Oceanography Commons^™

Leveraging Student Experience With Water For Active Learning In A Large Introductory Oceanography Classroom, Rebecca Freeman

Earth and Environmental Sciences Faculty Publications

No abstract provided.

Summertime Connecticut River Water Pathways And Wind Impacts, Yan Jia, Michael M. Whitney

Department of Marine Sciences

Long Island Sound is a large macrotidal estuary. Connecticut River as the primary freshwater source enters near the sound’s mouth. The summertime pathways of river water under low discharge and mild wind conditions are studied through both numerical simulations with a passive dye pulse and field surface drifter observations. Within the 19-day modeling analysis period, a third of the river dye pulse moves up-estuary with the near-bottom dense inflow into central and western sound with a spring-neap tidal modulation; another third leaves the sound with the near-surface outflow towards the continental shelf through Block Island Sound. The latter pathway is …

Aliased Tidal Variability In Mesoscale Sea Level Anomaly Maps, Edward Zaron, Richard D. Ray

Civil and Environmental Engineering Faculty Publications and Presentations

Sea level anomaly (SLA) maps are routinely produced by objective analysis of data from the constellation of satellite altimeter missions in operation since 1992. Beginning in 2014, changes in the Data Unification and Altimeter Combination System (DUACS) used to create the SLA maps resulted in improved spatial resolution of mesoscale variability, but it also increased the levels of aliased tidal variability compared to the methodology employed prior to 2014. The present work investigates the magnitude and spatial distribution of these tidal signals, which are typically smaller than 1 cmin the open ocean but can reach tens of centimeters in the …

Along-Shelf Connectivity And Circumpolar Gene Flow In Antarctic Silverfish (Pleuragramma Antarctica), Jilda Alicia Caccavo, Chiara Papetti, Maj Wetjen, Rainer Knust, Julian R. Ashford, Lorenzo Zane

OES Faculty Publications

The Antarctic silverfish (Pleuragramma antarctica) is a critically important forage species with a circumpolar distribution and is unique among other notothenioid species for its wholly pelagic life cycle. Previous studies have provided mixed evidence of population structure over regional and circumpolar scales. The aim of the present study was to test the recent population hypothesis for Antarctic silverfish, which emphasizes the interplay between life history and hydrography in shaping connectivity. A total of 1067 individuals were collected over 25 years from different locations on a circumpolar scale. Samples were genotyped at fifteen microsatellites to assess population differentiation and …

Predicted Deepwater Bathymetry From Satellite Altimetry: Non-Fourier Transform Alternatives, Maxsimo Salazar

Dissertations

Robert Parker (1972) demonstrated the effectiveness of Fourier Transforms (FT) to compute gravitational potential anomalies caused by uneven, non-uniform layers of material. This important calculation relates the gravitational potential anomaly to sea-floor topography. As outlined by Sandwell and Smith (1997), a six-step procedure, utilizing the FT, then demonstrated how satellite altimetry measurements of marine geoid height are inverted into seafloor topography. However, FTs are not local in space and produce Gibb’s phenomenon around discontinuities. Seafloor features exhibit spatial locality and features such as seamounts and ridges often have sharp inclines. Initial tests compared the windowed-FT to wavelets in reconstruction of …

Late Quaternary Evolution And Stratigraphic Framework Influence On Coastal Systems Along The North-Central Gulf Of Mexico, Usa, Robert Hollis

Master's Theses

Coastal systems in the Gulf of Mexico are threatened to reduced sediment supply, storm impacts and relative sea level rise (RSLR). The geologic record can provide insights of geomorphic threshold crossings (formation, progradation, transgression, destruction) to these forcing mechanisms to predict future barrier evolution to climate change. The stratigraphic framework and antecedent topography directly influence coastal evolution over geologic timescales. This study synthesizes ~2100km of geophysical data, 700+ sediment cores, and 63 radiocarbon dates to regionally map two sequence boundaries, multiple ravinement surfaces and fourteen depositional facies. One marine isotope stage (MIS) 6 valley’s fill provided up to 300 x10 …

Dynamics Of Prochlorococcus Diversity And Photoacclimation During Short-Term Shifts In Water Column Stratification At Station Aloha, Anne W. Thompson, Ger Van Den Engh, Nathan A. Ahlgren, Kathleen Kouba, Samantha Ward, Samuel T. Wilson, David M. Karl

Biology Faculty Publications and Presentations

The cyanobacterium Prochlorococcus is the dominant phototroph in surface waters of the vast oligotrophic oceans, the foundation of marine food webs, and an important component of global biogeochemical cycles. The prominence of Prochlorococcus across the environmental gradients of the open ocean is attributed to its extensive genetic diversity and flexible chlorophyll physiology, enabling light capture over a wide range of intensities. What remains unknown is the balance between temporal dynamics of genetic diversity and chlorophyll physiology in the ability of Prochlorococcus to respond to a variety of short (approximately 1 day) and longer (months to year) changes in the environment. …

Trash Talk: The Effects Of Plastic Pollution On Seabirds In Narragansett Bay, Erin A. O'Neill

Pell Scholars and Senior Theses

Plastic pollution in the ocean is a global concern with more than 8 million tons of plastic dumped into our oceans every year. This policy paper assesses plastic pollution in Narragansett Bay and the negative implications it holds on local seabird populations. Also, essential background information on plastic production and throwaway culture is provided. Moreover, the biological significance of seabirds is described, highlighting the vital role such populations play in local ecosystems such as Narragansett Bay. This paper contributes research to the global issue of plastic pollution by observing declining native wildlife life populations, such as seabirds, on a local …

Lighting A Path To Biofouling Prevention: Investigating The Effect Of Ultraviolet Light On Biofouling, Cierra Rose Braga

Theses and Dissertations

Ultraviolet light (UV) is considered an environmentally friendly antifouling method because it disrupts biological growth without the release of harmful toxins. The application of UV for the marine shipping industry is a relatively new concept, and there still remains many unknowns before it can be fully implemented. This research investigated several aspects of applying UVC for the control of fouling. A novel method of using embedded UV LEDs within a silicone coating for fouling control proved to be very effective at preventing fouling. The research also investigated the effect of using an external UVC light treatment to control fouling on …

Evolution Of 21st Century Sea Level Rise Projections, Andra J. Garner, Jeremy L. Weiss, Adam Parris, Robert E. Kopp, Radley M. Horton, Jonathan T, Overpeck, Benjamin P. Horton

School of Earth & Environment Departmental Research

The modern era of scientific global‐mean sea level rise (SLR) projections began in the early 1980s. In subsequent decades, understanding of driving processes has improved, and new methodologies have been developed. Nonetheless, despite more than 70 studies, future SLR remains deeply uncertain. To facilitate understanding of the historical development of SLR projections and contextualize current projections, we have compiled a comprehensive database of 21st century global SLR projections. Although central estimates of 21st century global‐mean SLR have been relatively consistent, the range of projected SLR has varied greatly over time. Among studies providing multiple estimates, the range of upper projections …

Flux Of Particulate Elements In The North Atlantic Ocean Constrained By Multiple Radionuclides, Christopher T. Hayes, Erin E. Black, Robert F. Anderson, Mark Baskaran, Ken O. Buesseler, Matthew A. Charette, Hai Cheng, J. Kirk Cochran, R. Lawrence Edwards, Patrick Fitzgerald, Phoebe J. Lam, Yanbin Lu, Stephanie O. Morris, Daniel C. Ohnemus, Frank J. Pavia, Gillian Stewart, Yi Tang

Environmental Science and Geology Faculty Research Publications

Sinking particles strongly regulate the distribution of reactive chemical substances in the ocean, including particulate organic carbon and other elements (e.g., P, Cd, Mn, Cu, Co, Fe, Al, and 232Th). Yet, the sinking fluxes of trace elements have not been well described in the global ocean. The U.S. GEOTRACES campaign in the North Atlantic (GA03) offers the first data set in which the sinking flux of carbon and trace elements can be derived using four different radionuclide pairs (238U:234Th ;210Pb:210Po; 228Ra:228Th; and 234U:230Th) at stations co-located with sediment trap fluxes for comparison. Particulate organic carbon, particulate P, and particulate Cd …

Impacts Of Pacific Ssts On Atmospheric Circulations Leading To California Winter Precipitation Variability: A Diagnostic Modeling, Boksoon Myoung, Sang-Wook Yeh, Jinwon Kim, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

One of the primary meteorological causes of the winter precipitation deficits and droughts in California (CA) is anomalous developments and maintenance of upper-tropospheric ridges over the northeastern Pacific. In order to understand and find the key factors controlling the winter precipitation variability in CA, the present study examines two dominant atmospheric modes of the 500 hPa geopotential height in the Northern Hemisphere using an Empirical Orthogonal Function (EOF) and their associated large-scale circulation patterns for the last 41 winters (1974/75–2014/15). Explaining 17.5% of variability, the second mode (EOF2) shows strong anti-cyclonic circulations in the North Pacific and cyclonic circulations in …

Evaluation Of Spatial Generalization Characteristics Of A Robust Classifier As Applied To Coral Reef Habitats In Remote Islands Of The Pacific Ocean, Justin J. Gapper, Hesham El-Askary, Erik J. Linstead, Thomas Piechota

Mathematics, Physics, and Computer Science Faculty Articles and Research

This study was an evaluation of the spectral signature generalization properties of coral across four remote Pacific Ocean reefs. The sites under consideration have not been the subject of previous studies for coral classification using remote sensing data. Previous research regarding using remote sensing to identify reefs has been limited to in-situ assessment, with some researchers also performing temporal analysis of a selected area of interest. This study expanded the previous in-situ analyses by evaluating the ability of a basic predictor, Linear Discriminant Analysis (LDA), trained on Depth Invariant Indices calculated from the spectral signature of coral in one location …

A Deep Eastern Equatorial Pacific Thermocline During The Last Glacial Maximum, H. L. Ford, C. L. Mcchesney, J. E. Hertzberg, J. F. Mcmanus

OES Faculty Publications

The mean state and variability of the tropical Pacificis influenced by the depth of the thermocline. During the Last Glacial Maximum (~21,000 years ago), the zonal sea surface temperature gradient across the equatorial Pacific was reduced and productivity was generally lower than modern. To understand the thermocline depth’s role in determining the Last Glacial Maximum tropical mean state, we reconstruct the upper ocean δ¹⁸O profile from multiple species of planktic foraminifera. We synthesize existing records of surface and subsurface dwelling foraminifera to reconstruct the vertical δ¹⁸O gradient throughout the eastern equatorial Pacific. We find the thermocline …

Ground-Truthing Social Vulnerability Indices Of Alaska Fishing Communities, Anna Lavoie, Kim Sparks, Stephen Kasperski, Amber Himes-Cornell, Kristin Hoelting, Conor Maguire

All Faculty Scholarship for the College of the Sciences

Community vulnerability is increasingly evaluated through quantitative social indices, typically developed using secondary data sources rather than primary data collection. It is necessary to understand the validity of these indices if they will be used to inform policy and decision making. This paper presents a ground-truthing effort to validate quantitative indices that characterize the well-being of Alaska fishing communities. We utilized ethnographic data collected from 13 representative communities and a capital assets framework to ground-truth the indices, in which qualitative ranks of vulnerability were compared against quantitative indices. The majority (73.8%) of ranks were in complete or moderate agreement and …

Eddy Flux Measurements Of Sulfur Dioxide Deposition To The Sea Surface, Jack G. Porter, Warren J. De Bruyn, Eric S. Saltzman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Deposition to the sea surface is a major atmospheric loss pathway for many important trace gases, such as sulfur dioxide (SO2). The air–sea transfer of SO2 is controlled entirely on the atmospheric side of the air–sea interface due to high effective solubility and other physical– chemical properties. There have been few direct field measurements of such fluxes due to the challenges associated with making fast-response measurements of highly soluble trace gases at very low ambient levels. In this study, we report direct eddy covariance air–sea flux measurements of SO2, sensible heat, water vapor, and momentum. The measurements were made over …

Tidal-, Wind-, And Buoyancy-Driven Dynamics In The Barataria Estuary And Its Impact On Estuarine-Shelf Exchange Processes, Linlin Cui

LSU Doctoral Dissertations

A three-dimensional, high-resolution, Finite-Volume Coastal Ocean Model (FVCOM) was used to study the dynamics of Barataria Estuary located in the Southeastern Louisiana. Three numerical experiments with different discharge scenarios, including the actual discharge (average ~ 160 m³ s^-1) from the Davis Pond Diversion (DPD) over three months from April to June 2010, no discharge (NO), and the proposed Mid-Barataria Diversion (MBD) with a constant discharge of 850 m³ s^-1, were conducted to investigate the impacts of river diversions on salinity gradients and residence times in the estuary. The three-month average salinity indicated that surface …

The Influence Of Habitat Preference On Longitudinal Population Composition And Distribution Of Groupers (Serranidae) In Chumbe Island Coral Park, Zanzibar Tanzania, Caroline Daley

Independent Study Project (ISP) Collection

A survey of six common grouper (Serranidae) species was conducted on both the western protected and eastern unprotected reefs around Chumbe Island. Species, estimated maturity, and fundamental niche and general habitat preference was extrapolated based on observed realized niche and qualified according to substrate, depth, slope position, and general reef region. Abundance, biomass density, and biodiversity of Serranid populations were compared among locations on the reef with habitat preference in mind in order to best assess how habitat influences population composition, distribution, and health. The results of this study provide depth to previous research on the protected reef and indicate …

Correlations Between Reef Health And Vertical Zonation On Ushongo Village Reef And Fungu Zinga Reef, Daniel Gates

Independent Study Project (ISP) Collection

While the existence of vertical zonation on coral reefs is well-known, the driving mechanisms and the influence each has is not clear. This study seeks to investigate the influence of reef health on vertical zonation. Reef health is used as a potential factor since it is essentially a broad description of reef diversity. Therefore, a healthy reef which is very diverse is likely to have more and different interspecies interactions than an unhealthy one. This project investigates whether these altered interactions results in different depth distributions of various coral types, categorized broadly by colony shape. Reef health did not seem …

Characterizing Diatom Biofilms And Their Influence On The Sand Biogeochemistry Of High Energy Beaches, Logan C. Jarrell

Honors Theses

High energy beaches are among the most dynamic ecological settings on Earth. Compared to mudflats, diatoms of high energy beaches have been more neglected in the literature, particularly true of the intertidal biofilms that form and dissipate with nutrient cycling and light intensity over the tidal cycle. Although short lived, the productivity of these biofilms may be critical to the organic-poor sand. Through sediment coring and subsequent analyses of the uppermost sand of three suspected biofilm stations—non-runnel, runnel crest, and runnel trough—along with seemingly bare sand as a control, this study sought to verify the presence of diatom biofilms and …

Habitat Preferences Of Blue Marlin (Makaira Nigricans) And Black Marlin (Istiompax Indica) In The Eastern Pacific Ocean, Nima Farchadi, Michael G. Hinton, Andrew R. Thompson, Zhi-Yong Yin

Theses

Overexploitation and climate change can reduce the abundance and shift the spatial distribution of marine species. Determining the habitat suitability of a mobile pelagic species, such as Makaira nigricans (BUM) and Istiompax indica (BLM), can help describe their spatiotemporal distribution patterns over a broad spatial scale, which is a crucial need for fisheries management. Using 14 years (1997-2010) of Inter-American Tropical Tuna Commission (IATTC) catch data from purse-seine vessels in the eastern Pacific Ocean (EPO), we modeled the dynamic habitat suitability of BUM and BLM in response to environmental variables within the EPO using a species distribution model (MaxEnt) with …

Sea Squad, Liam Geary Baulch

The Goose

The Sea Squad is a band of cheerleaders against climate change. Taking action as a team in formation, they gather momentum, inviting all people to cheer with them, mimicking the infinitely expandable nature of the seas' molecular structure. The work was developed and performed as a bilingual project at Est-Nord-Est in Saint-Jean-Port-Joli, Quebec, Canada, and has since been performed and exhibited internationally. The following poems are some of the chants that Sea Squad use to get a crowd cheering together against climate change.

Reconstruction Of Sea Level Around The Korean Peninsula Using Cyclostationary Empirical Orthogonal Functions, Se-Hyeon Cheon, Benjamin D. Hamlington, Kyung-Duck Suh

OES Faculty Publications

Since the advent of the modern satellite altimeter era, the understanding of the sea level has increased dramatically. The satellite altimeter record, however, dates back only to the 1990s. The tide gauge record, on the other hand, extends through the 20th century but with poor spatial coverage when compared to the satellites. Many studies have been conducted to create a dataset with the spatial coverage of the satellite datasets and the temporal length of the tide gauge records by finding novel ways to combine the satellite data and tide gauge data in what is known as sea level reconstruction. However, …

The Effects Of Density Gradients On The Distribution And Behavior Of Copepods, Connor Cayson

Theses

Observations of fine-scale behavioral dynamics of zooplankton may shed insight into much larger-scale ecosystem patterns and phenomena. Some zooplankton, such as copepods, are known to aggregate near density gradients; however, it is not clear the extent to which density gradients alone affect copepod distribution and behavior, since these gradients are often associated with phytoplankton layers. In this study, we investigated the behavior of Calanus pacificus in response to salinity gradients through laboratory experiments observed with high-resolution video and analyzed using computational techniques. Image data were collected using two cameras recording continuously for a duration of 30 minutes or more, allowing …

Using Local Fishery Monitoring To Understand Small-Scale Coastal Fisheries In Tanzania, Matthew Robertson

LSU Master's Theses

Nearshore marine fisheries provide the main source of protein for nearly 9 million people in the coastal villages of Tanzania, yet for decades the fisheries have shown signs of overexploitation. These fisheries are small-scale and co-managed by local coastal communities in groups known as Beach Management Units (BMUs). BMUs monitor individual fishing trip data (e.g. gear, vessel, taxa); however, these data have only been analyzed in nationally aggregated statistics and to our knowledge, are not presently used in management decision making. The present thesis aimed to identify the forms of data and information that local fishery monitoring can record about …

Next Generation Sequencing Methods For Coastal Zone Water Quality Monitoring, Catherine Iskrenko

HCNSO Student Capstones

When analyzing the water quality of the coastal zone, culture-based techniques have been utilized most often to identify Fecal Indicator Bacteria in samples. Since the advent of the Sanger Method for DNA sequencing, other techniques have arisen that provide significantly more information on the microorganisms in sample, but they are still not the mainstream for water quality analysis. This capstone reviews and compares culture-based techniques, DNA sequencing, RNA sequencing, qPCR for biomarker, and 16S rDNA sequencing to highlight their merits and shortcomings for analyzing environmental water samples. The technique presented that provides the broadest range of information (including the identification …

Bubble Stream Production By Belugas (Delphinapterus Leucas), Megan Slack

Theses

Bubble stream production in belugas has been poorly characterized and its function is not well understood. I examined behavioral states when producing bubble streams (“bubbling”), and when bubbling calls, to determine whether bubbling was significantly associated with a particular call category or behavioral state. Using 19 hours of video and audio recordings collected over a two-day period, I quantified bubble streams of a 4-month old calf and an unrelated adult female housed together. Based on the overall activity budgets and pool of vocalizations for both animals, I calculated the expected counts of bubble streams with and without vocalizations, assuming that …

Geotraces And Beyond: Studies Of Trace Elements In Coastal And Open Ocean Waters With An Emphasis On The Effects Of Oxygen Depletion And Hydrothermal Plumes, Peng Ho

Dissertations

We investigated various dissolved trace element (dTE) distributions in two distinct areas: the coastal northern Gulf of Mexico and the eastern tropical Pacific Ocean.

A multi-year (2007‒2011) chemical time series of eight stations in the western Mississippi Sound (MS) and northwestern Mississippi Bight (MB) was undertaken to examine the factors affecting chemical distributions in this dynamic region. Key findings include the frequent development of bottom water hypoxia in MB during late spring-summer, the likely contribution of submarine groundwater discharge (SGD) to the material flows, and observation of effects of episodic events including tropical storms and the opening of the Bonnet …

The Feasibility Of Using Inherent Optical Properties And The Apparent Optical Property Remote Sensing Reflectance To Estimate Suspended Particulate Matter, Particularly For Use In Airborne Hydrographic Surveys, Sarah Epps

Dissertations

Airborne hydrographic surveys are routinely used to create and update nautical charts around the world. This research is intended to assist in maximizing the utility of the data products made available from those surveys in accordance with the current survey–once, use–many–times initiatives. Specifically, this project evaluates the feasibility of using the data available airborne hydrographic systems that utilize bathymetric lasers and hyperspectral sensors to estimate the concentration of suspended particulate matter (SPM). SPM is sometimes also called suspended sediment. The ability to chart spatial distributions of SPM utilizing hydrographic survey systems already in operation will assist researchers, managers, and stakeholders …

Hydrodynamic Drivers Of Dissolved Oxygen Variability Within A Highly Developed Tidal Creek In Myrtle Beach, South Carolina, Douglas Matthew Pastore

Electronic Theses and Dissertations

Erosion and water quality degradation have been observed in Singleton Swash in Myrtle Beach, SC, and have been hypothesized to be related to migration of the beach-face channel. Dredging this channel temporarily fixes erosional threats to nearby infrastructure but the effects on water quality are not well understood. It is hypothesized that variations in dissolved oxygen (DO) concentration (used here as a proxy for water quality) within the water column are related to changes in vertical mixing and transport due to oceanic tidal forcing. This study utilizes current meters, pressure sensors, and optical DO probes to measure and study the …