Digital Commons Network^™

The Effect Of Historic Shipwrecks On Sediment Microbiomes In The Northern Gulf Of Mexico, Melissa Brock

Master's Theses

Microorganisms are ubiquitously distributed across all aquatic habitats, but it is the environmental conditions of a habitat that determine which microorganisms can thrive in terms of abundance or metabolic activity. Habitats that experience consistent physical and chemical environmental conditions repeatedly favor specific taxonomic groups which may result in a microbial assemblage that is commonly associated with that habitat (i.e., a core microbiome). Core microbiomes have been identified for a variety of natural marine habitats including methane seeps, wood falls, octocoral, and deep-sea sediments. However, it was unknown if the presence of man-made structures on the seafloor, including historic shipwrecks, also …

Inferred Function And Dynamics Of Microbial Communities From The Northern Gulf Of Mexico, Deepesh Tourani

HCNSO Student Theses and Dissertations

Microbial communities, or microbiomes, are the major drivers of global biogeochemical cycles, acting as primary producers and decomposers across the water column in the oceans. Thus, they reflect changes in physicochemical properties and nutrient composition of the ocean. However, this correlation between ecological changes and the function of marine microbiomes is poorly understood. Large-scale oceanic events such as the bottom-water oxygen-depleted zone (i.e., “dead zone”) and the Deepwater Horizon oil spill in the Gulf of Mexico (GoM) render the ecosystem fragile. These events decrease survival rates of pelagic and coastal macrofauna and affect the biodiversity of the region. As part …

Spatial And Seasonal Differences In The Top Predators Of Easter Island: Essential Data For Implementing The New Rapa Nui Multiple‐Uses Marine Protected Area, Naiti A. Morales, Erin E. Easton, Alan M. Friedlander, Euan S. Harvey, Rodrigo Garcia, Carlos F. Gaymer

School of Earth, Environmental, & Marine Sciences Faculty Publications

1. Reef fishes are an important component of marine biodiversity, and changes in the composition of the assemblage structure may indicate ecological, climatic, or anthropogenic disturbances. To examine spatial differences in the reef fish assemblage structure around Easter Island, eight sites were sampled during autumn and summer 2016–2017 with baited remote underwater video systems.
2. To determine seasonal changes, quarterly (seasonal) sampling was conducted at five of those eight sites. Fifteen pelagic species of fishes were recorded during this study, some of which have not previously been recorded in scuba surveys, including the Galapagos shark (Carcharhinus galapagensis, Snodgrass & Heller, …

Examining The Effect Of Interstitial Space On Eastern Oysters (Crassostrea Virginica): Applications Of Photogrammetry And Three-Dimensional Modeling, Bailie Lavan

Masters Theses, 2010-2019

Global oyster populations have decreased by as much as 99% in the past century. Oysters are known ecosystem engineers, providing benthic habitat for macrofauna, linking benthic and pelagic food webs, improving water quality, and mitigating shoreline erosion. Restoration efforts are critical in re-establishing native oyster populations. In the Chesapeake Bay, where oyster loss is primarily due to severe over harvest, artificial substrates with geometric shapes are widely used in restoration efforts. However, natural oyster reefs form emergent shapes with a high degree of aggregation and many interstitial spaces (three-dimensional volumetric spaces between oysters within a reef). The lack of interstitial …

Ocean Robots Uncover Microbial Secrets, Susan Evans, Jim Birch, John A. Breier, Michael V. Jakuba, Mak A. Saito, Julie Robidart

School of Earth, Environmental, & Marine Sciences Faculty Publications

Life on Earth began in the sea, and the oceans continue to support life on our planet. Of particular importance is the ability of marine microbes to exist in a complex web of relationships where substances are continually transformed and exchanged.

Depth-Dependent Environmental Drivers Of Microbial Plankton Community Structure In The Northern Gulf Of Mexico, Cole Easson, Jose Lopez

Biology Faculty Articles

The Gulf of Mexico (GoM) is a dynamic marine ecosystem influenced by multiple natural and anthropogenic processes and inputs, such as the intrusion of warm oligotrophic water via the Loop Current, freshwater and nutrient input by the Mississippi River, and hydrocarbon inputs via natural seeps and industrial spills. Microbial plankton communities are important to pelagic food webs including in the GoM but understanding the drivers of the natural dynamics of these passively distributed microorganisms can be challenging in such a large and heterogeneous system. As part of the DEEPEND consortium, we applied high throughput 16S rRNA sequencing to investigate the …

Role Of Managed Marine Areas On The Diversity And Individual Responses Of Rocky Intertidal Shore Grazers In Central Chile, Kathy Liu

Scripps Senior Theses

Many different types of marine benthic herbivores or “grazers” inhabit coastal intertidal zones and play a crucial role in inter- and shallow subtidal ecosystems. Chile has one of the most diverse intertidal zones, but many intertidal grazers are exploited for human consumption. Marine protected areas (MPAs) and marine management and exploitation areas (MEAs) are promising tools for Chile to combat over exploitation of these grazer and other marine resources. This study surveyed the impact of sites with contrasting management on the diversity and abundance of all intertidal grazers and their impact on the size frequency and shell length-body weight allometry …

An Evaluation Of Sciaenid Growth In The Gulf Of Mexico, Shane Flinn

LSU Master's Theses

Growth models estimate life history parameters that are used in the management of fisheries stocks. The most commonly used growth model in fisheries is the von Bertalanffy growth model (VBGM), yet it has been shown to provide a poor fit for length-at-age data of some species and other models exist. I reviewed 196 peer-reviewed age and growth studies and 50 NOAA stock assessments to examine temporal trends in the use of growth models and model selection in fisheries. I found that the use of multi-model frameworks has increased since the year 2000 and information theoretic approaches are replacing goodness-of-fit and …

The Temporal And Spatial Dynamics Of Larval Supply, Settlement, And Adult Populations Of Chthamalus Fissus Within The La Jolla, California Rocky Intertidal, Catharine Hargenrader

Theses

The role of post-settlement processes in benthic invertebrate recruitment dynamics has been well established; however, more recently, studies have been resolving the pre-settlement processes and environmental variables that may shape initial settlement. We examined the major space occupying barnacle Chthamalus fissus to determine the spatial and temporal dynamics of settlement in relation to larval supply, adult populations, and habitat characteristics (including elevation as a proxy for immersion, proximity to water’s edge, and the availability of free space) within the La Jolla, CA rocky intertidal. With respect to habitat characteristics, we investigated the influence of available free space on the dynamics …

Evaluating The Efficacy Of Using Geomorphology As A Surrogate To Benthic Habitat On The Miami Terrace, Kim D. Smith

HCNSO Student Theses and Dissertations

The deep-sea is a vast and relatively sparsely characterized domain. As little as 0.01% of deep-sea benthic habitats have been characterized in detail. Characterizing the distribution of organisms and environmental components of the deep-sea is pivotal to the creation and implementation of successful resource management. Benthic habitat maps are a good method to inventory and characterize deep-sea habitats. Recent advances in technology, such as multibeam sonar and remotely operated vehicles (ROVs), have allowed for greater understanding of these ecosystems. As it is difficult and expensive to collect data deep-sea benthic community composition, environmental surrogates of biological data would be economically …

Population Dynamics Of The Threatened Staghorn Coral, Acropora Cervicornis, And The Development Of A Species-Specific Monitoring Protocol, Elizabeth Goergen

HCNSO Student Theses and Dissertations

Historically, Acropora cervicornis was found in high densities on many Caribbean, Florida, and Gulf of Mexico reefs. A disease outbreak in the late 1970s and 80s caused up to 99% loss of A. cervicornis cover at some sites, leaving populations sparsely distributed throughout its range and typically found as isolated colonies. Even though populations are depauperate causing a decrease in sexual reproduction, its fast growth rate and ability to reproduce through asexual fragmentation affords this species the potential for quick recovery and population growth. However, limited to no natural recovery has been documented. Many of these populations are poorly studied …

Spatial Dynamics And Mixing Of Bluefin Tuna In The Atlantic Ocean And Mediterranean Sea Revealed Using Next-Generation Sequencing, Gregory N. Puncher, Alessia Cariani, Gregory E. Maes, Jeroen Van Houdt, Koen Herten, Rita Cannas, Naiara Rodriguez-Ezpeleta, Aitor Albania, Andone Estonba, Molly Lutcavage, Alex Hanke, Jay Rooker, James S. Franks, Joseph M. Quattro, Gualtiero Basilone, Igaratza Fraile, Urtzi Laconcha, Nicolas Goñi, Ai Kimoto, David Macías, Francisco Alemany, Simeon Deguara, Salem W. Zgozi, Fulvio Garibaldi, Isik K. Oray, Firdes Saadet Karakulak, Noureddine Abid, Miguel N. Santos, Piero Addis, Haritz Arrizabalaga, Fausto Tinti

Faculty Publications

The Atlantic bluefin tuna is a highly migratory species emblematic of the challenges associated with shared fisheries management. In an effort to resolve the species’ stock dynamics, a genomewide search for spatially informative single nucleotide polymorphisms (SNPs) was undertaken, by way of sequencing reduced representation libraries. An allele frequency approach to SNP discovery was used, combining the data of 555 larvae and young‐of‐the‐year (LYOY) into pools representing major geographical areas and mapping against a newly assembled genomic reference. From a set of 184,895 candidate loci, 384 were selected for validation using 167 LYOY. A highly discriminatory genotyping panel of 95 …

Extraction Of Metazoan Meiofauna From Muddy Deep-Sea Samples: Operator And Taxon Effects On Efficiency, Melissa Rohal, David Thistle, Erin E. Easton

School of Earth, Environmental, & Marine Sciences Faculty Publications

Deep-sea metazoan meiofaunal specimens are usually extracted from muddy samples by centrifugation in a fluid in which meiofauna tend to float and sediment particles tend to sink. Although the procedure is in common use, its efficiency has seldom been examined. The study reported here showed that well-trained operators extracted metazoan meiofauna with efficiencies that were different enough to be a concern in quantitative studies. Therefore, samples should be assigned to operators in a stratified-random manner. In the course of these studies, both operators also extracted individuals of the common nematode family Desmoscolecidae significantly less efficiently than other nematode families, a …

Descriptive Density Models Of Scyphozoan Jellyfish In The Northern Gulf Of Mexico, Katrina T. Aleksa, Redwood W. Nero, Jerry D. Wiggert, William M. Graham

Faculty Publications

Jellyfish play an important role in the food web of many coastal environments but are generally considered a nuisance to scientific fieldwork and industrial and economic trades. A better understanding of how jellyfish densities and distributions are affected by environmental parameters could elucidate population trends and provide assistance in ecological research and undesirable human interactions. In this study, abundance data for scyphozoan medusae, Chrysaora sp. and Aurelia spp., were extracted from Southeast Area Monitoring and Assessment Program trawling surveys for the northern Gulf of Mexico (nGoM) during the summer and fall months. Both in situ and satellite oceanographic measurements were …

Killi-Data News (Spring), Tyrone Genade

Killifish Research Review

This is the start of Killi-Data News’ second year. In this first issue of the year we have the usual review of research pub- lications as well as input from Martin Reichard on his lab’s Nothobranchius research. Martin is responding to my reviews of his lab’s work in the previous edition. I am serious about making sure the content in this newsletter is reliable but I erred in the previous edition and Martin has written extensively to correct my mistake in the section “Erratum”. This reply is welcomed and owed to readers. I must confess that I don’t know everything …

Killi-Data News (Spring), Tyrone Genade

Killifish Research Review

This is the start of Killi-Data News’ second year. In this first issue of the year we have the usual review of research pub- lications as well as input from Martin Reichard on his lab’s Nothobranchius research. Martin is responding to my reviews of his lab’s work in the previous edition. I am serious about making sure the content in this newsletter is reliable but I erred in the previous edition and Martin has written extensively to correct my mistake in the section “Erratum”. This reply is welcomed and owed to readers. I must confess that I don’t know everything …

Modeling Chlorophyll Concentrations On The Ohio River Using Remotely Sensed Data, Thaddaeus Stephen Tuggle

Theses, Dissertations and Capstones

Traditional direct water quality methodologies limit the ability to spatially and temporally predict algal blooms in lotic systems due to the size and characteristics of large river systems. Algal blooms potentially can be predicted by knowing the spatial and temporal patterns of change in cyanobacteria concentrations at large scales. Remote sensing studies investigating freshwater algal blooms, some known to secrete harmful toxins, are primarily conducted on lentic systems while large lotic systems are greatly ignored. In this study I developed a chlorophyll concentration estimation model for the Ohio River using a satellite remote sensing approach. Ground-truth water quality measures, including …

Ecological And Indigenous Community Impacts Of Oil Spill Mortality In Alaskan Marine Ecosystems, Paul M. Suprenand, Carie Hoover, Cameron H. Ainsworth, L. Dornberger, C. J. Johnson

Marine Science Faculty Publications

While hydrocarbon exploration and extraction in the Arctic ebbs and flows, reduced sea ice has opened new travel routes across the Arctic. The opening of the Northwest Passage has allowed larger ships (including oil tankers) and higher traffic into remote regions. More ice loss is expected in the future. With this comes the potential for hydrocarbon spills. To quantify the ecosystem impacts of a spill in the Alaska North Slope region, an Ecospace model using the Ecopath with Ecosim software was developed. We highlight the impacts of four potential hydrocarbon contamination scenarios: a subsurface crude oil pipeline release, a surface …

Confronting The Challenges Of Whale Avoidance By Large Vessels To Reduce Collision Risk: A Quantitative Approach, Jennifer E. Helm

Graduate Student Theses, Dissertations, & Professional Papers

Disturbance of wildlife by human transportation infrastructure is ubiquitous. This type of human-wildlife conflict has the potential to negatively impact wildlife population growth rates, especially for at-risk species like large whales. While many whale populations are rebounding as a result of a moratorium on commercial whaling, increasing ship traffic constitutes a significant threat to whale conservation efforts in the form of ship-whale collisions (“ship strikes”). Ship strike avoidance is difficult because vessel operators can only see whales when they are breaking the surface of the water, or “available for detection,” and even then, they will only see them a fraction …

Clarifying The Range Of The Endangered Largetooth Sawfish In The United States, Jason C. Seitz, John D. Waters

Gulf and Caribbean Research

The United States population of the endangered Largetooth Sawfish (Pristis pristis) has a high probability of extinction. It is critical to identify areas with valid historical records as these areas may be important to the recovery of the species. The U.S. range is reported to extend as far east as Florida based on one vouchered specimen and 3 historical records from this state. Three of these reports presume a local capture location despite a lack of locality data. The vouchered specimen was presumed captured in southern Florida, but evidence suggests otherwise. Dried specimens observed in Florida were most likely imported …

Modeling Canopy Effect In The Great Lakes Cladophora Model, Ankita Bakshi

Dissertations, Master's Theses and Master's Reports

Cladophora glomerata is a filamentous green alga native to the Great Lakes. However, its nuisance growth in phosphorus rich waters negatively affects the lakes’ aesthetic and water quality. The Great Lakes Cladophora Model (GLCM) v1, developed in 1982, was the first mechanistic model to simulate Cladophora growth basing phosphorus availability and environmental conditions followed by Cladophora Growth Model and GLCM v2. In this study, the light and temperature mediation factors for Cladophora net growth are revised as a necessary step prior to the development of a self-shading algorithm. The concept of a fixed-value, maximum achievable biomass (carrying capacity) employed in …

Ecological Implications Of Foraging And Life-History In Three Cold-Adapted Species, Andrew Von Duyke

Dissertations, Master's Theses and Master's Reports

This research investigates the ecology of: ringed seals (Pusa hispida), moose (Alces alces), and bowhead whales (Balaena mysticetus). Each of these species draws upon specialized strategies to meet the physical demands of life in their extreme environments. However, they are currently experiencing unprecedented changes in their habitats. This work adds to what is known about the behavior, physiology, and population dynamics of cold-adapted species—providing insights of value for an improved understanding of foraging and life-history theory, and informing conservation and ecosystem monitoring efforts. Chapter 1 provides a brief introduction to the scope of work …

Climate Metric Coherence: Stationarity Of The Relationships Between North Pacific Climate Indices And Ecological Processes In The Gulf Of Alaska, Michael Opiekun

Theses and Dissertations

The Pacific Decadal Oscillation (PDO) has been used to characterize the dominant basin-scale climate variability, in the North Pacific. The PDO index has been correlated to Pacific salmon (Oncorhynchus spp.) population dynamics in the Gulf of Alaska (GOA) during the late 1900s, but the stationarity of the statistical relationships between salmon production and the basin-scale index (and between the regional physical processes and the basin-scale index) has not been quantified. A change in the relationship between the PDO and salmon catches has been noted during the late 1980s, motivating further investigation of variability in climate and ecosystem properties during this …

Pros And Cons Of Marine Zoological Parks According To Marine Conservationists, Kayla L. Patama

HCNSO Student Capstones

Throughout history zoos and aquariums have satisfied a number of different, albeit to some, conflicting roles (Ballantyne, Packer, Hughes, & Dierking, 2007). In recent years, zoos and aquariums have shifted their focus on taking a proactive role in wildlife conservation and promoting conservation learning among their visitors. The present capstone addresses the justifications that marine conservationists see in marine zoological parks and how they believe parks can become more relevant and valuable in the future. A 65 question survey (Appendix I) was distributed to marine science professionals online through personal contact between June and September 2017 questioning participant’s personal opinions …

Ecological And Oceanographic Influences On Leatherback Turtle Behavior And Scyphozoan Jellyfish Distributions In The Gulf Of Mexico, Katrina Aleksa

Dissertations

Leatherback turtles (Dermochelys coriacea) are a wide-ranging, oceanic species that feed exclusively on gelatinous zooplankton. Leatherback have been spotted in the Gulf of Mexico (GoM) for several decades and consistently had a high level of interactions with longline fisheries. However, no quantitative studies have been performed to address the spatiotemporal distribution of these turtles in the GoM. This research determines 1) leatherback movements and high-use areas in the GoM, 2) their association with oceanographic features, 3) the distribution and density of two abundant medusae in the northern GoM and any association with biophysical parameters, and 4) the body …

Evaluating Social Network Dynamics Of Bigg’S Killer Whales (Orcinus Orca) And Vessel Traffic Within A Transboundary Region: Implications For Conservation Management, Courtney Smith

Dissertations

The social lives of animals are defined by group dynamics based on the nature and strength of associations and movements between individuals, often resulting in highly complex and interconnected social networks. However, understanding of how environmental variables may shape this structure is poorly understood. Within the inland waters of Washington State and southern Vancouver Island, British Columbia, mammal-eating Bigg’s (transient) killer whales occur in relatively small, but stable social groups. Group size and occurrence in recent years has increased, coinciding with a growing whale watching industry. Given the central importance of the social network within killer whale population dynamics, such …

Frontline Experiences From Changing Fisheries Bycatch Paradigms, David Kerstetter

Marine & Environmental Sciences Faculty Proceedings, Presentations, Speeches, Lectures

No abstract provided.

Population Density, Distribution, Richness & Health Of Shallow Water Caribbean Porifera From An Unesco Biosphere Reserve, St. John, Usvi, Patrick Michael Vojnyk

Theses, Dissertations and Culminating Projects

Porifera is an important phylum of organisms in benthic ecosystems that filter water, act as biogenic habitat, and provide 3-dimentional structure. Sponge diversity and abundance are often used as bio-indicators for good or improving water quality in a system. Transects were performed during July 2015, January 2016, and July 2016 to determine species richness, density, and assess necrotic pinacoderm tissue decay of species of poriferans in St. John, USVI. 6,800 individuals and 17 different species were recorded during observation periods in Great and Little Lameshur Bays. Results indicate that the non-cryptic species Amphimedon compressa and Aplysina fiulva had the highest …

Larval Rockfish Diversity Abundance Dynamics In Association With A Marine Protected Area In The Southern California Bight, Dustin Chen

Theses

Marine protected areas (MPAs) are areas aimed at protecting natural and cultural resources that are often proposed as a way to alleviate the effects of overfishing on populations of targeted species; these areas have varying degrees of fishing and recreational use restrictions. In order to assess MPA efficacy, it is important to determine the mechanisms by which the presence of MPAs affect reproductive output within and potentially even beyond their boundaries. I attempted to address this through studying the responses of rockfish (Sebastes spp.) larval abundances to the presence of the Cowcod Conservation Areas (CCAs) located within the Southern California …

Causes And Consequences Of Individual Phenotypic Differences In Brachyuran Crabs With A Focus On Behavior, Benjamin A. Belgrad

Theses and Dissertations

Individual variation defines almost every morphological, physiological, and behavioral aspect of populations and is a fundamental component of many ecosystem processes. Recent work indicates that accounting for these individual differences can enhance our ability to predict community responses to environmental disturbances which is becoming increasingly important in an era of extraordinary global change. However, our understanding of how different individual characteristics are connected to each other and governed by the environment remains limited.

This study sought to evaluate the relationship between individual behavior, physiological condition, and local habitat for Brachyuran crabs as well as the subsequent strength of their predator-prey …