Marine Biology Commons^™

Prochlorococcus Death By A Ubiquitous Zooplankton Filter Feeder, Avery Harman

University Honors Theses

Prochlorococcus is a globally abundant cyanobacterium that can help reveal the ecology of microorganisms in the ocean. Specifically, mortality by zooplankton such as appendicularians is globally important and Prochlorococcus can help reveal some of the choices made around feeding for this ubiquitous filter feeder. Two ecotypes of Prochlorococcus were introduced to appendicularians to determine if appendicularian feed selectively between these ecotypes. Further, a single ecotype of Prochlorococcus was fed to appendicularians over a variety of life stages to determine if retention rate changed with appendicularian life stage. My results reveal that there is no significant selection between the two Prochlorococcus …

Effects Of Intertidal Position On The Response To Oxygen And Desiccation Stress In The Common Acorn Barnacle, Balanus Glandula, Megan M. Dotterweich

Master's Theses

Sessile invertebrates in the rocky intertidal experience intermittent periods of air exposure due to tidal flux, presenting risks of temperature extremes, hypoxia, nutrient limitation, and most dangerously, desiccation. Microscale variation in severity and frequency of these risks is widely dependent on vertical position within the intertidal zone. Common acorn barnacles (Balanus glandula) have a wide vertical distribution in the intertidal, creating large differences in microhabitat between the highest and lowest individuals in the population. This study set out to explore whether tidal position dependent differences exist in the response to oxygen and desiccation stress in B. glandula. …

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 …

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 …

Responses Of A Pine Flatwoods Specialist Treefrog To Prescribed Fire, Ian Biazzo

Electronic Theses and Dissertations, 2020-

Coarse outcomes of prescribed fires are well-understood, but fine scale impacts on many assemblages are still unknown. When fire approaches, animals escape to unburned areas, hide in place, or are killed by fire. Treefrogs are unique in their use of trees for most of their adult nonbreeding activities. This reliance on uplands and three-dimensional landscape composition makes them a great model to study prescribed fire impacts. We focused analyses on an upland flatwoods specialist comprising 99% of our captures, the pinewoods treefrog Dryophytes femoralis. We assessed this species' responses to prescribed fire using two separate before-after-control-impact replicated field experiments 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 …

Larval Fish Export In Response To Varying Compensating Gate Discharge At The Sault Rapids, St. Marys River, Signe F.K. Vandrunen

All NMU Master's Theses

The St. Marys River (SMR) forms the border between Michigan, USA and Ontario, Canada connecting lakes Superior and Huron. Discharge is controlled by a compensating gate system upstream of the SMR rapids. Because spring and summer discharge fluctuates widely, resource managers required information on how flow variability influences larval fish drift. I estimated annual larval fish export in relation to variable discharge during 2018-2021 and compared results to published habitat model predictions. Mean discharge and water temperature were lowest in 2021 and highest in 2019. Water warming rates during high discharge differed from low discharge trends. Across years, I identified …

Evaluating The Impact Of Intersecting Research And Outreach Marine Science Programs On Elementary And Undergraduate Students, Randi J. Sims

All Theses

Climate change is one of the most destructive forces our ocean is currently experiencing. Despite this, many students are not taught the basics of climate change science and ocean literacy in public school systems. My work seeks to combat these deficits through educational experiences in marine science for undergraduate and local elementary students through three studies incorporating marine-science based research and outreach. (1) Through undergraduate marine science research and outreach, students enrolled for long durations or with positive mentorship increased their conceptual understanding of marine science concepts, altered their attitudes towards climate change and science, and were more likely to …

Repeated Boat Noise Exposure Damages Inner Ear Sensory Hair Cells And Decreases Hearing Sensitivity In Atlantic Croaker (Micropogonias Undulatus), Gina A. Badlowski

University of New Orleans Theses and Dissertations

No abstract provided.

Juvenile Dispersal And Genetic Connectivity In The Sea Turtle 'Lost Years', Katrina Phillips

Electronic Theses and Dissertations, 2020-

Juvenile dispersal is a life history strategy found across taxa and habitat types. In this dissertation, I examine juvenile dispersal in an evolutionary context and explore the conditions that support high dispersal, which necessitates subsequent ontogenetic habitat shifts. I use a sea turtle study system to evaluate the genetic and behavioral patterns associated with juvenile dispersal and ontogenetic shifts in marine environments. Specifically, I focus on four sea turtle species found in the northeastern Gulf of Mexico in the early life stage known as the 'lost years': green turtles (Chelonia mydas), Kemp's ridleys (Lepidochelys kempii), loggerheads (Caretta caretta), and hawksbills …

Role Of Biological Clocks In Ant Behavioral Plasticity And Parasitic Manipulation Of Ant Behavior, Biplabendu Das

Electronic Theses and Dissertations, 2020-

Living organisms exhibit daily rhythms as a way to anticipate predictable fluctuations in their environment. Such daily rhythmicity is the phenotypic outcome of oscillating genes and proteins, driven by an endogenous biological clock. Clock-controlled behavioral rhythms are inherently "flexible" since their phase, amplitude, and period can change throughout an animal's life hallmarked by changes in so-called chronotype. How this inherent plasticity of clock-controlled rhythms is linked to plasticity of behavior is still an open question in biology. Characterizing the various mechanistic links between plasticity of the animal clock and behavioral state will not only shed light on the molecular underpinnings …

Histological Comparison Of Shark Dermis Across Various Ecomorphologies, Olivia Schuitema

UNF Graduate Theses and Dissertations

The integument plays essential roles in the structural support, protection, and hydrodynamic capability among fishes. Most shark skin research has been done on the external epidermal layer containing the dermal denticles, while the larger dermis layer has been mostly ignored. The dermis layer in sharks is composed of two layers, the upper stratum laxum and the lower stratum compactum, holding supportive collagen and elastin fibers. There may be morphological and compositional differences in the dermis layers across various species of sharks, although the extent of such is unknown. These potential differences may be represented by various dermal thicknesses and different …

Aortic Pressure And Heart Rate In The Lobster Homarus Americanus Are Modulated By Mechanical Feedback And Neuropeptides, Grace Marie Hambelton

Honors Projects

Baroreceptors are stretch receptors located in the aorta of mammals; in response to increased afterload, they elicit a decrease in heart rate, creating a negative feedback loop that lowers blood pressure. Although lobsters (Homarus americanus) do not have baroreceptors like mammals, closely related land crabs have been shown to have baroreceptor-like responses. Heart contraction is also regulated by the Frank-Starling response, where increasing stretch or preload increases the contractile force of the heart. In addition to these types of biomechanical modulations, lobsters use a central pattern generator, the cardiac ganglion, to maintain synchronicity of the heartbeat. The heart …

Transgenerational Plasticity Causes Differences In Uv-Tolerance Of Intertidal And Subtidal Populations Of The Purple Sea Urchin, Strongylocentrotus Purpuratus, Yareli Alvarez, Nikki L. Adams

Master's Theses

Planktonic larvae of marine organisms are increasingly being exposed and required to respond to a changing physical environment. Adult sea urchins occupy both intertidal and subtidal waters and broadcast spawn gametes into the water column to contend with variable physical conditions. To answer how populations of invertebrates residing at different depths adequately prepare their offspring to cope with different levels of ultraviolet radiation (UVR), we collected adult purple sea urchins, Strongylocentrotus purpuratus, from four sites (two intertidal and two subtidal (~15 m deep)) on the central coast of CA to compare UV tolerance in offspring. Our measurements of UVA …

Comparative Study Of Spectral Sensitivity, Irradiance Sensitivity, Spatial Resolution And Temporal Resolution In The Visual Systems Of Aratus Pisonii And Ocypode Quadrata, Ruchao Qian

All HCAS Student Capstones, Theses, and Dissertations

Autrum’s studies (1950, 1958) on terrestrial arthropods first revealed that the visual systems of arthropods reflected their lifestyles and habitats, demonstrating that rapidly moving predatory diurnal species tend to have better temporal resolution than slower moving nocturnal species. In order to test Autrum’s hypothesis that visual adaptions are driven by predator/prey interactions, the visual physiology of a nocturnal fast-moving predatory crab, the Atlantic ghost crab (Ocypode quadrata), and a diurnal herbivorous crab, the mangrove tree crab (Aratus pisonii), was examined and compared. Spectral sensitivity, irradiance sensitivity, and temporal resolution of the crabs were quantified using the …

Steady Heartbeat: Field And Laboratory Studies Indicate Unexpected Resilience To High Temperatures For The Ribbed Mussel Geukensia Demissa, Ashlyn N. Smith Ms.

Honors College Theses

Salt marshes are important ecosystems found along the coast of Georgia. Salt marshes are hosts to diverse organisms that interact with each other to promote many ecosystem services, such as storm buffering and flooding, and absorption of excess nutrients. Among these diverse organisms is the ribbed mussel, Geukensia demissa. Mussels are a foundation species in this intertidal landscape, and without them the whole salt marsh would be negatively affected. The purpose of this investigation was to explore the thermal stress response of G. demissa to rising temperatures. Mussels were collected from three locations that were landlocked, close to a …

Multivariate Habitat-Based Predictive Modeling Of Three Demersal Rockfish Species In Central California, Georgia R. Martel

Cal Poly Humboldt theses and projects

Accurate, spatially explicit models of rockfish abundance are critical in implementing ecosystem-based management strategies and designating essential fish habitats and marine protected areas. Multibeam bathymetry methods and visual, non-extractive submersible transect surveys were combined to collect environmental variables and fish abundance data at three distinct sites within the study region. Zero-adjusted models were developed using habitat classification analyses of high-resolution (5 m) digital elevation models. Model accuracies were assessed by using a reserved subset of the original datasets. To demonstrate that a model’s predictive power was linked to its spatial origins, Mean Absolute Error and coefficient of determination values were …

Novel Mechanism For Turning Performance In Bluefin Tuna, Abigail Downs

West Chester University Master’s Theses

Scombrid fishes can attain exceptional swimming speeds due to their thunniform, lift-based propulsion, large muscle mass, and fusiform body shape. A rigid body restricts maneuverability for aquatic organisms. To test if turning maneuvers by the rigid-bodied Pacific bluefin tuna (Thunnus orientalis) are constrained, captive animals were video recorded from above as the animals routinely swam around a large circular tank or during feeding bouts. The turning performance was classified into three different types of turns: 1) glide turn, where the tuna uses the caudal fin as a rudder to passively move through the turn, 2) powered turn, where …

Non-Invasive Method For Leptin Supplementation In Zebrafish (Danio Rerio), Regan Mcnamara

Williams Honors College, Honors Research Projects

I tested the hypothesis that recombinant leptin protein can be introduced to zebrafish in vivo through non-invasive soaking in a solution containing the protein. One way to study various molecules’ effects in vivo is through intraperitoneal or intracerebroventricular injections during the embryonic or larval stage, which is invasive, difficult to administer, and can have a high mortality rate. 48 hours post fertilization (hpf) zebrafish were soaked in a His-tagged recombinant leptin protein solution at 10 nM and 100 nM concentrations (produced by Genscript). After soaking, zebrafish larvae were washed extensively to remove all recombinant protein on their exterior before homogenization. …

Effects Of Intertidal Position On Metabolism And Behavior In The Acorn Barnacle, Balanus Glandula, Kali Horn

Master's Theses

The intertidal zone is characterized by persistent, tidally-driven fluctuations in both abiotic (e.g., temperature, [O₂], salinity) and biotic (e.g., food availability, predation) conditions, which makes this a very physiologically challenging habitat for resident organisms. The magnitude and degree of variability of these environmental stressors differs between intertidal zones, with the most extreme physiological stress often being experienced by organisms in the high intertidal. Given that many of the fluctuating conditions in this environment are primary drivers of metabolic rate (e.g., temperature, [O₂], food availability), we hypothesized that sessile conspecifics residing in different tidal zones would exhibit …

Comparing Feeding Accuracy Between High And Low Predation Trinidad Guppies, Lydia J. Bonnell

Honors College Theses

Efficient feeding accuracy could increase an organism’s survival. Although local adaptation in Trinidad guppies is common, the effects on accuracy are unknown. Guppies were wild caught in 2015 and 2017, filmed while capturing prey. Accuracy wasn’t different within samples but differed across samples, possibly due to the prey types used.

Size And Age Structure Of Introduced Populations Of Blue Catfish (Ictalurus Furcatus) In Two Kansas Reservoirs And Implications For Management, Ernesto Flores

Master's Theses

ABSTRACT

The introduction of a new fish species into an aquatic ecosystem can bring about many challenges for fisheries managers. Questions might arise for the manager regarding the initial sportfish survival rate, grow rate, reproduction and recruitment, and what kind of impact will the introduction have on the already established populations found in the water body. A new population of fish is often protected using length limit regulations, allowing biologists to gain insight on whether the population will be self-sustaining or in need of periodic stockings. Age and growth information is used to understand population dynamics, estimate annual mortality and …

Effects Of Drift Macroalgae On Sediment Nitrogen Cycling In Thalassia Testudinum Beds Of St. Joseph Bay, Fl, Erica Strope

Master of Science in Integrative Biology Theses

Anthropogenic nitrogen (N) loading and eutrophication can affect valuable ecosystem services and seagrass habitats by modifying structural and functional aspects of estuarine communities including increasing and prolonging macroalgae blooms. In some contexts, macroalgae may play a key role in N cycling pathways because they can alter sediment chemistry. Previous research has associated drift macroalgae blooms with elevated dissolved inorganic N concentrations in sediments as a result of increased remineralization of organic matter, but drift macroalgae effects on microbial N transformation pathways are not well understood. This study quantified the effects of macroalgae on estuarine N cycling in Thalassia testudinum seagrass …

Evaluating In Situ Grazing Patterns Of Lytechinus Variegatus And Their Effects On Seagrass Beds Of Thalassia Testudinum, Adrianna Parson

Master of Science in Integrative Biology Theses

The sea urchin Lytechinus variegatus is a known grazer of the seagrass Thalassia testudinum, and has been known to denude vast stands of seagrass beds at high densities. Outside of these denudation events, the effects of sea urchins on seagrass are poorly understood. This study examines the effects of L. variegatus on T. testudinum in situ, to understand how sea urchins are affecting seagrasses in situ. Results indicate that urchins were found in the offshore portion of the seagrass bed at densities up to 4 urchins/m². Changes in temperature and sediment size in the bay indicate …

Establishing Relationships Among Environmental Stressors, Host Immune Status, And Wasting Disease Susceptibility In The Dominant Seagrass Species Thalassia Testudinum, Paige Joy Duffin

UNF Graduate Theses and Dissertations

A growing body of evidence supports the observation that marine disease outbreaks, especially those caused by opportunistic pathogens, are increasing in frequency and severity. One genus of such pathogens, Labyrinthula, has been identified as the causative agent of seagrass wasting disease, an epidemic that has historically plagued seagrass beds around the world. It is suspected that pathogenicity is intimately linked to the ability of the host to initiate defense responses, but a lack of compelling evidence prevents any meaningful application of preliminary observations. This body of work investigated the roles of host genotype, host immune status, and environmental stressors …

Evidence For Extra-Gastric Expression Of The Proton Pump H+/K+ -Atpase In The Gills And Kidney Of The Teleost Oreochromis Niloticus, Ebtesam Barnawi

Theses and Dissertations (Comprehensive)

It is well known that stomach acid secretion by oxynticopeptic cells of the gastric mucosa is accomplished by the H⁺/ K⁺-ATPase (HKA), which is comprised of the HKα1 (gene: atp4a) and HKβ (gene: atp4b) subunits. However, the role of the HKA in extra-gastric organs such as the gill and kidney is less clear especially in fishes. This pump may contribute to active ion and/or acid-base regulation either through direct ion transport or through secondary transport proteins against unfavorable concentration gradients via the energy derived from ATP hydrolysis. In the present work I have demonstrated …

The Population Genetics Of Morro Bay Eelgrass (Zostera Marina), Julia Gardner Harencar

Master's Theses

Seagrass populations are in decline worldwide. Zostera marina (eelgrass), one of California’s native seagrasses, is no exception to this trend. In the last 8 years, Morro Bay, California has lost 95% of its eelgrass. Eelgrass is an ecosystem engineer, providing important ecosystem services such as sediment stabilization, nutrient cycling, and nursery habitats for fish. The failure of recent restoration efforts necessitates a better understanding of the causes of eelgrass decline in this estuary. Previous research on eelgrass in California has demonstrated a link between population genetic diversity and eelgrass bed health, ecosystem functioning, and resilience to disturbance and extreme climatic …

Measuring Fertilization In Populations Of Sea Scallop (Placopecten Magellanicus): Developing And Testing Methods In The Laboratory And Field, Skylar Bayer

Electronic Theses and Dissertations

Most marine organisms are broadcast spawners, releasing their sperm and eggs into the water column. Methods of measuring in situ fertilization have proven successful with a few model species, which are reviewed in my introductory chapter. However, many commercially exploited species, such as the sea scallop Placopecten magellanicus, have been neglected. Sea scallop populations have greatly increased from fishing closures, but the mechanism behind this response is uncertain, particularly in regard to fertilization. In this dissertation I developed a methodology of measuring fertilization success and spawning events of P. magellanicus, tested it in laboratory and field settings, and …

Divergent Responses Of Larval And Juvenile Blue Mussels To Low Salinity Exposure, Melissa A. May

Electronic Theses and Dissertations

In this study, we compared the osmotic stress response of larval and juvenile blue mussels (Mytilus edulis) at the transcriptomic, metabolomic, and whole organism levels. Blue mussels inhabit coastal areas, where they face climate-induced reductions in nearshore salinity. Despite their ecological and economic importance, scientists do not fully understand the underlying transcriptomic and cellular mechanisms of the osmotic stress response in blue mussels or how the ability to respond to stress changes throughout development. Blue mussels spend the first weeks of life developing through several larval stages in the plankton. These early life history stages are more vulnerable …

Roles Of Siphon Flows In Suspension Feeding, Kevin Du Clos

Electronic Theses and Dissertations

Benthic marine suspension feeders provide an important link between benthic and pelagic ecosystems. The strength of this link is determined by suspension-feeding rates. Many studies have measured suspension-feeding rates using indirect clearance-rate methods, which are based on the depletion of suspended particles. Direct methods that measure the flow of water itself are less common, but they can be more broadly applied because clearance-rate measurements are affected by properties of the cleared particles. We present pumping rates for three species of suspension feeders, the clams Mya arenaria and Mercenaria mercenaria and the tunicate Ciona intestinalis, calculated using a direct method …