Marine Biology Commons^™

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 …

Community Ecology And Disease Dynamics In Pacific Oysters: Unraveling Microbiome-Pathogen Interactions In The Wild, Victoria E. Cifelli

Cal Poly Humboldt theses and projects

In the context of multispecies microbial assemblages, disruptions can occur when there are alterations in host conditions, such as the onset of a disease. Notably, viruses have the potential to reshape a host's microbial community. However, the role of the host's habitat and environment, which could be pivotal in communities with shifting niche space and habitat filters, is often overlooked in host-microbe-pathogen interactions. Recognizing the importance of these factors, I employed a field-based approach to understand microbial community dynamics in the presence of disease. To address the influence of geographical location, I conducted an analysis involving healthy and infected oysters …

Flaws In The Methodologies For Organic Carbon Analysis In Seagrass Blue Carbon Soils, Oscar Serrano, Ines Mazarrasa, James W. Fourqurean, Eduard Serrano, Jeffrey Baldock, Jonathan Sanderman

Research outputs 2022 to 2026

The ability to accurately measure organic carbon (OC) in marine sediments or soils is overall taken for granted in scientific communities, yet this seemingly mundane task remains a methodological challenge when the soil matrix contains calcium carbonate (CaCO3), creating inaccuracies in Blue Carbon estimates. Here, we compared five common methods combining acidification, combustion, and wet oxidation pre-treatments for determination of OC in sediments and soils containing CaCO3 based on the analyses of artificial soil mixtures made of different OC and CaCO3 contents, and multiple soils from Australian seagrass cores. The results obtained showed that methods involving acidification pre-treatment entailed −17 …

Drones For Large-Scale Wildlife Surveys: Raw Data To Support Manuscript - Hodgson Et Al, Amanda Hodgson

Research Datasets

We conducted trial ScanEagle drone surveys of dugongs in Shark Bay, Western Australia, covering the full extent of the drone’s range (~ 100 km), concurrently with observer surveys, with drone flying above or just behind the piloted aircraft. We aimed to test the assumption that drone imagery could provide comparable detection rates of dugongs to human observers when influenced by same environmental conditions. Data in "All data for analysis - Shark Bay Hodgson et al" include a summary of the sightings from both platforms per transect segment, including associated environmental covariates. Also included are details of each dugong group sighted …

The Influence Of Abiotic And Biotic Conditions On Lifecycle Stages Is Critical For Estuarine Seagrass Resilience, Chanelle Webster, Paul S. Lavery, Caitlyn O'Dea, Marta Sanchez Alarcon, Chandra Salgado Kent, Mcmahon

Research outputs 2022 to 2026

Abiotic and biotic factors influence seagrass resilience, but the strength and relative importance of the effects are rarely assessed over the complete lifecycle. This study examined the effects of abiotic (salinity, temperature, water depth) and biotic (grazing by black swans) factors on Ruppia spp. over the complete lifecycle. Structures were set up in two estuaries ( – 33.637020, 115.412608) that prevented and allowed natural swan grazing of the seagrasses in May 2019, before the start of the growing season. The density of life stage(s) was measured from June 2019 when germination commenced through to January 2020 when most of the …

Decline Of Seagrass (Posidonia Oceanica) Production Over Two Decades In The Face Of Warming Of The Eastern Mediterranean Sea, Victoria Litsi-Mizan, Pavlos T. Efthymiadis, Vasilis Gerakaris, Oscar Serrano, Manolis Tsapakis, Eugenia T. Apostolaki

Research outputs 2022 to 2026

* The response of Posidonia oceanica meadows to global warming of the Eastern Mediterranean Sea, where the increase in sea surface temperature (SST) is particularly severe, is poorly investigated. * Here, we reconstructed the long-term P. oceanica production in 60 meadows along the Greek Seas over two decades (1997–2018), using lepidochronology. We determined the effect of warming on production by reconstructing the annual and maximum (i.e. August) SST, considering the role of other production drivers related to water quality (i.e. Chla, suspended particulate matter, Secchi depth). * Grand mean (±SE) production across all sites and the study period was 48 …

Coastal Groundwater-Dependent Ecosystems Are Falling Through Policy Gaps, Madeleine Dyring, Melissa M. Rohde, Ray Froend, Harald Hofmann

Research outputs 2022 to 2026

Coastal groundwater-dependent ecosystems (GDEs), such as wetlands, estuaries and nearshore marine habitats, are biodiversity hotspots that provide valuable ecosystem services to society. However, coastal groundwater and associated ecosystems are under threat from groundwater exploitation and depletion, as well as climate change impacts from sea-level rise and extreme flood and drought events. Despite many well-intentioned policies focused on sustainable groundwater use and species protection, coastal GDEs are falling through gaps generated by siloed policies and as a result, are declining in extent and ecological function. This study summarized then examined policies related to the management of coastal groundwater and connected ecosystems …

Submerged Aquatic Vegetation Response To Submarine Groundwater Discharge, Brielle K. Robbins

College of Graduate Studies: Theses & Dissertations

Ecosystem services provided by seagrass meadow communities in Florida Bay propagate economic opportunity and carbon sequestration among many other benefits. Recent seagrass die-off events have threatened Florida Bay’s ecosystem and its ability to provide these services. These impacts fuel ongoing research investigating the complex causes of seagrass die-offs. While previous research has described how water quality parameters can lead to seagrass die-offs, there is still much to be explored regarding the proximate causes for these water quality changes. The aquifers underneath the bay may hold the missing pieces in our understanding of die-off events, as submarine groundwater discharge (SGD) can …

Use Of Hematological Markers To Assess Physiological Condition And Health Status In Free-Ranging Sand Tiger Sharks (Carcharias Taurus), Chestina N. Craig

College of Graduate Studies: Theses & Dissertations

The contents of blood can provide information about the physiological condition and health of vertebrates. This study seeks to better understand the stress physiology and blood bacteria presence of the sand tiger shark (Carcharias taurus), as sharks are known to have unique physiology and immune systems. In this study the blood metabolites glucose, lactate, and ketones (3-hydroxybuteric acid and acetoacetate), were used to understand how biotic and abiotic factors affect the acute stress response to capture and handling. Metabolite concentrations from blood plasma were analyzed using colorimetric assays. Glucose and ketones showed no significant responses to capture and …

Investigating Salinity Intrusion Effects On Sapelo Island, Georgia Using Benthic Macroinvertebrate Bioindicators, Raymond Paul Kidder Ii

College of Graduate Studies: Theses & Dissertations

Coastal wetlands are threatened by the compounding effects of sea level rise and historical land modification. Historically, much of Sapelo Island, Georgia was deforested and drained using a series of ditches and canals to create arable land fit for agriculture and to provide drainage to the inhabited parts of the island. Today, this network of artificial channels is believed to be facilitating the movement of saltwater from the nearby estuary into freshwater areas on the interior of the island. This study aimed to better understand the frequency and magnitude of salinity intrusion events along with their resulting impacts to the …

River Report. State Of Lower St. Johns River Basin, Florida: Water Quality, Fisheries, Aquatic Life, Contaminants, 2023, Environmental Protection Board, Jacksonville Florida, University Of North Florida, Jacksonville University, Gerry Pinto, Brian P. Zoellner, Christopher Baynard, Gretchen Bielmyer-Fraser, Dale Casamatta, Charles Closmann, Nisse Goldberg, Ashley Johnson, Scott Jones, William Penwell, Radha Pyati, Adam Rosenblatt

State of the River Report

No abstract provided.

Multi-Chamber Silencer Composed Of Screw-Perforated Tubes And Straight-Perforated Tubes, Tian-Syung Lan, Min-Chie Chiu

Journal of Marine Science and Technology–Taiwan

The use of silencers to reduce noise is mandatory due to severe hearing damage caused by high venting noise in the engine room of ocean-going vessels. While straight and perforated tubes have been used as acoustical elements in traditional silencer design, studies have shown that the acoustical design still requires improvement. To enhance acoustical efficiency, the use of multi-chamber mufflers is proposed composed of screw and perforated tubes. Additionally, a mathematical finite element model built for acoustical simulation using the COMSOL program expedites the analysis of silencers with complicated acoustical elements. A sensitivity analysis of transmission loss concerning the geometric …

Rapid Species Identification Of Meretrix Lusoria And Three Other Meretrix Clams Using Pcr And Rflp Analysis Of The Mitochondrial Coii Gene., Chia-Hsuan Sung, Liang-Jong Wang, Chang-Wen Huang

Journal of Marine Science and Technology–Taiwan

Meretrix clams are among the most economically important species of bivalves in Eastern Asia and Taiwan. In the past, the identification of these hard clams depended on the shell morphology; however, species identification based on shell markings and shapes confuses the taxonomy of the Meretrix genus. The DNA molecular information is useful and can easily identify them accurately and quickly, especially the sequence of mitochondrial DNA. In this study, a PCR method to analyze the mitochondrial cytochrome c oxidase II (COII) gene was developed to rapidly identify of M. lusoria, M. lamarckii, M. lyrata and M. petechialis. Four different species …

Bearing Capacity Factor Characteristics Of Footings On Double-Layered Cohesive Soils, Chao-Ming Chi, Zheng-Shan Lin, Yu-Shu Kuo

Journal of Marine Science and Technology–Taiwan

In this study, the bearing capacity of a surface foundation resting on a double-layered cohesive soil profile was investigated by applying a rotational mechanism and finite-difference numerical simulations. The bearing capacity factor behaviors of a surface footing on double-layered cohesive soils can be classified and illustrated using a characteristic chart. Depending on the soil strata strength ratio and normalized layer thickness, the soil-foundation system can be in the squeezing, factor-increasing, factor-decreasing, or constant factor zones. The results indicated that the trend of the curves in the characteristic chart computed from the asymmetric failure mechanism was in accordance with that of …

Research On Ice Resistance Of Ships Sailing In Floating Ice Floe, Zhixin Xiong, Xinyuan Wu, Yang Li

Journal of Marine Science and Technology–Taiwan

To study the ice resistance of ships in areas with floating ice, the Xuelong 2 icebreaker was simulated. A floating-ice model was established using the discrete-element method, and an ice particle array was generated using MATLAB. The effects of ice coverage and speed on ice drag were studied From the numerical simulation results, it can be seen that there is a certain trend in ice resistance under different ice coverage ranges, which changes with the change of speed.By comparing with the empirical formula and the numerical value of the ship model test, this numerical simulation results are relatively accurate.It also …

The Pre-Processing Of Wt Blade Images By Ss And Bilateral Filter With Machine Learning Frameworks, Joy Iong-Zong Chen, Chien-Yeh Lee, Wien-Chieh Lo

Journal of Marine Science and Technology–Taiwan

This paper discusses the motivation behind turbine migration and addresses the challenges of using NN (neural network) computing systems. Moreover, it focuses on high-dimensional data from WT (wind turbine) blades. The three key aspects addressed in this study are turbine migration, overfitting, and strict feature selection. To evaluate the performance of the machine learning system, the study considers the characteristics of WT blades, specifically the similarity in blade color and the differences in shape. The authors apply pre-processing techniques, in particular a bilateral filter, in conjunction with the SS (selective synthesizer) of blade fouling patterns. The SS method adopts the …

Nitrogen Isotopes In Deep Sea Corals; A Potential Tracer Of Paleoceanographic Conditions, Sylvia Bergerud

Scripps Senior Theses

Abstract

In the face of anthropogenic climate change, increasing pressure is being mounted on contextualizing current climate altercations compared to those of the past. One key tracer of climate variation is the isotopic ratio of 15N compared to 14N, which tracks biological and chemical reactions throughout the N cycle. However, it is difficult to find accurate palaeoceanographic records of N isotope fractionation, as most sedimentary and organic samples are subject to extensive diagenesis, degradation, and erosive processes. Scleractinian corals present a potential solution to this lack of accurate data. Multiple studies indicate that, due to their protective aragonite skeletons and …

Shallow Water Coral Distribution And Its Response To Climate Change, Amaury De Jesus

Dissertations and Theses

Shallow water corals are one of the main reef-building organisms that secrete carbonates as their skeletons, and therefore, are one of the major sinks of CO2 in the ocean. These reef builders are also very crucial to marine environments and human society. As the global energy demand continues rising, fossil fuel burning increases at a faster pace despite the increase in energy supply using clean and renewable energy. The increase of CO2 in the atmosphere has been shown to exacerbate global warming and may cause ocean acidification, threatening the habitat of shallow-water corals. Many recent observations show alarming signs of …

Jonathan Franco López 1955 – 2023, Angel Moran-Silva, Rafael Chávez-López, Sergio Cházaro-Olvera

Gulf and Caribbean Research

No abstract provided.

Is Temperature, Dissolved Oxygen, Or Salinity Driving Oyster Mortality On Breakwaters?, Ashten Notz, Aaron Bland, Ronald Baker

Gulf and Caribbean Research

No abstract provided.