All summer 16, including sediment characteristics of the tidal freshwater zone!

lib group picThis summer has been a truly amazing learning experience that I will remember and cherish for years to come. I have met so many wonderful people at UTMSI and had the incredible opportunity to make great connections and friendships. I am sad today is my last day in Port Aransas, I will miss this campus, the staff, my mentors and fellow lab members and last but not least I will miss my REU family. I love you guys, thank you for all the amazing memories, without you this summer would have not been the same at all.

reu group picI learned so much in Amber Hardison and Jim McClelland’s lab this summer while working on my research project. With the help of my mentors and the grad students in my lab I successfully finished this summer by presenting my research. Below is a copy of the abstract used for my presentation in the REU research symposium: a summary of my research project and my findings. Cheers!

Tidal freshwater zones (TFZ) are understudied areas of rivers that experience tidal variations that swing between river and reservoir-like conditions. The TFZ often feature long residence time, slow flow rates, and even reverse flow directions. Such unique hydrodynamic conditions can affect nitrogen cycling within the zone profoundly, with possibly enhanced nitrogen transformation and removal in the interface between sediment and water. A lot of nitrogen cycling pathways take place in the sediment/water interface such as denitrification and remineralization. Thus, the physical characteristics of sediment, such as grain size distribution and porosity, may influence the organic content (OC) of sediments, which affect the cycling of nitrogen in the river. To understand the role of sediment-water processes in the transformation and removal of nitrogen in the TFZ, we 1) quantified grain size and porosity of sediments at five study sites along the TFZ in the Aransas and Mission rivers; 2) investigated how the physical characteristics of sediment could affect OC of sediments; 3) determined how OC varies spatially and seasonally within the TFZ.

group pic reu w deanaOur findings show the different geological characteristics in terms of grain size and porosity between both rivers. The sediments of the Mission get finer downstream. Carbon and nitrogen content follow similar pattern of grain size and porosity in both rivers. There is a strong correlation between the physical characteristics of the sediments and the organic content in the rivers. Mission has higher OC than Aransas, probably due to its higher sediment porosity. There is considerable spatial variability in the Aransas river. No obvious seasonal patterns of OC were found in the rivers. Overall, my result points out that physical characteristics of sediment have strong influence on OC which is important for respiration of microorganism communities. The data and the results of this study will be compiled with future research and thus provide a better understanding of the sediment/water interface and the nutrient cycling that occurs in the TFZ.


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