Marine Biology Commons^™

Planktonic Diatom Species Succession In San Francisco Bay (September 2015 - December 2017), Theresa Keith

Undergraduate Honors Theses

Since Hutchinson first described the “Paradox of the Plankton” in 1961, research has been done to determine how and why the coexistence of so many different species of phytoplankton is possible. A critical part of this question is species succession, or how the assemblage of phytoplankton in a region changes over time. This study examines the succession of planktonic diatoms in San Francisco Bay, CA (USA) from September 2015 through December 2017 using phytoplankton samples and environmental data. Periodic sampling was conducted at a site in the Golden Gate Strait and taxa were identified using light microscopy and scanning electron …

Factors Controlling The Community Structure Of Picoplankton In Contrasting Marine Environments, Jose Luis Otero-Ferrer, Pedro Cermeno, Antonio Bode, Bieito Fernandez-Castro, Josep M. Gasol, Xose Anxelu G. Moran, Emilio Maranon, Victor Moreira-Coello, Marta M. Varela, Marina Villamana, Beatriz Mourino-Carballido

Research outputs 2014 to 2021

The effect of inorganic nutrients on planktonic assemblages has traditionally relied on concentrations rather than estimates of nutrient supply. We combined a novel dataset of hydrographic properties, turbulent mixing, nutrient concentration, and picoplankton community composition with the aims of (i) quantifying the role of temperature, light, and nitrate fluxes as factors controlling the distribution of autotrophic and heterotrophic picoplankton subgroups, as determined by flow cytometry, and (ii) describing the ecological niches of the various components of the picoplankton community. Data were collected at 97 stations in the Atlantic Ocean, including tropical and subtropical open-ocean waters, the northwestern Mediterranean Sea, and …

Impacts Of Coastal Acidification On Louisiana Plankton, Amy Mallozzi

LSU Master's Theses

Anthropogenic input of carbon dioxide (CO₂) has an increasingly acidifying effect on the world’s oceans with the potential to impact biogeochemical cycles and food web dynamics. Coastal Louisiana is an area highly vulnerable to changing climate, but the unique local water chemistry created by input from the Mississippi and Atchafalaya Rivers makes the manifestation of elevated CO₂ and its biological implications difficult to predict. Louisiana estuaries are highly productive and support a large commercial market for the eastern oyster, Crassostrea virginica. This study explores the use of experimental microcosms to expose natural phytoplankton assemblages and larval …

Brine Shrimp Grazing And Fecal Production Increase Sedimentation To The Deep Brine Layer (Monimolimnion) Of Great Salt Lake, Utah, Piotr Maszczyk, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

Great Salt Lake (Utah) has a monimolimnion with high concentrations of salts, particulate matter, nutrients, and mercury. To test the importance of brine shrimp (Artemia franciscana) grazing on particulate matter flux, we created salinity gradients in 160-cm high columns, reflecting the lake’s gradient. Two experiments were performed in replicated columns with or without Artemia. Sediment traps were positioned at the bottoms of the mixolimnion (95 cm), chemolimnion (105 cm), or monimolimnion (140 cm). We hypothesized that because of the high salt densities of the monimolimnia, greater accumulation of sediments would be in the lower chemocline, than in …

Dna Barcoding Reveals A New Morphotype Of The Sugar Kelp, Saccharina Latissima, Dallin Brimley, Zakery Ford, Travis Gould, Brandon Guerra, Emily Haggett, Ian Jones, Elyse Johnson, Ken Peterson, Matthew Prout

Thinking Matters Symposium Archive

Phytoplankton blooms follow predictable annual cycles in the Gulf of Maine, characterized by a large spring bloom and a smaller bloom in the fall. Marine phytoplankton form the foundation of primary production in Gulf of Maine waters, and thus community changes in composition, and abundance could have cascading effects on our coastal ecosystems.

We set out to monitor the community composition, diversity, and abundance of the spring micro-phytoplankton bloom, at a Friends of Casco Bay water quality monitoring site, in South Portland, Maine. The Gulf of Maine is experiencing accelerated warming rates, and this type of monitoring can aid in …

The Influence Of Phytoplankton Size And Community Composition On Carbon Cycling And Planktonic Food Webs In The Sargasso Sea, Bridget Elise Cotti-Rausch

Theses and Dissertations

The Sargasso Sea is a dynamic physical environment located in the western North Atlantic where strong seasonal variability combines with forcing by mesoscale (~100 km) eddies. These drivers determine nutrient, light, and temperature regimes, and ultimate the size, composition and productivity of the phytoplankton community. My general objective was to determine how the structure and function of planktonic communities affected carbon export from the surface ocean in the Sargasso Sea. On four cruises (2011 and 2012; one eddy per cruise), I investigated links between water column structure, plankton community composition, size, and primary production (PP). I then combined PP data …

The Growth Response Of Two Diatom Species To Atmospheric Dust From The Last Glacial Maximum, Tim M. Conway, Linn J. Hoffmann, Eike Breitbarth, Robert F. Strzepek, Eric W. Wolff

Marine Science Faculty Publications

Relief of iron (Fe) limitation in the surface Southern Ocean has been suggested as one driver of the regular glacial-interglacial cycles in atmospheric carbon dioxide (CO2). The proposed cause is enhanced deposition of Fe-bearing atmospheric dust to the oceans during glacial intervals, with consequent effects on export production and the carbon cycle. However, understanding the role of enhanced atmospheric Fe supply in biogeochemical cycles is limited by knowledge of the fluxes and 'bioavailability' of atmospheric Fe during glacial intervals. Here, we assess the effect of Fe fertilization by dust, dry-extracted from the Last Glacial Maximum portion of the EPICA Dome …

Seascapes As A New Vernacular For Pelagic Ocean Monitoring, Management And Conservation, Maria T. Kavanaugh, Matthew J. Oliver, Francisco P. Chavez, Ricardo M. Letelier, Frank E. Muller-Karger, Scott C. Doney

Marine Science Faculty Publications

For terrestrial and marine benthic ecologists, landscape ecology provides a framework to address issues of complexity, patchiness, and scale—providing theory and context for ecosystem based management in a changing climate. Marine pelagic ecosystems are likewise changing in response to warming, changing chemistry, and resource exploitation. However, unlike spatial landscapes that migrate slowly with time, pelagic seascapes are embedded in a turbulent, advective ocean. Adaptations from landscape ecology to marine pelagic ecosystem management must consider the nature and scale of biophysical interactions associated with organisms ranging from microbes to whales, a hierarchical organization shaped by physical processes, and our limited capacity …

Sipper Plankton And Marine Snow Abundance And Distribution Data For The Northeastern Gulf Of Mexico: June 2012 – August 2014, Kendra L. Daly

C-IMAGE data

This dataset contains seasonal and interannual marine snow, phytoplankton, zooplankton, and larval fish abundance and distributions collected from the northeastern Gulf of Mexico using the Shadowed Image Particle Profiling Evaluation Recorder (SIPPER). The purpose of the dataset is to assess the seasonal and interannual zooplankton abundance and distribution after the Deepwater Horizon oil spill.

Preferential Depletion Of Zinc Within Costa Rica Upwelling Dome Creates Conditions For Zinc Co-Limitation Of Primary Production, P. Dreux Chappell, Jagruti Vedmati, Karen E. Selph, Heather A. Cyr, Bethany D. Jenkins, Michael R. Landry, James W. Moffett

OES Faculty Publications

The Costa Rica Dome (CRD) is a wind-driven feature characterized by high primary production and an unusual cyanobacterial bloom in surface waters. It is not clear whether this bloom arises from top-down or bottom-up processes. Several studies have argued that trace metal geochemistry within the CRD contributes to the composition of the phytoplankton assemblages, since cyanobacteria and eukaryotic phytoplankton have different transition metal requirements. Here, we report that total dissolved zinc (Zn) is significantly depleted relative to phosphate (P) and silicate (Si) within the upper water column of the CRD compared with other oceanic systems, and this may create conditions …

Synchronicity Between Ice Retreat And Phytoplankton Bloom In Circum‐Antarctic Polynyas, Yun Li, Rubao Ji, Meibing Jin, Julienne Stroeve

Marine Science Faculty Publications

Phytoplankton in Antarctic coastal polynyas has a temporally short yet spatially variant growth window constrained by ice cover and day length. Using 18‐year satellite measurements (1997–2015) of sea ice and chlorophyll concentrations, we assessed the synchronicity between the spring phytoplankton bloom and light availability, taking into account the ice cover and the incident solar irradiance, for 50 circum‐Antarctic coastal polynyas. The synchronicity was strong (i.e., earlier ice‐adjusted light onset leads to earlier bloom and vice versa) in most of the western Antarctic polynyas but weak in a majority of the eastern Antarctic polynyas. The west‐east asymmetry is related to sea …

Viruses And Metals In Ocean Food Webs: Top-Down And Bottom-Up Effects Of Marine Viruses And Trace Elements On Marine Picophytoplankton, Brady Robert Cunningham

Theses and Dissertations

Viruses are the most numerous biological entities in the ocean, playing a key role in microbial ecology and biogeochemical cycling. In order to replicate, viruses must first infect a host and then use the host’s cellular machinery to produce new viral particles. Some of the most abundant viral hosts in the subtropical open ocean are picophytoplankton. However, picophytoplankton growth is typically constrained by nutrient availability. In many regions of the ocean, iron (Fe) is only available in very low concentrations causing growth-limitation of picophytoplankton. Interestingly, the interactions between Fe-limitation and viral infection of picophytoplankton have not been extensively studied. This …

Assessing Biogeochemical Impacts And Environmental Conditions Associated With Cross-Shelf High Chlorophyll Plumes In The Northern Gulf Of Mexico, Erin Brooke Jones

Dissertations

The northern Gulf of Mexico is a complex marine system subject to episodic physical phenomena such as loop current eddies. Flow fields generated by these eddies can result in cross-shelf exchanges between riverine influenced shelf waters and the offshore water column. This study considers the impacts of high chlorophyll plumes (HCPs) resulting from cross-shelf exchanges to the bio-optical properties of affected waters and how these plumes are influenced by their environment. The seasonal, interannual and decadal chlorophyll cycles of the Gulf of Mexico and the northern Gulf of Mexico are described to provide context for evaluating the ecological effects of …

Iron Supply And Demand In Antarctic Shelf Ecosystem, D. J. Mcgillicuddy Jr., Peter N. Sedwick, Michael S. Dinniman, K. R. Arrigo, T. S. Bibby, B. J. W. Greenan, Eileen E. Hofmann, John M. Klinck, W. O. Smith Jr., S. L. Mack, C. M. Marsay, B. M. Sohst, G. L. Van Dijken

OES Faculty Publications

The Ross Sea sustains a rich ecosystem and is the most productive sector of the Southern Ocean. Most of this production occurs within a polynya during the November-February period, when the availability of dissolved iron (dFe) is thought to exert the major control on phytoplankton growth. Here we combine new data on the distribution of dFe, high-resolution model simulations of ice melt and regional circulation, and satellite-based estimates of primary production to quantify iron supply and demand over the Ross Sea continental shelf. Our analysis suggests that the largest sources of dFe to the euphotic zone are wintertime mixing and …

Benthic And Planktonic Microalgal Community Structure And Primary Productivity In Lower Chesapeake Bay, Matthew Reginald Semcheski

Biological Sciences Theses & Dissertations

Microalgal populations are trophically important to a variety of micro- and macroheterotrophs in marine and estuarine systems. In Chesapeake Bay, microalgae facilitate the survival and development of ecologically and economically relevant fauna, including shellfish and finfish populations. While regarded as significant components of coastal environments, microphytobenthic communities are historically understudied. In Chesapeake Bay, the importance of phytoplankton to the ecosystem is understood, but the contribution of microphytobenthos remains unclear. This project surveys intertidal microphytobenthic communities, in relation to phytoplankton communities, around lower Chesapeake Bay describing the taxonomic makeup of these populations, coupled with quantification of cell abundance, biomass, and primary …

Phytoplankton In Virginia Lakes And Reservoirs: Part Ii, Harold G. Marshall

Virginia Journal of Science

Phytoplankton composition from 16 Virginia lakes and reservoirs are discussed with emphasis on the dominant taxa, algal bloom producers, and potentially harmful species at these locations. This is a companion study to the more comprehensive publication regarding Virginia freshwater phytoplankton by Marshall (2013).

Sequence Diversity Of Ammonium Transporter Genes In Cultured And Natural Species Of Marine Phytoplankton, Lee-Kuo Kang, Jeng Chang

Journal of Marine Science and Technology–Taiwan

The sequence database of ammonium transporter (Amt1) genes in eukaryotic phytoplankton was expanded by obtaining new sequences from cultured strains and natural populations collected in the East China Sea (ECS). From unialgal cultures, 6 new Amt1 sequences belonging to the Bacillariophyceae, Dinophyceae, and Prasinophyceae were obtained. A phylogenetic analysis revealed that AMT1s of higher plants were most closely related to those in green algae. In addition, haptophyte and diatom AMT1s formed distinct monophyletic clades. Diatom AMT1s were further divided into 3 orthologous subclasses, and active gene duplications were observed in subclass III. As for mixed-species sequencing using ECS samples, 78 …

Phytoplankton And Nutrient Dynamics In A Tidally Dominated Eutrophic Estuary: Daily Variability And Controls On Bloom Formation, Ryan E. Morse, Margaret R. Mulholland, Todd A. Egerton, Harold G. Marshall

OES Faculty Publications

To better understand nutrient dynamics and factors that promote the initiation of algal blooms, the Lafayette River, a tidal subestuary of Chesapeake Bay that experiences seasonal algal blooms, was sampled daily for a period of 54 d in the fall of 2005. Three phytoplankton blooms (chl a concentrations exceeding twice the average of monthly measurements from 2000 to 2009) occurred during this period: a mixed bloom of Akashiwo sanguinea and Gymnodinium sp., a monospecific Skeletonema costatum bloom, and a monospecific Gymnodinium sp. bloom. Over the sampling period, nutrient concentrations increased following precipitation events and were elevated between bloom periods but …

Springtime Contribution Of Dinitrogen Fixation To Primary Production Across The Mediterranean Sea, E. Rahav, B. Herut, A. Levi, Margaret Mulholland, I. Berman-Frank

OES Faculty Publications

Dinitrogen (N-2) fixation rates were measured during early spring across the different provinces of Mediterranean Sea surface waters. N-2 fixation rates, measured using N-15(2) enriched seawater, were lowest in the eastern basin and increased westward with a maximum at the Strait of Gibraltar (0.10 to 2.35 nmol NL-1 d(-1), respectively). These rates were 3-7 fold higher than N-2 fixation rates measured previously in the Mediterranean Sea during summertime and we estimated that methodological differences alone did not account for the seasonal changes we observed. Higher contribution of N-2 fixation to primary production (4-8 %) was measured in the western basin …

The Effect Of Ph On The Metal Binding Capabilities Of Exopolymeric Substances From A Marine Benthic Diatom, Vanessa O'Donnell

All Theses And Dissertations

The marine sediment-water interface is a dynamic microenvironment containing diatoms, which produce exopolymeric substance (EPS). EPS has various functions for individual cells and for marine ecosystems. EPS substance is a species-specific composition that has strong absorptive qualities and is able to bind metals from even a very dilute aqueous solution. As industrially derived metals tend to accumulate in marine mudflats, where diatoms are the major EPS producing organisms, it is important to determine how marine benthic diatom EPS will bind with metals. To address the metal binding properties of diatom EPS, Cylindrotheca closteriums’ EPS was isolated by tangential flow filtration, …

Phytoplankton In Virginia Lakes And Reservoirs, Harold G. Marshall

Virginia Journal of Science

This study involves a phytoplankton summer/autumn survey in 46 Virginia lakes and reservoirs during 2010-2012. A total of 307 taxa were identified which included several filamentous and colonial cyanabacteria in bloom concentrations. With the exception of one natural lake, the other sites sampled represent impoundments created decades ago, with the majority presently classified as meso- or eutrophic. Among the cyanobacteria were 6 known toxin producers (Anabaena circinalis, Anabaena spiroides, Aphanizomenon flos-aquae, Cylindrospermopsis raciborskii, Limnothrix redekei, and Microcystis aeruginosa). The study characterizes phytoplankton populations in these aging freshwater habitats taken from a large number …

Phosphorus Cycling In The Sargasso Sea: Investigation Using The Oxygen Isotopic Composition Of Phosphate, Enzyme-Labeled Fluorescence, And Turnover Times, Karen Mclaughlin, Jill A. Sohm, Gregory A. Cutter, Michael W. Lomas, Adina Paytan

OES Faculty Publications

Dissolved inorganic phosphorus (DIP) concentrations in surface water of vast areas of the ocean are extremely low (<10 nM) and phosphorus (P) availability could limit primary productivity in these regions. We explore the use of oxygen isotopic signature of dissolved phosphate (δ¹⁸O_PO4) to investigate biogeochemical cycling of P in the Sargasso Sea, Atlantic Ocean. Additional techniques for studying P dynamics including ³³P-based DIP turnover time estimates and percent of cells expressing alkaline phosphatase (AP) activity as measured by enzyme-labeling fluorescence are also used. In surface waters, δ¹⁸O_PO4 values were lower than equilibrium by 3–6%, indicative of dissolved organic phosphorous (DOP) remineralization by extracellular enzymes. An isotope mass balance model using a variety of possible combinations of …

Diatom Proteomics Reveals Unique Acclimation Strategies To Mitigate Fe Limitation, Brook L. Nunn, Jessica F. Faux, Anna A. Hippman, Maria T. Maldonado, H. Rodger Harvey, David R. Goodlett, Philip W. Boyd, Robert F. Strzepek

OES Faculty Publications

Phytoplankton growth rates are limited by the supply of iron (Fe) in approximately one third of the open ocean, with major implications for carbon dioxide sequestration and carbon (C) biogeochemistry. To date, understanding how alteration of Fe supply changes phytoplankton physiology has focused on traditional metrics such as growth rate, elemental composition, and biophysical measurements such as photosynthetic competence (Fv/Fm). Researchers have subsequently employed transcriptomics to probe relationships between changes in Fe supply and phytoplankton physiology. Recently, studies have investigated longer-term (i.e. following acclimation) responses of phytoplankton to various Fe conditions. In the present study, the coastal diatom, Thalassiosira pseudonana, …

Seasonal Dynamics Of Mesodinium Rubrum In Chesapeake Bay, Matthew D. Johnson, Doane K. Stoecker, Harold G. Marshall

Biological Sciences Faculty Publications

The photosynthetic ciliate Mesodinium rubrum is a common member of coastal phytoplankton communities that is well adapted to low-light, turbid ecosystems. It supports the growth of, or competes with, harmful dinoflagellate species for cryptophyte prey, as well as being a trophic link to copepods and larval fish. We have compiled data from various sources (n = 1063), on the abundance and distribution of M. rubrum in Chesapeake Bay and its tributaries. Because M. rubrum relies on obtaining organelles from cryptophyte algae to maintain rapid growth, we also enumerated cryptophyte algae in the portion of these samples that we collected …

A Preliminary Examination Of An In Situ Dual Dye Approach To Measuring Light Fluxes In Lotic Systems, Elizabeth C. Minor, Elizabeth James, Jay A. Austin, Veronica Nelson, Ryan Lusk, Kenneth Mopper

Chemistry & Biochemistry Faculty Publications

Light is a critical parameter in aquatic ecosystems, affecting primary production and in situ photochemistry. However, measuring light exposure for suspended particles or dissolved components in a dynamic water column can be challenging with existing Eulerian approaches. Here, we assess the simultaneous deployment of two dyes differing in photolability (rhodamine WT and fluorescein) as a Lagrangian measure of sunlight exposure in a lotic system. Fluorescein is sensitive to light exposure; rhodamine WT is relatively photostable. We examined dye fluorescence at various pH, salinity, and temperature conditions. We also tested dye photolability as a function of pH and wavelength range. In …

Phytoplankton Abundance And Species Composition In Relation To Environmental Paramenters In Coastal Mississippi Waters, Luz Karime Molina

Master's Theses

Phytoplankton pigments from Coastal Mississippi waters were measured to determine the spatial and temporal distributions and composition of phytoplankton communities. Concentration of phytoplankton pigments were analyzed using High Performance Liquid Chromatography (HPLC) and the compositional changes in phytoplankton communities were determined with CHEMTAX 1.95. Surface water was collected for two years (September 2007-November 2009) at three sampling sites on a monthly basis. The stations were located at the Bay of St. Louis (station 1), the Mississippi Sound (station 4) and the Mississippi Bight (station 8), following a salinity gradient. A time series of the observations documented the variability of different …

Microzooplankton Grazing And Productivity In The Central And Southern Sector Of The Indian River Lagoon, Florida, Jennifer Putland, Tracey Sutton

Marine & Environmental Sciences Faculty Articles

Microzooplankton grazing was measured with the dilution method in the central and southern sectors of the Indian River Lagoon during summer 2006 and 2007. Microzooplankton actively grazed phytoplankton during all experiments. Grazing rates averaged (± SD) 0.956 ± 0.19 d^-1 and ranged from 0.54 to 1.36 d^-1. Phytoplankton carbon, measured by microscopy, averaged 314 ± 251 μg C L^-1 and ranged from 115 to 936 μg C L^-1. Microzooplankton ingestion rates averaged 303 ± 260 μg C L^-1d^-1 and ranged from 90 to 907 μg C L^-1d^-1. …

Phytoplankton Blooms: Their Occurence And Composition Within Virginia's Tidal Tributaries, Harold G. Marshall, Todd A. Egerton

Biological Sciences Faculty Publications

Sporadic algal bloom development within a 10 year monitoring program in Virginia tidal tributaries of Chesapeake Bay is reviewed. These blooms were common events, characteristically producing a color signature to the surface water, typically short lived, occurring mainly from spring into autumn throughout different salinity regions of these rivers, and were produced primarily by dinoflagellates. The abundance threshold levels that would identify bloom status from a non-bloom presence were species specific, varied with the taxon's cell size, and ranged from ca. 10 to 10(4) cells mL(-1). Among the most consistent sporadic bloom producers were the dinoflagellates Akashiwo sanguinea, Cochlodinium …

Dinoflagellate Cysts Within Sediment Collections From The Southern Chesapeake Bay, And Tidal Regions Of The James, York, And Rappahannock Rivers, Virginia, David W. Seaborn, Harold G. Marshall

Virginia Journal of Science

The upper 2 cm of sediment core samples from 70 stations in the tidal waters of three Virginia rivers and at 23 stations in the lower Chesapeake Bay were sampled for dinoflagellate cysts. The river sediment cysts were dominated by three common bloom producing species (Heterocapsa triquetra, Scrippsiella trochoidea, and Cochlodinium polykrikoides), whereas these were in low concentration on the Chesapeake Bay sediments which contained mainly dinoflagellate cysts of neritic and oceanic taxa. The mean sediment concentrations from stations in the James, York, and Rappahannock rivers were respectively 1174.8, 536.2, and 323.6 cysts g^-1. The mean …

Co2 Sensitivity Of Southern Ocean Phytoplankton, Philippe D. Tortell, Christopher D. Payne, Yingyu Li, Scarlett Trimborn, Bjorn Rost, Walker O. Smith, Christina Riesselman, Robert B. Dunbar, Peter Sedwick, Giacomo R. Ditullio

OES Faculty Publications

The Southern Ocean exerts a strong impact on marine biogeochemical cycles and global air-sea CO₂ fluxes. Over the coming century, large increases in surface ocean CO₂ levels, combined with increased upper water column temps. and stratification, are expected to diminish Southern Ocean CO₂ uptake. These effects could be significantly modulated by concomitant CO₂-dependent changes in the region's biol. carbon pump. Here we show that CO₂ concentrations affect the physiology, growth and species composition. of phytoplankton assemblages in the Ross Sea, Antarctica. Field results from in situ sampling and ship-board incubation experiments demonstrate that inorganic …