Marine Biology Commons^™

Psammocora Stellata Distribution At Devil's Crown, Floreana Island, Galápagos Islands, Ecuador, María José Guarderas Sevilla

All HCAS Student Capstones, Theses, and Dissertations

In the Galápagos Archipelago, the free-living nodular coral Psammocora stellata is a common species that does not form reef structures. However, it is a key component of the ecosystem by increasing habitat complexity and, consequently, species diversity. This species experienced a drastic decline in Devil’s Crown channel, Floreana Island, where it disappeared after the 1982-83 El Niño-Southern Oscillation, presumably by displacement of unattached colonies by strong surface waves and currents. This assemblage has now recovered to pre-impact levels. A combination of underwater photoquadrats from 2007 and 2009 and recent (2023) orthomosaics were used to determine changes in coral densities and …

Population Genomics, Ecology And Conservation Of Asterias Sea Stars In The North Atlantic, Melenia I. Giakoumis

Dissertations, Theses, and Capstone Projects

Uncovering how species respond to environmental change is a central question in biology (Ehrlén & Morris 2015; Habibullah et al. 2022). It is the key to elucidating the past, understanding the present and predicting the future of species’ population dynamics. This dissertation investigates the influence of environmental change on intertidal species’ distributions and genomics at several timescales, with implications for conservation.

Environmental changes have occurred throughout history, on a geological scale, and have shaped the global patterns of species’ distributions and population sizes. Biologists have long studied how geological history has shaped species distributions (Sanmartín 2012) in both terrestrial (Liu …

Predicting Marine Teleost Responses To Ocean Warming And Pollution, Akila Harishchandra

Electronic Theses and Dissertations

Ocean warming and pollution are two detrimental anthropogenic factors causing rapid marine ecosystem degradation recorded in the past decades. These factors alter the marine environment intolerable for many marine species, forcing them to either adapt or shift their contemporary habitat ranges to reduce the extinction risk embedded with environmental degradation. Estimating marine species’ habitat range shifts, and their potential for developing adaptive mechanisms are critical for ecosystem conservation and management, human health risk assessment, and climate change vulnerability assessments. Given that, for the first chapter of this thesis, we focused on developing a species distribution model (SDM) integrating marine species …

On The Edge Of The "Er-Ocean" State, Mariesa Travers

Masters Theses

This thesis will explore how hard coastal infrastructure methods can be redesigned by softening the coastal edge to support the ecosystem and enhance public access to the beach. By referencing and arguing against techniques used by the U.S. Army Corps of Engineers (USACE) as a solution to deal with coastal erosion, this process will propose a regenerated design system. Through a series of material experiments, this research works with natural processes and flows, to create transitory systems that erode and ebb with the coast.

Practical Solutions To The Invasion Of Lionfish In Utila, Honduras: Science, Education, Food, And Jewelry, Carolyn Corley

Undergraduate Honors Theses

Lionfish (Pterois sp.) are invasive species capable of devastating coral reef ecosystems due to their lack of predators, large appetites, generalist diet, high fecundity, and rapid spawning rates. As lionfish have expanded their distribution across the Caribbean, many conservation groups have taken it upon themselves to systematically remove these predators from environments where they are threatening native species. However, few have involved the community the way I observed while interning with the Whale Shark and Oceanic Research Center in Utila, Honduras. Protecting coral reefs is extremely important, especially in small communities like Utila, where the majority of people’s …

Building Artificial Reefs From Recycled Construction Materials: A Feasibility Study, Nicholas H. Lew

Construction Management

Naturally occurring reefs are some of the world’s most biologically diverse ecosystems formed by jagged rocks tucked slightly below sea level. In recent years global warming began to pose a major threat to many reef habitats. Most relevant is the increase in surface seawater temperatures that cause coral to bleach, taking away major food sources for larger marine species. Researchers have combated this by deploying artificial reefs in substitution for naturally formed limestone rock formations in order to promote the expansion of coastal habitats. This project specifically aims to utilize construction waste towards the production of artificial reefs, effectively upcycling …

Host-Microbe Interactions In Non-Native Estuarine Anemones: Biogeography And Temperature, Parker K. Lund

Cal Poly Humboldt theses and projects

Non-native species are increasing in prevalence around the world, resulting in negative economic and ecological impacts. However, the broad distributions of non-native species also offer a system for investigating the response of host-associated microbial communities to environmental factors across a range of ecological scales. At the broadest scale, I investigated the geography of microbial communities in the non-native estuarine anemone Diadumene lineata on the west coast of the United States of America. Across latitudes, microbial community composition was very similar and displayed a high percentage of Klebsiella spp. at all sites. However, the communities in California tended to exhibit higher …

Diversity And Distribution Of Bryozoans Of The Northern To Central Rocky Outer Coast Of California, Ismael Chowdhury

Cal Poly Humboldt theses and projects

The phylum Bryozoa is one of the most diverse groups of marine invertebrates, with a global distribution that spans marine and fresh waters. This study analyzes the Bryozoa in infralittoral communities on rocky surfaces from northern California (Point Saint George) to central California (Estero Bay), spanning 940 kilometers and encompassing 12 rocky intertidal sites. Although recent studies on bryozoan taxonomy and phylogeny have increased due to scanning electron microscopy (SEM) and high throughput sequencing, there is still a lack of studies on species found in shallow waters at intertidal depths, particularly in the northeastern Pacific. This study aims to expand …

Are Biodiverse Communities More Resistant To Invasion? A Case Study With Marine Fouling Communities, Taylor Robert Bruntil

Cal Poly Humboldt theses and projects

The theory of biotic resistance predicts that more diverse communities should be less susceptible to invasion by novel species, but given the opposing results of multiple observational and experimental studies in marine systems, it is unclear how changes in environmental conditions can affect invasion success in communities that differ in diversity. I used marine fouling communities to test how the diversity of the species present in an initial community (hereafter termed “resident species”) affected the establishment and growth of all species not present in the initial communities (hereafter termed “novel species”) at two locations at the Eureka Public Marina, in …

Caribbean Reef-Building Coral-Symbiodiniaceae Network: Identifying Symbioses Critical For System Stability In A Changing Climate, Shaman Patel

All HCAS Student Capstones, Theses, and Dissertations

Increasing global ocean temperatures and frequency of marine heatwaves pose dire consequences for coral reefs. High temperatures often lead to disruptions in coral symbiosis resulting in coral bleaching, increasing the mortality of corals. However, corals can potentially avoid bleaching peril by associating with thermally tolerant symbionts. Here we provide a tool for understanding symbiosis network stability of Caribbean reef-building corals. We created a network of Caribbean hermatypic corals and their associated Symbiodiniaceae phylotypes. A bleaching model was applied to this network to test for resilience and robustness (R50) to thermal stress. It was also layered with trait data for coral …

Crustacean Assemblage Structure Over The Charlie-Gibbs Fracture Zone Of The Mid-Atlantic Ridge Collected During The 2009 Henry B. Bigelow Expedition, Kathryn Medina

All HCAS Student Capstones, Theses, and Dissertations

The Charlie Gibbs Fracture Zone (CGFZ) consists of two nearly parallel fracture transform faults that intersect the Mid-Atlantic Ridge (MAR) axis. This area has high primary productivity and biomass levels due to the topography and water. A predominant hydrographic feature of the MAR is the Sub-Polar Front (SPF) which runs along the southern edge of the CGFZ and is known as a biogeographical boundary for multiple species. As part of The Census of Marine Life project Patterns and Processes of the Ecosystem of the northern Mid-Atlantic (MAR-ECO), this study analyzed the abundance and distribution patterns of the CGFZ crustacean community …

Impacts Of Nitrogen Enrichment On Corals – A Remote Sensing Approach, David E. Carrasco

Master's Projects and Capstones

Anthropogenic activities have resulted in ever-increasing threats to coral reefs globally, wherein the rate of environmental changes have exceeded the historical capacity of corals to adapt. This has threatened the persistence of coral ecosystems and their associated ecosystem services, which billions of people rely on for their livelihoods. The most prevalent stressor is nitrogen enrichment, which while present naturally, is exacerbated by the anthropogenic input of nutrients via the discharge of agricultural and urban waste waters. The focus is to answer the central research question of how nitrogen enrichment impacts corals, and how it interacts with other stressors with particular …

Accumulation Of Persistent Organic Pollutants In Marine Mammals: A Case Study On Cetaceans, Pinnipeds, And Sirenians, Alydia Moorhead

All HCAS Student Capstones, Theses, and Dissertations

Persistent organic pollutants (POPs) are lipophilic semi-volatile organic chemicals that present a range of challenges to marine biota, specifically marine mammals that often occupy a high trophic position in the food web. POPs have become a global problem since they have been shown to cause immunologic, teratogenic, carcinogenic, neurological, and reproductive complications in living organisms due to their resistance to biodegradation and their lipophilic nature. Marine mammals can accumulate these toxic substances through direct ingestion, trophic transfer, adsorption, and maternal offloading. They are susceptible to both bioaccumulation and biomagnification of POPs. Accumulation of POPs is affected by many variables, including …

Crassostrea Gigas Invasion In Southern California: Macrofaunal Diversity And Local Community Impacts Of Ecosystem Engineers On Estuarine Habitats, Noah Jansen-Yee

Theses

Many marine ecosystems are facing the growing threat of biological invasions. These invasions can have a variety of different impacts on ecosystems and their inhabitants. The Pacific oyster, Crassostrea gigas, is currently in the relatively early stages of invasion in San Diego estuaries. Crassostrea gigas is a large, filter-feeding bivalve that forms dense oyster beds on hard substrate. These oysters are known to outcompete native counterparts and drastically alter habitats where they are present. Crassostrea gigas is an ecosystem engineer that, through shell creation and formation of a dense oyster matrix, impacts ecosystems in a variety of direct and indirect …

Phylogenetic And Geographic Relationships Of Cheilostome Bryozoans In The Eastern Pacific, Hannah E. Lee

Cal Poly Humboldt theses and projects

The phylum Bryozoa is an incredibly diverse group of marine invertebrates with a widespread global distribution that is well suited for evolutionary studies but whose phylogenetic relationships are still poorly understood. Although recent studies on bryozoan taxonomies and phylogenies have increased, there is still a lack of assessment of species found at shallow water (<1 m) to intertidal depths. In this study, I aimed to expand the taxonomic sampling and assessment of the phylogenetic diversity of cheilostome bryozoans along the California coastline by utilizing mitochondrial DNA as well as inferring potential correlations between species presence and dispersal range both within and between rocky outer coast and sheltered harbor habitats. Illumina high-throughput sequencing was used to produce mitogenomes for cheilostome bryozoan samples collected off rocks from two rocky intertidal sites and off settlement panels from two harbor sites. Phylogenetic analyses generated evolutionary hypotheses of species relationships alongside geographic mapping of their distribution. This study identified 15 distinct species that represent 10 different families to form the first comprehensive phylogeny for multiple bryozoan families in California across a total range of approximately 973 km of coastline. Three genetically distinct species were found at multiple sites that are separated by a combination of rocky shores and sandy beaches, which indicates that the dispersal range of these species are not limited by geographic barriers along the coast of California. These results provide a future opportunity for further integration of this data with the phylogenies generated in this study to examine more robust evolutionary hypotheses for the phylogenetic and geographic relationships of Californian bryozoan species.

Ms Environmental Biology Capstone Project, Catherine Shapiro

Regis University Student Publications (comprehensive collection)

Chapter 1: Artificial light at night disrupts the biology of fishes. Chapter 2: Grant proposal to determine how artificial light at night affects Pumpkinseed fish. Chapter 3: Management of pinyon-juniper woodland impacts the occupancy of Pinyon Jays. Chapter 4: Stakeholder analysis of horseshoe crab fishing and its impacts on the Red Knot and biomedical industry.

A Characterization Of The Sandy Beach Surf Zone Fish Community And Their Ecology In Northern California And The Effects Of Marine Protected Areas, Katie B. Terhaar

Cal Poly Humboldt theses and projects

Historically written off as dull and homogenous, the dynamics of the sandy beach surf zone remains under studied world-wide. Northern California has been no exception to this global standard, as the sandy beach surf zone ecosystem in this region has yet to be characterized, and the effect of Marine Protected Areas (MPAs) on the fish and macroinvertebrate community fully ascertained.

Considered data-poor by local wildlife officials, commercially, recreationally and culturally important Amphistichus rhodoterus (redtail surfperch) and common Hyperprosopon ellipticum (silver surfperch) utilize the sandy beach surf zone in Northern California. Little is known about the effect of various environmental factors, …

Insights Into Halophilic Microbial Adaptation: Analysis Of Integrons And Associated Genomic Structures And Characterization Of A Nitrilase In Hypersaline Environments, Sarah Sonbol

Theses and Dissertations

Hypersaline environments are extreme habitats that can be exploited as biotechnological resources. Here, we characterized a nitrilase (NitraS-ATII) isolated from Atlantis II Deep brine pool. It showed higher thermal stability and heavy metal tolerance compared to a closely related nitrilase.

We also studied integrons in halophiles and hypersaline environments. Integrons are genetic platforms in which an integron integrase (IntI) mediates the excision and integration of gene cassettes at specific recombination sites. In order to search for integrons in halophiles and hypersaline metagenomes, we used a PCR-based approach, in addition to different bioinformatics tools, mainly IntegronFinder.

We found that integrons and …

Construction Of Dichotomous Taxonomic Keys For San Francisco Bay Planktonic Diatoms, Ria Angelica Laxa

Undergraduate Honors Theses

Planktonic diatoms exhibit high biodiversity in marine systems and make a significant contribution to water column primary productivity. This makes research on planktonic diatoms particularly important in measuring the health of coastal marine ecosystems. At the University of San Francisco (USF), undergraduate research has been conducted since September 2015 to study planktonic diatoms in San Francisco Bay. A previous study by Keith (2018), Planktonic Diatom Species Succession in San Francisco Bay, documented changes in species diversity over time, observing seasonal patterns in species richness as well as the effect of environmental factors such as salinity, temperature, and rainfall on species …

The Potential Influence Of Abiotic Conditions On Mussel Species Abundance In San Francisco Bay, Alexandra G. Farrell, M. Christina Vasquez Dr.

Honors Thesis

Climate change has negatively altered seawater conditions, which may have severe implications for marine ecosystems. Mussels are susceptible to environmental changes since they are primary consumers and filter-feeding bivalves. Two species of particular interest to the West Coast of the U.S. are Mytilus galloprovincialis and M. trossulus. M. trossulus is native to the California Coast and was historically prevalent from Southern California to Washington. However, with increased shipping and rising seawater temperature, M. galloprovincialis, an invasive species from the Mediterranean, pushed the species range of M. trossulus poleward. M. trossulus is more tolerant of cold seawater with variable salinity while …

Assessing Habitat Suitability Of Ribbed Mussels (Geukensia Demissa) In Georgia Salt Marshes By Examining Predicted Mussel Densities And Mussel Population Parameters, William K. Annis Jr

Electronic Theses and Dissertations

Geukensia demissa (ribbed mussel) is an ecology important bivalve that has the potential to contribute to salt marsh restoration. Understanding the factors that contribute to the distribution of mussels can help inform managers on choosing locations to optimize the survivorship of mussels in restoration projects. This study sought to model mussel densities across the coast of Georgia and to compare predicted mussel densities with mussel population parameters as means to gauge habitat suitability. Mussel densities were collected through field surveys across a range of salt marshes along the coast of Georgia and were compared with spatial data such as distance …

An Economic Analysis Of Using Retired Vessels To Create Artificial Reefs In Costa Rica, Josué González

Electronic Theses and Dissertations

ABSTRACT

The Republic of Costa Rica is a Central American country with only 0.03% of the world’s landmass, but 5% of the world’s biodiversity, making it a leading ecotourism destination. Ecotourism is one of the main sources of revenue for the country, but the degradation of coastal reefs has resulted in a significant loss of financial income for developing areas. As a result, many of these areas are searching for methods to revert the degradation of coral reefs.

Artificial reefs play an important ecological role in marine ecosystems due to their complexity and size. They help in the development of …

Global Conservation Status Of Croaker And Drum (Family: Sciaenidae) And Role Of The Maw Trade, Claire E. Gorman

Biological Sciences Theses & Dissertations

Understanding threats and drivers of extinction risk is critical to conserving marine biodiversity. Although marine bony fishes are some of the most diverse and abundant vertebrates in the world, overexploitation is the major threat to these taxa. Species in the family Sciaenidae are important marine resources in many parts of the world, supporting small- and large-scale fisheries for consumption and the international maw (dried swimbladder) trade. Sciaenids exhibit a diverse array of life history characteristics, such as high fecundity, large body size, formation of spawning aggregations, and longevity. Some characteristics increase their susceptibility to anthropogenic stressors. Despite being ecologically and …

Distributions And Abundances Of The Red Tide Dinoflagellate Alexandrium Catenella In The Eastern Gulf Of Maine And Bay Of Fundy In Relation To Diatoms In June, July And August Of 2019, Kimberly Lina D'Adamo

Electronic Theses and Dissertations

A series of three oceanographic survey cruises were conducted in June, July, and August of 2019 in the northeastern Gulf of Maine and Bay of Fundy. Surface water samples were collected and analyzed for enumerations of cell densities of the dinoflagellate Alexandrium catenella in relation to cell densities of diatoms. Hydrographic profiles of temperature, salinity, and nutrients (silicate and nitrate) were also made at each station. Data were analyzed to determine if there was any statistically significant evidence of allelopathic interference imparted by diatoms that impede A. catenella. A. catenella cells were most abundant in June, reaching 6,195 cells per …

A Reexamination Of The Freshwater Mussel Community Of The Little Miami River, Emily Davis

Undergraduate Honors Thesis Projects

Understanding the changes in biodiversity and local freshwater mussel populations is critical to mitigate the risks to these populations. Freshwater ecosystems continue to degrade rapidly. The freshwater mussel community of the Little Miami River is degraded and has been in decline for many years. The biodiversity contained within freshwater ecosystems is lost at unprecedented rates influenced by human activity. Freshwater mussels play a key role in understanding the effects of human activity on freshwater ecosystems as well as maintaining the health of freshwater habitats. However, they are also sensitive to changes and disturbances, in their ecosystems. This study involved monitoring …

The Chumash Heritage National Marine Sanctuary: An Exploration Of Changing The Discourse On Conservation, Arielle Ben-Hur

Pitzer Senior Theses

In 2015, the Northern Chumash Tribal Council submitted a National Marine Sanctuary Nomination to establish the Chumash Heritage National Marine Sanctuary– a means by which to ensure the protection of one of the most culturally and biologically diverse coastlines in the world. On October 5, 2015, John Armor of the National Oceanic and Atmospheric Administration (NOAA) responded to the nomination, adding it to the inventory of areas NOAA may consider in the future for national marine sanctuary designation.

In my thesis, I explore how the nomination of the Chumash Heritage National Marine Sanctuary acts as a platform from which Traditional …

The Vezo Communities And Fisheries Of The Coral Reef Ecosystem In The Bay Of Ranobe, Madagascar, Shane Abeare

University of New Orleans Theses and Dissertations

Madagascar, a country whose extraordinary levels of endemism and biodiversity are celebrated globally by scientists and laymen alike, yet historically has received surprisingly little research attention, is the setting of the present dissertation. Here, I contribute to the need for applied research by: 1) focusing on the most intensely fished section of the Toliara Barrier Reef, the Bay of Ranobe; 2) characterizing the marine environment, the human population, and the fisheries; and 3) collecting the longest known time-series of data on fisheries of Madagascar, thereby providing a useful baseline for future analyses. In Chapter 1, the bathymetry of the Bay …

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 …

Habitat Associations And Reproduction Of Fishes On The Northwestern Gulf Of Mexico Shelf Edge, Elizabeth Marie Keller

LSU Doctoral Dissertations

Several of the northwestern Gulf of Mexico (GOM) shelf-edge banks provide critical hard bottom habitat for coral and fish communities, supporting a wide diversity of ecologically and economically important species. These sites may be fish aggregation and spawning sites and provide important habitat for fish growth and reproduction. Already designated as habitat areas of particular concern, many of these banks are also under consideration for inclusion in the expansion of the Flower Garden Banks National Marine Sanctuary. This project aimed to gain a more comprehensive understanding of the communities and fish species on shelf-edge banks by way of gonad histology, …

Spatial And Temporal Variation In The Diet Composition Of Zooplankton In Mission Bay, Bryanna Paulson

Theses

Analyses of quantitative data on zooplankton diets are vital for understanding the drivers of zooplankton abundance within an ecosystem. Such analyses also provide insight into trophic pathways within the lower planktonic food web, which support populations of higher trophic level species. This study used carbon and nitrogen stable isotope ratios of size-fractionated plankton in Mission Bay, San Diego, CA to examine the spatial and temporal variation in zooplankton trophic ecology and determine potential environmental drivers of zooplankton community structure. Carbon stable isotopes reflect primary production sources in an organism’s diet, and nitrogen stable isotope ratios can be used to estimate …