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Full-Text Articles in Life Sciences

Analyzing Spatial Patterns In Reefscape Ecology Via Remote Sensing, Benthic Habitat Mapping, And Morphometrics, Shanna K. Dunn Dec 2009

Analyzing Spatial Patterns In Reefscape Ecology Via Remote Sensing, Benthic Habitat Mapping, And Morphometrics, Shanna K. Dunn

HCNSO Student Theses and Dissertations

A growing number of scientists are investigating applications of landscape ecology principles to marine studies, yet few coral reef scientists have examined spatial patterns across entire reefscapes with a holistic ecosystem-based view. This study was an effort to better understand reefscape ecology by quantitatively assessing spatial structures and habitat arrangements using remote sensing and geographic information systems (GIS).

Quantifying recurring patterns in reef systems has implications for improving the efficiency of mapping efforts and lowering costs associated with collecting field data and acquiring satellite imagery. If a representative example of a reef is mapped with high accuracy, the data derived …


Extraction And Analysis Of Coral Reef Core Samples From Broward County, Florida., Anastasios Stathakopoulos Dec 2009

Extraction And Analysis Of Coral Reef Core Samples From Broward County, Florida., Anastasios Stathakopoulos

HCNSO Student Theses and Dissertations

The reefs off Broward County exist as three shore-parallel, sequentially deeper terraces named the "inner", "middle", and "outer" reefs and also a shallower, nearshore ridge complex. These structures span the continental coast of southeast Florida from Palm Beach County to southern Miami-Dade County and were characterized as relict, early Holocene shelf-edge and mid-shelf reefs along with limestone ridges. Presently, the reefs are colonized by a fauna characteristic of West Atlantic/Caribbean reef systems. Scleractinian coral cover is low except for a few dense patches of Acropora cervicornis, while Acropora palmata is absent except for a few individual living colonies.

Coral …


Conservation Genetics And Systematics Of Several Turtles Species In The Southeastern United States, Joshua Robert Ennen Dec 2009

Conservation Genetics And Systematics Of Several Turtles Species In The Southeastern United States, Joshua Robert Ennen

Dissertations

Chelonians (i.e., turtles) are an imperiled group of reptiles with about 66% of the recognized species listed as threatened by the IUCN. Most chelonian species have a unique set of life history traits (i.e., longevity, delayed sexual maturity, and low juvenile survivorship), which makes their populations exceedingly sensitive to increases in adult and juvenile moralities. With numerous anthropogenic effects (e.g., habitat alteration, exploitation, and over harvesting) negatively influencing mortality rates, chelonians have experienced global precipitous declines and extinctions.

This dissertation focuses on species within two chelonian genera, Gopherus and Graptemys. Although these two genera are vastly different ecologically, they are …


Remote Sensing Of Harmful Algal Blooms In The Mississippi Sound And Mobile Bay: Modelling And Algorithm Formation, Dan Martin Holiday Dec 2009

Remote Sensing Of Harmful Algal Blooms In The Mississippi Sound And Mobile Bay: Modelling And Algorithm Formation, Dan Martin Holiday

Dissertations

The incidence and severity of harmful algal blooms have increased in recent decades, as have the economic effects of their occurrence./The diatom Pseudo-nitzschia spp. caused fisheries closures in Mobile Bay during 2005 due to elevated levels of domoic acid. In the previous 4 years Karenia brevis counts of >5,000 cells L"1 have occurred in Mobile Bay and the Mississippi Sound. Population levels of this magnitude had previously been recorded only in 1996. Increases in human populations, urban sprawl, development of shoreline properties, sewage effluent and resultant changes in NP ratios of discharge waters, and decline in forest and marsh lands, …


Experimental Population Dynamics Of Amyloodiniumocellatum In The Spotted Seatrout, Cynoscion Nebulosus, And The Red Snapper, Lutjanus Campechanus, Ignacio Masson Dec 2009

Experimental Population Dynamics Of Amyloodiniumocellatum In The Spotted Seatrout, Cynoscion Nebulosus, And The Red Snapper, Lutjanus Campechanus, Ignacio Masson

Dissertations

Amyloodinium ocellatum is a parasitic dinoflagellate that infects warm water marine bony fishes and causes high mortalities in aquaculture settings. It has three life history stages: the feeding trophont, the reproductive tomont, and the infective dinospore. This dissertation describes the characteristics of A. ocellatum infections in juvenile spotted seatrout, Cynoscion nebulosus, and red snapper, Lutjanus campechanus, studies the survival and fecundities of the stages in the life cycle of the parasite and presents a population model for A. ocellatum.

At 25°C and 33 ppt, the peak of trophont detachment occurred on day 2 postinfection in spotted seatrout and day 3 …


Diet Composition Of Swordfish, Xiphias Gladius, Within The Straits Of Florida, Amy Marie Heemsoth Nov 2009

Diet Composition Of Swordfish, Xiphias Gladius, Within The Straits Of Florida, Amy Marie Heemsoth

HCNSO Student Theses and Dissertations

A diet study of swordfish, Xiphias gladius, was conducted in the Straits of Florida from April 2007 to December 2008. The stomachs of 131 swordfish were analyzed. Thirteen species of teleosts, three species of cephalopods, and one species of crustacean were observed in the diet. Cephalopods dominated the swordfish diet by weight (73.38%), number (69.90%), and occurrence (80.91%) and ranked highest in importance in the diet when calculating the index of relative importance (IRI). Teleosts followed by weight (25.16%), number (26.34%), occurrence (68.18%), and IRI (3,510.97). The prey species with the greatest dietary importance was Illex sp followed by …


Segregation Of Palaemonid Shrimp Along The Shark River Estuary: Implications For Trophic Function, Lauren C. Mccarthy Aug 2009

Segregation Of Palaemonid Shrimp Along The Shark River Estuary: Implications For Trophic Function, Lauren C. Mccarthy

HCNSO Student Theses and Dissertations

This study examined the abundance, distribution, and spatiotemporal variation of palaemonid shrimp species in relation to season and salinity in the Shark River Estuary, Everglades National Park (ENP), Florida, USA. Five palaemonid species occurred in the samples: Palaemonetes paludosus, P. pugio, P. intermedius, Palaemon floridanus, and Leander paulensis; L. paulensis was collected only during the wet season. Overall, shrimp catches in traps doubled in the dry season. Catches in the upper estuary were dominated by P. paludosus, particularly in the wet season, while catch per unit effort (CPUE) at the most downstream, …


Bridging Functional Genomics And Toxicogenomics Through Dna Microarrays In A Fish Model, Shuzhao Li Aug 2009

Bridging Functional Genomics And Toxicogenomics Through Dna Microarrays In A Fish Model, Shuzhao Li

Dissertations

In a case study of finding gene expression signatures for environmental stressors in Cyprinodon variegatus, this dissertation examines several important issues of applying DNA microarray technology to fish toxicogenomics. The most relevant disciplines, fish toxicogenomics and computational systems biology are reviewed in Chapter 1. Chapter 2 reviews major aspects of DNA microarray technology.

On DNA microarrays, even for probes that target the same transcript, large variations are seen in the probe signals. These variations are partly dependent and partly independent on probe sequences. Chapter 3 estimates the sequence independent variation by combining experimental and computational approaches. Chapter 4 and …


Factors Influencing The Environmental Quality Of The Bay Of Saint Louis, Mississippi And Implications For Evolving Coastal Management Policies, Pradnya Ankush Sawant Aug 2009

Factors Influencing The Environmental Quality Of The Bay Of Saint Louis, Mississippi And Implications For Evolving Coastal Management Policies, Pradnya Ankush Sawant

Dissertations

The Bay of St. Louis, MS is a small northern Gulf of Mexico estuary that has been identified by the Mississippi Department of Environmental Quality (MDEQ) as an impaired waterbody for its designated uses, mainly due to the presence of pollutant pathogens. A systematic study of this estuary was important to understand the behavior and responses of the bay to several natural and anthropogenic forcing factors. A 14- month long study (bimonthly sampling) to evaluate its environmental quality was undertaken from April 2003 to May 2004. Environmental quality was defined as "the health of an ecosystem characterized in terms of …


Changing Fecundity And Reproductive Output In Females Of A Chesapeake Bay Population Of Blue Crab, Callinectes Sapidus, Shannon L. Wells Jul 2009

Changing Fecundity And Reproductive Output In Females Of A Chesapeake Bay Population Of Blue Crab, Callinectes Sapidus, Shannon L. Wells

OES Theses and Dissertations

The Chesapeake Bay blue crab, Callinectes sapidus, is an important species both ecologically and as a fishery. Fishery dependent and independent data indicate that the population declined abruptly in the mid-1990s and has remained low. Previous work prior to the decline in population abundance found a significant relationship between size and fecundity for mature females. As with many heavily fished populations, this population has experienced a reduction in the size at maturity. The objectives of this study were to reassess the fecundity of the population, determine the lipid and protein energy allocated for reproduction, and to examine the concentrations …


Effect Of The Herbivorous Channel Clinging Crab (Mithrax Spinosissimus) On Patch Reef Algal Communities In The Florida Keys, Florida (Usa), Angela M. Mojica Osorio Jul 2009

Effect Of The Herbivorous Channel Clinging Crab (Mithrax Spinosissimus) On Patch Reef Algal Communities In The Florida Keys, Florida (Usa), Angela M. Mojica Osorio

Biological Sciences Theses & Dissertations

Coral reefs worldwide are undergoing dramatic habitat modification from coral to macroalgal dominance due to water pollution, coral diseases, global. warming, and the loss of herbivores. This phase-shift bas been particularly severe on Caribbean reefs due in large measure to the decline of piscine and echinoderm grazers, whose presence appears crucial for stemming the decline of coral reefs and enhancing their resilience. Virtually unknown, however, is the role of other macrograzers in coral reef ecosystems. This is the first study to examine the feeding ecology and grazer effect of the herbivorous West Indian spider crab (Mithrax spinosissimus) on inshore patch …


An Analysis Of Policies And Conservation Techniques To Reduce The Accidental Deaths Of Sea Turtle Hatchlings Due To Light Pollution In Broward County, Fl., Megan Wilson May 2009

An Analysis Of Policies And Conservation Techniques To Reduce The Accidental Deaths Of Sea Turtle Hatchlings Due To Light Pollution In Broward County, Fl., Megan Wilson

HCNSO Student Theses and Dissertations

Light pollution is any excessive or obtrusive man made light source which disrupts the natural environment. Hatchling marine turtles are adversely affected by light pollution and therefore unlit nesting beaches are essential habitats for all marine turtle species. In Broward County, the most significant conservation issue facing nesting and hatchling marine turtles is the amount of light pollution present on urban sea turtle nesting beaches. The reduction of hatchling mortality from light pollution is an ongoing conservation goal of the State of Florida, Broward County, and the Broward County Sea Turtle Conservation Project (BCSTCP). Conservation techniques and policies intended to …


Oceanic-Atmospheric Modes Of Variability And Their Effect On River Flow And Blue Crab (Callinectes Sapidus) Abundance In The Northcentral Gulf Of Mexico, Guillermo Humberto Sanchez-Rubio May 2009

Oceanic-Atmospheric Modes Of Variability And Their Effect On River Flow And Blue Crab (Callinectes Sapidus) Abundance In The Northcentral Gulf Of Mexico, Guillermo Humberto Sanchez-Rubio

Dissertations

Oceanic-atmospheric modes of variability occur on interdecadal, multidecadal, decadal, and interannual timescales and their influence on climate around the world has been confirmed. The present study investigates Mississippi River and Pascagoula River flows in response to the influence of one or more of the four oceanic-atmospheric modes of variability: the Pacific Decadal Oscillation (PDO), the Atlantic Multidecadal Oscillation (AMO), the North Atlantic Oscillation (NAO), and the El Nino Southern Oscillation (ENSO). These modes of variability are present in phases: PDO warm (PDOw) and cold (PDOc), AMO warm (AMOw) and cold (AMOc), NAO positive (NAOp) and negative (NAOn), and ENSO warm …


The Effects Of Climate Variability On The Structure Of The Phytoplankton Community In Tumaco Bay, Colombia, Ingrid Garcia-Hansen Honkala May 2009

The Effects Of Climate Variability On The Structure Of The Phytoplankton Community In Tumaco Bay, Colombia, Ingrid Garcia-Hansen Honkala

Dissertations

Spatiotemporal variability in the diatom and dinoflagellate community structure and chlorophyll a (chl a) concentrations in Tumaco Bay during the 1993-2005 period was related clearly to seasonal and interannual variability in environmental conditions due to the migration of the Inter-tropical Convergence Zone (ITZC) and the influence of El Nino Southern Oscillation (ENSO) events. A total of 134 species of diatoms that belong to 57 genera, and 78 species of dinoflagellates that belong to 25 genera were identified during the survey. The diatom community was the dominant group in the waters of the bay, being the most abundant with the greatest …


Differential Response Of Amp Activated Protein Kinase (Ampk) And Hsp70 To Temperature Stress In The Gastropod, Nucella Lapillus, Emily Zimmermann Apr 2009

Differential Response Of Amp Activated Protein Kinase (Ampk) And Hsp70 To Temperature Stress In The Gastropod, Nucella Lapillus, Emily Zimmermann

All Theses And Dissertations

Populations of the gastropod Nucella lapillus are polymorphic for shell color, with light-colored shells predominating on warmer, wave-protected shores and dark-colored shells limited primarily to cooler, wave-exposed shores. During thermal stress, darker shells attain higher body temperatures than lighter shells. These results suggest that heat stress may determine field distribution patterns. However, there is currently little evidence of physiological consequences of thermal stress in these organisms. Following the guiding hypothesis that heat stress leads to cellular energy depletion, we explored whether the central energy regulator AMP-activated Protein Kinase (AMPK) is activated by heat stress. We compared this response in both …


A Bio-Optical Model For Syringodium Filiforme Canopies, Margaret A. Stoughton Apr 2009

A Bio-Optical Model For Syringodium Filiforme Canopies, Margaret A. Stoughton

OES Theses and Dissertations

Seagrasses are significant ecological and biogeochemical agents in shallow water ecosystems throughout the world. In many regions, seagrass meadows occupy a sufficient fraction of the coastal zone, and generate optical signatures that can be observed from space. Bio-optical models of light absorption and scattering by submerged plant canopies for certain species such as Thalassia testudinum and Zostera marina have successfully modeled the plane irradiance distribution and photosynthesis within the submerged canopies. Syringodium filiforme differs &om T. testudinttm and Z marina, in leaf morphology and canopy architecture. The objective of this study was to develop a radiative transfer model that …


Determining The Distribution Of Antibiotic Resistant And Fecal Indicator Bacteria In The Ohio River, Caitlin Nicole Swecker Jan 2009

Determining The Distribution Of Antibiotic Resistant And Fecal Indicator Bacteria In The Ohio River, Caitlin Nicole Swecker

Theses, Dissertations and Capstones

The Ohio River extends 981 miles from Pittsburgh, PA to Cairo, Ill providing drinking water to over three million people, a natural habitat for aquatic life, a public recreation resource, a major transportation route, and a source of water for industry. The Guyandotte River is a highly impacted tributary emptying into the Ohio River in Huntington, WV. The objectives of this study were to determine if sediment load is correlated to the number of antibiotic resistant bacteria (ARB) and determine if a single surface sample is a sufficient representative measurement of ARB populations in a large river. In 2007, subsurface …


Developing A Monitoring Protocol For The Monkey River Watershed, Belize, Central America, Sean Elliott Collins Jan 2009

Developing A Monitoring Protocol For The Monkey River Watershed, Belize, Central America, Sean Elliott Collins

Theses, Dissertations and Capstones

The study of tropical aquatic systems has been limited. Research in developing countries can be challenging due to inadequate resources and cultural variety. Generally, efforts are concentrated on developing and maintaining economic stability rather than ecological sustainability. The aim of this project was to preliminarily develop and utilize a rapid bioassessment protocol (RBP) for the Monkey River watershed in Belize by determining which metrics best described overall stream health. Like biomonitoring protocols already established for temperate systems, a regional tropical aquatic watershed monitoring program should provide information including stream and watershed health. These protocols score systems on a variety of …


Application Of Remote Sensing To Examine Changes In Bird Communities Over A Gradient Of Urbanization, John E. Northeimer Jan 2009

Application Of Remote Sensing To Examine Changes In Bird Communities Over A Gradient Of Urbanization, John E. Northeimer

Theses, Dissertations and Capstones

Interest in urban ecology and the impact of urbanization on natural resources has increased over the last decade. Studies have related degradation of water quality and loss of biodiversity to increased urbanization. Avian species comprise an important part of the urban ecology. Surveys of bird populations can provide insight into the effects of urbanization on species composition, diversity, and distribution. A search of available literature revealed no published comprehensive avian surveys completed during the breeding season within the city of Huntington, West Virginia. The purpose of this study was to provide an initial characterization of land bird populations during the …


Anthropogenic Causes Of Copepod Mortality And Bacterial Decomposition Of Copepod Carcasses, Samantha L. Bickel Jan 2009

Anthropogenic Causes Of Copepod Mortality And Bacterial Decomposition Of Copepod Carcasses, Samantha L. Bickel

Dissertations, Theses, and Masters Projects

Although zooplankton carcasses can be quite prevalent within aquatic systems, they have largely been overlooked in most zooplankton population studies. Anthropogenic stressors can potentially increase the overall abundance of carcasses on a local scale. Once a carcass is present within a system, the fate of its biomass is of considerable interest as it may be remineralized within the water column or transported to depth. Through the collection of field samples I assessed the possibility of an anthropogenic stressor (boat-generated turbulence) as a potential source of nonconsumptive mortality. I also conducted a series of laboratory experiments to monitor the decomposition of …


A Numerical Modeling Study On Barotropic And Baroclinic Responses Of The Chesapeake Bay To Hurricane Events, Kyoung-Ho Cho Jan 2009

A Numerical Modeling Study On Barotropic And Baroclinic Responses Of The Chesapeake Bay To Hurricane Events, Kyoung-Ho Cho

Dissertations, Theses, and Masters Projects

The barotropic and baroclinic responses of the Chesapeake Bay to forcings from two hurricanes were investigated by using unstructured-grid three-dimensional hydrodynamic models. The model domain includes Chesapeake Bay proper, the tributaries, and its extended continental shelf in the mid-Atlantic Bight. Two hurricanes were studied: Hurricane Floyd of September, 1999 and Hurricane Isabel of September, 2003, both of which made landfall within 100 km of the Chesapeake Bay mouth. Hurricane Floyd in 1999 passed through the entrance of the Bay from southwest to northeast along the coastlines of Virginia as a Category 1 storm, whereas Hurricane Isabel in 2003 made landfall …


Cultural Eutrophication And The Clam Macoma Balthica: Evidence For Trophic Disruption And Effects On Blue Crabs, Bryce J. Brylawski Jan 2009

Cultural Eutrophication And The Clam Macoma Balthica: Evidence For Trophic Disruption And Effects On Blue Crabs, Bryce J. Brylawski

Dissertations, Theses, and Masters Projects

Cultural eutrophication (CE) is the allochthonous input introduction of a quantity of matter, such as sediments, organic material, or nutrients, into a water body over the pre-anthropogenic (natural) levels. In most coastal estuaries CE has come to refer primarily to an increase in the concentration of phyto-nutrients. CE has been identified as the cause of very graphic phenomena such as hypoxia and fish kills. In this work I examine the potential for CE to alter the composition of the primary producer community and potentially alter or disrupt the benthic food web, using Macoma balthica as an indicator species. A series …


The Influence Of Artificial Reef Associated Fish Assemblages And Varying Substrates On Coral Recruitment, T. Patrick Quinn Jan 2009

The Influence Of Artificial Reef Associated Fish Assemblages And Varying Substrates On Coral Recruitment, T. Patrick Quinn

HCNSO Student Theses and Dissertations

This study examined enhancing coral recruitment to artificial substrate by manipulating fish assemblages and the use of coral attractant substrates. One hundred sixty artificial reef modules were organized into 40 four-module replicate configurations (quads) of varying complexity to induce different fish assemblages. The deployment array consisted of the 40 quads, each in a square configuration with three to four-meter sides (approximately 1 m separation between modules) measured from the outside corners. The quads were divided into four fill treatments of differing complexity: Empty, Small, Mixed, and Large. Each quad had four potential coral attractant treatments on settlement plates: CaCO3, iron, …


Assessing Genetic Variation Within And Among Native Populations And Hatchery Stocks Of Crassostrea Ariakensis Using Microsatellite Markers, Jie Xiao Jan 2009

Assessing Genetic Variation Within And Among Native Populations And Hatchery Stocks Of Crassostrea Ariakensis Using Microsatellite Markers, Jie Xiao

Dissertations, Theses, and Masters Projects

Assessing genetic variation within and among native populations and hatchery stocks of Crassostrea ariakensis using microsatellite markers In response to the dramatic decline of eastern oyster (Crassostrea virginica) populations in the Chesapeake Bay, introduction of the non-native Asian oyster Crassostrea ariakensis has been proposed. Currently several hatchery stocks of C. ariakensis, derived from a few wild populations along the coast of Japan and China, are being maintained in U.S. hatcheries in the Pacific northwest and on the east coast. In recent years, as the risks of the proposed introduction are being assessed, these hatchery animals have been widely used for …


Predation And Thermal Stress Affect Color Change In The Symbiotic Sea Anemone Aiptasia, Samantha L. Hamlin Jan 2009

Predation And Thermal Stress Affect Color Change In The Symbiotic Sea Anemone Aiptasia, Samantha L. Hamlin

WWU Graduate School Collection

Bleaching is the disruption of the symbiotic relationship between anthozoans and zooxanthellae. The term bleaching refers to the host appearing lighter--sometimes becoming completely white--as a result of losing their symbiotic dinoflagellates, their photosynthetic pigments, or both. Research has demonstrated that many abiotic factors, such as temperature, ultraviolet radiation, and salinity, cause bleaching. However, we know little about the role that biotic factors, such as predation, may play in coral bleaching. Additionally, little is known about the combined effects of different stressors, and whether these effects are additive or not. If effects are synergistic and difficult to predict, then much more …


Hydrography And Phytoplankton Distribution In The Amundsen And Ross Seas, Glaucia M. Fragoso Jan 2009

Hydrography And Phytoplankton Distribution In The Amundsen And Ross Seas, Glaucia M. Fragoso

Dissertations, Theses, and Masters Projects

The phytoplankton of the Ross Sea have been intensively studied during the last decade, as opposed to the Amundsen Sea, where virtually nothing is known about phytoplankton taxonomy and distribution. Blooms in the Ross Sea are usually composed of diatoms and the prymnesiophyte Phaeocystis antarctica; diatoms are often dominant in strongly stratified waters during the summer, whereas P. antarctica usually dominates in less stratified waters in the south-central polynya during spring. This study focused on understanding the environmental variables that influence the spatial patterns of phytoplankton assemblages during late summer and early fall, 2007, and late spring and early summer, …


Investigating The Relationships Between Recruitment Indices And Estimates Of Adult Abundance For Striped Bass, Weakfish, And Atlantic Croaker, Justine R. Woodward Jan 2009

Investigating The Relationships Between Recruitment Indices And Estimates Of Adult Abundance For Striped Bass, Weakfish, And Atlantic Croaker, Justine R. Woodward

Dissertations, Theses, and Masters Projects

Establishing the relationships between recruitment indices and estimates of adult abundance using fishery-independent data continues to remain one of the principal challenges faced by fisheries scientists due to the lack of concurrent monitoring programs designed to target different life stages of the same species. In Chesapeake Bay, however, multiple, fishery-independent surveys currently monitor the relative abundance of YOY and adult fishes. Using the available data from these surveys, the relationships between estimates of relative abundance for young-of-year and adults of striped bass (Morone saxatilis), weakfish (Cynoscion regalis), and Atlantic croaker (Micropogonias undulatus) were examined. Year-class strength was reflected in subsequent …


Egg Capsule Hatching Success In Rapana Venosa And Urosalpinx Cinerea In Relation To Temperature And Salinity, Stephanie M. Gera Jan 2009

Egg Capsule Hatching Success In Rapana Venosa And Urosalpinx Cinerea In Relation To Temperature And Salinity, Stephanie M. Gera

Dissertations, Theses, and Masters Projects

The maintenance of a population within the geographic range is influenced by the physical and environmental conditions under which breeding occurs. It is hypothesized that environmental conditions under which egg capsules are successfully hatched will influence the range of potential habitat of the invasive veined rapa whelk, Rapana venosa, and the native Atlantic oyster drill, Urosalpinx cinerea, in the Chesapeake Bay. This study examines the environmental conditions of temperature, salinity, and the time of deposition of egg capsules within the reproductive period (here quantified as cumulative number of day degrees at egg capsule deposition). The range of R. venosa and …


Function Of Seed-Bank Ecology In Mid-Atlantic Semi-Annual And Perennial Zostera Marina Beds, Jessie C. Jarvis Jan 2009

Function Of Seed-Bank Ecology In Mid-Atlantic Semi-Annual And Perennial Zostera Marina Beds, Jessie C. Jarvis

Dissertations, Theses, and Masters Projects

The effects of water quality and sediment composition on mid-Atlantic semi-annual and perennial Zostera marina reproductive success, seed-bank viability, and seed germination were elucidated using laboratory and in situ experiments, quantitative field observations, and ecological model simulations. The sediment seed-bank was found to play a large role in the recovery of perennial Z. marina beds in the Chesapeake Bay and in the yearly re-establishment of beds in North Carolina which were determined to have a semi-annual life history. However, the resiliency provided by sediment seed-bank for both semi-annual and perennial Z. marina beds was limited as seeds remained viable for …


Multi-System Analysis Of Nitrogen Use By Phytoplankton And Heterotrophic Bacteria, Paul B. Bradley Jan 2009

Multi-System Analysis Of Nitrogen Use By Phytoplankton And Heterotrophic Bacteria, Paul B. Bradley

Dissertations, Theses, and Masters Projects

Traditional measurements of phytoplankton N uptake have been confounded by bacterial retention on filters used in 15N uptake studies, and such methodological obstacles have limited our understanding of phytoplankton-bacterial interactions regarding N cycling. In this research, uptake of various inorganic and organic N substrates by phytoplankton and bacteria was measured in several marine ecosystems using two distinct approaches: size fractionation into phytoplankton and bacterial size classes, and flow cytometric (FCM) sorting of autotrophic cells. Comprehensive assessments of N uptake dynamics were conducted in Chesapeake Bay, the Mid-Atlantic Bight, and Raunefjord, Norway, with supplementary data collected from the York River, Virginia …