Digital Commons Network^™

Use Of Spectrofluorometry To Detect Petroleum Hydrocarbons In The Marine Environment, Mary Iris Abercrombie

USF Tampa Graduate Theses and Dissertations

The genesis of this research was the Deepwater Horizon oil spill, which discharged petroleum and gas into the Gulf of Mexico for 87 days in 2010. High-resolution fluorescence spectroscopy was employed for the detection of petroleum in seawater samples following the oil spill. Fluorescence arises from the chemical structure of π-bonding in C=C bonds, especially those in aromatic structures. Spectrofluorometry was also used to observe and track the formation of petroleum plumes in seawater undergoing controlled physical dispersion in a wave tank, both with and without the addition of chemical dispersant. Further, the changing fluorescence characteristics of a broad range …

High-Resolution Investigation Of Event Driven Sedimentation: Response And Evolution Of The Deepwater Horizon Blowout In The Sedimentary System, Rebekka A. Larson

USF Tampa Graduate Theses and Dissertations

This Dissertation combines the investigation of the sedimentological impacts of the Deepwater Horizon (DwH) blowout event in the deep-sea benthos, with the refinement and advancement of methods and approaches for high-resolution investigations of events preserved in sedimentary records. An approach that combined, rapid collection of cores, a continued annual time series collection of cores, and high-resolution sampling and analyses, in particular short-lived Radioisotopes (SLRad), enabled the temporal resolution required to detect the sedimentary response to the short-duration DwH event, and evaluate post-event sedimentation patterns at a comparable time scale (months).

The collection of 179 sediment cores from 80 sites between …

Regeneration Of Trace Metals During Phytoplankton Decay: An Experimental Study, Adrienne P. Hollister

USF Tampa Graduate Theses and Dissertations

Trace metals act as important nutrients, and sometimes toxins, to phytoplankton and other marine microorganisms. When phytoplankton decay, the elements in their cells are released back into the water column through regeneration (also referred to as remineralization), one of the processes responsible for governing concentrations of dissolved trace metals and macronutrients in depth profiles. In order to experimentally study regeneration, controlled experimental incubations of mixed phytoplankton assemblages from the Gulf of Mexico (GoM) and monocultures of the diatom Pseudo-nitzschia dolorosa and the dinoflagellate Karenia brevis were placed in the dark and monitored as they decayed with naturally present bacteria. Over …