Oceanography Commons^™

Flujos De Servicios Ecosistémicos En Un Área Marina Protegida Del Atlántico Sur: Perspectivas Desde El Análisis De La Teoría De Redes, Mitch Porter

Independent Study Project (ISP) Collection

En cuestiones de gestión de áreas protegidas, los servicios ecosistémicos se tienen cada vez más en cuenta junto con la conservación de la biodiversidad. Sin embargo, las decisiones que se toman sobre la conservación de los servicios ecosistémicos no suelen incluir los posibles efectos en cascada de la pérdida de biodiversidad sobre la provisión de servicios. Los conocimientos de la teoría de redes y los estudios de robustez pueden proporcionar una metodología para evaluar la vulnerabilidad de estos servicios frente la estructura trófica de los ecosistemas que los proveen. A través de una serie de simulaciones de extinción para la …

Organism Communities On Giant Clam Shells As Compared To The Surrounding Substrate In Reefs Around Lizard Island, Queensland, Gayatri Singla

Independent Study Project (ISP) Collection

Coral reef ecosystems are facing destruction at the hands of anthropogenic climate change. Therefore, it is essential that we move to better understand the ecosystem functions of the organisms present in reefs. One such family whose ecosystem function we are unfamiliar with are the giant clams (family Cardiidae). As unique and abundant macrofauna, they have the potential to play an important role in their environment. The goal of our study was to determine how giant clams function as settlement substrata. We conducted 151 observational surveys of epibionts residing on living giant clam shells and of the organism communities in the …

Understanding The Role Of The Jet Streams And Gulf Stream Eddies On The Northwest Atlantic Marine Heatwaves, Lydia Rose Duncan Sims

Theses and Dissertations

The Northwest (NW) Atlantic is one of the fastest warming regions in the global ocean and in the recent decade has experienced several extreme temperature events. These extreme anomalous temperature events are known as Marine Heatwaves (MHWs), which are forced by a variety of physical processes that affect the heat source and sink of the water column. These MHWs have been increasing globally in duration and frequency due to anthropogenic warming, and have increased ecological damage seen in mass mortality events of economically viable species. Within the NW Atlantic, several key processes encourage the formation of MHWs, such as the …

Organic Carbon Decay Mediated By Mesopelagic Microbial Communities, Noah Jonathan Craft

OES Theses and Dissertations

Substantial remineralization of organic carbon occurs in the mesopelagic zone (i.e., the biological pump), the efficiency of which is responsible for the oceans’ capacity to store carbon originally derived from the atmosphere. To better understand how a substrate’s composition influences its degradation by mesopelagic microbial communities, we added treatments made of live algal cells, dead particulate organic carbon and dissolved organic carbon from ¹⁴C-labeled algal cultures to mesopelagic water collected in-situ. Each incubation took place in the laboratory over a period of months, during which PO¹⁴C, DO¹⁴C, ATP, prokaryote abundances and biochemical fractions were measured. …

Approaches To Assessing Nutrient Coupling In Open Ocean Datasets, James M. Moore, Claire P. Till

IdeaFest: Interdisciplinary Journal of Creative Works and Research from Cal Poly Humboldt

Nutrient coupling describes a process where the biogeochemical cycles of two elements are linked by being incorporated similarly into biomass. This paper uses data from the GEOTRACES GP16 cruise (Eastern Pacific Zonal Transect) to investigate the relationship between certain macronutrients generally coupled to trace elements in terms of their oceanic distributions with the notable exception of in an oxygen minimum zone: cadmium-phosphate and zinc-silicate. There are many methods applied to oceanographic data to correlate analyte concentrations; while they are often presented independently in literature, here we attempt to use them in conjunction for a more thorough interpretation. By compiling 1) …

Uncertainties In Retrieval Of Remote Sensing Reflectance From Ocean Color Satellite Observations, Eder I. Herrera Estrella

Dissertations, Theses, and Capstone Projects

Ocean Color radiometry uses remote sensing to interpret ocean dynamics by retrieving remote sensing reflectance (������) from satellite imagery at different scales and over different time periods. ������ spectrum characterizes the ocean color that we observe, and from which we can discern concentrations of chlorophyll, organic and inorganic particles, and carbon fluxes in the ocean and atmosphere. ������ is derived from the total radiance at the top of the atmosphere (TOA). However, it only represents up to ten percent of the total signal. Hence, the retrieval of ������ from the total radiance at TOA involves the application of atmospheric correction …

Supporting Data For Figures In "Mixing Of The Connecticut River Plume During Ambient Flood Tides: Spatial Heterogeneity And Contributions Of Bottom-Generated And Interfacial Mixing", Michael M. Whitney

Department of Marine Sciences

This archive contains the supporting data for figures in the manuscript "Mixing of the Connecticut River plume during ambient flood tides: Spatial heterogeneity and contributions of bottom-generated and interfacial mixing" by Michael M. Whitney. The objectives of this modeling study are 1) characterizing the spatial heterogeneity of turbulent buoyancy fluxes, 2) partitioning turbulent buoyancy fluxes into bottom-generated and interfacial shear contributions, and 3) quantifying contributions to plume-integrated mixing within the tidal plume. Data are from the Regional Ocean Modeling System (ROMS) results for idealized model configurations. The Zip file (Figure_data.zip) contains MATLAB data files, which are named FigureXX_data.mat. Variable names …

Supporting Data For Figures In "Wind-Enhanced Separation Of Large-Scale River Plumes From Coastal Corners", Michael M. Whitney

Department of Marine Sciences

This archive contains the supporting data for figures in the manuscript "Wind-enhanced separation of large-scale river plumes from coastal corners" by Michael M. Whitney. This study analyzes idealized models to quantify how large-scale river plumes and wind-driven currents interact at perpendicular coastal corners. Data are from the Regional Ocean Modeling System (ROMS) results for idealized model configurations. The Zip file (Figure_data.zip) contains MATLAB data files, which are named FigureXX_data.mat. Variable names and units correspond to graphed data of each figure in manuscript. Full descriptions of research methods and results are included in manuscript.

Ocean Wave-Coherent Temperature And Humidity Near-Surface Vertical Distributions And Their Effect On Radar Performance Over The Ocean, Mathew James Stanek

Electronic Theses and Dissertations

Large knowledge gaps concerning the effect of ocean surface waves on near-surface vertical distributions of temperature and humidity in the marine atmospheric surface layer exist due to practical limitations and sensor fidelity challenges of direct measurements. Wave effects on these distributions between the wave trough and crest are least studied within the literature. These scalar distributions influence atmospheric refractivity, which can lead to anomalous propagation of electromagnetic energy. Measurements of temperature and humidity are classically made using rocket- or radiosondes and fixed weather stations, and can utilize tethered profiling systems. However, these measurement systems have limitations when obtaining measurements near …

Applications Of Artificial Intelligence To Improve Coastal Ocean Modeling, Dongliang Shen

Electronic Theses and Dissertations

Numerical Modeling (NM) is widely used to simulate and predict hydrodynamic processes and marine particle movements in coastal oceans, particularly during extreme weather events and emergencies. NM offers the capability to realistically simulate multiple state variables and fill gaps caused by scarce observations. However, inherent uncertainties exist in all NMs, primarily arising from the following three factors: 1) insufficient observations leading to uncertain model initial and boundary conditions, 2) inevitable truncation errors due to coarse model resolution, and 3) imperfect physics parameterization schemes for sub-grid processes, especially those related to waves. The consequences of these uncertainties are that 1) even …

History Of Ice-Rafting In The Arctic Ocean During Glacial Maxima Through Marine Isotope Stage 6, Shannon M. Cofield

OES Theses and Dissertations

Numerous studies attempted to reconstruct Arctic paleoclimate, specifically ice mass timing and locations, during glacial maxima. While some regions, like the Barents-Svalbard Ice Sheet (BSIS) are well-studied, they may benefit from a high-resolution paleo proxy. Other regions are highly contested, such as the East Siberian Sea or the presence of a central Arctic Ocean ice mass.

This research uses an Fe-grain provenance method to (1) define how the BSIS behaved during Marine Isotope Stage (MIS) 2, 4, and 6, and when it retreated; (2) determine the presence and ages of Shelf Ice Masses (SIMs) in the Beaufort Sea and East …

Tidal Flooding In The Mid-Atlantic Region Of The Us: Water Quality Effects In The Lower Chesapeake Bay, Alfonso Macias Tapia

OES Theses and Dissertations

Many coastal areas around the globe suffer from nutrient pollution and its environmental, social, and economic consequences. Nutrient inputs can come from point (e.g., the end of a pipe) and nonpoint sources, from which the former are better constrained as sampling need only be conducted at a discharge point. Given the temporal and spatially extensive nature of tidal flooding events, they can represent another type of nonpoint source of nutrients to adjacent water bodies heretofore, unexamined and quantified. Most studies examining impacts of tidal flooding have focused on threats to resources on land, such as urban infrastructure and human health …

Nitrogen Cycling In The Lower Chesapeake Bay And Mid- And South Atlantic Bight, Yifan Zhu

OES Theses and Dissertations

Nitrogen (N) is central to marine primary production; its availability often limits the capacity and rates of primary productivity in most of the world’s oceans. Contrastingly, estuaries frequently receive anthropogenic N loading, oftentimes resulting in eutrophication, harmful algal blooms (HABs), and substantially degraded water quality. Nutrient variability in both estuaries and oceanic regimes results from meteorological forcing and physical processes, including wind-induced, tidal, and mesoscale mixing and upwelling. In this dissertation, a comprehensive investigation of N variability and cycling and its links to physical-biogeochemical processes was conducted using time-series monitoring approaches, flux estimations, satellite imaging, biogeochemical measurements, and molecular analyses. …

Interactive Effects Of The Partial Pressure Of Co2, Temperature, And Nutrient-Limitation On The Physiology And Growth Of The Coccolithophore E. Huxleyi Grown On A 12:12 L:D Cycle Of Illumination, James Bradley

LSU Master's Theses

I studied the interactive effects of pCO2, temperature, and nutrient limitation on the growth and physiology of the marine coccolithophore, Emiliania huxleyi. This was done to look at the effect of climate change factors on the widespread and abundant calcifying marine organism as a predictor of what the future has to hold. The strain of E. huxleyi (PnB 272 B10) was grown on a 12:12 L:D cycle of illumination and exposed to either high or low pCO2 under nutrient-replete or nitrate-limited conditions across a temperature range of 10–28C. I examined the direct and interactive effects of temperature, pCO2, and nutrient …

Exploring The Impact Of Eddies On Southern Ocean Biogeochemical Structure Using Bgc-Argo Float Observations, Nicola J. Guisewhite

USF Tampa Graduate Theses and Dissertations

The Southern Ocean plays a crucial role in global ocean circulation, and global heat and nutrient transport. However, this region is both distant and dangerous and is therefore largely under-sampled and understudied. Methods to fill in biogeochemical data-gaps include using limited in-situ data in models to output biogeochemical property estimates, but a number of recent studies have raised concerns about how most Southern Ocean models do not resolve eddies. Eddies are known to impact biogeochemistry around the globe but little is known about their impact in the Southern Ocean. This study examines temperature, salinity, oxygen, nitrate, and dissolved inorganic carbon …

Reef Benthic Fauna And Sediment Characterization, Robert M. Cerrato, Matthew Sclafani

School of Marine & Atmospheric Sciences Faculty Publications

High-resolution backscatter and bathymetric maps created by multibeam sonar surveys were used to identify different seafloor bottom types within existing, potentially expanded, and newly proposed reef areas in New York waters. Existing sites included Smithtown in Long Island Sound (LIS), and Rockaway, Atlantic Beach, Hempstead, Yellowbar, Kismet, Fire Island, Twelve Mile along the South Shore. Potential expansions are proposed on the South Shore for McAllister, Moriches, and Shinnecock reefs in addition to a new site called Sixteen Fathom. In Long Island Sound, new sites are proposed for Huntington/Oyster Bay, Port Jefferson/Mount Sinai, and Mattituck. Grab samples were collected within these …

Ocean Connectivity And Habitat Characteristics Predict Population Genetic Structure Of Seagrass In An Extreme Tropical Setting, Udhi E. Hernawan, Kor-Jent Van Dijk, Gary A. Kendrick, Ming Feng, Oliver Berry, Christopher Kavazos, Kathryn Mcmahon

Research outputs 2022 to 2026

Understanding patterns of gene flow and processes driving genetic differentiation is important for a broad range of conservation practices. In marine organisms, genetic differentiation among populations is influenced by a range of spatial, oceanographic, and environmental factors that are attributed to the seascape. The relative influences of these factors may vary in different locations and can be measured using seascape genetic approaches. Here, we applied a seascape genetic approach to populations of the seagrass, Thalassia hemprichii, at a fine spatial scale (~80 km) in the Kimberley coast, western Australia, a complex seascape with strong, multidirectional currents greatly influenced by extreme …

State Of The Fisheries: Status Reports And Aquatic Resources Of Western Australia 2021/22, Department Of Primary Industries And Regional Development, Western Australia, S J. Newman, B S. Wise, K G. Santaro, D J. Gaughan

Status Reports of the Fisheries and Aquatic Resources

Aquatic resources within Western Australia (WA) are in good condition, and this has positioned WA as a global leader in sustainable fisheries management. The sustainable fisheries of WA continue to support our strong economy and regional communities. Nonetheless, the lack of a consistent approach to build in the knowledge of Traditional Owners remains a gap in our longer-term fisheries science in Western Australia.

Climate change and climate variability continues to impact fish stocks, challenging our ability to effectively monitor, assess, and manage fish stocks. We are continually working with our stakeholders, and the broader community to be adaptive, responsive, and …

Three-Dimensional Higher-Order Compressive Sensing For Raypath Separation In An Acoustic Waveguide, Fengyan Zhong

Journal of Marine Science and Technology–Taiwan

In an acoustic waveguide, the separation of multiple raypaths, especially close raypaths, is a challenging task in the presence of colored noise due to interference in the acoustic eld. In this paper, a three-dimensional higher-order compressive sensing method for raypath separation is proposed. The method is applied on an array-to-array experimental conguration where both emitter and reception arrays are used. With the array-to-array conguration, the raypaths are characterized by three parameters including arrival direction, departure direction, and arrival time. Furthermore, the performance of the proposed algorithm is illustrated by simulations and experiments. The numerical results based on simulation illustrate that …

Projection Of Sea Surface Temperature Based On Empirical Mode Decomposition And Its Application In Typhoon Number Forecast, Wen-Cheng Huang, Jung-Chen Lee

Journal of Marine Science and Technology–Taiwan

The primary objective of this paper is to demonstrate the applicability of empirical mode decomposition (EMD) in projecting non-stationary daily sea surface temperature (SST) series, and the other is to apply the projected series of SST to estimate the number of typhoons. The study focuses on an area ranging from 5°N~25°N and 110°E~170°E, collecting daily sea temperature data and typhoons records within this region. The findings conclusively indicate that the EMD-based data generation method proposed in this paper can effectively addresses the limitations of previous hydrological models in generating non-stationary series, signifying a significant advancement in hydrological time series modeling …

Symbiotic Ucyn-A Strains Co-Occurred With El Niño, Relaxed Upwelling, And Varied Eukaryotes Over 10 Years Off Southern California, Colette Fletcher-Hoppe, Yi-Chun Yeh, Yubin Raut, J. L. Weissman, Jed A. Fuhrman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Biological nitrogen fixation, the conversion of N₂ gas into a bioavailable form, is vital to sustaining marine primary production. Studies have shifted beyond traditionally studied tropical diazotrophs. Candidatus Atelocyanobacterium thalassa (or UCYN-A) has emerged as a focal point due to its streamlined metabolism, intimate partnership with a haptophyte host, and broad distribution. Here, we explore the environmental parameters that govern UCYN-A’s presence at the San Pedro Ocean Time-series (SPOT), its host specificity, and statistically significant interactions with non-host eukaryotes from 2008-2018. 16S and 18S rRNA gene sequences were amplified by “universal primers” from monthly samples and resolved into Amplicon …

Estimation Of Quantitative Genetic Parameters Of The Eastern Oyster (Crassostrea Virginica) In The Gulf Of Mexico, Heather King

Master's Theses

The decline of natural oyster reefs in Gulf of Mexico (Gulf) states has stimulated the development of aquaculture to support the industry and restoration programs. Gulf habitats feature diverse salinity environments that may require oysters bred for habitat-specific optimal genetic characteristics. In this work, genetic parameters for performance in habitats with different salinity were estimated. In September 2020, 102 males and 102 females sourced from 17 natural reefs across the northern Gulf were bred according to 2 males x 2 females non-overlapping factorial crossing designs, resulting in 204 full and half sibs. All families were pooled after fertilization according to …

Assessing Dynamics And Trends Of Co2 Flux On The Louisiana Shelf, Claire Mcguire

Master's Theses

The Gulf of Mexico on an annual timescale acts as a sink for ­CO₂. Previous studies have investigated regional-scale trends in the Gulf based on model output. In our investigation of the northern Gulf of Mexico, and especially the area surrounding the Louisiana delta, we found different trends compared with previous studies of the open ocean Gulf and broader shelf region. Predictions of global patterns of the ocean CO₂ cycle require regional studies of unique areas like the Louisiana Shelf. The Louisiana Shelf is a shallow system, has input from river systems, experiences seasonal hypoxia, and is …

The Mobility Of Long-Lived Radioisotopes And Their Burial In The Marine Environment, Neil Redmond

Dissertations

Marine sediments record chemical signals that reflect past environmental conditions. It is important to establish how these signals are created and whether they may be altered over time so that they can be useful for reconstructing ocean history. Measurements of uranium isotopes are used as a novel proxy for sedimentary diagenetic processes (Chapter 2). Because ²³⁴U can be ejected from mineral lattice during the decay of ²³⁸U, it creates a pool of U in porewater that is potentially mobilized and then deposited elsewhere in the core. We found that alpha-recoiled ²³⁴U is sensitive to differences in sediment …

Understanding The Impacts Of Topobathymetric Data On Storm Surge Model Predictions, Sydni Crain

Master's Theses

The topobathymetric characteristics of a region are regularly altered by natural and anthropogenic causes. This directly impacts the resulting storm surge during a hurricane. The primary goal of this research was to gain a better understanding of the impact that topography and bathymetry have on storm surge models, particularly the Advanced Circulation (ADCIRC) Model. Hurricane Zeta (2020) and Hurricane Ida (2021) were chosen as case studies; therefore, the Gulf of Mexico (GOM) was chosen as the study site. This research was completed by comparing ADCIRC storm surge results which were based on older, lower-resolution data with results derived from more …

Evaluating The Relationship Between Methane Seeps And Seafloor Geomorphology On The Northern Us Atlantic Margin, Gabriel Hernandez

Theses and Dissertations

Methane seeps are a transport pathway for carbon from seafloor sediments to the marine environment with important implications for global biogeochemical cycling. Accordingly, there is substantial interest in better understanding the processes that control seep location and predicting the distribution of seeps with existing seafloor datasets. Visual evaluation of methane seeps, in multibeam sonar water column data, suggests a spatial relationship between seeps and specific seafloor morphologic features such as ridge crests. In this thesis, seafloor geomorphology at 1996 seep detection sites on the US Atlantic margin was quantitatively characterized by geomorphologic phonotype, bathymetric position index, slope, rugosity, and aspect …

Determining The Refractive Index Of Phytoplankton Via Direct Measurement Of Cellular Structures, Michael Kamowski

Master's Theses

The refractive index of phytoplankton has never been directly measured before despite its importance towards studying the optical characteristics of marine particles. Previous attempts to measure it have been done through indirect methods. While these methods have proven useful, they contain assumptions about the particles morphology and composition that cause for uncertainty with the measurements. Through the use of the 3D Cell Explorer, a high precision holotomographic microscope, the RI of phytoplankton can be directly measured for the first time. With volume measurements, the phytoplankton were found to not display a single bulk RI, instead the bulk RI was different …

Atmospheric Impacts From The 2010 Deepwater Horizon Oil Spill, Charles Philip Johnson

LSU Master's Theses

Although the ecological devastations induced by an oil spill are well studied, the hydrometeorological impacts from a long-term slick have gone unnoticed. The ocean-surface alterations stemming from the lasting oil footprint increase solar radiation absorption which in turn alters the surface pressure and moisture gradients and wind speeds thereby influencing precipitation surrounding the oil spill. Revealing the potential impacts from these could better aid in the safety of crews cleaning spills and provide a better understanding of how humans alter the landscape. This thesis examines the changes in local hydrometeorology brought on by the 2010 summer Deepwater Horizon (DWH) oil …

The Dynamics Of Sedimentary Chlorophyll Α At A High-Energy Beach, Sarah (Gray) Abel

Honors Theses

Productive sandy beaches are one of the most crucial areas serving our ecosystem today. While often overlooked in scientific research, productive beaches have many essential functions that lead to the preservation and protection of many different species as well as ecological wellness and stability. A key factor that is linked to this productivity is the presence of chlorophyll in the sediments. Piston cores of the sediments at the low-tide mark at Waties Island, South Carolina, were collected across multiple years and subsequently analyzed for chlorophyll concentrations through fluorometry after acetone extraction and acidification. Each core profile was processed to calculate …

Investigation Of A Possible Switch Of Benthic Photosynthetic Organisms And Phytoplanktonic Organisms In White Point Swash, South Carolina, Nathan Easterling

Honors Theses

This research study examined the possible switch from benthic photosynthetic organisms to phytoplankton in the water column at White Point Swash, Long Bay, South Carolina, and what is causing this switch to occur. During Dr. Hannides’ and his group’s studies at this and other swashes in the past, they noticed this phenomenon of the benthic photosynthetic organisms taking over during a certain time and then the phytoplankton in the water column taking over during a different time. In this study, I measured the relative benthic macroalgal area coverage and sedimentary chlorophyll a concentration as measures of the abundance of benthic …