Marine Biology Commons^™

Biophysical Factors Affecting Habitat Suitability For Crassostrea Virginica, Jason D. Tilley

Dissertations

Oyster reefs provide a variety of important ecosystem services. However, the mortality rate of eastern oyster, Crassostrea virginica, the dominant species that produces oyster reefs in the northern Gulf of Mexico, is increasing at an alarming rate due to a variety of abiotic and biological factors. I examined how biophysical factors, including the less-studied fatty acid profiles of the suspended particulate matter on which oysters feed, influenced morphometric condition of C. virginica.

I sampled suspended particulate matter (SPM) and oysters in-situ in the western Mississippi Sound, which historically supported the majority of oyster production in Mississippi waters. Sampling …

Quantifying The Role Of Water Quality On Nitrogen Cycling In A Trophic Estuary, Kayla Gonzalez-Boy

Symposium of Student Scholars

Jobos Bay Estuary is an intertidal, tropical estuary located in southern Puerto Rico. The estuary covers about 12 km² and has a variety of habitats, such as seagrass beds, mangroves, mud flats, and coral reefs, which play important roles in sediment trapping and water quality maintenance. Seagrasses also serve as nursery and feeding grounds and provide shelter for macrofauna. Currently, the role of seagrasses and water quality on nitrogen (N) cycling in trophic estuaries is not well constrained. Understanding variations in sediment-based effects on N cycling rates and transformations, and how they are associated with water quality, is an …

Microcystin Aids In Cold Temperature Acclimation: Differences Between A Toxic Microcystis Wildtype And Non-Toxic Mutant, Gwendolyn F. Stark, Robbie M. Martin, Laura E. Smith, Bofan Wei, Ferdi L. Hellweger, George S. Bullerjahn, R. Michael L. Mckay, Gregory L. Boyer, Steven W. Wilhelm

Great Lakes Institute for Environmental Research Publications

For Microcystis aeruginosa PCC 7806, temperature decreases from 26 °C to 19 °C double the microcystin quota per cell during growth in continuous culture. Here we tested whether this increase in microcystin provided M. aeruginosa PCC 7806 with a fitness advantage during colder-temperature growth by comparing cell concentration, cellular physiology, reactive oxygen species damage, and the transcriptomics-inferred metabolism to a non-toxigenic mutant strain M. aeruginosa PCC 7806 ΔmcyB. Photo-physiological data combined with transcriptomic data revealed metabolic changes in the mutant strain during growth at 19 °C, which included increased electron sinks and non-photochemical quenching. Increased gene expression was observed for …

A Colonial-Nesting Seabird Shows Limited Heart Rate Responses To Natural Variation In Threats Of Polar Bears, Erica A. Geldart, Oliver P. Love, Andrew F. Barnas, Christopher M. Harris, H. Grant Gilchrist, Christina A.D. Semeniuk

Great Lakes Institute for Environmental Research Publications

Several predator-prey systems are in flux as an indirect result of climate change. In the Arctic, earlier sea-ice loss is driving polar bears (Ursus maritimus) onto land when many colonial nesting seabirds are breeding. The result is a higher threat of nest predation for birds with potential limited ability to respond. We quantified heart rate change in a large common eider (Somateria mollissima) breeding colony in the Canadian Arctic to explore their adaptive capacity to keep pace with the increasing risk of egg predation by polar bears. Eiders displayed on average higher heart rates from baseline when polar bears were …

Rapidly Developed, Optimized, And Applied Wastewater Surveillance System For Real-Time Monitoring Of Low-Incidence, High-Impact Mpox Outbreak, Chandler H. Wong, Zhihao Zhang, Walaa Eid, Julio Plaza-Diaz, Pervez Kabir, Shen Wan, Jian Jun Jia, Elisabeth Mercier, Ocean Thakali, Lakshmi Pisharody, Nada Hegazy, Sean E. Stephenson, Wanting Fang, Tram B. Nguyen, Nathan T. Ramsay, R. Michael Mckay, Ryland Corchis-Scott, Alex E. Mackenzie

Great Lakes Institute for Environmental Research Publications

Recent MPOX viral resurgences have mobilized public health agencies around the world. Recognizing the significant risk of MPOX outbreaks, large-scale human testing, and immunization campaigns have been initiated by local, national, and global public health authorities. Recently, traditional clinical surveillance campaigns for MPOX have been complemented with wastewater surveillance (WWS), building on the effectiveness of existing wastewater programs that were built to monitor SARS-CoV-2 and recently expanded to include influenza and respiratory syncytial virus surveillance in wastewaters. In the present study, we demonstrate and further support the finding that MPOX viral fragments agglomerate in the wastewater solids fraction. Furthermore, this …

A Combined Microscopy And Single-Cell Sequencing Approach Reveals The Ecology, Morphology, And Phylogeny Of Uncultured Lineages Of Zoosporic Fungi, Kensuke Seto, D. Rabern Simmons, C. Alisha Quandt, Thijs Frenken, Alden C. Dirks, Rebecca A. Clemons, Katelyn M. Mckindles, R. Michael L. Mckay, Timothy Y. James

Great Lakes Institute for Environmental Research Publications

Environmental DNA analyses of fungal communities typically reveal a much larger diversity than can be ascribed to known species. Much of this hidden diversity lies within undescribed fungal lineages, especially the early diverging fungi (EDF). Although these EDF often represent new lineages even at the phylum level, they have never been cultured, making their morphology and ecology uncertain. One of the methods to characterize these uncultured fungi is a single-cell DNA sequencing approach. In this study, we established a large data set of single-cell sequences of EDF by manually isolating and photographing parasitic fungi on various hosts such as algae, …

Heightened Heart Rate But Similar Flight Responses To Evolved Versus Recent Predators In An Arctic Seabird, Erica A. Geldart, Oliver P. Love, H. Grant Gilchrist, Andrew F. Barnas, Christopher M. Harris, Christina A.D. Semeniuk

Great Lakes Institute for Environmental Research Publications

Predator-prey dynamics in the Arctic are being altered with changing sea ice phenology. The increasing frequency of predation on colonial nesting seabirds and their eggs by the polar bear (Ursus maritimus) is a consequence of bears shifting to terrestrial food resources through a shortened seal-hunting season. We examined antipredator responses in a colony of nesting Common Eiders (Somateria mollissima) on East Bay Island, Nunavut, Canada, which is exposed to established nest predators, such as arctic fox (Vulpes lagopus), but also to recent increases in polar bear nest predation due to the bears’ lost on-ice hunting opportunities. Given eiders’ limited eco-evolutionary …

Du Undergraduate Showcase: Research, Scholarship, And Creative Works, Caitlyn Aldersea, Justin Bravo, Sam Allen, Anna Block, Connor Block, Emma Buechler, Maria De Los Angeles Bustillos, Arianna Carlson, William Christensen, Olivia Kachulis, Noah Craver, Kate Dillon, Muskan Fatima, Angel Fernandes, Emma Finch, Colleen Cassidy, Amy Fishman, Andrea Francis, Stacia Fritz, Simran Gill, Emma Gries, Rylie Hansen, Shannon Powers, Jacqueline Martinez, Zachary Harker, Ashley Hasty, Mykaela Tanino-Springsteen, Kathleen Hopps, Adelaide Kerenick, Colin Kleckner, Ci Koehring, Elijah Kruger, Braden Krumholz, Maddie Leake, Lyneé Alves, Seraphina Loukas, Yatzari Lozano Vazquez, Haley Maki, Emily Martinez, Sierra Mckinney, Mykaela Tanino-Springsteen, Audrey Mitchell, Kipling Newman, Audrey Ng, Megan Lucyshyn, Andrew Nguyen, Stevie Ostman, Casandra Pearson, Alexandra Penney, Julia Gielczynski, Tyler Ball, Anna Rini, Christina Rorres, Simon Ruland, Helayna Schafer, Emma Sellers, Sarah Schuller, Claire Shaver, Kevin Summers, Isabella Shaw, Madison Sinar, Claudia Pena, Apshara Siwakoti, Carter Sorensen, Madi Sousa, Anna Sparling, Alexandra Revier, Brandon Thierry, Dylan Tyree, Maggie Williams, Lauren Wols

DU Undergraduate Research Journal Archive

DU Undergraduate Showcase: Research, Scholarship, and Creative Works

Sulfolipid Substitution Ratios Of Microcystis Aeruginosa And Planktonic Communities As An Indicator Of Phosphorus Limitation In Lake Erie, Robbie M. Martin, Maddie K. Denney, Helena L. Pound, Justin D. Chaffin, George S. Bullerjahn, R. Michael L. Mckay, Arthur Zastepa, Katarina A. Jones, Hector F. Castro, Shawn R. Campagna, Steven W. Wilhelm

Great Lakes Institute for Environmental Research Publications

Phosphorus (P) availability frequently limits primary production in lakes, influences the physiology of phytoplankton, shapes community structure, and can stimulate or constrain the formation of cyanobacterial blooms. Given the importance of P, numerous methods are available to assess P stress in phytoplankton communities. Marine phytoplankton are known to substitute sulfolipids for phospholipids in response to P limitation. We asked whether sulfolipid substitution might serve as an additional indicator of P stress in freshwater phytoplankton communities. The question was addressed using cultures of Microcystis aeruginosa, Lake Erie microcosms, and surveys of lipid profiles in Lake Erie during a Microcystis spp. bloom. …

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 …

Spatio-Temporal Connectivity Of The Aquatic Microbiome Associated With Cyanobacterial Blooms Along A Great Lake Riverine-Lacustrine Continuum, Sophie Crevecoeur, Thomas A. Edge, Linet Cynthia Watson, Susan B. Watson, Charles W. Greer, Jan J.H. Ciborowski, Ngan Diep, Alice Dove, Kenneth G. Drouillard, Thijs Frenken, Robert Michael Mckay, Arthur Zastepa, Jérôme Comte

Great Lakes Institute for Environmental Research Publications

Lake Erie is subject to recurring events of cyanobacterial harmful algal blooms (cHABs), but measures of nutrients and total phytoplankton biomass seem to be poor predictors of cHABs when taken individually. A more integrated approach at the watershed scale may improve our understanding of the conditions that lead to bloom formation, such as assessing the physico-chemical and biological factors that influence the lake microbial community, as well as identifying the linkages between Lake Erie and the surrounding watershed. Within the scope of the Government of Canada’s Genomics Research and Development Initiative (GRDI) Ecobiomics project, we used high-throughput sequencing of the …

Interactions Between Chytrids Cause Variable Infection Strategies On Harmful Algal Bloom Forming Species, Katelyn M. Mckindles, R. Michael L. Mckay, George S. Bullerjahn, Thijs Frenken

Great Lakes Institute for Environmental Research Publications

Cyanobacteria have a great diversity of natural enemies, such as herbivores and pathogens, including fungal pathogens within the Chytridiomycota (chytrids). While these pathogens have been previously described on a select number of cyanobacterial hosts and are suspected to play a significant ecological role, little is understood about species interactions and how competition between parasites can affect epidemic development and bloom formation. Here, three Planktothrix agardhii isolates from Sandusky Bay, Lake Erie (OH, USA) were challenged in monoculture and polyculture against infection by three isolates (C1, C2, C10) of their obligate chytrid fungal pathogen, Rhizophydiales sp. The chytrid isolates were inoculated …

Comparative Metabolomic Analysis Of Exudates Of Microcystin-Producing And Microcystin-Free Microcystis Aeruginosa Strains, Yuan Zhou, Jun Xu, Hugh J. Macisaac, Robert Michael Mckay, Runbing Xu, Ying Pei, Yuanyan Zi, Jiaojiao Li, Yu Qian, Xuexiu Chang

Great Lakes Institute for Environmental Research Publications

Cyanobacterial harmful algal blooms (cHABs) dominated by Microcystis aeruginosa threaten the ecological integrity and beneficial uses of lakes globally. In addition to producing hepatotoxic microcystins (MC), M. aeruginosa exudates (MaE) contain various compounds with demonstrated toxicity to aquatic biota. Previously, we found that the ecotoxicity of MaE differed between MC-producing and MC-free strains at exponential (E-phase) and stationary (S-phase) growth phases. However, the components in these exudates and their specific harmful effects were unclear. In this study, we performed untargeted metabolomics based on liquid chromatography-mass spectrometry to reveal the constituents in MaE of a MC-producing and a MC-free strain at …

Change And Stasis Of Distinct Sediment Microbiomes Across Port Everglades Inlet (Pei) And The Adjacent Coral Reefs, Lauren E. Krausfeldt, Jose V. Lopez, Catherine Bilodeau, Hyo Won Lee, Shelby L. Casali

Biology Faculty Articles

Deep water ports are human built coastal structures that by definition welcome ship traffic and disturbance. Evidence is accumulating that enhanced port activities such as dredging or deepening have negatively affected nearby natural habitats. Port Everglades Inlet (PEI) is a large active South Florida cargo port for over two million people and lies adjacent to coral reefs, dwindling mangroves, and recreational beaches. In this study, the microbial communities of PEI and adjacent reef sediments were characterized to serve as indicators for change due to dredging and assess anthropogenic influence on these sensitive ecosystems by sequencing the V4 region of 16S …

Targeting A Free Viral Fraction Enhances The Early Alert Potential Of Wastewater Surveillance For Sars-Cov-2: A Methods Comparison Spanning The Transition Between Delta And Omicron Variants In A Large Urban Center, Liang Zhao, Qiudi Geng, Ryland Corchis-Scott, Robert Michael Mckay, John Norton, Irene Xagoraraki

Great Lakes Institute for Environmental Research Publications

Introduction: Wastewater surveillance has proven to be a valuable approach to monitoring the spread of SARS-CoV-2, the virus that causes Coronavirus disease 2019 (COVID-19). Recognizing the benefits of wastewater surveillance as a tool to support public health in tracking SARS-CoV-2 and other respiratory pathogens, numerous wastewater virus sampling and concentration methods have been tested for appropriate applications as well as their significance for actionability by public health practices. Methods: Here, we present a 34-week long wastewater surveillance study that covers nearly 4 million residents of the Detroit (MI, United States) metropolitan area. Three primary concentration methods were compared with respect …

Multi-Year Molecular Quantification And ‘Omics Analysis Of Planktothrix-Specific Cyanophage Sequences From Sandusky Bay, Lake Erie, Katelyn M. Mckindles, Makayla Manes, Michelle Neudeck, Robert Michael Mckay, George S. Bullerjahn

Great Lakes Institute for Environmental Research Publications

Introduction: Planktothrix agardhii is a microcystin-producing cyanobacterium found in Sandusky Bay, a shallow and turbid embayment of Lake Erie. Previous work in other systems has indicated that cyanophages are an important natural control factor of harmful algal blooms. Currently, there are few cyanophages that are known to infect P. agardhii, with the best-known being PaV-LD, a tail-less cyanophage isolated from Lake Donghu, China. Presented here is a molecular characterization of Planktothrix specific cyanophages in Sandusky Bay. Methods and Results: Putative Planktothrix-specific viral sequences from metagenomic data from the bay in 2013, 2018, and 2019 were identified by two approaches: homology …

Actionable Wastewater Surveillance: Application To A University Residence Hall During The Transition Between Delta And Omicron Resurgences Of Covid-19, Ryland Corchis-Scott, Qiudi Geng, Abdul Monem Al Riahi, Amr Labak, Ana Podadera, Kenneth K.S. Ng, Lisa A. Porter, Yufeng Tong, Jess C. Dixon, Sherri Lynne Menard, Rajesh Seth, R. Michael Mckay

Great Lakes Institute for Environmental Research Publications

Wastewater surveillance has gained traction during the COVID-19 pandemic as an effective and non-biased means to track community infection. While most surveillance relies on samples collected at municipal wastewater treatment plants, surveillance is more actionable when samples are collected “upstream” where mitigation of transmission is tractable. This report describes the results of wastewater surveillance for SARS-CoV-2 at residence halls on a university campus aimed at preventing outbreak escalation by mitigating community spread. Another goal was to estimate fecal shedding rates of SARS-CoV-2 in a non-clinical setting. Passive sampling devices were deployed in sewer laterals originating from residence halls at a …

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 …

Identification Of Novel Biosynthetic Gene Clusters Encoding For Polyketide/Nrps-Producing Chemotherapeutic Compounds From Marine-Derived Streptomyces Hygroscopicus From A Marine Sanctuary, Hannah Ruth Flaherty

Honors Theses and Capstones

Nearly one out of six deaths in 2020, around ten million people, were caused by cancer, making it a leading cause of death worldwide (WHO, 2022). This major public health issue, in addition to the rise of multidrug-resistant (MDR) pathogens, provides a high demand for the discovery of new pharmaceutical drugs to be used clinically to treat these conditions. The Streptomyces genus accounts to produce 39% of all microbial metabolites currently approved for human health, indicating its potential as an important species to study for antimicrobial and anticancer agents. The long linear genome of Streptomyces contains specialized sequences known as …