surface runoff in Taylor Slough, the Craighead Basin, the C-111 canal (Eastern Panhandle), and Shark River Slough, including the seasonality of flow. Diffuse seepage through the Buttonwood Embankment should also be investigated.
On the basis of modeling, annual freshwater flows through the Taylor Slough/Craighead Basin region to Florida Bay in 2050 will be about the same (127,000 acre-ft per year; 15.7x107 m3/year) under the expanded CERP scenario D13R4 as in the simulated current condition of 126,000 acre-ft per year (15.5x107 m3/year). Thus, this particular hydrologic component of the CERP is unlikely to affect salinity levels in the northeastern Bay. At the same time, annual freshwater flow through Shark River Slough, some of which migrates to the Bay indirectly and with a time lag, is projected to increase by almost 80% under the CERP scenario D13R4. The effects on nitrogen and phosphorus fluxes of increasing this freshwater flux to the Bay’s diffuse northwestern boundary need to be quantified.
Total loads of nitrogen from freshwater sources should be estimated as accurately as possible. A better understanding of the transport, bioavailability, and rates of transformation of DON and DOP (dissolved organic phosphorus) into forms that can be used by algae and macroscopic aquatic plants) of dissolved organic nitrogen is needed to provide insight into the effects of increases in nutrient-bearing freshwater flows to the Bay. Quantifying the magnitude of nutrient loadings by source (e.g., organic soils oxidation, urban and agricultural runoff, and regional atmospheric deposition) also will become relevant if steps to reduce nutrient loading to the Bay become necessary.
A historical characterization of the Bay’s water quality would be very useful for a perspective on restoration goals. Such a characterization would be based on anecdotal as well as any scientific information available.
There currently is no Florida Bay circulation model suitable for research and management purposes, although there are several candidates; such a model is essential to support a Bay water quality model and thus facilitate analysis of CERP effects on the Bay. The difficult and time-consuming tasks of selection, development, and application of a circulation model and water-quality model for the Bay should be key components of the Florida Bay & Florida Keys Feasibility Study.
To evaluate the effects of the CERP on Florida Bay, there must be a linkage of the output of the South Florida Water Management Model (SFWMM), which has a southern boundary of the mangrove zone, and input to the Bay models. One possibility for bridging this gap is the USGS TIME model, but its readiness for this purpose probably will not occur until well into 2003. The USGS SICS model (an early version of TIME) already is being used for this purpose in the Taylor Slough/C-111 canal area, although not formally interfaced to any Bay models. Additional questions of temporal and spatial resolution must also be resolved. Another option is the similarly structured SFWMD South Florida Regional Simulation Model (SFRSM), also currently under development. An interagency agreement on which model will most usefully serve as an interface between landside hydrologic and Bay hydrodynamic modeling is needed.
Estimates of the influence of the CERP on Florida Bay inferred from statistical and time series analysis of existing data and/or use of simpler “box models” such as FATHOM (Flux Accounting Tidal Hydrology Ocean Model) may be usefully employed while awaiting development of full-scale simulation models.
Human factors such as population growth and economic activity; and environmental events whose drivers are distant from Florida Bay and unrelated to CERP activities, such as hurricanes, flooding of the Mississippi River, atmospheric deposition of nutrients from emission sources remote to Florida Bay or its watershed, and sea-level rise; also may influence local conditions in Florida Bay. Research is needed to better define these potential effects and to integrate the results into predictive ecosystem-response models.
There is much to commend in the overall research effort in Florida Bay, and in the goals of the FBFKFS. But the evidence of potential changes in Florida Bay that will be caused by the CERP is sufficiently persuasive that the process of evaluation should begin as an early part of the FBFKFS. The