Abstract
The marine and estuarine ecosystems and living resources of Mississippi are of considerable importance to the area’s ecology and to the state’s economy. Dissolved oxygen is an important water quality parameter in determining oyster habitat suitability. A coupled hydrodynamic-water quality model was developed to study the oyster habitat suitability of the Western Mississippi Sound (WMSS) in the Northern Gulf of Mexico. The Visual Environmental Fluid Dynamic Code (VEFDC) was used to create a non-uniform grid-based model in four layers of the estuary’s depth. The input data for the model were provided from measurement gauge stations available within and near the computational grid, and the Lower Pearl River Model developed by TetraTech. The coupled hydrodynamic-water quality model was calibrated and validated against measured observed data for 2009 to 2017. The model was calibrated to dissolved oxygen (DO), chlorophyll a, NH3, and PO4. The Root Mean Square Error (RMSE), and Coefficient of Determination (R2) were applied as absolute and relative statistical measures of model performance. Measured dissolved oxygen in the western MS Sound shows stratification with higher levels of oxygen at the surface and lower levels at the bottom. Atmospheric reaeration is a source for dissolved oxygen in the top layers. Sediment oxygen demand is a sink for dissolved oxygen in the bottom layers. This study investigates the role of sediment oxygen demand and wind-based reaeration on modeled dissolved oxygen.
