Date of Award

Summer 8-2015

Degree Type


Degree Name

Doctor of Philosophy (PhD)


Marine Science

Committee Chair

Jerry D. Wiggert

Committee Chair Department

Marine Science

Committee Member 2

Stephan D. Howden

Committee Member 2 Department

Marine Science

Committee Member 3

Scott Milroy

Committee Member 3 Department

Marine Science

Committee Member 4

Steven E. Lohrenz

Committee Member 5

Richard W. Gould


The northern Gulf of Mexico is a complex marine system subject to episodic physical phenomena such as loop current eddies. Flow fields generated by these eddies can result in cross-shelf exchanges between riverine influenced shelf waters and the offshore water column. This study considers the impacts of high chlorophyll plumes (HCPs) resulting from cross-shelf exchanges to the bio-optical properties of affected waters and how these plumes are influenced by their environment. The seasonal, interannual and decadal chlorophyll cycles of the Gulf of Mexico and the northern Gulf of Mexico are described to provide context for evaluating the ecological effects of HCPs. To determine the ecological effects of such exchanges, a regional 2007 cross-shelf exchange event is investigated using remotely sensed observations. The offshore ratio of bio-optical signals observed during the exchange event implies a divergence in surface water composition from the typical composition. To explore the impact of this composition change on the regional carbon budget, net primary productivity (NPP) estimates during the exchange event are compared with the climatological estimates, revealing increases of up to 330% for the corresponding time period. Select HCP CHL fields are compared with physical parameters and environmental conditions to explore drivers of HCP formation and conditions affecting HCP characteristics. This work supports suppositions that HCPs form as the result of a complex river-wind-circulation system and adds to the current understanding of CHL dynamics in the northern Gulf of Mexico by showing an association between HCP frequency and environmental conditions.