Marine Biology Commons^™

Euhaplorchis Sp. A Effect On Social Behavior And Familiarity Of Gulf Killifish (Fundulus Grandis), Hannah Bauman

All HCAS Student Capstones, Theses, and Dissertations

Trophically transmitted parasites may manipulate their hosts’ phenotype (e.g., behavior, physiology, morphology) to increase the likelihood of transmission to the definitive host. In fishes, stable social groups develop familiarity over time through repeated interactions among individuals, and social preferences are often developed due to familiarity. Consequently, fishes often shoal with familiar fishes, a behavior that is likely to be protective against predation. Parasites may alter fish social dynamics in two ways: by decreasing association with familiar individuals, thereby isolating infected fish and making them more susceptible to predation by definitive hosts; and/or by incentivizing uninfected individuals to avoid infected fish …

Trophic Ecology Of Black Swallowers (Scombriformes: Chiasmodontidae: Chiasmodon) In The Deep-Pelagic Gulf Of Mexico, Travis J. Kirk

All HCAS Student Capstones, Theses, and Dissertations

The ecology of deep-pelagic predatory fishes remains poorly understood despite their importance as ecosystem regulators and energy transfer vectors. This study investigated the trophic ecology of three species of the predatory fish genus Chiasmodon (“black swallowers”) in the Gulf of Mexico, a region that serves as an analog for the global low-latitude deep pelagial, the world’s largest cumulative ecosystem. Foraging habits (e.g., selectivity, chronology, daily ration) of an “advanced” evolutionary fish in a system that is otherwise dominated by basal fish taxa, were quantitatively estimated via high-resolution stomach content analysis. A quantitative dataset of both predator and prey abundance, the …

Maneuverability Of Cuttlefish And Squid: An Integrated Kinematic And Hydrodynamic Analysis, Alissa Marie Ganley

Biological Sciences Theses & Dissertations

Turning is important for life underwater, playing roles in predator avoidance, prey capture, locomotion, and communication. While turning abilities have been explored in many taxa, little is known about maneuverability of cephalopods, such as cuttlefishes and squids. The objectives of this dissertation include: (1) quantifying the turning abilities of cuttlefish hatchlings and determining whether there are species-specific differences; (2) examining the turning capabilities of adult cuttlefishes, with the goal of comparing adult performance with that of conspecific hatchlings; and (3) quantifying how adult neritic squids perform turns to provide a broader context of maneuvering strategies in cephalopods. To investigate turning, …

Characterizing The Habitat Use Of Pacific Coast Feeding Group Gray Whales (Eschrichtius Robustus) And The Spatial And Temporal Variability Of Their Benthic And Planktonic Invertebrate Prey In Northern California, Robyn E. Norman

Cal Poly Humboldt theses and projects

As opportunistic foragers, the Eastern North Pacific population (~20,000) of gray whales (Eschrichtius robustus) feed on diverse benthic and planktonic invertebrates in northern Alaska foraging grounds before they undertake one of the largest yearly migrations of any mammal to breed in Baja California, Mexico. While most of the population travels to the summer foraging grounds in Alaska, a sub-group of whales (~230) called the Pacific Coast Feeding Group (PCFG) summer between British Columbia, Canada, and northern California. The diet of PCFG whales typically includes high-density and/or high-caloric prey items like mysids and diverse species of amphipods, yet a …

To Hum Or Not To Hum: Analyzing And Provoking Sound Production In The American Lobster (Homarus Americanus), Renske Kerkhofs

Honors Projects

American lobsters (Homarus americanus) produce humming sounds by vibrating their carapace. These sounds have a fundamental frequency on the order of 100 Hz, with multiple higher harmonics. Though I found no relationship between lobster carapace length and hum frequency, I observed sounds similarly structured to hums but with frequencies an order of magnitude higher, suggesting that lobsters may use a wider range of sounds than previously thought. Using laser vibrometry, I was able to pick up high frequencies of carapace vibration that were similar to those I observed on sound recordings. Lobsters seem to hum most readily when …

Habitat Utilization Of Marsh And Adjacent Submerged Landscape By Fish And Macroinvertebrates In A Gulf Of Mexico Tidal Oligohaline Environment, Tia Offner

Theses and Dissertations

Estuarine habitats are considered nursery habitats for fishes and invertebrates, but oligohaline environments are critically understudied. Using a seine net and fyke nets, we sampled Back Bay, Mississippi (USA), a low salinity estuary, once a month for a year to explore the temporal use of the marsh and adjacent submerged landscape by nekton species. We also looked at whether there is evidence of habitat preference in the most numerous nekton species. We used a novel habitat usage index (HUI) to compare seine and fyke net catches of our top 10 species, and evaluated catch size in relation to maturation size. …

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 …

Do Mesopelagic Fish Biomass Patterns Change In Response To Major Oceanographic Features In The Northern Gulf Of Mexico?, Ian M. Areford

All HCAS Student Capstones, Theses, and Dissertations

In recent years interest in mesopelagic fishes has grown due to their ecological significance and economic potential. A major outstanding question is how the assemblage is potentially structured by mesoscale (10 - 100s km) oceanographic features such as eddies, fronts, and riverine plumes. Mesoscale features are known to influence micronekton and zooplankton’s spatial distributions but data on individual mesopelagic fish species’ responses are limited. The Gulf of Mexico (GoM) is an area of particular interest due to its diverse mesopelagic fish assemblage, its well-defined mesoscale oceanographic features, its history of anthropogenic impacts such as oil spills, and its diverse mesopelagic …

Interactions Between Sediment Mechanical Structure And Infaunal Community Structure Following Physical Disturbance, William Cyrus Roger Clemo

<strong> Theses and Dissertations </strong>

Shallow, river-influenced coastal sediments are important for global carbon storage and nutrient cycling and provide a habitat for diverse communities of invertebrates (infauna). Elevated bed shear stress from extreme storms can resuspend, transport, and deposit sediments, disrupting the cohesive structure of muds, and sorting and depositing sand eroded from beaches. These physical disruptions can also resuspend or smother infauna, decreasing abundances and changing community structure. Infaunal activities such as burrowing, tube construction, and feeding can impact sediment structure and stability. However, little is known about how physical disturbance impacts short and long-term sediment habitat suitability and whether disturbance-tolerant infauna influence …

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 …

Parasites Versus Predation: The Role Of Chronic And Acute Parasite Exposure In Infection Risk And Anti-Predator Behavior, Delaney Farrell

All HCAS Student Capstones, Theses, and Dissertations

Parasites with complex, multi-host lifecycles often engage in host behavior manipulation to increase transmission between successive hosts. In intermediate fish hosts, previous research has measured increased frequency of conspicuous behaviors, decreased swimming performance, and reduced antipredator behavior, which would collectively increase the fish’s risk of predation. In ecosystems where this type of parasite increased trophic transmission (PITT) occurs, parasites can play a substantial role in food webs. In this study, I investigate how chronic versus acute exposure to the trematode Euhaplorchis sp. A. affects the antipredator behavior of the Gulf killifish Fundulus grandis. Using a fully crossed design, I …

Cadmium And Salinity Stressor Antagonism On Vallisneria Neotropicalis, Christopher P. Mikolaitis

<strong> Theses and Dissertations </strong>

Submerged macrophytes form the foundation of freshwater ecosystems. These organisms are sessile and are very susceptible to shifts in their environment. Heavy metals are of particular concern as they can be sequestered indefinitely in sediments and are readily taken up by rooted vegetation. In the presence of saltwater intrusions, these metals can interact with salt ions potentially changing their availability to submerged vegetation. In this study a freshwater macrophyte, Vallisneria neotropicalis, was used as a test species for interactive effects between Cd, a non-essential heavy metal, and salt stress. The metrics used to establish the individual as well as …

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 …

Dolphin Behavioral Responses To Uncrewed Aerial Systems As A Function Of Exposure, Height, And Type, Savannah Damiano

Electronic Theses and Dissertations

Uncrewed aerial systems (UAS) are becoming a standard tool in the study of cetaceans, however, a comparative assessment of animal responses to UAS has not been established to gauge the most effective systems for cetacean study. We utilized Dolphin Quest Bermuda’s eleven bottlenose dolphins as subjects for such an investigation taking place over five weeks in 2022 and five weeks in 2023. The dolphins were evaluated for investigative behavioral responses to six off-the-shelf UAS types and a custom fixed wing system. Each UAS was flown in decreasing height vertically above the main dolphin lagoon to evaluate dolphin behavioral responses in …

Optimizing Strategies To Hydraulically Plant Atlantic Salmon Eggs Based On Fry Dispersal Patterns, Ernest J. Atkinson

Electronic Theses and Dissertations

The Gulf of Maine Distinct Population Segment of Atlantic Salmon has suffered from habitat loss and exploitation over the last century. Hatchery supplementation has prevented the extirpation of the species, but stocking methods represent tradeoffs between survival, domestication, and logistics. Egg planting, the use of eyed embryos, maximizes natural rearing opportunities which can be important for adaptation. This method, however, is logistically demanding and requires significant labor over large spatial, but short temporal, scales dictated by the ontogeny of the fish. However, the survival and dispersal behavior of Atlantic Salmon fry immediately after emergence from eggs planted in artificial nests …

Striped Blenny (Chasmodes Bosquianus) Presence And Behavior Between Sunrise And Sunset At Oyster Landing, South Carolina, Madeline Schuetze

Honors Theses

Lunar and diel cycles of fishes can help to interpret their behaviors during their reproductive season. Temperate estuaries are used by many benthic fishes for shelter and reproduction. This study examined the behavior and presence of striped blennies (Chasmodes bosquianus) during diel and lunar cycles. PVC pipe shelters were placed to mimic oyster shell nests, a natural habitat for blennies, and cameras were placed to monitor these shelters in April, May, and June 2022, during the striped blenny reproductive period. Video footage was reviewed and analyzed for the presence and behavior of both male and female blennies. Male presence …

Rattus Norvegicus As A Biological Detector Of Clandestine Remains And The Use Of Ultrasonic Vocalizations As A Locating Mechanism, Gabrielle M. Johnston

Master's Theses

In investigations, locating missing persons and clandestine remains are imperative. One way that first responder and police agencies can search for the remains is by using cadaver dogs as biological detectors. Cadaver dogs are typically used due to their olfactory sensitivity and ability to detect low concentrations of volatile organic compounds produced by biological remains. Cadaver dogs are typically chosen for their stamina, agility, and olfactory sensitivity. However, what is not taken into account often is the size of the animal and the expense of maintaining and training the animal. Cadaver dogs are typically large breeds that cannot fit in …

Fecal Pellet Production By North Atlantic Zooplankton, Michael Gibson

Undergraduate Honors Theses

Fecal pellet carbon (FPC) production by zooplankton is a significant component of the ocean’s biological carbon pump: the suite of biological processes that mediate export of carbon to the deep ocean, ultimately leading to the sequestration of atmospheric carbon dioxide in the ocean. In this study, mesozooplankton (zooplankton 0.2 mm to ~2 cm) were collected from the epipelagic zone in the temperate North Atlantic Ocean during day and night in May 2021. Zooplankton were live separated into five size fractions and incubated on board ship in natural surface seawater to measure fecal pellet production rate of the mixed mesozooplankton community. …

Determination Of Cadmium Uptake In Crassostrea Virginica Shell Under Controlled Conditions, Joseph John Pavelites Ii

<strong> Theses and Dissertations </strong>

The objective of this thesis was to meet growing demand for the development of environmental biomonitors that protect ecosystems and public health. To do this, I determined the potential of oyster shell as a bioindicator of cadmium (Cd) in the environment by determining the mode of Cd uptake and relationships between Cd concentrations in the environment, shell, and soft tissues of juvenile eastern oysters (Crassostrea virginica Gmelin). I performed a review of the literature on the ability of oyster shell to retain metal contaminants and the factors that could affect this process (Chapter 2). I then reared C. virginica …

Trace Dna Detection Using Diamond Dye: A Recovery Technique To Yield More Dna, Leah Davis

Master's Theses

This study aspires to find a new screening approach to trace DNA recovery techniques to yield a higher quantity of trace DNA from larger items of evidence. It takes the path of visualizing trace DNA on items of evidence with potential DNA so analysts can swab a more localized area rather than attempting to recover trace DNA through the general swabbing technique currently used for trace DNA recovery. The first and second parts consisted of observing trace DNA interaction with Diamond Dye on porous and non-porous surfaces.

The third part involved applying the Diamond Dye solution by spraying it onto …

Exploring Host-Parasite Interactions In The Euhaplorchis Californiensis-Fundulus Parvipinnis System, Bennett J. Perry

All HCAS Student Capstones, Theses, and Dissertations

Parasites with complex life-cycles may alter their intermediate host’s phenotype to increase the chance of successful transmission to their next host. This parasite-induced host modification often occurs in the form of behavioral changes, such as increased frequency of irregular locomotor behaviors (e.g., conspicuous behaviors), particularly in systems where the parasite is transmitted trophically through a predation event. However, most empirical evidence of host behavioral modification by parasites comes from a few model host-parasite systems and are frequently studied following a stressor (e.g., simulated predator attack). One host species studied is the California killifish Fundulus parvipinnis, which is infected by …

Assessing The Dynamics Of The Southeast Florida Shark Community From 2013-2019 Via Catch Per Unit Effort And Stable Isotope Analysis, Alexandra Barth

All HCAS Student Capstones, Theses, and Dissertations

Sharks, as well as other top predators, are in drastic decline worldwide. As apex and near-apex predators, species such as nurse, lemon, and tiger sharks maintain balanced marine ecosystems by enacting top-down trophic control. However, this cascading effect is diminished with exploitation via commercial and recreational fishing. Sharks are generally long-lived, mature late, have long reproductive cycles, and produce few offspring. Much remains to be learned about the community structure, population trends and conservation statuses of shark populations worldwide. Comprehensive studies on the composition of the shark community in Southeast Florida north of Miami have been limited. This study assessed …

Evaluation Of Acoustic Telemetry Array Performance And Fine- Scale And Broad-Scale Spatial Movement Patterns For Coral Reef Species In Culebra, Puerto Rico, Roxann Cormier

Masters Theses

Acoustic telemetry is an important tool when studying the spatial ecology of marine animals. First, it is important to identify the challenges of using this tool in shallow tropical marine environments before tracking marine animals. One significant issue that can influence the effectiveness of acoustic telemetry is the efficiency or detectability of acoustic signals by receivers. Understanding factors influencing detection efficiency of acoustic tags is especially important for fine-scale positioning systems (such as the VEMCO positioning system, VPS) that use detections in an overlapping receiver network to calculate geographic positions of tagged fish. I modelled the efficiency of an acoustic …

Using Podcasts To Bring National Estuarine Research Reserves Into The Classroom For Grades 6-12, Kaitlyn M. Dirr

Senior Theses

In a typical classroom setting, there are significant challenges to exposing students to concepts related to earth sciences and the environment. These challenges are exacerbated when conveying lessons about geographic areas with limited access, such as oceans and coastlines (Louv, 2010). It is now more important than ever for environmental education to improve and adapt to our changing world. Educators may have the opportunity to bring these subjects to life by using media content such as podcasts to introduce students to new places and the scientists, managers and educators that work in those spaces. In the United States, there exists …

Movement, Behavior, And Trophic Ecology Of A Pelagic Predator Guild In The Eastern Tropical Pacific Ocean, Ryan Keith Logan

All HCAS Student Capstones, Theses, and Dissertations

Pelagic apex predators exert strong influences on ecological communities, and often support valuable commercial or recreational fisheries worldwide. Yet, due to their rarity and pelagic lifestyle, many species, such as billfishes, have proven particularly difficult to study at resolutions necessary to define dynamics of recovery from fishery interaction, physical interaction with environmental features and prey exploitation, and competitive interactions among other billfish predators. This leads to a paucity of knowledge on billfish ecology and habitat use, and hinders management efforts. With the ever-improving and miniaturization of technology and oceanographic datasets, the ability to define and quantify these interactions of fish …

What Drives Larval Condition For Northern Anchovy (Engraulis Mordax)? Implications For Coastal Pelagic Species Recruitment Fluctuations And Fishery Management Practices, Michelle Robidas

Theses

Discerning the causes of population boom and bust cycles for coastal pelagic species (CPS) has been a major focus of fisheries management research for over a century. Year-class strength is contingent on larval survival and condition, which can be influenced by larval size at age and growth rate. These two factors, in turn, can be affected by maternal investment and environmental variables such as water temperature, salinity, oxygen, and chlorophyll a. We evaluated each of these factors from 127 two to eight week-old Northern Anchovy (Engraulis mordax) larvae off the coast of San Diego to San Francisco, …

Controls Of Physical Drivers On The Formation And Toxicity Of Harmful Cyanobacteria Blooms (Cyanohabs), Courtney N. Hammond

LSU Master's Theses

Estuaries within the Gulf of Mexico are exhibiting profound alterations due to climatic changes and the implementation of coastal restoration activities. These changes are attributed to the increasing frequency of harmful cyanobacteria blooms (cyanoHABs) within Lake Pontchartrain, an estuary located in southeastern Louisiana, USA. There is a better understanding into how the opening of the Bonnet Carré Spillway (BCS) impacts cyanoHAB formations compared to the effect of other physical drivers when the spillway doesn’t dominate the system. The goal of this study is to provide a greater understanding of the baseline conditions when the BCS is closed and determine what …

Effects Of Ph, Eelgrass, And Settlement Substrate On The Growth Of Juvenile Magallana (Crassostrea) Gigas, A Commercially Important Oyster Species, Johnny S. Roche

Cal Poly Humboldt theses and projects

Worsening ocean acidification (OA), resulting from ongoing absorption of atmospheric carbon dioxide (CO₂) by the oceans, threatens marine life globally. Calcifying organisms, especially their early life stages, are particularly vulnerable; this includes the economically important Pacific oyster, Magallana (Crassostrea) gigas. Uptake of dissolved CO₂ through photosynthesis by seagrasses, like eelgrass (Zostera marina), may benefit calcifying organisms by increasing pH and carbonate availability. I conducted laboratory and field experiments to quantify carbonate chemistry modification by eelgrass and potential mitigation of OA impacts on growth in juvenile Pacific oysters. In the laboratory experiment, daytime …

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 …

Effects Of Oyster Aquaculture On Elasmobranch Abundance And Habitat Use In Humboldt Bay, Ca, Rose Harman

Cal Poly Humboldt theses and projects

Habitat modification from aquaculture can have large effects on natural communities, with the habitat complexity provided by aquaculture structure positively influencing benthic invertebrates and small fish abundance. However, the effects of aquaculture on larger predatory fish like elasmobranchs (i.e., sharks and rays), which use nearshore habitat to forage and provide top-down control of these ecosystems, is largely unknown. Over two years, I deployed baited remote underwater video systems (BRUVS) to examine the effects of oyster aquaculture and environmental variables such as habitat (mudflat or eelgrass), salinity (ppt), turbidity (m), temperature (°C), pH (mV), dissolved oxygen (mg · L^-1), …