Marianne Dietz, MS Student (D. Hollander, advisor)
College of Marine Science
University of South Florida

B.S., Environmental Science, University of Delaware, 2005
B.A., Biology, University of Delaware, 2005

Research Interests:

My research focuses on reconstructing ecologic and environmental changes in the northern Gulf of Mexico, one of the largest areas of chronic hypoxia in the world. Every year, large quantities of nutrients from the continent are delivered via the Mississippi River to the Gulf, causing large annual production blooms which lead to well-documented oxygen depletion in the water column. Based on field observations conducted since the mid-1980’s, both the severity of oxygen depletion and the spatial extent of the chronically hypoxic zone on the Louisiana continental shelf have increased significantly and is largely attributed largely to anthropogenic influences, particularly an increase in the use of nitrogen-based commercial fertilizers within the Mississippi River drainage basin beginning in the 1950’s. However, what the environment on the shelf was like prior to 1980’s is not well known. I am using molecular organic geochemical techniques to analyze the specific biological sources contributing to sedimentary organic matter on the Louisiana shelf to get an ideal of the changes in the ecosystem as a result of prolonged hypoxic conditions on both modern and historic time-scales.

Publications & Presentations

Dietz, M.E., Van Vleet, E.S., Hollander, D.J. A Multiproxy Approach to Investigating Ecosystem Change in Response to the Development of Modern and Historic Low-Oxygen Conditions on the Louisiana Continental Shelf. Poster Presentation, ASLO Ocean Sciences Meeting 2008 *Won Outstanding Student Poster Presentation Award (Download Poster in PDF format, 984kb)