Identifier

etd-10212015-201521

Degree

Master of Science (MS)

Department

Environmental Sciences

Document Type

Thesis

Abstract

Two consecutive storms made landfall along the Northern Gulf of Mexico on June and August 2012 (Tropical Storm Debby, 06/26/2012; Isaac, 08/28/2012, Category (Cat) 1 Saffir-Simpson Hurricane Scale). Each storm passed within 48 to 273 km of one of seven wetland-estuary transition zone sampling sites, and indirect storm effects associated with changes in freshwater discharge and an inflow of inorganic nutrients were observed at five of the seven sites. To assess the impacts of the 2012 hurricanes on hydrology, nutrient concentrations, and phytoplankton concentrations at transition zones along the Gulf Coast, a within-sites analysis along with a seasonal analysis were conducted to differentiate between seasonality and any deviations caused by storm effects at that particular site. Along with the within-sites analysis, a between-site analysis was also conducted to distinguish any trends among sites that were collective after the passing of a storm. Finally, to better understand the status of nutrient limitation at each site, enrichment experiments were conducted, with an emphasis on phosphorous and nitrogen, to determine the limiting nutrient. The results of the before-and-after nutrient analysis were generally consistent, with nitrate, phosphate, silicate, and ammonium levels decreasing, and chlorophyll concentrations increasing, thus suggesting that the storm stimulated nutrient uptake and phytoplankton growth. At some sites low post-storm nutrient concentrations appeared to be part of a seasonal pattern of declining nutrient concentrations rather than the result of phytoplankton uptake stimulated by passage of the storm.

Date

2015

Document Availability at the Time of Submission

Secure the entire work for patent and/or proprietary purposes for a period of one year. Student has submitted appropriate documentation which states: During this period the copyright owner also agrees not to exercise her/his ownership rights, including public use in works, without prior authorization from LSU. At the end of the one year period, either we or LSU may request an automatic extension for one additional year. At the end of the one year secure period (or its extension, if such is requested), the work will be released for access worldwide.

Committee Chair

Laws, Edward

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