Life Sciences Commons^™

Deep Ocean Vehicle Applications And Modifications, Nichole "Nikki" T. Arm

Master's Theses

This project had two primary goals: (1) to explore opportunities to further a deep-ocean vehicle’s reach using alternative pressure spheres, and (2) to implement an existing deep-ocean vehicle (lander) in active scientific research.

I gained a greater understanding of the limitations and design choices made for existing pressure spheres using Finite Element Analysis (FEA). My simplified FEA model predicted sphere failure for the existing 30% Fiber Glass 70% Nylon injection molded spheres at an external pressure of 3,954psi or 2,690m ocean-depth (only a 7.38% error compared to the tested minimum failure depth), so I determined it a valid model. I …

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. …

Effects Of Intertidal Position On The Capacity For Anaerobic Metabolism And Thermal Stress Response In The Common Acorn Barnacle, Balanus Glandula, Kyra Anderson

Master's Theses

Intertidal habitats are characterized by dynamic, tidally-driven fluctuations in abiotic and biotic factors. Many of the environmental stressors that vary across the intertidal (e.g., temperature, oxygen, food availability, predation pressure) are strong drivers of metabolic rate in ectotherms. As such, we predicted that there may be pronounced differences in the metabolic and stress physiology of conspecific sessile invertebrates occupying at different relative tidal heights. The common acorn barnacle Balanus glandula represents an ideal model organism in which to investigate the possibility of tidal height-dependent physiological differences, owing to their wide distribution in the intertidal zone and their eurytolerant nature. In …

The Response Of Marine Synechococcus To A Landscape Of Environmental Stressors: A Proteomic Exploration, Dana E. Michels

Master's Theses

In the field of marine microbial ecology, many questions remain unanswered with regards to the physiological trade-offs made by phytoplankton to maximize growth (e.g., nutrient acquisition) and minimize loss (e.g., predation defenses). These tradeoffs, which occur at the cellular level, have wide reaching impacts on food web dynamics and global biogeochemical cycles. In the first chapter, we explored the use of a non-canonical amino acid (NCAA) technique, bioorthogonal non-canonical amino-acid tagging (BONCAT), in phytoplankton model systems. This technique has potential to work well in natural systems by enabling isolation of only newly synthesized proteins during an incubation period with the …

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 …

Quantifying The Ecological Drivers And Impacts Of Parrotfish Predation On Caribbean Corals Communities, Hannah Sima Rempel

Master's Theses

Parrotfishes (Scarinae) are dominant Caribbean herbivores that play an important role in reducing coral-algae competition by grazing algae; yet some species are also occasional coral predators (corallivores) and thereby can have direct negative impacts on coral growth and survivorship. There is concern that parrotfish corallivory may contribute to substantial long-term declines in targeted coral species, particularly in areas with a high biomass of parrotfishes and low cover of corals. However, the capacity of target coral species to heal from parrotfish predation and the ecological drivers of corallivory are poorly understood.

In Chapter 1, we examined the patterns of coral healing …

Cal Poly Pier Master Plan, Troy A. Lawson

Master's Theses

The Cal Poly Pier (Pier) Master/Facility Plan (FP) document provides the vision of the future for the Pier, a marine science research facility. The Plan facilitates project development and management of the Pier while meeting university and department research goals. Specifically, the FP document establishes goals and strategies to direct long-term development of the Pier, streamlines agency approval and permit requirements, provides context for pier management, and assists the permitting process for future development as it relates to regulatory permits and programmatic growth on the Cal Poly Pier to help meet goals of the Center for Coastal Marine Sciences (CCMS). …

Pismo Clams (Tivela Stultorum) In Califorina: Population Status, Habitat Associations, Reproduction, And Growth, Alexandria R. Marquardt

Master's Theses

Marine shellfish play a vital role in intertidal ecosystems and coastal communities, but many of these fisheries are small-scale and lack the necessary monitoring to ensure long-term sustainability. Effective management often requires information on key demographic parameters, such as population status, reproduction and growth. Pismo clams (Tivela stultorum) are a culturally important and iconic species in California, which supported a thriving commercial and recreational fishery throughout much of the 1900’s. However, Pismo clam populations have declined statewide in recent decades and are attributed to human harvest and predation by California sea otters (Enhydra lutris); However, no …

Patterns In Size Distribution And Catch Of Rockfish (Sebastes Spp.) In Fisheries-Independent And Fisheries- Dependent Hook-And-Line Surveys On The Central Coast Of California, Rose Elizabeth Dodgen

Master's Theses

Stock assessments are statistical models which characterize the state of a population of fish. Data for stock assessment models of West Coast nearshore groundfish come largely from fisheries-dependent sources. Incorporating fisheries-independent data would increase data availability. A potential source of fisheries-independent data which is comparable to existing fisheries-dependent data is the California Collaborative Fisheries Research Program (CCFRP), a Marine Protected Area (MPA) monitoring study. We are interested in understanding the context in which CCFRP could be implemented into assessments of nearshore groundfish, specifically rockfish. To investigate this, we used management-relevant metrics to examine three questions concerning the implementation of CCFRP …

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 …

Effects Of Barotrauma On Four Species Of Pacific Rockfishes (Sebastes Spp.), Lesley Salter

Master's Theses

Physoclistic fish, such as Pacific rockfishes (genus Sebastes), have closed swim bladders that help them regulate their buoyancy. When anglers catch these fish and reel them to the surface, gases within their swim bladder expand due to the decrease in pressure. This can cause their swim bladder to over inflate––a condition known as barotrauma. Overly buoyant fish experiencing barotrauma often struggle to swim back to dwelling depth if released at the ocean’s surface. These fish may experience high rates of mortality by thermal shock caused by the warmer surface temperatures, starvation, predation, or vision problems caused by barotrauma. Assisted …

Physiological Response Of The Giant Acorn Barnacle, Balanus Nubilus, To Air Exposure, Emily Jane Resner

Master's Theses

The giant acorn barnacle, Balanus nubilus, is a resident of the subtidal and low intertidal rocky shoreline on the Pacific Coast of North America (Alaska to Baja California). B. nubilusis notable for having the largest muscle fibers in the animal kingdom; fiber diameters that can exceed 3mm in adults! At such extreme sizes these muscle cells may be at risk for insufficient oxygen delivery to mitochondria owing to low SA:V ratios and long intracellular diffusion distances. Oxygen limitation to these muscles may be further exacerbated during low tide air exposure (emersion) or environmental hypoxia events, which are increasing …

Foraging Ecology Of Parrotfishes In The Greater Caribbean: Impacts Of Specialization And Dietary Preferences On Marine Benthic Communities, Madelyn V. Roycroft

Master's Theses

Coral reefs are one of the world’s most diverse yet heavily impacted marine ecosystems. As a result of many direct and indirect stressors, coral reefs have experienced major degradation over the last several decades. Declines in coral reefs in the Caribbean have been particularly acute and generally associated with the loss of key herbivores and an increase in algae. Herbivorous fishes such as parrotfishes can positively impact coral reefs by removing algae that compete with corals for light and space. However, many parrotfishes are also important coral predators. Predation on corals, known as corallivory, can adversely affect coral growth, reproduction …

Evaluating Recruitment Seasonality Of Red Abalone (Haliotis Rufescens) To Inform Fisheries Management And Conservation Policy, Leslie Christine Hart

Master's Theses

Recruitment, the addition of new individuals to a population, must be understood to make predictions about population growth of marine invertebrates. Red abalone (Haliotis rufescens) represent a former important commercial fishery in California, and until recently, supported a major recreational fishery. However, there have been statewide declines since the 1960s due to overfishing, disease, and climatic factors. Thus, understanding population dynamics to inform management and population restoration is critical. Recruitment dynamics of red abalone are poorly understood, with no prior knowledge of seasonal trends. To address this knowledge gap, I assessed monthly (July 2016-June 2017) and annual (2012-2016) …

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 …

The Insulin-Like Growth Factor-1 (Igf1) System As A Potential Biomarker For Nutritional Status And Growth Rate In Pacific Rockfish (Sebastes Spp.), Nicole L. Hack

Master's Theses

Growth performance in vertebrates is regulated by environmental factors including the quality and quantity of food, which influences growth via endocrine pathways such as the growth hormone (GH) / insulin-like growth factor somatotropic axis. In several teleost fishes, circulating concentrations of insulin-like growth factor-1 (Igf1) correlate positively with growth rate, and it has been proposed that plasma Igf1 levels may serve as an indicator of growth variation for fisheries and aquaculture applications. Here, I tested whether plasma Igf1 concentrations might serve as an indicator of somatic growth in olive rockfish (Sebastes serranoides), one species among dozens of rockfishes …

Effect Of Oxygen-Limiting Tidal Conditions On Muscle Metabolism And Structure In The Giant Acorn Barnacle, Balanus Nubilus, Katie O. Grady

Master's Theses

Crustacean muscle fibers are some of the largest cells in the animal kingdom, with fiber diameters in the giant acorn barnacle (Balanus nubilus) exceeding 3 mm. Sessile animals with extreme muscle sizes and that live in the hypoxia-inducing intertidal zone – like B. nubilus – represent ideal models for probing the effects of oxygen limitation on muscle cells. We investigated changes in metabolism and structure of B. nubilus muscle in response to: normoxic immersion, anoxic immersion, or air emersion, for acute (6h) or chronic (6h exposures twice daily for 2wks) time periods. Following exposure, we immediately measured hemolymph …

Rearing Temperature Affects The Expression Of Proteins In The Adhesive Of The Striped Acorn Barnacle, Balanus Amphitrite, Melissa J. Daugherty

Master's Theses

Barnacles are dominant hard–fouling organisms in marine waters. They attach to substrates by secreting a complex proteinaceous adhesive. Understanding the chemical composition of this multi–protein underwater adhesive and how it is affected by environmental variables, such as oceanic temperatures, is critical for developing nontoxic solutions to control biofouling. Previous experiments in our lab revealed an inverse relationship between critical removal stress (CRS) and temperatures at which barnacles were reared. Further investigations showed that this correlation is not attributed to differences in physical properties such as barnacle size or short–term changes in the viscosity of adhesive. Therefore, the observed effects may …

Multi-Stress Proteomics: The Global Protein Response To Multiple Environmental Stressors In The Porcelain Crab Petrolisthes Cinctipes, Michael A. Garland

Master's Theses

Global climate change is increasing the number of hot days along the California coast as well as increasing the incidence of off-shore upwelling events that lower the pH of intertidal seawater; thus, intertidal organisms are experiencing an increase in more than one stress simultaneously. This study seeks to characterize the global protein response of the eurythermal porcelain crab Petrolisthes cinctipes to changes in thermal, pH, and tidal regime treatments, either combined or individually. The first experiment examined temperature stress alone and sought to determine the effect of chronic temperature acclimation on the acute heat shock response. We compared the proteomic …

Investigation Of Larval Sensory Systems In The Marine Bryozoan, Bugula Neritina, Heather Leigh Price

Master's Theses

Bugula neritina is a sessile marine bryozoan with a pelagic larval stage. Larvae frequently settle on boat hulls, facilitating the introduction of B. neritina to bays and estuaries worldwide. Adrenergic agonists, such as the vertebrate hormone noradrenaline, inhibit larval settlement in a variety of marine invertebrate species, including B. neritina. Light also inhibits B. neritina larval settlement, yet the underlying mechanisms by which light and adrenergic compounds exert their effects on larvae are not well understood. Octopamine is considered the invertebrate analog of noradrenaline, and may be an endogenous hormone involved in larval settlement pathways. I observed the effects of …

Identification Of Saccharina Groenlandica (Phaeophyceae) Around The Svalbard Archipelago: Dna Barcoding Using Cytochrome C Oxidase Subunit 1 (Coi), Anniken Lydon

Master's Theses

In the Arctic, brown algae (kelps) and seaweeds are ecologically important: providing habitat, protection, and nutrients for invertebrate and vertebrate species living in nearshore environments. Migrations of biota between the North Pacific and North Atlantic Oceans have occurred periodically during Earth’s history leading to colonization of the Arctic Ocean. Around 3.5 Mya the “Great Trans-Arctic Biotic Interchange” occurred and the Laminariales order of kelp, thought to be of North Pacific origin, underwent a massive radiation and speciation event around the Arctic Ocean. Phylogenetic analysis performed on “Laminaria-like” specimens collected from six sampling locations around the Svalbard Archipelago identified …

Assessing Physiological Thresholds For Eelgrass (Zostera Marina L.) Survival In The Face Of Climate Change, Carolyn Jane Ewers

Master's Theses

Seagrasses are well known for the important ecological roles they play in coastal marine waters worldwide. However, the severe rate of decline observed in seagrasses this century is expected to accelerate with climate change. Conservation efforts can be improved by quantifying physiological thresholds of seagrasses and using these estimates in modeling to forecast changes in distribution. This study examines the response of eelgrass (Zostera marina L.) across current temperatures to look for early warning signs of vulnerability and to evaluate the ways we determine critical thresholds for survival. Whole eelgrass ramets, collected from three beds in Morro Bay, California, …

An Analysis Of Human Disturbance To Rocky Intertidal Communities Of San Luis Obispo County, Grant Tyler Waltz

Master's Theses

ABSTRACT

An Analysis Of Human Disturbance To Rocky Intertidal Communities Of San Luis Obispo County

Grant Tyler Waltz

The number of coastal areas open to public access in California and San Luis Obispo County is increasing due to the acquisition by California State Parks of land previously owned by private entities. For example, California State Parks acquired property from the Hearst Corporation in 2005, which included 18 miles of coastline. California State Parks is responsible for providing public access in these newly acquired areas and also for maintaining the health of the natural systems found on these properties. Part of …