Marine Biology Commons^™

Phytoplankton Community Distribution And Light Absorption Properties In The Northern Gulf Of Mexico, Sumit Chakraborty

Dissertations

The theme of this dissertation was to understand the spatio-temporal dynamics of the phytoplankton community, its light absorption properties, and its relationship to underlying physicochemical processes. Understanding these phenomena will benefit efforts to predict pathways of carbon transformation in the ocean, to estimate primary productivity (PP) and to characterize distributions of phytoplankton communities using ocean color remote sensing.

This research entailed four different studies, which address different objectives. The first two studies dealt with phytoplankton community composition and its relationship to environmental variables. A chemotaxonomic approach was used, which was successful in revealing distinct phytoplankton assemblages in distinct water mass …

Habitat Characterization, Habitat Use And Associated Growth Of Juvenile Spotted Seatrout (Cynoscion Nebulosus) In A Mississippi Bay System: Implications For Stock Enhancement Practices, Joseph Read Hendon

Dissertations

The spotted seatrout (Cynoscion nebulosus) is the most targeted recreational fishery species in Mississippi coastal waters. Consequently, the Seatrout Population Enhancement Cooperative stock enhancement program was initiated to investigate methods for supplementing this heavily exploited population. Given ecological data needs for both wild and hatchery-reared (HR) juveniles of the species, habitat mapping, directed sampling and a caging study were conducted. Submerged aquatic vegetation (SAV), oyster shell and non-vegetated substrates were mapped at water depths < 2 m in Point aux Chenes Bay, Mississippi, using a sidescan sonar, which provided more accurate estimations of habitat coverage, particularly for SAV, compared to point-based sampling. Applying habitat strata delineated from sidescan mapping, late-juvenile spotted seatrout [125 - 275 mm total length (TL)] were sampled in SAV, marsh-edge and non-vegetated habitats as part of a seasonal gill net survey conducted in 2011 and 2012. Spotted seatrout ranging from 138 to 485 mm TL were collected using a smallmesh gill net, and 65% of collected individuals fell within the targeted late-juvenile size range. Overall mean catch-per-unit-effort of C. nebulosus did not differ for abundance or biomass between years, but both metrics were significantly higher in SAV habitats. Employing cage enclosures that …

Community Metrics And Trophic Dynamics In Tidal Creeks In An Anthropogenically Fragmented, Coastal Landscape, Michael Robert Lowe

Dissertations

Salt marsh landscapes are among the most anthropogenically altered ecosystems in the world. Urbanization (i.e., accumulation of impervious cover and man made structrues) of the coastal landscape can disrupt the delivery of numerous ecosystem services. Among the many services provided by salt marsh habitats, they serves as the primary habitats for distinct macroinfauna (i.e., benthic and epibenthic macrofauna) and nekton (i.e., fish and decapod crustaceans) assemblages. In this dissertation, I used a number of metrics to test the overarching hypothesis that coastal urbanization has negative consequences for salt marsh faunal assemblages. Chapter I uses a landscape ecology approach to show …

Tactile Behavior In A Group Of Captive Rough-Toothed Dolphins As A Function Of Opportunities To Play With Objects, Kelly Ann Caffery

Dissertations

Cetaceans live in complex physical and social environments that are frequently changing. In contrast, the captive environment for marine mammals is often lacking in stimulation. As a result, enrichment is often used to increase species-typical behaviors and enhance the well-being of the animals. The purpose of this study was to compare the effects of enrichment objects on the social behavior of a group of seven captive rough-toothed dolphins (Steno bredanensis). Observations of this species in the wild suggest it may have a particular affinity for tactile and object play behaviors. Therefore, these behavior categories were a primary focus …

Evaluation Of Human Fecal Pollution In Mississippi Coastal And Creek Waters Using Library Independent Markers, Christopher John Flood

Dissertations

The objective of this study was to determine whether statistically valid correlations could be elucidated between standard indicator bacteria (enterococci and fecal coliforms) from coastal creek and marine samples and the presence of four library independent molecular markers that are human or sewage specific. Eight hundred and nineteen samples were collected between August 2007 and July 2010 to determine enterococcal and fecal coliform counts and the presence of genetic markers for sewage indicator organisms Methanobrevibacter smithii, human specific Bacteroides sp., Bacteroides thetaiotaomicron, and Fecalibacterium sp. During the course of this study environmental parameters were measured and statistically analyzed to determine …

Accessing Learning In The Adult Zebrafish With A Novel Associative Learning Task, David Joseph Jouandot Ii

Dissertations

The zebrafish (Danio rerio) is accepted in the developmental and genomic communities as a model organism. However, the capacity for the zebrafish as a behavioral model has yet to be fully acknowledged. The research presented provides evidence validating the novel task, aids in gaining a better understanding of the learning processes, and identifies individual differences. The novel associative learning task differs from any present well established behavioral model and lends itself to future development. The task provides the zebrafish community with a high output behavioral task which is readily replicated and allows one researcher to test between eight …