Marine Biology Commons^™

Aerobic Degradation Of Α-, Β-, Γ-Hexachlorocyclohexane By Narragansett Bay Bacterioplankton, Ian M. Rambo

Senior Honors Projects

Hexachlorocyclohexanes (HCHs) are a family of chlorinated organic compounds that were previously used as agricultural insecticides. HCHs are recognized as persistent organic pollutants due to their toxicity, recalcitrant properties, and tendency to bioaccumulate in food webs. Although HCH was first synthesized in 1825, its use was not widespread until the discovery of the insecticidal activity of the γ-HCH isomer in 1942. γ-HCH and its toxic waste isomers α-HCH and β-HCH were banned from production and use by the United Nations in 2009, yet these chemicals still present environmental problems due to their persistence in soils and surface waters. HCHs continue …

The Perfect Fit

Colby Magazine

From the classrooms and laboratories of Mayflower Hill, they found their niche in science. Microbiologist Carrie Harwood ’73, transplant surgeon Patrick Wood ’75, and marine biologist Paul Wade ’80 have passion for their professions.

Combined Effects Of Co2 And Light On Large And Small Isolates Of The Unicellular N2-Fixing Cyanobacterium Crocosphaera Watsonii From The Western Tropical Atlantic Ocean, Nathan S. Garcia, Fei-Xue Fu, Cynthia L. Breene, Elizabeth K. Yu, Peter W. Bernhardt, Margaret R. Mulholland, David A. Hutchins

OES Faculty Publications

We examined the combined effects of light and pCO₂ on growth, CO₂-fixation and N₂-fixation rates by strains of the unicellular marine N₂-fixing cyanobacterium Crocosphaera watsonii with small (WH0401) and large (WH0402) cells that were isolated from the western tropical Atlantic Ocean. In low-pCO₂-acclimated cultures (190ppm) of WH0401, growth, CO₂-fixation and N₂-fixation rates were significantly lower than those in cultures acclimated to higher (present-day approximate to 385ppm, or future approximate to 750ppm) pCO² treatments. Growth rates were not significantly different, however, in low-pCO₂-acclimated cultures of …

Effects Of The Parasitic Dinoflagellate Hematodinium Sp. On Blue Crab (Callinectes Sapidus) Activity Predation And Habitat Selection, John M. Tiggelaar Ii

Biological Sciences Theses & Dissertations

The blue crab Callinectes sapidus occurs along the Atlantic and Gulf coasts of the United States, and in high salinity regions, they are subject to lethal infection by the parasitic dinoflagellate Hematodinium. In Virginia's seaside estuaries, the prevalence of Hematodinium infection of C. sapidus can sometimes exceed 50%, threatening the commercial fishery for this species. Indeed, other commercially important crustacean fisheries have approached collapse due to Hematodinium infections. Most studies of this host-parasite interaction have focused on epidemiology, host-pathogen dynamics, and pathogen transmission, and little is known about the impact of the parasite on host behavior and population dynamics. …

Multi-Partner Interactions In Corals In The Face Of Climate Change, Koty H. Sharp, Kim B. Ritchie

Arts & Sciences Faculty Publications

Recent research has explored the possibility that increased sea-surface temperatures and decreasing pH (ocean acidification) contribute to the ongoing decline of coral reef ecosystems. Within corals, a diverse microbiome exerts significant influence on biogeochemical and ecological processes, including food webs, organismal life cycles, and chemical and nutrient cycling. Microbes on coral reefs play a critical role in regulating larval recruitment, bacterial colonization, and pathogen abundance under ambient conditions, ultimately governing the overall resilience of coral reef systems. As a result, microbial processes may be involved in reef ecosystem-level responses to climate change. Developments of new molecular technologies, in addition to …

Diversity And Dynamics Of Bacterial Communities In Early Life Stages Of The Caribbean Coral Porites Astreoides, Koty H. Sharp, Dan Distel, Valerie J. Paul

Arts & Sciences Faculty Publications

In this study, we examine microbial communities of early developmental stages of the coral Porites astreoides by sequence analysis of cloned 16S rRNA genes, terminal restriction fragment length polymorphism (TRFLP), and fluorescence in situ hybridization (FISH) imaging. Bacteria are associated with the ectoderm layer in newly released planula larvae, in 4-day-old planulae, and on the newly forming mesenteries surrounding developing septa in juvenile polyps after settlement. Roseobacter clade-associated (RCA) bacteria and Marinobacter sp. are consistently detected in specimens of P. astreoides spanning three early developmental stages, two locations in the Caribbean and 3 years of collection. Multi-response permutation procedures analysis …

Human Pathogen Shown To Cause Disease In The Threatened Elkhorn Coral Acropora Palmata, Kathryn Patterson Sutherland, Sameera Shaban, Jessica L. Joyner, James W. Porter, Erin K. Lipp

Faculty Publications

Coral reefs are in severe decline. Infections by the human pathogen Serratia marcescens have contributed to precipitous losses in the common Caribbean elkhorn coral, Acropora palmata, culminating in its listing under the United States Endangered Species Act. During a 2003 outbreak of this coral disease, called acroporid serratiosis (APS), a unique strain of the pathogen, Serratia marcescens strain PDR60, was identified from diseased A. palmata, human wastewater, the non-host coral Siderastrea siderea and the corallivorous snail Coralliophila abbreviata. In order to examine humans as a source and other marine invertebrates as vectors and/or reservoirs of the APS pathogen, challenge experiments …

Abundance Of Eukaryotic Microbes In The Deep Subtropical North Atlantic, Danielle Morgan-Smith, Gerhard J. Herndl, Hendrik M. Van Aken, Alexander B. Bochdansky

OES Faculty Publications

The meso- and bathypelagic ocean comprises the largest habitat on earth, yet we know very little about the distribution and activity of protists in this environment. These small eukaryotes are responsible for controlling bacterial abundance in the surface ocean and are major players in the material and energy transfer of pelagic food webs. In this paper, we quantify microbial eukaryotes in the deep North Atlantic, as well as provide a basic characterization of eukaryote community changes through the water column. To this end, we counted organisms using 2 different approaches: (1) catalyzed reporter deposition fluorescence in situ hybridization (CARD-FISH, also …

Characterization Of Putative Iron Responsive Genes As Species-Specific Indicators Of Iron Stress In Thalassiosiroid Diatoms, Leann P. Whitney, Jeremy J. Lins, Margaret P. Hughes, Mark L. Wells, P. Dreux Chappell

OES Faculty Publications

Iron (Fe) availability restricts diatom growth and primary production in large areas of the oceans. It is a challenge to assess the bulk Fe nutritional health of natural diatom populations, since species can differ in their physiological and molecular responses to Fe limitation. We assayed expression of selected genes in diatoms from the Thalassiosira genus to assess their potential utility as species-specific molecular markers to indicate Fe status in natural diatom assemblages. In this study, we compared the expression of the photosynthetic genes encoding ferredoxin (a Fe-requiring protein) and flavodoxin (a Fe-free protein) in culture experiments with Fe replete and …

Estuarine Nitrifiers: New Players, Patterns And Processes, Anne E. Bernhard, Annette Bollmann

Biology Faculty Publications

Ever since the first descriptions of ammonia-oxidizing Bacteria by Winogradsky in the late 1800s, the metabolic capability of aerobic ammonia oxidation has been restricted to a phylogenetically narrow group of bacteria. However, the recent discovery of ammonia-oxidizing Archaea has forced microbiologists and ecologists to re-evaluate long-held paradigms and the role of niche partitioning between bacterial and archaeal ammonia oxidizers. Much of the current research has been conducted in open ocean or terrestrial systems, where community patterns of archaeal and bacterial ammonia oxidizers are highly congruent. Studies of archaeal and bacterial ammonia oxidizers in estuarine systems, however, present a very different …

Bacterial Acquisition In Juveniles Of Several Broadcast Spawning Coral Species, Koty H. Sharp, Kim B. Ritchie

Arts & Sciences Faculty Publications

Coral animals harbor diverse microorganisms in their tissues, including archaea, bacteria, viruses, and zooxanthellae. The extent to which coral-bacterial associations are specific and the mechanisms for their maintenance across generations in the environment are unknown. The high diversity of bacteria in adult coral colonies has made it challenging to identify species-specific patterns. Localization of bacteria in gametes and larvae of corals presents an opportunity for determining when bacterial-coral associations are initiated and whether they are dynamic throughout early development. This study focuses on the early onset of bacterial associations in the mass spawning corals Montastraea annularis, M. franksi, M. faveolata, …

Antimicrobial Potential Of Selected Actinomycetes Isolated From The Marine Ecosystem., Nur Rahimatul Hayati Abdul Rahman

Student Works (2010-2019)

Actinomycetes are widespread in marine ecosystem. They are of interest in research field as they are capable to produce bioactive secondary metabolites which can be developed into useful pharmaceutical products. An example of the product is antibiotics which can be used to treat infectious diseases. The potential of antibacterial and antifungal activity of eleven marine derived actinomycetes from the genus Streptomyces were studied. They were tested against bacteria Enterobacter faecalis, Staphylococcus aureus, Bacillus subtilis, Pleisiomonas shigelloides and Pseudomonas aeruginosa and fungi Candida parapsilosis and Candida albicans. Primary screening by the cross streak method and secondary screening by diffusion using paper …

Bryostatins: Biological Context And Biotechnological Prospects, Amaro E. Trindade-Silva, Grace E. Lim-Fong, Koty H. Sharp

Arts & Sciences Faculty Publications

Coral animals harbor diverse microorganisms in their tissues, including archaea, bacteria, viruses, and Bryostatins are a family of protein kinase C modulators that have potential applications in biomedicine. Found in miniscule quantities in a small marine invertebrate, lack of supply has hampered their development. In recent years, bryostatins have been shown to have potent bioactivity in the central nervous system, an uncultivated marine bacterial symbiont has been shown to be the likely natural source of the bryostatins, the bryostatin biosynthetic genes have been identified and characterized, and bryostatin analogues with promising biological activity have been developed and tested. Challenges in …

Phocine Distemper Virus Induced Demyelination In The Spinal Cord Of Infected Harbor Seals (Phoca Vitulina), Thomas Siemens

All Theses And Dissertations

Phocine Distemper Virus (PDV) is a Morbillivirus that has been responsible for the death of approximately 40,000 phocid seals in the last three decades. The most commonly reported pathology is virally induced demyelination of the cerebrum and brainstem which leaves axons bare and limits their conductivity of action potentials. While these conditions have been studied at length, there is little mention of spinal cord involvement. This study aims to determine whether demyelination found in the brainstem continues into the cervical spinal cord. The results indicate that demyelination in the cervical spinal cord does not occur alongside the brainstem. It is …

Interactions Between Changing Pco2, N2 Fixation, And Fe Limitation In The Marine Unicellular Cyanobacterium Crocosphaera, Fei-Xue Fu, Margaret R. Mulholland, Nathan S. Garcia, Aaron Beck, Mark E. Warner, Sergio A. Sañudo, David A. Hutchins

OES Faculty Publications

We examined the physiological responses of steady-state iron (Fe)-replete and Fe-limited cultures of the biogeochemically critical marine unicellular diazotrophic cyanobacterium Crocosphaera at glacial (19 Pa; 190 ppm), current (39 Pa; 380 ppm), and projected year 2100 (76 Pa; 750 ppm) CO₂ levels. Rates of N₂ and CO₂ fixation and growth increased in step with increasing partial pressure of CO₂ (pCO₂), but only under Fe- replete conditions. N₂) and carbon fixation rates at 75 Pa CO₂ were 1.4-1.8-fold and 1.2-2.0-fold higher, respectively, relative to those at present day and glacial pCO_{2 …}

Ship Ballast Tanks: How Microbes Travel The World, Fred C. Dobbs

OES Faculty Publications

As the international shipping fleet travels the oceans, it carries with it hidden cargoes of microbes. Fred C. Dobbs explores the hazards posed and what can be done to counteract them.

Chemical Defenses: From Compounds To Communities, Valerie J. Paul, Koty H. Sharp

Arts & Sciences Faculty Publications

Marine natural products play critical roles in the chemical defense of many marine organisms and in some cases can influence the community structure of entire ecosystems. Although many marine natural products have been studied for biomedical activity, yielding important information about their biochemical effects and mechanisms of action, much less is known about ecological functions. The way in which marine consumers perceive chemical defenses can influence their health and survival and determine whether some natural products persist through a food chain. This article focuses on selected marine natural products, including okadaic acid, brevetoxins, lyngbyatoxin A, caulerpenyne, bryostatins, and isocyano terpenes, …

Fisheries Research Contract Report No. 15 - Aquatic Animal Health Subprogram: Pilchard Herpesvirus Infection In Wild Pilchards (Frdc Project No. 2002/044) Final Report, Brian Jones, Melanie Crockford, Richard Whittington, Mark Crane, Graham Wilcox

Fisheries Research Contract Reports

In 1995 and again in 1998/9, millions of pilchards (Sardinops sagax neopilchardus) were found dead or dying off the coast of Australia. Some pilchards in New Zealand were also affected during the 1995 epizootic. The epizootics moved progressively in a "bushfire-like" manner against the prevailing currents at a rapid speed. An uncharacterised herpesvirus, pilchard herpesvirus (PHV), was associated with both mortality events and, based on its occurrence in affected fish and the disease pathogenesis, generally accepted as the causative agent, although experimental evidence of its role was not established. Until recently, rapid and sensitive methods to detect PHV were not …

Densities Of Fecal Indicator Bacteria In Tidal Waters Of The Ballona Wetlands, Los Angeles County, California, John H. Dorsey

Center for Urban Resilience Scholarship

Densities of fecal indicator bacteria (FIB) represented by total coliforms, E. coli and enterococci were measured within tidal channels of the Ballona Wetlands (Los Angeles County) to see if the wetlands act as a sink or source for these bacteria and to measure increases in FIB densities during wet weather. Samples were collected on 10 days over a 1-yr period beginning February 2003 at four sites within the wetlands and one site in Ballona Creek opposite the west tide gate. Incoming flood and outgoing ebb tides were sampled during each sampling event at each station. Water from Ballona Creek may …

Myxozoan Genera: Definition And Notes On Taxonomy, Life-Cycle Terminology And Pathogenic Species, Jiří Lom, Iva Dyková

Harold W. Manter Laboratory of Parasitology: Library Materials

A list of myxozoan genera is presented in the current taxonomical scheme. These genera are defined; their type species and most important pathogens along with their hosts are listed. Simultaneously, definitions of actinospore stages representing sexual stages of the myxosporean life cycle are given; altogether, 17 actinospore collective groups with 180 types have been described. Life cycles of the two classes of the phylum Myxozoa, Malacosporea and Myxosporea, are briefly outlined with specification of the appropriate terms. Up to now, 4 malacosporean and 2,180 myxosporean species assigned to a total of 62 genera, have been established. The surviving classification of …

Fisheries Research Contract Report No. 9 - Enhancing The Emergency Disease Response Capability Of The Western Australian Department Of Fisheries And Industry Bodies Associated With Freshwater Crayfish. Aquatic Animal Health Subprogram: Frdc Project No. 2003/671, Frances Stephens, Brian Jones, Iain East, Karina Scott, Simon Bennison

Fisheries Research Contract Reports

CRAYFISH PLAGUE IS A MAJOR DISEASE AFFECTING FRESHWATER CRAYFISH IN SOME AREAS OF THE WORLD. THE DISEASE HAS NEVER BEEN REPORTED IN AUSTRALIA. THE SIMULATION EXERCISE THAT WAS UNDERTAKEN AS PART OF THIS PROJECT WAS A RESPONSE TO A FICTITIOUS OUTBREAK OF CRAYFISH PLAGUE.

Funding for this project was provided to enable an exercise simulating an outbreak of crayfish plague to be conducted in Western Australia. Crayfish plague is a fungal disease (Aphanomyces astaci) that has devastated some freshwater crayfish populations in Europe but has never been recorded in Australia. The exercise was planned arounda fictitious outbreak of crayfish plague …

Dinitrogen Fixation And Release Of Ammonium And Dissolved Organic Nitrogen By Trichodesmium Ims101, Margaret R. Mulholland, Deborah A. Bronk, Douglas G. Capone

OES Faculty Publications

Two methods used to measure dinitrogen (N₂) fixation (acetylene reduction and ¹⁵N₂ uptake) often result in different N₂ fixation rates. Part of the discrepancy may arise from the observation that Trichodesmium can release a fraction of their recently fixed N₂ as dissolved organic nitrogen (DON) and/or ammonium (NH4 ⁺). To resolve outstanding issues regarding N₂ fixation and the production of dissolved combined nitrogen (N) by Trichodesmium, we conducted a comprehensive analysis of N₂ fixation and the production of DON and NH₄⁺ in cultures of Trichodesmium IMS101. We performed …

Endocrine-Disrupting Effects Of Cattle Feedlot Effluent On An Aquatic Sentinel Species, The Fathead Minnow, Edward Orlando, Alan Kolok, Gerry Binzcick, Jennifer Gates, Megan Horton, Christy Lambright, L. Earl Gray Jr., Ana M. Soto, Louis J. Guilette

Biology Faculty Publications

Over the last decade, research has examined the endocrine-disrupting action of various environmental pollutants, including hormones, pharmaceuticals, and surfactants, in sewage treatment plant effluent. Responding to the growth of concentrated animal feeding operations (CAFOs) and the pollutants present in their wastewater (e.g., nutrients, pharmaceuticals, and hormones), the U.S. Environmental Protection Agency developed a new rule that tightens the regulation of CAFOs. In this study, we collected wild fathead minnows (Pimephales promelas) exposed to feedlot effluent (FLE) and observed significant alterations in their reproductive biology. Male fish were demasculinized (having lower testicular testosterone synthesis, altered head morphometrics, and smaller …

The Role Of Physical, Chemical, And Microbial Heterogeneity On The Field-Scale Transport And Attachment Of Bacteria, Brian J. Mailloux, Mark E. Fuller, Tullis C. Onstott, James Hall, Hailiang Dong, Mary F. Deflaun, Sheryl H. Streger, Randi K. Rothmel, Maria Green, Donald J. P. Swift, Jon Radke

OES Faculty Publications

A field-scale bacterial transport experiment was conducted at the Narrow Channel Focus Area of the South Oyster field site located in Oyster, Virginia. The goal of the field experiment was to determine the relative influence of subsurface heterogeneity and microbial population parameters on flow direction, velocity, and attachment of bacteria at the field scale. The field results were compared with results from laboratory-scale column experiments to develop a method for predicting field-scale bacterial transport. The field site is a shallow, sandy, unconfined, aerobic aquifer that has been characterized by geophysical, sedimentological, and hydrogeological methods. Comamonas sp. strain DA001 and a …

Enrichments And Isolations Of Mesophilic And Thermophilic Iron-Reducing Microbes From Deep-Sea Hydrothermal Vents And The Deep Subsurface, Melissa Mary Kendall

Dissertations and Theses

Microbes inhabiting the deep subsurface play an important role in geochemical processes and may be of practical value in bioremediation and biotechnology. Hydrothermal vents and the deep gold mines of South Africa have be likened to "windows" into the subsurface biosphere. The aim of this research was to isolate and characterize microbes involved in iron-cycling from deep-sea hydrothermal vents and from the deep gold mines of the Witwatersrand Basin. Three mesophilic bacteria, strains BB4, W3, and A6 were isolated from sulfide chimneys at 13°N and a thermophilic bacterium, strain GB21 was isolated from Guaymas Basin on the East Pacific Rise. …

Nitric Oxide And Cnidarian-Dinoflagellate Symbioses: Pieces Of A Puzzle, Henry G. Trapido-Rosenthal, Katherine H. Sharp

Arts & Sciences Faculty Publications

The presence of nitric oxide synthase (NOS) activity is demonstrated in the tropical marine cnidarian Aiptasia pallida and in its symbiotic dinoflagellate algae, Symbiodinium bermudense. Enzyme activity was assayed by measuring the conversion of arginine to citrulline. Biochemical characterization of NOS from Aiptasia was characterized with respect to cellular localization, substrate and cofactor requirements, inhibitors, and kinetics. In response to acute temperature shock, anemones retracted their tentacles. Animals subjected to such stress had lower NOS activities than did controls. Treatment with NOS inhibitors caused tentacular retraction, while treatment with the NOS substrate L-arginine inhibited this response to stress, as did …

Bioavailability And Trophic Transfer Of Humic-Bound Copper From Bacteria To Zooplankton, Emile M. Lores, Jonathan Pennock

School of Marine Science and Ocean Engineering

ABSTRACT:

The effect of humic acid (HA) on uptake and transfer of Cu by selected marine organisms from the microbial loop was determined. Bacteria grown with and without 15 µg Cu l^-1 and with and without 10 mg Suwannee River Humic Acid (SRHA) l^-1 were fed to Uronema sp. The Uronema were subsequently fed to Acartia tonsa to determine the effect of humic acid on the uptake and transfer of Cu from bacteria to copepods. The presence of 10 mg SRHA l^-1 reduced Cu uptake in A. tonsa by an average of 54% and significantly reduced the …

Vertical Profiles Of Virus-Like Particles And Bacteria In The Water Column And Sediments Of Chesapeake Bay, Usa, Lisa A. Drake, Keun-Hyung Choi, A. G. Edward Haskell, Fred C. Dobbs

OES Faculty Publications

Vertical profiles of virus-like particles (VLPs) and bacteria were determined by near-synoptic sampling through the water column and 15 to 25 cm into the sediment at 5 stations across the mouth of Chesapeake Bay, USA. VLPs were about 10 times more abundant in the pore water (grand mean = 3.6 x 10(8) VLPs ml(-1)) than in the water column (grand mean = 3.8 x 10(7) VLPs ml(-1)). Similarly, bacteria counts were about 3 times higher in the pore water (grand mean = 6.5 x 10(6) bacteria ml(-1)) than in the water column (grand mean = 2.4 x 10(6) bacteria ml(-1)). …

Thermophilic Bacterial Activity In A Deep-Sea Sediment From The Pacific Ocean, Fred C. Dobbs, Karen A. Selph

OES Faculty Publications

Thermophilic bacterial activity was detected in a deep-sea sediment sample from the South Pacific Ocean at 12 degrees S, 135 degrees W, an area of the seafloor distant from known hydrothermal venting. Incubation of sediments amended with C-14-glutamate indicated maximal respiration (evolution of (CO2)-C-14) and assimilation (incorporation of C-14 into acid-precipitated macromolecules) of substrate at 52 degrees C, relative to 4 and 22 degrees C. A parallel experiment at another site (2 degrees S, 140 degrees W) yielded no evidence of thermophily. Thermophilic bacteria may be deposited in deep-sea sediments following their long-distance dispersal from hydrothermal vents (e.g. the East …

Cascading Disturbances In Florida Bay, Usa: Cyanobacteria Blooms, Sponge Mortality, And Implications For Juvenile Spiny Lobsters Panulirus Argus, Mark J. Butler Iv, John H. Hunt, William F. Herrnkind, Michael J. Childress, Rodney Bertelsen, William Sharp, Thomas Matthews, Jennifer M. Field, Harold G. Marshall

Biological Sciences Faculty Publications

Florida Bay, the shallow lagoon separating mainland Florida and the Florida Keys, USA, is experiencing an unprecedented series of ecological disturbances. In 1991, following reports of other ecosystem perturbations, we observed widespread and persistent blooms of cyanobacteria that coincided with the decimation of sponge communities over hundreds of square kilometers. Juvenile Caribbean spiny lobsters Panulirus argus, among other animals, rely on sponges for shelter; the impact of sponge loss on the abundance of lobsters and their use of shelter, in particular, has been dramatic. The loss of sponges on 27 experimental sites in hard bottom habitat in central Florida Bay …