Marine Biology Commons^™

Element Contamination In Port Everglades – Preparing For Ecological Impacts, Laura White

All HCAS Student Capstones, Theses, and Dissertations

Port dredging is of economic importance worldwide but its impacts to the marine environment through the remobilization of elemental contaminants are not well understood. A massive deepening and widening of Port Everglades, Florida, will begin in 2023. Contaminated sediment disturbed during the dredging process could be released and prove to be harmful to three coral reef tracks located beginning 1.5 miles away from the port. This study focused on identifying and quantifying 14 different trace elements: arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), mercury (Hg), lead (Pb), manganese (Mn), molybdenum (Mo), nickel (Ni), selenium (Se), tin (Sn), …

Phytoplankton Community Response To Upwelling Events: Distribution And Abundance Investigated Using Genomic Methods, Sveinn V. Einarsson

OES Theses and Dissertations

Upwelling events are known to support blooms of phytoplankton, important primary producers at the base of the oceanic food web. Phytoplankton community structure changes in response to upwelling support higher trophic level growth and increased efficiency of carbon export from the euphotic zone. While these events occur globally, this study examined upwelling in coastal regions, where alongshore winds can drive Ekman transport and upwelling of deeper waters. The two upwelling regimes examined were the California Current System and the Alaskan Beaufort Sea. In the California Current System, the relative diatom community composition was examined using 18S sequencing to determine how …

The Influence Of Bottom Type And Water Column Stratification On Reef Fish Community Structure At Gray’S Reef National Marine Sanctuary, Bridget Campbell

Honors Theses

Understanding the physical and oceanographic differences across reef habitats can help researchers assess how those differences influence fish distribution and community structure, which leads to a better understanding of what a healthy reef system looks like. The traditional methods used to assess fish communities on temperate reefs are limited and often focus solely on either the reef structure or water column conditions alone. An assessment of both data sets yields a more complete understanding of the ecosystem as a whole. In this study, Gray’s Reef National Marine Sanctuary (GRNMS) was surveyed both inside and outside a Marine Protected Area (MPA) …

Blue Carbon In South Florida's Mangroves: The Role Of Large Roots And Necromass, Zoë I. Shribman

LSU Master's Theses

Blue carbon sequestration and storage in mangroves largely result from belowground biomass allocation in response to flooded anaerobic soil conditions and nutrient availability. Biomass allocation to belowground roots is a major driver of mangrove soil formation and organic matter accumulation leading to blue carbon storage potential. Belowground biomass sampling in mangroves is labor intensive, limiting data availability on biomass stocks, particularly for large roots (>20 mm diameter) and necromass (dead roots). The mangrove nutrient model (NUMAN) uses mostly literature values to parameterize a soil cohort approach to simulate depth distribution of root mass and organic carbon concentration. We evaluated …

Connecting Communities To Coastal Resilience: Enhancing Sustainability Through Public Participation In Salt Marsh Management And Restoration In Suffolk County, Ny, Jennifer L. Mcgivern

Dissertations, Theses, and Capstone Projects

Coastal resiliency is becoming significantly more critical to the livelihood of coastal communities as the frequency and intensity of storm events increases and is exacerbated by rising sea levels due to climate change. In October 2012 Superstorm Sandy impacted the New York-New Jersey area costing over $70 billion in storm damages and 147 lives lost, as storm surges surpassed record highs for the region. Protruding more than 100 miles into the Atlantic Ocean with over 1,000 miles of shoreline, Long Island is particularly vulnerable to the increasingly ferocious and numerous storms as well as the rising sea levels that climate …

Estuarine Microbiomes And Biogeochemistry: Impacts Of Spatiotemporal Variation, Algal Blooms, And Microplastics, Samantha Grace Fortin

Dissertations, Theses, and Masters Projects

Estuaries are biogeochemical hotspots connecting terrestrial and coastal ecosystems. Anthropogenic disturbances, including increased nitrogen loading and plastic pollution, may have significant impacts on estuarine carbon and nitrogen cycling by altering microbiome structure and functions. The overarching goal of this dissertation was to examine how microbiomes and their associated biogeochemical processes are influenced by natural variation and anthropogenic disturbances in the York River Estuary (YRE). In chapter 2, spatial and temporal variation in benthic microbiomes and the rates of denitrification, anaerobic ammonium oxidation (anammox), and dissimilatory nitrate reduction to ammonium (DNRA) were examined to determine biotic and abiotic drivers of nitrogen …

Rapid Warming Events In A Small Coastal Upwelling Embayment, Tatjana E. Ellis

Physics

Temperature variability in the nearshore coastal ocean influences various biological processes and can drive changes in biodiversity and habitat range. Despite recent progress, there are still significant gaps in the understanding of drivers of temperature variability in upwelling bays, particularly at higher frequencies. In this study, we analyzed a decade of nearshore temperature measurements both inside and outside a small coastal embayment located in central California [San Luis Obispo (SLO) bay], as well as temperature data from satellites, to characterize rapid warming events. We found that rapid warming events, defined using rates of temperature change across different thresholds, occurred more …

Seasonal Controls On Nearshore Hypoxia In A Small Coastal Embayment, Stephen Alexander Huie

Physics

Dissolved oxygen (DO) is an important biogeochemical factor that strongly influences nearshore coastal ecosystems. Low DO (hypoxic) events can cause physiological stressful environments for ecological and economically important species, potentially leading to mass mortalities. In order to better assess drivers of coastal hypoxia, we collected data from monthly cruises on the inner shelf and nearshore moorings inside and outside a small coastal embayment (San Luis Obispo Bay on the Central California Coast) across the full upwelling season (March to August). During the late spring and early summer, we found that the nearshore near-bottom temperature-DO (T-DO) relationship aligned with the shelf …

Developing A Method To Track Marine Snow Aggregation Through Individual Collisions Using Stereoscopic Imaging, Riley Henning

Theses

The aggregation of individual phytoplankton into marine snow allows particles to sink more quickly, thus resulting in the transport of particulate organic carbon from surface waters to the deep ocean. Aggregate formation has previously been measured in experiments indirectly by quantifying how particle size or particle concentration changes over time. Here, I present my thesis in which I applied high-resolution imaging to quantify aggregate formation using two different methodologies.

We conducted experiments to investigate aggregate formation using stereoscopic imaging, tracking individual particles directly in a 3D volume. Phytoplankton cultures were rolled in cylindrical tanks and imaged by two cameras illuminated …

Response Of Coastal Ichthyoplankton Assemblages Off Northern California To Seasonal Oceanographic And Climate Variability, Blair M. Winnacott

Cal Poly Humboldt theses and projects

This study analyzed samples collected along the Trinidad Head Line (41°N) to characterize variability in the ichthyoplankton assemblage in coastal waters off northern California from late 2007 through 2019, a period during which a major marine heatwave (MHW; late 2014-16) strongly perturbed the ecosystem. I augmented visual identification with genetic techniques to resolve the species composition of visually cryptic larval rockfishes (Sebastes spp.). While taxonomic composition off northern California was largely similar to studies off Oregon and Washington, and cross-shelf structure and seasonal patterns in species’ abundance were generally consistent with the distribution and phenology of parental stocks, interannual …

Improving Observation, Assessment, And Management Of Atlantic Coastal Sharks, Cassidy Dawn Peterson

Dissertations, Theses, and Masters Projects

Coastal sharks represent a group of stocks for which observation, assessment, and management are particularly challenging. Large distributional ranges, complex migratory behavior, low economic value, and relatively few observations in fishery independent surveys hinder relative abundance estimation. Assessing stock status of coastal sharks is encumbered by limited data availability, data quality, and knowledge of life history strategy. Further, coastal sharks are challenging to manage due to their slow intrinsic population growth rates, competing stakeholder interests, history of overexploitation, and in some cases, subjection to international exploitation. This dissertation aimed to improve the capacity to observe relative abundance of coastal sharks. …

Heat Stress During Larval Stages On Coral Survivorship For M. Capitata, Sarah Woo

Pitzer Senior Theses

Very little is known about how heat stress during larvae stages effect larvae survivorship, early coral recruit settlement, and later stage coral survivorship. We focused on determining how heat stress during larvae stages effected Montipora capitata survivorship over time. After thermally stressing larvae, we asked how many larvae survived the treatment, how the treatment affected settlement, how many larvae survived the heat treatment but did not settle, and later stage coral survivorship experienced residual effects from the heat stress treatment. We exposed coral larvae to ambient seawater temperatures at 30°C and heated seawater temperatures to 34°C for an hour and …

Down In Arms: Marine Climate Stress Inhibits Growth And Calcification Of Regenerating Asterias Forbesi (Echinodermata: Asteroidea) Arms, Hannah L. Randazzo

Honors Projects

Anthropogenic CO₂ is changing the pCO₂, temperature, and carbonate chemistry of seawater. These processes are termed ocean acidification (OA) and ocean warming. Previous studies suggest two opposing hypotheses for the way in which marine climate stress will influence echinoderm calcification, metabolic efficiency, and reproduction: either an additive or synergistic effect. Sea stars have a regenerative capacity, which may be particularly affected while rebuilding calcium carbonate arm structures, leading to changes in arm growth and calcification. In this study, Asterias forbesi were exposed to ocean water of either ambient, high temperature, high pCO₂, or high temperature …

Dealing With Many Species: Improving Methodology For Forming And Assessing Species Complexes, Kristen Omori

Dissertations, Theses, and Masters Projects

In the United States, the Magnuson-Stevens Reauthorization Act mandates that all federally fished species must have catch limits, which can be challenging for data-limited species. One approach is to assess and manage a group of species with similar life history characteristics, vulnerability to the fishery, and overlapping geographic distributions in a single management unit, or a complex (i.e., stock or species complex). Using the Gulf of Alaska (GOA) Other Rockfish complex as a case study, the main goals of this dissertation are five-fold: 1) review species complexes in the United States; 2) compare multivariate techniques for assigning species to complexes; …

Quantifying The Increased Resiliency Of Chesapeake Bay Hypoxia To Environmental Conditions: A Benefit Of Nutrient Reductions, Luke Thomas Frankel

Dissertations, Theses, and Masters Projects

Seasonal hypoxia is a characteristic feature of the Chesapeake Bay as a result of anthropogenic eutrophication from agriculture and urban development throughout the watershed. Although in recent years coordinated management efforts have successfully reduced the flux of nutrients into the Bay, the overall goal of sufficient oxygen concentrations below the pycnocline for living resources remains unfulfilled. This was particularly apparent in 2018 and 2019 when the volume of hypoxic water exceeded the long-term (35-year) average due to anomalously high riverine discharge. To quantify the impact of watershed nutrient reductions, conventional statistical methods were employed in concert with a 3-D numerical …

Resolving Variability In Size Structure In An Individual-Based Model For The North Pacific Krill, Euphausia Pacifica, Roxanne Robertson

Cal Poly Humboldt theses and projects

Individual-based models (IBMs) have emerged as a powerful tool for ecological research and are particularly well suited to studies of plankton ecology. In this thesis, I develop an IBM for the North Pacific krill, Euphausia pacifica, with the goal of replicating observed variability in size-structure in the northern California Current Ecosystem. Krill, and E. pacifica in particular, are central to the structure and function of the California Current Ecosystem. Their response to environmental forcing translates climate variability to higher trophic levels and underpins broader ecosystem responses. Recent observations indicate environmental and climate-related shifts in E. pacifica size distributions, which …