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Full-Text Articles in Oceanography

A Statistical Fetch Model For Water Wave Glint Correction Using Worldview-3 Imagery, Amanda Jade Quintanilla May 2024

A Statistical Fetch Model For Water Wave Glint Correction Using Worldview-3 Imagery, Amanda Jade Quintanilla

Theses and Dissertations

Sun glint in satellite imagery of the water surface contaminates the upwelling signal received by a detector. Many models exist that attempt to correct for this wave facet effect and phenomena. In this work a model for sun glint correction is created using the comparison of image transects between two nearly simultaneously collected images of the same area, although with differing sensor geometry. One image utilized in this research is almost entirely glint free while the other is contaminated by water wave facet glint. Although many models for removing sun glint exist based on various techniques, none are completely accurate, …


Changes In Reef Tourism’S Adaptive Capacity After Severe Climate Disturbances, Henry Bartelet, Michele Barnes, Lalu Bakti, Graeme S. Cumming Apr 2024

Changes In Reef Tourism’S Adaptive Capacity After Severe Climate Disturbances, Henry Bartelet, Michele Barnes, Lalu Bakti, Graeme S. Cumming

Quantitative Methods and Information Technology Faculty Publications

Knowledge about adaptive capacity and its determinants has increased significantly over the last decade. However, most research on adaptive capacity has been static, not considering how adaptive capacity might change over time, particularly after severe disturbances. We studied the adaptive capacity dynamics of Asian-Pacific reef tourism operators affected by coral bleaching and tropical cyclones compared with a control group with non-affected operators. We found that impacts from tropical cyclones were associated with frequent changes in adaptive capacity. Notably, we found a reduction in tangible attributes (assets and flexibility) of adaptive capacity, whereas intangible attributes (agency and social organization) increased. Our …


Interactive Effects Of Co2, Temperature, And Nitrate Limitation On The Growth And Physiology Of Marine Cyanobacterium Synechococcus Sp. Ccmp 1334, Alyssa K. Sharbaugh Mar 2024

Interactive Effects Of Co2, Temperature, And Nitrate Limitation On The Growth And Physiology Of Marine Cyanobacterium Synechococcus Sp. Ccmp 1334, Alyssa K. Sharbaugh

LSU Master's Theses

The marine cyanobacterium Synechococcus sp. CCMP 1334 was grown in a continuous culture system on a 12:12 h light:dark cycle at all combinations of low and high pCO2 (400 and 1000 ppmv, respectively), nitrate availability (nitrate-limited and nutrient-replete conditions), and temperatures of 21°C, 24°C, 28°C, 32°C, and 35°C. The maximum median nutrient-replete growth rate was ~1.15 d−1 at 32 –35°C. Median growth rates at 1000 ppmv pCO2 were higher than those at 400 ppmv at all temperatures, but most of the differences were statistically insignificant. Carbon:nitrogen ratios were independent of pCO2 at a fixed relative growth rate but decreased with …


Sensor Analytics For Subsea Pipeline And Cable Inspection: A Review, Connor R. Vincent Mar 2024

Sensor Analytics For Subsea Pipeline And Cable Inspection: A Review, Connor R. Vincent

LSU Master's Theses

Submarine pipelines and cables are vital for transmitting physical and digital resources across bodies of water, necessitating regular inspection to assess maintenance needs. The safety of subsea pipelines and cables is paramount for sustaining industries such as telecommunications, power transmission, water supply, waste management, and oil and gas. Incidents like those involving the Nord Stream subsea pipeline and the SEA-ME-WE 4 subsea communications cable exemplify the severe economic and environmental consequences of damage to these critical infrastructures. Existing inspection methods often fail to meet accuracy requirements, emphasizing the need for advancements in inspection technologies. This comprehensive survey covers the sensors …


Maine Lobstermen's Association Whale Update, Amber-Jean Nickel, Maine Lobstermen's Association Feb 2024

Maine Lobstermen's Association Whale Update, Amber-Jean Nickel, Maine Lobstermen's Association

Fisheries

The Maine Lobstermen's Association “has been closely following the death of Right Whale 5120 found dead on Martha’s Vineyard on January 28th. The MLA was shocked and dismayed when NOAA Fisheries announced on February 14th that the rope removed from the deceased whale 'is consistent with the rope used in Maine state water trap/pot buoy lines.’”

“Maine lobstermen have made many changes to how we fish to avoid harming a Right whale which makes this news hard to believe. As we move forward, MLA will push back on NOAA’s finding until the industry’s questions about the entanglement and how NOAA …


Sulfate Enhances The Adsorption And Retention Of Cu(Ii) And Zn(Ii) To Dispersed And Aggregated Iron Oxyhydroxide Nanoparticles, Emma M. Kocik, Abigail Kim, Miranda L. Aiken, Lauren Smith, Christopher S. Kim Feb 2024

Sulfate Enhances The Adsorption And Retention Of Cu(Ii) And Zn(Ii) To Dispersed And Aggregated Iron Oxyhydroxide Nanoparticles, Emma M. Kocik, Abigail Kim, Miranda L. Aiken, Lauren Smith, Christopher S. Kim

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The adsorption and retention of metal ions to nanoscale iron (hydr)oxides in aqueous systems is significantly influenced by prevailing environmental conditions. We examined the influence of sulfate, the second most common anion in seawater that is present in many other natural aquatic systems, on the adsorption and retention of Cu(II) and Zn(II) to synthetic iron oxyhydroxide nanoparticles (NPs) and their aggregates. Batch uptake experiments with monodisperse NPs and NPs aggregated by changes in pH, ionic strength, and temperature were conducted over sulfate concentrations ranging from 0 to 0.30 M. The introduction of 0.03 M sulfate significantly increased the initial adsorption …


Southern Maine, New Hampshire, And Northern Massachusetts Continental Shelf Geophysical Database: 2022 Field Campaign – Grain Size Data, Station Summaries, And Seafloor Photographs, Larry G. Ward, Rachel C. Morrison, Michael Bogonko Feb 2024

Southern Maine, New Hampshire, And Northern Massachusetts Continental Shelf Geophysical Database: 2022 Field Campaign – Grain Size Data, Station Summaries, And Seafloor Photographs, Larry G. Ward, Rachel C. Morrison, Michael Bogonko

Data Catalog

Presented in this data report are the geophysical data collected during a major field campaign in 2022, with the purpose of obtaining ground truth for the expansion and improvement of high-resolution surficial geology maps of the western Gulf of Maine (WGOM) and for the description of reference sites developed for future evaluations of acoustic systems (Ward et al., 2021a; 2021b). Data from the UNH Ocean Engineering 972 Hydrographic Field Course classes in 2021 and 2022 are also included. This expansion of the geophysical database is being used to verify seafloor classifications in previously mapped areas that lack sufficient data, and …


A Computational Profile Of Invasive Lionfish In Belize: A New Insight On A Destructive Species, Joshua E. Balan Jan 2024

A Computational Profile Of Invasive Lionfish In Belize: A New Insight On A Destructive Species, Joshua E. Balan

The Journal of Purdue Undergraduate Research

Since their discovery in the region in 2009, invasive Indonesian-native lionfish have been taking over the Belize Barrier Reef. As a result, populations of local species have dwindled as they are either eaten or outcompeted by the invaders. This has led to devastating losses ecologically and economically; massive industries in the local nations, such as fisheries and tourism, have suffered greatly. Attempting to combat this, local organizations, from nonprofits to ecotourism companies, have been manually spear-hunting them on scuba dives to cull the population. One such company, Reef Conservation Institute (ReefCI), operating out of Tom Owens Caye outside of Placencia, …


Ecological Assessment Of Drainage Water Input On The Water Quality Of A Coastal Estuary, Mediterranean Coast Of Egypt, Fatma A. Zaghloul, Hoda A. E. Hemaida, Hayat M. Faragallah, Ahmed A. Radwan Jan 2024

Ecological Assessment Of Drainage Water Input On The Water Quality Of A Coastal Estuary, Mediterranean Coast Of Egypt, Fatma A. Zaghloul, Hoda A. E. Hemaida, Hayat M. Faragallah, Ahmed A. Radwan

Blue Economy

El Mex Bay, located west of Alexandria City, is identified as a hot spot of pollution along the Mediterranean coast of Egypt. It is a large, shallow, and turbid water body of socioeconomic importance. However, El Mex Bay receives a large amount of untreated industrial wastewater, as well as agricultural runoff from different land-based sources.

A comprehensive environmental study was carried out seasonally during 2020-2021. To evaluate the effect of this discharged wastewater on the water quality of El Mex Bay.

The physicochemical parameters were measured at both the surface and near-bottom water at nine stations.

Principal component analysis indicated …


Complex Dynamics Of Coral Gene Expression Responses To Low Ph Across Species, Veronica Z. Radice, Ana Martinez, Adina Paytan, Donald C. Potts, Daniel J. Barshis Jan 2024

Complex Dynamics Of Coral Gene Expression Responses To Low Ph Across Species, Veronica Z. Radice, Ana Martinez, Adina Paytan, Donald C. Potts, Daniel J. Barshis

Biological Sciences Faculty Publications

Coral capacity to tolerate low pH affects coral community composition and, ultimately, reef ecosystem function. Low pH submarine discharges (‘Ojo’; Yucatán, México) represent a natural laboratory to study plasticity and acclimatization to low pH in relation to ocean acidification. A previous >2‐year coral transplant experiment to ambient and low pH common garden sites revealed differential survivorship across species and sites, providing a framework to compare mechanistic responses to differential pH exposures. Here, we examined gene expression responses of transplants of three species of reef‐building corals (Porites astreoides, Porites porites and Siderastrea siderea) and their algal endosymbiont communities …


A Comparison Of Adenosine Triphosphate With Other Metrics Of Microbial Biomass In A Gradient From The North Atlantic To The Chesapeake Bay, Alexander B. Bochdansky, Amber A. Beecher, Joshua R. Calderon, Alison N. Stouffer, Nyjaee N. Washington Jan 2024

A Comparison Of Adenosine Triphosphate With Other Metrics Of Microbial Biomass In A Gradient From The North Atlantic To The Chesapeake Bay, Alexander B. Bochdansky, Amber A. Beecher, Joshua R. Calderon, Alison N. Stouffer, Nyjaee N. Washington

OES Faculty Publications

A new, simplified protocol for determining particulate adenosine triphosphate (ATP) levels allows for the assessment of microbial biomass distribution in aquatic systems at a high temporal and spatial resolution. A comparison of ATP data with related variables, such as particulate carbon, nitrogen, chlorophyll, and turbidity in pelagic samples, yielded significant and strong correlations in a gradient from the tributaries of the Chesapeake Bay (sigma-t = 8) to the open North Atlantic (sigma-t = 29). Correlations varied between ATP and biomass depending on the microscopic method employed. Despite the much greater effort involved, biomass determined by microscopy correlated poorly with other …


Re-Evaluating Hydrogen Sulfide As A Sink For Cadmium And Zinc In The Oxic To Suboxic Upper Water Column Of The Pacific Ocean, N. R. Buckley, E. E. Black, J. A. Kenyon, N. T. Lanning, M. Sieber, T. M. Conway, J. N. Fitzsimmons, G. A. Cutter Jan 2024

Re-Evaluating Hydrogen Sulfide As A Sink For Cadmium And Zinc In The Oxic To Suboxic Upper Water Column Of The Pacific Ocean, N. R. Buckley, E. E. Black, J. A. Kenyon, N. T. Lanning, M. Sieber, T. M. Conway, J. N. Fitzsimmons, G. A. Cutter

OES Faculty Publications

Hydrogen sulfide is produced by heterotrophic bacteria in anoxic waters and via carbonyl sulfide hydrolysis and phytoplankton emissions under oxic conditions. Apparent losses of dissolved cadmium (dCd) and zinc (dZn) in oxygen minimum zones (OMZs) of the Atlantic and Pacific Oceans have been attributed to metal-sulfide precipitation formed via dissimilatory sulfate reduction. It has also been argued that such a removal process could be a globally important sink for dCd and dZn. However, our studies from the North Pacific OMZ show that dissolved and particulate sulfide concentrations are insufficient to support the removal of dCd via precipitation. In contrast, apparent …


Delayed Coastal Inundations Caused By Ocean Dynamics Post-Hurricane Matthew, Kyungmin Park, Emanuele Di Lorenzo, Yinglong J. Zhang, Tal Ezer, Fei Yi Jan 2024

Delayed Coastal Inundations Caused By Ocean Dynamics Post-Hurricane Matthew, Kyungmin Park, Emanuele Di Lorenzo, Yinglong J. Zhang, Tal Ezer, Fei Yi

CCPO Publications

Post Hurricane Abnormal Water Level (PHAWL) poses a persistent inundation threat to coastal communities, yet unresolved knowledge gaps exist regarding its spatiotemporal impacts and causal mechanisms. Using a high-resolution coastal model with a set of observations, we find that the PHAWLs are up to 50 cm higher than the normal water levels for several weeks and cause delayed inundations around residential areas of the U.S. Southeast Coast (USSC). Numerical experiments reveal that while atmospheric forcing modulates the coastal PHAWLs, ocean dynamics primarily driven by the Gulf Stream control the mean component and duration of the shelf-scale PHAWLs. Because of the …


Exploring Market Segmentation For Autonomous Ferries, Ashari Fitra Rachmannullah, Taih Cherng Lirn, Kuo Chung Shang Jan 2024

Exploring Market Segmentation For Autonomous Ferries, Ashari Fitra Rachmannullah, Taih Cherng Lirn, Kuo Chung Shang

Journal of Marine Science and Technology

This study aims to investigate the determinants that underlie psychographic segmentation in the domain of autonomous ferries (AFs) by using the theory of planned behaviour (TPB) as a guiding theoretical construct. The paper focuses on Indonesian individuals who had previously utilised conventional ferry services. TPB was applied as a catalyst to identify possible market segmentation among potential AF passengers. In this study, cluster analysis is used to differentiate passengers by their perception of using AFs. The results identified three market segments through cluster analysis based on passengers’ perceptions of using AFs: Resource-Limited, Resource-Capable, and Value-Optimistic. Among these segments, the Resource-Capable …


Fretting Corrosion Wear Of Titanium-Based Alloy (Ti-6al-4v) In 0.9 Wt.% Nacl Solution, Chen-En Lu, Wen-Ken Li, Hung-Hua Sheu, Jeou-Long Lee, Hung-Bin Lee Jan 2024

Fretting Corrosion Wear Of Titanium-Based Alloy (Ti-6al-4v) In 0.9 Wt.% Nacl Solution, Chen-En Lu, Wen-Ken Li, Hung-Hua Sheu, Jeou-Long Lee, Hung-Bin Lee

Journal of Marine Science and Technology

In this study, a high precision fretting tribo-corrosion tester used to analyze the wear and corrosion behavior of Ti alloys in a fretting motion condition. The tester, operated in a ball-on-plate mode, was employed in the fretting corrosion study of metallic bio-materials (Ti and Ti-6Al-4V) under different loads (0 and 10 N), electrolytes (0.9 wt% NaCl and SBF) and fixed displacement frequency (1 Hz). Using profilometer, optical microscope in the experimental analysis and three-body mechanism in the theoretical analysis, the fretting corrosion performances of these bio-medical metals, such as velocity accommodation characteristics, friction, wear, and scratch profile were examined in …


A New-Type Deep Learning Model Based On Shapley Regulation For Containerized Freight Index Prediction, Yen-Chang Shih, Ming-Shue Lin, Taih-Cherng Lirn, Jih-Gau Juang Jan 2024

A New-Type Deep Learning Model Based On Shapley Regulation For Containerized Freight Index Prediction, Yen-Chang Shih, Ming-Shue Lin, Taih-Cherng Lirn, Jih-Gau Juang

Journal of Marine Science and Technology

In this study, we have crafted an innovative methodology that represents a groundbreaking synthesis of deep learning techniques with cooperative game theory. In this study, we use the accuracy of data prediction by different LSTM models as a measurement index and assign different LSTM models corresponding weights through the Shapley value calculation method to construct a more accurate predictive analysis model. We use this improved Shapley regulation model to calibrate a long short-term memory (LSTM) neural network by using historical freight data to predict the China Container Freight Index (CCFI), the leading export container freight index commonly used in China. …


Applicability Of Reducing Valve Timing Overlap For Diesel Engines Under High Exhaust Back Pressure, Chien-Cheng Chen, Yuan-Liang Jeng, Shun-Chang Yen Jan 2024

Applicability Of Reducing Valve Timing Overlap For Diesel Engines Under High Exhaust Back Pressure, Chien-Cheng Chen, Yuan-Liang Jeng, Shun-Chang Yen

Journal of Marine Science and Technology

The exhaust back pressure of diesel engines becomes increasing higher nowadays. As an example, the De-NOx system and DE-SOx system necessitated by the increasingly stringent emission standards, would result in increased exhaust back pressure for those diesel engines adopting such systems. Some ships adopt underwater exhaust system to save space on the working deck and to reduce noise and air pollution, while the hydrostatic pressure under water level has made the exhaust back pressure of diesel engines getting much higher. Under high exhaust back pressure, to keep discharging exhaust unhindered and operating smoothly for diesel engine, it often results in …


Adaptive Prediction Horizon Energy-Saving Collision-Free Mpc Of Ships Based On Ship-Shore Cooperation, Han Xue, Enjie Yang Jan 2024

Adaptive Prediction Horizon Energy-Saving Collision-Free Mpc Of Ships Based On Ship-Shore Cooperation, Han Xue, Enjie Yang

Journal of Marine Science and Technology

ABSTRACT:In order to perform the close association between ship maneuvering control and energy consumption through the control strategy, this paper designs an adaptive prediction horizon based energy-saving robust nonlinear model predictive control (APHERNMPC) for underactuated ships to deal with the actual control and state constraints during berthing based on ship-shore cooperation. An improved Emperor Penguin Optimizer (EPO) method is proposed for collision avoidance decision. To solve the problems of falling into local optimum and reducing the convergence speed, the traditional EPO is improved based on Sobol sequence in order to enhance the diversity and ergodicity of the population. The multi-ship …


Elimination Of Noise In A Ship Cabin Using Multi-Layered Acoustic Boards: An Apso And Sa Approach, Min-Chie Chiu, Ho-Chih Cheng Jan 2024

Elimination Of Noise In A Ship Cabin Using Multi-Layered Acoustic Boards: An Apso And Sa Approach, Min-Chie Chiu, Ho-Chih Cheng

Journal of Marine Science and Technology

A high level of noise, combined with pure tones, is often encountered in ship's cabins, leading to severe psychological and physiological issues for the crew. To address this problem, an indoor noise abatement solution becomes necessary that utilizes efficient acoustic boards integrated with resonators, positioned along the inner walls of the cabin. However, the thickness of the acoustic boards must be strictly limited due to maintenance and operational considerations. This limitation results in insufficient sound absorption capabilities and a restricted range of tuned frequencies, as the resonating frequency of a standard Helmholtz resonator is closely tied to its cavity. A …


Integrating Climatological-Hydrodynamic Modeling And Paleohurricane Records To Assess Storm Surge Risk, Amirhosein Begmohammadi, Christine Y. Blackshaw, Ning Lin, Avantika Gori, Elizabeth Wallace, Kerry Emanuel, Jeffrey P. Donnelly Jan 2024

Integrating Climatological-Hydrodynamic Modeling And Paleohurricane Records To Assess Storm Surge Risk, Amirhosein Begmohammadi, Christine Y. Blackshaw, Ning Lin, Avantika Gori, Elizabeth Wallace, Kerry Emanuel, Jeffrey P. Donnelly

OES Faculty Publications

Sediment cores from blue holes have emerged as a promising tool for extending the record of long-term tropical cyclone (TC) activity. However, interpreting this archive is challenging because storm surge depends on many parameters including TC intensity, track, and size. In this study, we use climatological-hydrodynamic modeling to interpret paleohurricane sediment records between 1851 and 2016 and assess the storm surge risk for Long Island in The Bahamas. As the historical TC data from 1988 to 2016 is too limited to estimate the surge risk for this area, we use historical event attribution in paleorecords paired with synthetic storm modeling …


On The Links Between Sea Level And Temperature Variations In The Chesapeake Bay And The Atlantic Meridional Overturning Circulation (Amoc), Tal Ezer, Teresa Updyke Jan 2024

On The Links Between Sea Level And Temperature Variations In The Chesapeake Bay And The Atlantic Meridional Overturning Circulation (Amoc), Tal Ezer, Teresa Updyke

CCPO Publications

Recent studies found that on long time scales there are often unexplained opposite trends in sea level variability between the upper and lower Chesapeake Bay (CB). Therefore, daily sea level and temperature records were analyzed in two locations, Norfolk in the southern CB and Baltimore in the northern CB; surface currents from Coastal Ocean Dynamics Application Radar (CODAR) near the mouth of CB were also analyzed to examine connections between the CB and the Atlantic Ocean. The observations in the bay were compared with daily Atlantic Meridional Overturning Circulation (AMOC) observations during 2005–2021. Empirical Mode Decomposition (EMD) analysis was used …


A Model For Community-Driven Development Of Best Practices: The Ocean Observatories Initiative Biogeochemical Sensors Data Best Practices And User Guide, Hilary I. Palevsky, Sophie Clayton, Heather Benway, Mairead Maheigan, Dariia Atamanchuk, Roman Battisi, Jennifer Batryn, Annie Bourbonnais, Ellen M. Briggs, Filipa Carvalho, Alison P. Chase, Rachel Eveleth, Rob Fatland, Kristen E. Fogaren, Jonathan Peter Fram, Susan E. Hartman, Isabela Le Bras, Cara C. M. Manning, Joseph A. Needoba, Merrie Beth Neely, Hilde Oliver, Andrew C. Reed, Jennie E. Rheuban, Christina Schallenberg, Ian Walsh, Christopher Wingard, Kohen Bauer, Baoshen Chen, Jose Cuevas, Susana Flecha, Micah Horwith, Melissa Melendez, Tyler Menz, Sara Rivero-Calle, Nicholas P. Roden, Tobias Steinhoff, Paulo Nicolás Trucco-Pignata, Michael F. Vardaro, Meg Yoder Jan 2024

A Model For Community-Driven Development Of Best Practices: The Ocean Observatories Initiative Biogeochemical Sensors Data Best Practices And User Guide, Hilary I. Palevsky, Sophie Clayton, Heather Benway, Mairead Maheigan, Dariia Atamanchuk, Roman Battisi, Jennifer Batryn, Annie Bourbonnais, Ellen M. Briggs, Filipa Carvalho, Alison P. Chase, Rachel Eveleth, Rob Fatland, Kristen E. Fogaren, Jonathan Peter Fram, Susan E. Hartman, Isabela Le Bras, Cara C. M. Manning, Joseph A. Needoba, Merrie Beth Neely, Hilde Oliver, Andrew C. Reed, Jennie E. Rheuban, Christina Schallenberg, Ian Walsh, Christopher Wingard, Kohen Bauer, Baoshen Chen, Jose Cuevas, Susana Flecha, Micah Horwith, Melissa Melendez, Tyler Menz, Sara Rivero-Calle, Nicholas P. Roden, Tobias Steinhoff, Paulo Nicolás Trucco-Pignata, Michael F. Vardaro, Meg Yoder

OES Faculty Publications

The field of oceanography is transitioning from data-poor to data-rich, thanks in part to increased deployment of in-situ platforms and sensors, such as those that instrument the US-funded Ocean Observatories Initiative (OOI). However, generating science-ready data products from these sensors, particularly those making biogeochemical measurements, often requires extensive end-user calibration and validation procedures, which can present a significant barrier. Openly available community-developed and -vetted Best Practices contribute to overcoming such barriers, but collaboratively developing user-friendly Best Practices can be challenging. Here we describe the process undertaken by the NSF-funded OOI Biogeochemical Sensor Data Working Group to develop Best Practices for …


Region-Specific Drivers Cause Low Organic Carbon Stocks And Sequestration Rates In The Saltmarsh Soils Of Southern Scandinavia, Carmen Leiva-Dueñas, Anna E. L. Graversen, Gary T. Banta, Jeppe N. Hansen, Marie L. K. Schrøter, Pere Masqué, Marianne Holmer, Dorte Krause-Jensen Jan 2024

Region-Specific Drivers Cause Low Organic Carbon Stocks And Sequestration Rates In The Saltmarsh Soils Of Southern Scandinavia, Carmen Leiva-Dueñas, Anna E. L. Graversen, Gary T. Banta, Jeppe N. Hansen, Marie L. K. Schrøter, Pere Masqué, Marianne Holmer, Dorte Krause-Jensen

Research outputs 2022 to 2026

Saltmarshes are known for their ability to act as effective sinks of organic carbon (OC) and their protection and restoration could potentially slow down the pace of global warming. However, regional estimates of saltmarsh OC storage are often missing, including for the Nordic region. To address this knowledge gap, we assessed OC storage and accumulation rates in 17 saltmarshes distributed along the Danish coasts and investigated the main drivers of soil OC storage. Danish saltmarshes store a median of 10 kg OC m−2 (interquartile range, IQR: 13.5–7.6) in the top meter and sequester 31.5 g OC m−2 yr−1 (IQR: 41.6–15.7). …


A Preliminary Study On Floating Flexible Otec Cold Water Pipe, Nai Kuang Liang, Hai Kuan Peng Dec 2023

A Preliminary Study On Floating Flexible Otec Cold Water Pipe, Nai Kuang Liang, Hai Kuan Peng

Journal of Marine Science and Technology

Ocean Thermal Energy Conversion (OTEC) requires a large amount of cold seawater. The traditional rigid pipe, semi-rigidly fixed onto the ship bottom is not easy to install and disassemble, so the Floating Flexible Cold Water Pipe (FFCWP) flexibly connected to the ship is proposed. A small FFCWP was designed, fabricated, and successfully installed and recovered in the sea. The flexible pipe adopts commercially available fire ventilation snake pipe. The pipe wall material strength must be improved in the future. Assuming that the drag coefficient Cd value is 1.5, a numerical calculation is employed to simulate the FFCWP attitude from the …


Machine Learning With Multi-Source Data To Predict And Explain Marine Pilot Occupational Accidents, Gokhan Camliyurt, Youngsoo Park, Daewon Kim, Won Sik Kang, Sangwon Park Dec 2023

Machine Learning With Multi-Source Data To Predict And Explain Marine Pilot Occupational Accidents, Gokhan Camliyurt, Youngsoo Park, Daewon Kim, Won Sik Kang, Sangwon Park

Journal of Marine Science and Technology

Marine pilot occupational accidents during transfer to/from ships are the primary concern of the International Marine Pilots’ Association (IMPA) and industry professionals. There are multiple transfer methods for marine pilots, with the most common being the pilot boat. To reach the mother ship bridge, the following stages must be safely completed: car transfer, walking on the pier, pier to pilot boat, pilot transfer by boat, cutter to pilot ladder, mother ship freeboard climbing, and ship deck to the bridge. Each stage has its own risk. Previous accident records and expert opinions are commonly used to conduct a risk analysis and …


Evaluation Of Operational Performance Of Wusongkou Cruise Port Through Network Data Envelopment Analysis, Qian-Feng Wang, Guo-Ya Gan, Xin-Liang Ye, Hsuan-Shih Lee Dec 2023

Evaluation Of Operational Performance Of Wusongkou Cruise Port Through Network Data Envelopment Analysis, Qian-Feng Wang, Guo-Ya Gan, Xin-Liang Ye, Hsuan-Shih Lee

Journal of Marine Science and Technology

As major hubs for cruise berthing and passenger transfers, cruise ports in China were developing rapidly in the years before the COVID-19 pandemic because of an ever-growing regional market. Wusongkou Cruise Port is the most important port for cruise ships in China, and this study evaluated the operational performance of this port during 2011–2020. To this end, two-stage network data envelopment analysis was conducted to evaluate the port’s operation performance; subsequently, the change trajectory of the port’s operational efficiency during 2011–2020 was determined, and the potential reasons for the identified changes are discussed. Finally, suggestions for improving the operational performance …


Quantifying Tidewater Glacier-Fjord Environments In The Rapidly Changing Regions Of West And South Greenland, Sydney Baratta Dec 2023

Quantifying Tidewater Glacier-Fjord Environments In The Rapidly Changing Regions Of West And South Greenland, Sydney Baratta

Electronic Theses and Dissertations

The Greenland Ice Sheet has undergone rapid mass loss over the last four decades, primarily through solid and liquid discharge at marine-terminating outlet glaciers. The acceleration of these glaciers is in part due to the increase in temperature of ocean water in contact with the glacier terminus. However, quantifying meltwater injection and heat transport can be challenging due to iceberg abundance, which threatens instrument survival and fjord accessibility. Additionally, acceleration and eventual retreat of tidewater glaciers onto land can change glacier forcing, completely altering fjord water-meltwater dynamics. Here, we couple in situ and remote sensing methods to quantify the upper-layer …


Computational Fluid Dynamics Modeling Of Internal Wave Interactions On Conch Reef, Florida Keys, Megan Miller Dec 2023

Computational Fluid Dynamics Modeling Of Internal Wave Interactions On Conch Reef, Florida Keys, Megan Miller

All HCAS Student Capstones, Theses, and Dissertations

Internal waves breaking on continental shelves play a significant role in mixing and nutrient delivery to coral reef ecosystems. As internal solitary waves, or solitons, propagate shoreward onto continental slopes, they can become unstable and break into turbulent bores that bring cool, nutrient-rich sub-thermocline water shoreward onto coral reefs. The propagation of turbulent bores generated by internal waves interacting with a complex surface creates high-frequency variabilities in the thermal and nutrient environment of Conch Reef in the Florida Keys, which has been studied previously. Here, I have created a three-dimensional model using ANSYS Fluent Computational Fluid Dynamics (CFD) software to …


Biophysical Factors Affecting Habitat Suitability For Crassostrea Virginica, Jason D. Tilley Dec 2023

Biophysical Factors Affecting Habitat Suitability For Crassostrea Virginica, Jason D. Tilley

Dissertations

Oyster reefs provide a variety of important ecosystem services. However, the mortality rate of eastern oyster, Crassostrea virginica, the dominant species that produces oyster reefs in the northern Gulf of Mexico, is increasing at an alarming rate due to a variety of abiotic and biological factors. I examined how biophysical factors, including the less-studied fatty acid profiles of the suspended particulate matter on which oysters feed, influenced morphometric condition of C. virginica.

I sampled suspended particulate matter (SPM) and oysters in-situ in the western Mississippi Sound, which historically supported the majority of oyster production in Mississippi waters. Sampling …


Investigating The Effects Of A Southward Flow In The Southeastern Florida Shelf Using Robotic Instruments, Alfredo Quezada Dec 2023

Investigating The Effects Of A Southward Flow In The Southeastern Florida Shelf Using Robotic Instruments, Alfredo Quezada

All HCAS Student Capstones, Theses, and Dissertations

We deployed a Slocum G3 glider fitted with an acoustic Doppler current profiler (ADCP), a Conductivity-Temperature-Depth sensor (CTD), optics sensor channels, and a propeller on the Southeastern Florida shelf. The ADCP and CTD provide continuous measurements of Northern and Eastern current velocity components, salinity, temperature, and density, throughout the water column in a high-current environment. The optics sensor channels are able to provide measurements of chlorophyll concentrations, colored dissolved organic matter (CDOM), and backscatter particle counts. Additionally, for one of the glider deployments, we deployed a Wirewalker wave-powered profiling platform system also fitted with an ADCP and a CTD in …