Marine Biology Commons^™

Gene Expression Profiles As Molecular Indicators Of Dissolved Oxygen Stress In Grass Shrimp Palaemonetes Pugio Holthuis 1949, Tiandao Li

Dissertations

Occurrence and severity of hypoxia is increasing in coastal and estuarine environments, and recovery of impacted habitats and living resources is slow. Detection of early biological effects of hypoxia is needed for timely remedial action to be taken. The overall objectives of this research was to develop molecular indicators of dissolved oxygen stress to assess the biological impact of hypoxia in coastal estuaries and validate their use through a combination of laboratory and field studies. To achieve these goals, grass shrimp, Palaemonetes pugio, oxygen-sensitive and hypoxia-tolerant species abundant in estuarine systems, were exposed to hypoxia under controlled laboratory conditions, and …

Yellow Head Virus: Transmission And Genome Analyses, Hongwei Ma

Dissertations

Yellow head virus (YHV) is an important pathogen to shrimp aquaculture. Among 13 species of naturally YHV-negative crustaceans in the Mississippi coastal area, the daggerblade grass shrimp, Palaemonetes pugio, and the blue crab, Callinectes sapidus, were tested for potential reservoir and carrier hosts of YHV using PCR and real time PCR. The YHV replicated in the daggerblade grass shrimp, and was still detectable on 36 d post-inoculation, causing 8% mortality after injection. However, YHV did not replicate in the blue crab. These data suggest that the daggerblade grass shrimp could act as a reservoir host for YHV. Storage conditions of …

Review Of The Genus Polycheria Haswell, A Symbiotic Group Of Amphipods (Crustacea: Dexaminidae) With Descriptions Of New Species From Florida, The Caribbean Sea, And The Indo-Pacific Region, John Milton Foster

Dissertations

Systematics and taxonomy of the dexaminid amphipod genus Polycheria Haswell (Dexamindae: Amphipoda), whose members are cosmopolitan associates of tunicates and sponges, are confused. This is due in large part to the many inadequate and incomplete descriptions and poorly some executed illustrations, especially for the early studies on the group. Previously, 22 nominal species or forms have been described or designated in the literature. The purpose of this study is to critically review and clarify the systematics of this enigmatic genus. Based on personal collections and on specimens from museums, five new species are designated and 22 species or forms are …

A Comparison Of Scleractinian Coral Abundance Between Natural And Artificial Substrata In A High-Latitude Environment Off Broward County, Florida, Usa, Deron James Bauer

HCNSO Student Theses and Dissertations

The Dania Beach Erojacks Artificial Reef was deployed off the coast of Broward County, Florida on December 31, 1967 as a way to help combat beach erosion. Over the last forty years, the linear pile of concrete hexapods has become an important habitat, for scleractinian corals, octocorals, algae, crustaceans, mollusks, and fish. This study focuses on the density and size of the scleractinian corals found on this artificial reef and how it compares to that of the nearby natural reef. In addition, the impact of two hurricanes on the shallow portion of the artificial reef was documented. In the 2-year …

A Phylogeny Of The Snappers (Lutjanidae; Percoidei) Inferred From Cytochrome B Sequence Data, Matthew R. Semcheski

Biological Sciences Theses & Dissertations

The Lutjanidae are economically and ecologically important fishes commonly known as snappers. A morphological study of Lutjanidae concluded that it contained four subfamilies and that together with the family Caesionidae, form the superfamily Lutjanoidea. Although this view was supported elsewhere in the literature, it was later contradicted, treating the caesionids as members of the Lutjanidae. In order to infer a phylogeny of genera within Lutjanidae, the complete cytochrome b gene (1140bp) of 21 lutjanid taxa was sequenced and analyzed along with 19 lutjanid, caesionid, and outgroup sequences obtained from GenBank. Data were analyzed for base composition stationarity and saturation. Phylogenetic …

An Analysis Of Dwarf And Pygmy Sperm Whale (Kogia Sp.) Stranding Data In The Southeast United States, Nicole M. O'Brien

HCNSO Student Theses and Dissertations

Pygmy sperm whales (Kogia breviceps) and dwarf sperm whales (Kogia sima) strand frequently in the southeastern United States (SEUS). To detect seasonal trends in Kogia sp. strandings across the SEUS, all 979 stranding events from 1977 through 2005 were segregated by month. A peak in strandings occurred in the late summer and early fall (July – October). The entire SEUS was divided into segments of similar coastline orientation, 1) North and South Carolina, 2) Georgia and the east coast of Florida, 3) Florida Keys, 4) west coast of Florida, 5) Florida panhandle, Alabama and Mississippi, 6) …

Evaluating Vascular Plant Composition And Species Richness On Horn Island, Mississippi, Using Passive And Active Remote Sensing In Conjunction With Ground Based Measurements, Kelly Lynn Lucas

Dissertations

Barrier island vegetation is subjected to chronic abiotic stressors combined with periodic storm events that favor species adapted to harsh environments. These islands are the first landforms to be affected by changes in coastal subsidence and sea-level rise. Evaluating changes in vegetation is important for understanding the impact of global climate change on coastal environments.

This study assesses vegetation composition and plant species richness on Horn Island, Mississippi using ground data in conjunction with remotely sensed spectral and LIDAR data. The goals of this research are to: 1) classify and map vegetation composition on Horn Island using hyperspectral and LIDAR …

A Systematic And Taxonomic Review Of The Family Pseudotanaidae (Crustacea: Peracarida: Tanaidacea) Based Primarily On Morphometry Cladistic Analyses, Jerry Alan Mclelland

Dissertations

Species of the tanaid family Pseudotanaidae, established by Jurgen Sieg in 1973, have been reported from all the world's oceans in depths ranging from near the surface to below 6,000 m. The family currently consists of 46 characteristically small tanaidomorph species residing in two subfamilies, the Cryptocopinae (seven species) and the Pseudotanainae (39 species). Members of the more ancestral Crytocopinae differ from the Pseudotanainae by having females with four rather than three antennule articles and a complete separation of the maxilliped endites. The primary objective of this study was to test the hypothesis that the current structure of the family …

Spatial And Trophic Dynamics Of A Macrofaunal Community On A High Energy Intertidal Sandflat, Sharon Ann Tatem

Biological Sciences Theses & Dissertations

Spatial and trophic interactions between macrofaunal species were studied in a high energy intertidal system during spring-summer low tides. Bioturbation by the enteropneust hemichordate, Balanoglossus aurantiacus (Girad), as evidenced by large fecal mounds, was a conspicuous feature on the sandflat Sediment characteristics were compared between ambient (non-fecal) and B. aurantiacus fecal mound types (fresh-oxidized, fresh-reduced, aged-oxidized, and aged-reduced). Fecal material was differentiated by age based on the presence or absence of mucus and the time of fecal deposition. The color of fecal material was used to assign oxidative state. Multiple isotopes (carbon, nitrogen, sulfur) were used to determine the origins …

Influences Of The Loggerhead Sponge (Spheciospongia Vesparium) And The Vase Sponge (Ircinia Campana) On Nearshore Hard-Bottom Community Development In The Florida Keys, Scott Donahue

Biological Sciences Theses & Dissertations

Sponges, octocorals, and stony corals are the dominant sessile fauna within shallow, hard-bottom communities in the Florida Keys, FL (USA). The sponge component of these communities is not well studied and has been cyclically decimated from as early as 1844, most recently in south-central Florida Bay in 1991 and 1992, in apparent association with phytoplankton blooms. The purpose of this research was to examine ways in which sponges may contribute to the maintenance of hard-bottom communities. Specifically, I investigated: 1) the effect of sponges and physical structures on local sea floor scouring and thus the potential for maintenance of hard-bottom; …

A Seascape Approach To Predicting Reef Fish Distribution, Brian K. Walker

Oceanography Faculty Theses and Dissertations

Linking small-scale measurements of species distributions to broad-scale seascapes is necessary to understanding and predicting organismal distributions and their dynamics. This applies to reef fish populations as well. Reef fish studies are often limited to small spatial scales because of logistical and economic constraints; however, viewing the data at larger spatial scales might elucidate unforeseen relationships and patterns and facilitate regional management and conservation efforts. To address this growing need, an empirical model was created to predict reef fish abundance and species richness for the entire seascape using the relationship between the fish, benthic habitats, and GIS-derived topographic complexity metrics …

Characterization Of Unusual Gymnamoebae Isolated From The Marine Environment, Margaret Wacera Mbugua

Theses, Dissertations and Capstones

Amoebae are important heterotrophic protists (protozoa) and this study focuses on three unusual forms from the marine environment. Amoebae are ubiquitous and play an important role as consumers in microbial communities. A common coastal ctenophore (Mnemiopsis sp.) is known to harbor an undescribed naked amoeba on the comb plate surface. The nature of the symbiotic association is unknown although electron microscopy suggests these micrograzers are degrading comb plates (Moss et al., 2001). A second amoeba isolate from mangrove waters is new to science by virtue of its distinctive trophic form that does not conform to any described species. …

Natural Mortality Of Blue Crab: Estimation And Influence On Population Dynamics, David A. Hewitt

Dissertations, Theses, and Masters Projects

The blue crab Callinectes sapidus supports one of the most important fisheries in the Chesapeake Bay and is the leading contributor to blue crab landings in the United States. Assessment and management of blue crab stocks has been hampered by a lack of estimates of natural mortality rates, a key parameter in assessment models. In Chapter 2, we demonstrate that the approach used for estimating natural mortality that had been used in past assessments was flawed, and provide justification for a superior alternative. In Chapter 3, we synthesize our current understanding of natural mortality rates in adult blue crab and …

Age, Growth, And Demography Of The Sandbar Shark, Carcharhinus Plumbeus, Over Temporal And Spatial Scales, Jason G. Romine

Dissertations, Theses, and Masters Projects

Numbers of sandbar sharks, Carcharhinus plumbeus, in the Northwest Atlantic have experienced drastic declines since the early 1980's reaching their minima during the early 1990's. Catch rates in the early 1990's were a mere 25% of those during the 1980's. Such drastic reductions in other fish stocks have often caused compensatory responses, most notably the cod stocks in the Northwest Atlantic. Compensatory responses in depressed populations may include decreased natural mortality, increased fecundity, or increased growth rates. Compensation for population fluctuations below carrying capacities have been recognized for many terrestrial and oceanic r-selected organisms, but few instances have been noted …

Growth And Grazing Of Microzooplankton In Response To The Harmful Alga Heterosigma Akashiwo In Prey Mixtures, Sylvia Lynne Graham

WWU Graduate School Collection

Heterosigma akashiwo is one of the most ichthyotoxic species of phytoplankton, severely impacting marine ecosystems and economies worldwide. Microzooplankton may play a role in regulating blooms of this alga. This study tested the effects of H. akashiwo, when part of a mixed-prey assemblage, on the growth and feeding of microzooplankton. A saturating prey concentration of 200 μg C l-1 was determined for three ciliate species: Favella sp., Strombidinopsis acuminatum, and Metacylis sp. This was used as the total prey concentration for dual-prey experiments in which the three ciliate species were exposed to reciprocal concentrations of H. akashiwo and a beneficial …

Movements And Home Ranges Of Harbor Seals (Phoca Vitulina) In The Inland Waters Of The Pacific Northwest, Sarah E. Hardee

WWU Graduate School Collection

Marine resources are under increasing human pressure and conservation managers are using tools such as marine reserves to increase target fish stocks. However, marine predators may respond to the resultant changes in fish abundance. Harbor seals, Phoca vitulina, are abundant marine predators in the inland waters of the Pacific Northwest with the potential to influence the recovery of depressed fish stocks, yet relatively little is known about their movement patterns and home range sizes in the region. To describe harbor seal behavior, I deployed satellite and time-depth recorder tags during April and May 2007 on 20 individuals at three haul-out …

Impacts Of Gelatinous Zooplankton On Dissolved Organic Matter Cycling And Bacterioplankton Communities In The York River Estuary, Robert Howard Condon

Dissertations, Theses, and Masters Projects

Large gelatinous zooplankton (GZ) blooms of lobate ctenophores, Mnemiopsis leidyi, and scyphomedusae, Chrysaora quinquecirrha , occur throughout Chesapeake Bay and its tributaries. The mechanisms of GZ bloom formation, and the roles GZ blooms play in dissolved organic matter (DOM) and carbon (C) cycling are not fully understood. During 2003--2006, I conducted laboratory experiments and field surveys in the lower York River to determine factors controlling timing and magnitude of GZ blooms, and to evaluate their effects on C cycling. Highest biomass of M. leidyi occurred in early summer (May-June) and in late winter. Peaks in ctenophore biomass in the mesohaline …

Bottom-Up And Top-Down Controls On Sedimentary Ecosystem Functioning In A Seagrass Habitat, Amanda C. Spivak

Dissertations, Theses, and Masters Projects

Coastal seagrass ecosystems are complex habitats that are increasingly influenced by human perturbations. Disturbances that affect the strength of bottom-up (i.e. resource availability) and top-down (i.e. consumer) controls may also influence biomass distribution between trophic levels, sediment biogeochemistry, and seagrass ecosystem metabolism. Here, I experimentally tested how top-down and bottom-up perturbations interact with community structure (diversity, food chain length of epibenthic consumers) to alter sediment biogeochemistry and ecosystem metabolism in an experimental eelgrass (Zostera marina ) system. My data indicated that resource availability influenced SOM composition and ecosystem metabolism. Light availability tended to be a stronger determinant of SOM composition …

The Colonial Zoanthid Palythoa Caribaeorum: Population Dynamics On Southeast Florida Reefs, Joanna C. Walczak

HCNSO Student Theses and Dissertations

The colonial zoanthid Palythoa caribaeorum (Cnidaria, Zoanthidea) (Duchassaing and Michelotti 1861) is a major benthic component of most Caribbean reefs and is an extremely aggressive spatial competitor (Suchanek and Green 1981). This study looks at annual visits to 16 permanent monitoring sites over 3 reef designations (Inshore Ridge Complex, Middle Reef, and Outer Reef) in Broward County, Florida from 2002-2006. The data obtained in this study fills an informational void regarding the role of zoanthids in the southeast Florida reef benthic community. The study was conducted in two parts. Part One used digital imagery analysis to quantify the spatial cover …

Community Dynamics In Submersed Aquatic Vegetation: Intermediate Consumers As Mediators Of Environmental Change, James G. Douglass

Dissertations, Theses, and Masters Projects

Natural ecosystems are strongly affected by changes in resource supply (bottom-up forces) and by changes in upper trophic levels (top-down forces). The extent to which these processes impact a system depends largely on the responses of organisms at middle trophic levels. In seagrass beds, a group of mid-level consumers known as mesograzers form a critical link in the chain of impact, connecting seagrass and epiphytic algae with predatory fishes and crustaceans. I observed dramatic seasonal and interannual changes in mesograzer abundance and species composition in eelgrass (Zostera marina) beds of lower Chesapeake Bay, Virginia, and endeavored to explain the top-down …

Understanding The Reproductive Behavior And Population Condition Of The Sandbar Shark (Carcharhinus Plumbeus) In The Western North Atlantic: A Molecular Approach To Conservation And Management, David S. Portnoy

Dissertations, Theses, and Masters Projects

The sandbar shark, Carcharhinus plumbeus, has a discontinuous cosmopolitan distribution and is exploited throughout much of its range. In the western North Atlantic, it constitutes the majority of the directed commercial fishery. The stock has declined greatly since the fisheries' inception and has not shown signs of recovery despite the implementation of management practices. Like many highly vagile marine species, it is difficult to obtain information about the sandbar shark through direct observation. Therefore, the goal of this dissertation is to use a molecular approach to examine aspects of behavior and reproduction, providing information useful in conservation and management. to …

Mesopelagic Zooplankton Feeding Ecology And Effects On Particle Repackaging And Carbon Transport In The Subtropical And Subarctic North Pacific Ocean, Stephanie E. Wilson

Dissertations, Theses, and Masters Projects

Differences in zooplankton community structure and diet within the mesopelagic zone (base of euphotic zone to 1000 m) play a key role in affecting the efficiency by which organic matter is exported to depth, but how the structure of mesopelagic food webs change with depth or location is poorly known. I examined how mesopelagic zooplankton affect particle export in an oligotrophic (Hawaii Ocean Time-series site ALOHA) compared to a mesotrophic (Japanese time series site K2) open-ocean system. In the first part of the study, I investigated how fecal pellet characteristics change with depth in order to quantify the extent of …

Interspecific Interactions In Oyster Reef Communities: The Effect Of Established Fauna On Oyster Larval Recruitment, Brian B. Barnes

Dissertations, Theses, and Masters Projects

The behaviors of oyster larvae are difficult to monitor or experimentally manipulate, especially in field conditions. As a result, little is known of the fate of oysters in the larval portion of their life cycle, prior to recruitment. At the transition from pelagic larvae to benthic adults, larvae are likely to come into contact with many invertebrates resident on oyster reefs. Of these, fouling epifauna are generally believed to reduce the settlement of interspecific larvae through competitive exclusion and predation. Studies of these interactions, however, often utilize artificial settlement panels, which can exhibit different recruitment patterns to those observed on …

Stable Isotope Dynamics In Summer Flounder Tissues, With Application To Dietary Assessments In Chesapeake Bay, Andre Buchheister

Dissertations, Theses, and Masters Projects

Stable isotope techniques were applied to summer flounder, Paralichthys dentatus, in Chesapeake Bay to elucidate the relative importance of different prey groups on the growth and productivity of this species. Prior to field application, a laboratory diet-shift study was conducted to evaluate methodological assumptions and obtain necessary isotopic parameters. Specifically, the goals of the laboratory study were to 1) determine isotopic turnover rates and fractionations of δ13C and δ15N in liver, whole blood, and white muscle and 2) estimate the relative importance of growth and metabolic processes on isotopic turnover. Groups of captive juvenile summer flounder (130-255mm total length) were …

Effects Of Shoreline Development And Oyster Reefs On Benthic Communities In Lynnhaven, Virginia, Amanda Sue Lawless

Dissertations, Theses, and Masters Projects

Shoreline hardening and construction of restoration oyster reefs are occurring at rapid rates throughout Chesapeake Bay and little research has been conducted to determine whether installment of a hardened shoreline and oyster reef placement has an effect on the surrounding benthic infaunal communities. I investigated the effects of shoreline development and oyster reefs on benthic communities in Lynnhaven, Virginia. Throughout Lynnhaven, I determined the effects of shoreline type (natural marsh, oyster reef, rip-rap and bulkhead), sediment grain size, Total Organic Carbon/Total Nitrogen (TOC/TN) of the sediment, and predation (caging study) on density, biomass, and diversity of benthic infauna. An information-theoretic …

Zooplankton Community Structure In A Cyclonic And Mode-Water Eddy In The Sargasso Sea, Bethany Rose Eden

Dissertations, Theses, and Masters Projects

Recent evidence suggests that mesoscale eddies are an important mechanism for supplying nutrients to the surface waters of oligotrophic gyres. However, little is known about the biological response to these physical perturbations. Because mesozooplankton play a key role in food-web interactions and the flux of carbon and other elements from surface waters, changes in mesozooplankton community structure can affect biogeochemical cycling. During the summers of 2004 and 2005, respectively, we followed the development of a cyclonic eddy and an anti-cyclonic mode-water eddy in the Sargasso Sea. Zooplankton tows were conducted across both eddies using a Multiple Opening and Closing Net …