The Development and Proliferation of Summer Algal Blooms in the Oligo/Poly-Haline Portion of the Chesapeake Bay - Observational and Numerical Modeling Studies

• Main Author: Wang, Zhengui
• Format: Text
• Language: English
• Published: W&M ScholarWorks 2018
• Subjects: Oceanography; James River; Back River
• Online Access: https://scholarworks.wm.edu/etd/1516639690; https://doi.org/10.21220/V54434; https://scholarworks.wm.edu/context/etd/article/1255/viewcontent/Wang_vims_0261D_10030.pdf

Algal blooms occur annually in many parts of the Chesapeake Bay. The causes of algal blooms are complex and can be different in different regions. In this study, we will conduct data analysis for the observed data and adopt various methods to investigate algal bloom phenomenon in three separate regions in the oligo/poly-haline portion of the Bay. Chapter 1 provides a general introduction of the algal bloom research in the Chesapeake Bay. In Chapter 2, an observational analysis and a numerical study on the algal blooms in Back River were conducted. A hypothesis was made that high pH can trigger sediment phosphorus release, which in turn can enhance chlorophyll-a and further increase pH to form a positive feedback loop. to test this theory, water quality model ICM coupled onto SCHISM was applied in Back River to study the phenomenon. Moreover, a pH model was developed to describe the aquatic chemistry. The model results with and without pH model were compared with Bay Program observations for verifying our hypothesis. It proves the importance of sediment phosphorus release on the algal blooms in Back River. In Chapter 3, a theoretical study combined with data analysis on cyanobacteria blooms dynamics was conducted in the upper tidal James River. The theory integrates the physical transport and biological effects, which leads to a simple governing equation composed of an advection term and a phytoplankton net growth term, in both linear and nonlinear forms. In this study, we derived a general analytic solution to the equation. Then, we applied the theory in the tidal freshwater portion of the James River. The theoretical predictions of chlorophyll concentrations were compared with observational data and verified the validity of the solution. In addition, the factors related to the local chlorophyll maximum in tidal freshwater rivers were discussed. In Chapter 4, an observational analysis and numerical experiments were performed to investigate the algal bloom in the polyhaline of the Chesapeake Bay. This exploratory ...