This is the final report of our effort under Coastal Marine Environmental Modeling: Part III. Coastal Marine Environmental Modeling targets the development of numerical models of estuarine shelf interactions with the ultimate objectives of formulating a coupled hydrodynamic-ecological model that includes biological and sedimentological components. Under Part II, a two-dimensional depth-integrated hydrodynamic model, that includes baroclinic pressure gradient, was developed. This model has been applied to various estuaries in Louisiana, namely, Terrebonne/Timbalier Bay, Barataria Bay, Chandeleur-Breton Sound and Fourleague Bay. A simplified version of the hydrodynamic model has been coupled to a simple ecological model that includes suspended sediments, nutrients and phytoplankton, to simulate a spring bloom in Fourleague Bay.