Wednesday, August 8, 2007 - 9:45 PMEcosystem-based management of Florida Bay and its Everglades Watershed
Christopher J. Madden, South Florida Water Management District
The trend toward ecosystem-based management (EBM) of coastal systems is accelerating. The $8 billion ecosystem restoration of the Everglades and Florida Bay is undergoing whole-system planning in which EBM considers the Everglades in an integrated way that maximizes system-wide benefits. The components of the Everglades-Florida Bay ecosystem are connected hydrologically by a slow flow of freshwater discharging into Florida Bay. Ecosystem processes are dependent on hydrologic characteristics such as the timing, quantity and quality of water inflows to the bay, the depth and schedule of wetland inundation upstream, and degree of hydrological connectivity of ecosystem components. This case study presents a paired conceptual and numerical ecological model used in designing the restoration of Florida Bay’s seagrass community. The bay’s estuarine character is compromised by reduced freshwater inflow and diminished circulation. This reduced flow is implicated in a catastrophic mortality of seagrass in 1987, impacting nearly 30,000 ha of Thalassia. The EBM strategy for the Everglades-Florida Bay system relies heavily on simulation modeling at all levels for designing and evaluating different management alternatives for freshwater inputs and for predicting seagrass community response to management. The model is calibrated for six basins representative of different sectors within the estuary and is linked to a spatially explicit water transport model yielding a landscape-based tool that describes the growth, community composition, physical structure and nutrient dynamics of the seagrass community. Evaluations of freshwater requirements, timing and distribution and water quality of inflows are used in determination of final restoration design and operations.