et al. 1964). Dominant tnolluskan 



fauna in recent sediments (Scholl 

 1963) also confirms that a definite 

 fresh to brackish to marine environ- 

 ment has prevailed along this same 

 axis in the bay over the past 5000 

 years. 



As the bay was gradually sub- 

 merging to form an open water estu- 

 ary, inundation by tides, primarily 

 through the Shark River Slough to 

 the north, modified the historical 

 drainage pattern. Thus a seasonally 

 oscillating "double" gradient was 

 established; one dominating during 

 the wet season in the northeast/ 

 southwest direction representing the 

 historical freshwater flow influ- 

 ence; the other dominating the dry 

 season in the northwest/southeast 

 direction representing the effect of 

 tidal inundation and flushing. 



In 1957 the situation was even 

 further modified by the opening of 

 the Buttonwood Canal which connected 

 Whitewater Bay to Florida Bay by way 

 of Coot Bay. Under the pre-canal 

 conditions. Coot Bay and southeast- 

 ern Whitewater Bay were extremely 

 sensitive to the effects of wind, 

 particularly along the southeast/ 

 northwest axis. With southeast 



winds, water was effectively drained 

 through Tarpon Creek into Whitewater 

 Bay, while during sustained north- 

 west winds, water "piled up" in the 

 small bay. It is significant to 



note also, that under both condi- 

 tions daily tidal fluctuations were 

 nearly obliterated by wind action. 



After the Buttonwood Canal 

 opened, the piling up of water in 

 Coot Bay under northwest winds was 

 all but eliminated. Flow constric- 

 tion by Tarpon Creek continued to 

 allow some build up in Whitewater 

 Bay, but Coot Bay was essentially 

 well flushed. The hydrologic con- 

 nection between Coot Bay and Florida 



Bay disrupted the seasonal cycle of 

 water supply to the small lakes 

 south of Coot Bay. These had pre- 

 viously received input from the 

 overflow of waters in Coot Bay 

 (Tabb et al. 1962), especially dur- 

 ing the dry season when northwest 

 winds are most frequent. Presently 

 the Buttonwood Canal is being closed 

 in an effort to reestablish the 

 historical conditions. 



The timing of the wet and dry 

 seasons in Whitewater Bay, as re- 

 flected in minimum and maximum 

 salinities, has been shown to be 

 approximately 3 months out of phase 

 with flow from the Tamiami Canal to 

 the north (Figure 34). As fresh- 

 water inflow peaks, the salinities 

 line up in a distinct southwest- 

 northeast gradient consistent with 

 the orientation of the water supply 

 (Figure 35). As freshwater inflow 

 subsides, salinity gradients tend to 

 reorient along the bay's southeast 

 to northwest axis consistent with 

 the main direction of tidal flows. 

 Extreme losses to evapotranspiration 

 often lead to salinities greater 

 than in open sea water as evidenced 

 in Figure 35. Especially intense 

 localized conditions of rainfall or 

 drought can, however, produce con- 

 siderable variation in these general 

 seasonal patterns (Clark 1971). 



5.5 TAYLOR SLOUGH 



Surface discharge from Taylor 

 Slough arises from two sources: 



(1) local rainfall; and 



(2) overland sheetflow origi- 

 nating from Shark River 

 overflow and Tamiami Canal 

 between levees 30 and 67 A. 



As presented earlier, rainfall 

 in Taylor Slough averages around 

 150 cm (59 in) annually, with a peak 

 in September and a low in December 

 (Earle and Hartwell 1973). Likewise, 



81 



