hussain, Ray-Shyan Wu, Kai-Chun Yu

Journal of Marine Science and Technology–Taiwan

Hydrologic modeling is a commonly used tool to understand the rainfallerunoff processes of gauged and ungauged catchments for proper quantitative estimation of water resources availability. In the present study, an attempt is made to simulate surface runoff using a physically based semi-distributed hydrological (HEC-HMS) model for four local-scale tributary catchments of Kaohsiung area Taiwan. The input physical parameters of the model were calculated and preprocessed in HEC-GeoHMS based on digital elevation model (DEM), land use, soil and hydro-meteorological data. The model performance was satisfactory with Nash Sutcliffe Efficiency (NSE) ¼ 0.51 to 0.86 and the coefficient of determination (R2) ¼ …


Evaluating Key Factors Of Container Shipping Lines From The Perspective Of High-Tech Industry Shippers, Chien-Lung Hsu, Tien-Chun Ho Mar 2021

Evaluating Key Factors Of Container Shipping Lines From The Perspective Of High-Tech Industry Shippers, Chien-Lung Hsu, Tien-Chun Ho

Journal of Marine Science and Technology–Taiwan

Because of the changes in customers' needs and demands created by the development of container transport in the 1960s, the global container transport business has become increasingly competitive. With the high-tech industry ranged with one of the few competitive industries in Taiwan from 2002, container shipping lines have been forced to implement innovative operating patterns to meet the evolving demands of the high-tech industry shippers. This study conducts a survey questionnaire of domestic high-tech industry shippers to explore the different factors affecting their selection of container shipping lines, evaluating the key influencing factors by maritime marketing's 4C framework: customer needs, …


Beach Topography Surveying Using Unmanned Aerial Vehicle Photogrammetry Technology, Hui-Ming Fang, Kuan-Tsung Chang, Sung-Shan Hsiao, Shih-Peng Chiang Mar 2021

Beach Topography Surveying Using Unmanned Aerial Vehicle Photogrammetry Technology, Hui-Ming Fang, Kuan-Tsung Chang, Sung-Shan Hsiao, Shih-Peng Chiang

Journal of Marine Science and Technology–Taiwan

The mechanisms of in situ topography changes must be identified for spatial planning in coastal areas. In this study, the authors used in situ direct measurement methods and indirect remote-sensing technologies to develop a method for beach topography surveillance. Unmanned aerial vehicles (UAVs) have advantages of high portability and mobility and low operating altitude. Therefore, a UAV was equipped with a lightweight camera and a positioning system that comprised a global positioning system and an inertial measurement unit. Aerial photogrammetry and aerial triangu-lation methods were adopted for matching image feature points to obtain the corresponding topographic points in the sand. …


Monitoring 2019 Bonnet Carré Spillway Impacts - Final Report, J. Read Hendon, Jerry D. Wiggert, Jill Hendon Dec 2020

Monitoring 2019 Bonnet Carré Spillway Impacts - Final Report, J. Read Hendon, Jerry D. Wiggert, Jill Hendon

Faculty Publications

Due to the multiple and extended openings of the Bonnet Carré Spillway in 2019, the University of Southern Mississippi (USM) was tasked by the Mississippi Department of Marine Resources to conduct ecological sampling in the Mississippi Sound and adjacent waters. in an effort to better understand the impacts of the extensive freshwater diversion of Bonnet Carré Spillway operations on Mississippi's coastal and marine resources. The period of performance for this project was June 1, 2019, to August 31, 2019. This technical report summarizes the three months of weekly surveys and analyses, over June - August 2019, conducted by the University …


Trace Metals And The Environment: Studying The Behaviour Of Iceland’S Glacially Sourced Trace Metals, Owen Bailey Oct 2020

Trace Metals And The Environment: Studying The Behaviour Of Iceland’S Glacially Sourced Trace Metals, Owen Bailey

Independent Study Project (ISP) Collection

Trace metal contamination in marine ecosystems is a problem for every trophic level, from zooplankton up to humans. The mobility and uptake availability of these metals depend on such environmental parameters as salinity, temperature, and pH, among others. To explore the effects of varying parameters on dissolved metal behaviour, I studied the Jökulsárlón glacial lagoon, into which the Breidamerkurjökull glacier deposits trace metals from volcanic ash through glacial melt. In this study I develop and follow a sampling procedure to analyze trace metal concentrations in the lagoon, while additionally discussing the behaviour and impact of trace metals, focusing on cadmium, …


Statement Of World Aquatic Scientific Societies On The Need To Take Urgent Action Against Human-Caused Climate Change, Based On Scientific Evidence [Dear Colleague Letter], Scott A. Bonar, Brian R. Murphy, Leanne H. Roulson, Jesse T. Trushenski, Douglas J. Austen, Michael Edward Douglas Jul 2020

Statement Of World Aquatic Scientific Societies On The Need To Take Urgent Action Against Human-Caused Climate Change, Based On Scientific Evidence [Dear Colleague Letter], Scott A. Bonar, Brian R. Murphy, Leanne H. Roulson, Jesse T. Trushenski, Douglas J. Austen, Michael Edward Douglas

United States Fish and Wildlife Service: Publications

Dear Colleague Letter from the American Fisheries Society to fellow scientific societies, July 25, 2020, about the urgent need for responsive collective action to mitigate impending radical climate change. Includes the Statement of World Aquatic Scientific Societies on the Need to Take Urgent Action Against Human-Caused Climate Change, Based on Scientific Evidence, emphasizing the importance of aquatic ecosystems. Includes extensive citations and notes.

"Water is the most important natural resource on Earth as it is vital for life. Aquatic ecosystems, freshwater or marine, provide multiple benefits to human society, such as provisioning of oxygen, food, drinking water, genetic resources; regulation …


Phosphorus Variability In The Area Of Influence Of The Mid-Barataria Sediment Diversion, Peter Mates Jul 2020

Phosphorus Variability In The Area Of Influence Of The Mid-Barataria Sediment Diversion, Peter Mates

LSU Master's Theses

Man-made levees along the lower Mississippi River prevent delivery of sediment from building and maintaining Louisiana’s coastal wetlands. The Mid-Barataria sediment diversions is designed to reintroduce Mississippi River water, sediment, and nutrients into the sediment-starved Barataria Basin. Phosphorus (P) is an important macronutrient for regulating primary production in coastal marine ecosystems. Wetlands can serve as a sink or source for phosphorus to the overlying water column through various retention and release processes, dependent on concentration. Louisiana coastal systems can be phosphorus limited due to much higher concentrations of bioavailable Nitrogen in river water. The high soluble molar N:P ( >50:1) …


Identification And Quantification Of Microplastic Pollution In Water Samples And Four Species Of Fish From The Mississippi River, Kerrin E. Toner Jul 2020

Identification And Quantification Of Microplastic Pollution In Water Samples And Four Species Of Fish From The Mississippi River, Kerrin E. Toner

LSU Master's Theses

Microplastics (£5 mm) have become a persistent anthropogenic pollutant and a growing environmental concern with evidence of them being found throughout several ecosystems. In recent years, there has been a growing recognition that rivers play a major role in transporting plastics from the land to the sea. The Mississippi River is the largest river in North America, draining land populated by over 100 million people. With high numbers of microplastics found in the waters of the northern of the Gulf of Mexico, it is likely that the Mississippi River is the primary source of these plastics. This study quantifies and …


Seasonal Transport Of Dissolved Inorganic Carbon And Total Alkalinity Across The Louisiana Shelf, Michelle M. Anderson Jun 2020

Seasonal Transport Of Dissolved Inorganic Carbon And Total Alkalinity Across The Louisiana Shelf, Michelle M. Anderson

LSU Master's Theses

Rivers and wetlands are a major source of terrestrial derived carbon for coastal ocean margins. Unfortunately, Louisiana’s wetlands are threatened by ongoing high rates of erosion, deterioration, and unprecedented rates of river water discharge that changes seasonally, leading to a net loss of terrestrial carbon into the northern Gulf of Mexico (nGOM). There exists a current lack of understanding about the distribution of dissolved inorganic carbon (DIC) and total alkalinity (TAlk) within the shallowest regions of the Louisiana shelf. Even less is known about how the transport of DIC alters seasonally with changes in river outflow and shelf currents. Quantifying …


Microplastics In Mississippi River Fishes: A Watershed Approach, Ahmed Gad Jun 2020

Microplastics In Mississippi River Fishes: A Watershed Approach, Ahmed Gad

LSU Master's Theses

Microplastics are plastic particles less than 5mm that come from different sources, such as industrial products, cosmetics, and the breakdown of the macroplastics. Microplastics derive from terrestrial sources but concentrate in flowing freshwaters where they may enter aquatic food webs. The northern Gulf of Mexico has shown very high microplastic concentrations, which are assumed to be sourced from the Mississippi River and its watershed. This study seeks to study microplastics in fish in the Mississippi River and the Gulf of Mexico. Fish stomachs and intestines from fish underwent chemical digestion, filtration, and microplastics identification and enumeration through FT-IR spectrometry. Chapter …


Internet Of Things For Environmental Sustainability And Climate Change, Abdul Salam Jan 2020

Internet Of Things For Environmental Sustainability And Climate Change, Abdul Salam

Faculty Publications

Our world is vulnerable to climate change risks such as glacier retreat, rising temperatures, more variable and intense weather events (e.g., floods, droughts, and frosts), deteriorating mountain ecosystems, soil degradation, and increasing water scarcity. However, there are big gaps in our understanding of changes in regional climate and how these changes will impact human and natural systems, making it difficult to anticipate, plan, and adapt to the coming changes. The IoT paradigm in this area can enhance our understanding of regional climate by using technology solutions, while providing the dynamic climate elements based on integrated environmental sensing and communications that …


On The Frontlines - The Fishermen Of Ibrahim Hyderi, Muhammad Haris Aslam Khan Dec 2019

On The Frontlines - The Fishermen Of Ibrahim Hyderi, Muhammad Haris Aslam Khan

MSJ Capstone Projects

Climate change has become a matter of recent debate for much of the world. According to a report published by a German watch, a non-governmental organization, in 2019, Pakistan among the five countries at severe risk of climate change disasters.

During the last two decades, Pakistan saw more than 141 extreme climatic catastrophes. Only in 2016, more than 566 people died due to these conditions.

A report published by Asian Development Bank in 2017 indicates Pakistan’s climate change profile. It states that more than 1,600 people have lost their lives in the super flood of 2010 alone. A loss of …


Coastal Stream Salinity And Its Impacts On Pemba Agriculture, Sara Mccormack Oct 2019

Coastal Stream Salinity And Its Impacts On Pemba Agriculture, Sara Mccormack

Independent Study Project (ISP) Collection

The extent of saltwater inundation of coastal streams was assessed on Pemba Island near agricultural areas in northeastern and northwestern regions of the island. Conductivity and pH were measured from water samples collected at various distances along the stream to determine the extent of salinity at different points in the tidal cycle. This salinity data, as well as the context of recent weather events, runoff, and geological characteristics of the region were used to determine the primary factors that influence changes in surface water salinity. The primary factor that influences surface water salinity was determined to be changes in stream …


Estuarine Dissolved Organic Carbon Flux From Space: With Application To Chesapeake And Delaware Bays, Sergio R. Signorini, Antonio Mannino, Marjorie A.M. Friedrichs, Pierre St-Laurent, John Wilkin, Aboozar Tabatabai, Raymond G. Najjar, Eileen E. Hofmann, Fei Da, Hanqin Tian, Yuanzhi Yao Jun 2019

Estuarine Dissolved Organic Carbon Flux From Space: With Application To Chesapeake And Delaware Bays, Sergio R. Signorini, Antonio Mannino, Marjorie A.M. Friedrichs, Pierre St-Laurent, John Wilkin, Aboozar Tabatabai, Raymond G. Najjar, Eileen E. Hofmann, Fei Da, Hanqin Tian, Yuanzhi Yao

CCPO Publications

This study uses a neural network model trained with in situ data, combined with satellite data and hydrodynamic model products, to compute the daily estuarine export of dissolved organic carbon (DOC) at the mouths of Chesapeake Bay (CB) and Delaware Bay (DB) from 2007 to 2011. Both bays show large flux variability with highest fluxes in spring and lowest in fall as well as interannual flux variability (0.18 and 0.27 Tg C/year in 2008 and 2010 for CB; 0.04 and 0.09 Tg C/year in 2008 and 2011 for DB). Based on previous estimates of total organic carbon (TOCexp) exported by …


Evaluating Seasonal Nutrient Fluxes In Emerging And Eroding Wetlands Of The Louisiana Delta Plain, Kiran Upreti Mar 2019

Evaluating Seasonal Nutrient Fluxes In Emerging And Eroding Wetlands Of The Louisiana Delta Plain, Kiran Upreti

LSU Doctoral Dissertations

Deltaic wetlands can ameliorate high NO3- loads via denitrification, a dominant NO3- reduction pathway in inland and coastal habitats. Dissimilatory Nitrate Reduction to Ammonia (DNRA), in contrast to denitrification, conserves N within the system and has been found to be favored over denitrification with increase in salinity and temperature. There are no studies in the Louisiana Deltaic plain with simultaneous estimation of denitrification and DNRA. Increased P availability has been shown to increase denitrification so it is essential to understand P biogeochemistry when studying N cycle. Here, we evaluated net denitrification using N2:Ar and …


Assessing The Skill Of The Improved Treatment Of Riverine Freshwater In The Community Earth System Model Relative To A New Salinity Climatology, Qiang Sun, Michael M. Whitney, Frank O. Bryan, Yu-Heng Tseng Jan 2019

Assessing The Skill Of The Improved Treatment Of Riverine Freshwater In The Community Earth System Model Relative To A New Salinity Climatology, Qiang Sun, Michael M. Whitney, Frank O. Bryan, Yu-Heng Tseng

Department of Marine Sciences

Recent studies have explored the sensitivity of global ocean model simulations to the treatment of riverine freshwater and the representation of estuarine processes via an estuary box model (EBM) applied within CESM. This study builds on these efforts by assessing the model skill score relative to a new salinity climatology. The new climatology averages the original observational data of the World Ocean Database directly onto the CESM ocean-component tracer-grid cells without spatial interpolation, smoothing, or other gap-filling techniques to mitigate coastal ocean salinity bias present in the World Ocean Atlas. The mean squared error (MSE) for coastal upper ocean salinity …


Characterizing Freshwater Phytoplankton Dynamics With Electro-Optical Remote Sensing, Michael Sayers Jan 2019

Characterizing Freshwater Phytoplankton Dynamics With Electro-Optical Remote Sensing, Michael Sayers

Dissertations, Master's Theses and Master's Reports

Freshwater lakes are an important component contributing to ecosystem health and biodiversity on local, regional, and global scales. And while lakes only represent <5% of the global surface area, they are often very productive systems which contribute significantly to carbon cycling dynamics and freshwater fish production on a number of spatial scales. Due to the remote location and sheer size of some of these lakes it has proven difficult to adequately document changes in water quality. Significant challenges exist to adequately monitor water quality, and in particular phytoplankton dynamics, over large spatial and temporal scales using traditional in situ methods. Satellite electro-optical remote sensing offers a potential tool to provide better characterization of phytoplankton dynamics for a variety of freshwater systems. This work resulted in an approach to quantify global summer phytoplankton abundance using a newly developed remote sensing derived chlorophyll-a product. This product was also used in conjunction with a newly created carbon fixation model to assess global freshwater phytoplankton production which provided new insights into the role freshwater systems play in the …


Ebullition Of Oxygen From Seagrasses Under Supersaturated Conditions, Matthew H. Long, Kevin Sutherland, Scott D. Wankel, David J. Burdige, Richard C. Zimmerman Jan 2019

Ebullition Of Oxygen From Seagrasses Under Supersaturated Conditions, Matthew H. Long, Kevin Sutherland, Scott D. Wankel, David J. Burdige, Richard C. Zimmerman

OES Faculty Publications

Gas ebullition from aquatic systems to the atmosphere represents a potentially important fraction of primary production that goes unquantified by measurements of dissolved gas concentrations. Although gas ebullition from photosynthetic surfaces has often been observed, it is rarely quantified. The resulting underestimation of photosynthetic activity may significantly bias the determination of ecosystem trophic status and estimated rates of biogeochemical cycling from in situ measures of dissolved oxygen. Here, we quantified gas ebullition rates in Zostera marina meadows in Virginia, U.S.A. using simple funnel traps and analyzed the oxygen concentration and isotopic composition of the captured gas. Maximum hourly rates of …


Hydroclimate Drivers And Atmospheric Dynamics Of Floods, Nasser Najibi Jan 2019

Hydroclimate Drivers And Atmospheric Dynamics Of Floods, Nasser Najibi

Dissertations and Theses

Our preliminary survey showed that most of the recent flood-related studies did not formally explain the physical mechanisms of long-duration and large-peak flood events that can evoke substantial damages to properties and infrastructure systems. These studies also fell short of fully assessing the interactions of coupled ocean-atmosphere and land dynamics which are capable of forcing substantial changes to the flood attributes by governing the exceeding surface flow regimes and moisture source-sink relationships at the spatiotemporal scales important for risk management. This dissertation advances the understanding of the variability in flood duration, peak, volume, and timing at the regional to the …


Micro-Spi Sediment Profile Imaging Micro-Inspector, Andrew P. Corvin, Caleb T. Davies, Matt R. Ferrari Jun 2017

Micro-Spi Sediment Profile Imaging Micro-Inspector, Andrew P. Corvin, Caleb T. Davies, Matt R. Ferrari

Mechanical Engineering

This project was proposed by Dr. Brian Paavo through a desire to more easily study the benthic sediment layers of the ocean. To do so, he asked us to build a simple and compact machine for use in sediment profile imagery (SPI). Although devices like this already exist, they are all large scale devices that require a ship with a crane to deploy, which is expensive and time consuming. Instead, he desired a “micro” SPI, which is capable of being deployed from a small vessel that can easily navigate shallow waters. Our interpretation of these requirements was as follows: a …


Groundwater And Tidal Controls On Wetland Hydrology, Julie J. Metz Wetland Mitigation Bank, Woodbridge, Virginia, Benjamin Stuart Hiza Apr 2017

Groundwater And Tidal Controls On Wetland Hydrology, Julie J. Metz Wetland Mitigation Bank, Woodbridge, Virginia, Benjamin Stuart Hiza

OES Theses and Dissertations

Julie J. Metz Wetlands Mitigation Bank, a 92-hectare freshwater wetland located in Woodbridge, Virginia, borders the tidally-influenced Neabsco Creek. Seven pods separated by earthen berms were built by Wetland Studies and Solutions Inc. (WSSI) in 1995 and 1997 by removing the toe of small sandy alluvial fans and covering the underlying coarse gravel bed with a low permeability cap. The basal Quaternary gravels were deposited in a creek valley incised into a thick sand-and-clay Cretaceous delta. The alluvial-fan apron developed at the base of steep slopes along the sides of the valley. Pressure transducer data from five monitoring wells along …


Crowdsourcing Global Wastewater Data, Don Mosteller, Sam Cohen, Cory Nestor, Angel Hsu, Omar Malik Sep 2015

Crowdsourcing Global Wastewater Data, Don Mosteller, Sam Cohen, Cory Nestor, Angel Hsu, Omar Malik

Yale Day of Data

No time to waste: Crowdsourcing global wastewater treatment data

Worldwide, over 80 percent of wastewater is discharged into water bodies without undergoing treatment, severely impairing human well-being and ecosystem vitality along the way. National performance on wastewater treatment is difficult to quantify and is poorly understood due to a lack of common definitions, poor data collection standards, and limited historical data. To address this, the Yale Environmental Performance Index (EPI), a research group that produces a biennial ranking of country-level environmental performance, developed a first-of-its kind national wastewater treatment indicator.[1]

The indicator assesses wastewater treatment performance for 183 countries, …


Improved Monitoring Of The Changjiang River Plume In The East China Sea During The Monsoon Season Using Satellite Borne L-Band Radiometers, Bumjun Kil May 2015

Improved Monitoring Of The Changjiang River Plume In The East China Sea During The Monsoon Season Using Satellite Borne L-Band Radiometers, Bumjun Kil

Dissertations

Measurement of sea surface salinity (SSS) from Satellite borne L-band (1.4 GHz, 21cm) radiometers (NASA Aquarius/SAC-D and ESA SMOS) in the East China Sea (ECS) is challenging due to the uncertainty of SSS caused by land thermal emissions in the antenna side lobes and because of strong radio frequency interference (RFI) due to illegally emitted man-made sources. RFI contamination in the ECS has gradually decreased because of the on-going international efforts to eliminate broadcasts in the protected L-band radio-astronomy frequency band. The present dissertation focuses on carefully eliminating the remaining RFI contamination in retrieved SSS, and masking out regions close …


A Survey Of Aquatic Organisms For The Cyanotoxin Beta-Methylamino-L-Alanine (Bmaa), Ian M. Sammler Apr 2015

A Survey Of Aquatic Organisms For The Cyanotoxin Beta-Methylamino-L-Alanine (Bmaa), Ian M. Sammler

OES Theses and Dissertations

Cyanobacteria blooms are increasing globally as a result of eutrophication. Many cyanobacteria are potentially harmful, not only because of the oxygen depleted zones created when they decay, but also because of the toxins they produce. β- Methylamino-L-alanine (BMAA), reportedly produced by many species of cyanobacteria, is a non-proteinogenic amino acid that has been linked to the development of neurodegenerative diseases (amyotrophic lateral sclerosis (ALS) and Alzheimer's) in humans. This study presents results from an assessment of BMAA in cyanobacteria and their grazers from the lower Chesapeake Bay and Lake Erie regions. BMAA was analyzed in samples prepared with the EZ:Faast™ …


Characterization And Photodegradation Of Dissolved Organic Matter (Dom) From A Tropical Lake And Its Dominant Primary Producer, The Cyanobacteria Microcystis Aeruginosa, Thais B. Bittar, Aron Stubbins, Armando A. H. Vieira, Kenneth Mopper Jan 2015

Characterization And Photodegradation Of Dissolved Organic Matter (Dom) From A Tropical Lake And Its Dominant Primary Producer, The Cyanobacteria Microcystis Aeruginosa, Thais B. Bittar, Aron Stubbins, Armando A. H. Vieira, Kenneth Mopper

Chemistry & Biochemistry Faculty Publications

This study investigates optical and high-resolution molecular signatures and photochemical degradation of DOM from the Barra Bonita Reservoir (BB-DOM), a tropical eutrophic lake, as well as from its dominant phytoplankton species, the cyanobacteria Microcystis aeruginosa (Microcystis-DOM). Consistent with a predominantly autotrophic source, BB-DOM and Microcystis-DOM exhibited high protein-like fluorescence and contained a large number of aliphatics. Microcystis-DOM was enriched in peptide-like formulae, while BB-DOM had higher chromophoric and fluorescent DOM(CDOM and FDOM) and was enriched in moderately unsaturated formulae, indicating additions of terrigenous DOM and/or in situ processing of autochthonous material in the lake. Consistent with …


The Saco River Plume: A Discussion Of The Near-Field Dynamics, Barbara A. Fortier Jul 2014

The Saco River Plume: A Discussion Of The Near-Field Dynamics, Barbara A. Fortier

All Theses And Dissertations

This study focused on the freshwater discharge plume from the Saco River in southwestern Maine to determine the mechanisms responsible for the largest impacts on the near-field dynamics in this region. We examined the forcing factors that tended to increase the plume's spatial extent upshelf of the river mouth. Salinity, temperature, and density data were collected during cruises from May through November 2010 and by two surface moorings deployed upshelf of the Saco River mouth. We found a distinct variation in the latitude of the upshelf boundary of the plume during and after periods of high discharge. Furthermore, we found …