hydrologic budget of the Florida 

 Keys, especially where the circula- 

 tion is restricted. Such restricted 

 environments include: (1) the large, 

 complex, and subdivided lagoonal en- 

 vironment of Florida Bay; (2) small, 

 complex lagoonal environments bor- 

 dering the Keys and the mainland, 

 e.g., Blackwater Sound and Barnes 

 Sound; (3) small sea island lagoonal 

 environments of the Keys, e.g.. 

 Coupon Bight, Upper S ugar loaf Sound, 

 Buttonwood Sound; and (4) intertidal 

 and supratidal areas, e.g.. Crane 

 Key tidal flats, supratidal mud 

 flats on Sugarloaf Key (Multer 

 1977). The restricted circulation 

 of these areas in combination with 

 strong seasonal winds, clear skies, 

 extended dry season, and relatively 

 high temperatures promotes evapora- 

 tive processes resulting in seasonal 

 salinity variations of as much as 50 

 parts per thousand (Ginsburg 1956). 



Evaporation usually peaks in 

 late spring and early summer, when 

 maximum winds, negligible rainfall, 

 and clear skies prevail (Lloyd 

 1964). During drought years such as 

 those experienced during the summer 

 of 1956, the peak shifts more to the 

 middle or late summer months (Chew 

 1961). Chew (1961) also suggests 

 that the proximity of a station to 

 nearshore currents may significantly 

 influence evaporation. Stations 



located only short distances from 

 one another, one in open water, the 

 other apparently within the "current 

 shadow" described by Marmer (1954), 

 exhibit radical differences in sa- 

 linity over relatively short time 

 intervals. 



Water Quality 



The water quality of the Flori- 

 da Bay side of the Florida Keys was 

 addressed, in part, in the section 

 on Florida Bay hydrology and water 

 quality. As stated in that section, 

 water quality data in this region is 



fairly limited (Schmidt and Davis 

 1978), restricted basically to data 

 on salinity, temperature, and to a 

 lesser extent, turbidity. Some 



additional data omitted in the 

 earlier section and of a more site 

 specific nature regarding the near- 

 shore bay environment of the upper 

 Keys follows. 



Lynts (1966) and Evink (1981) 

 report on seasonal changes in the 

 interior bay zone, specifically of 

 Buttonwood and Blackwater Sounds, 

 respectively. Evink (1981) observes 

 salinity ranges between 30 ppt and 

 40 ppt near Snake Point in north- 

 eastern Blackwater Sound over a 14 

 month period. The maximum and mini- 

 mum salinities follow the delayed 

 seasonal response previously discus- 

 sed, resulting in low salinities in 

 winter and high salinities in sum- 

 mer. Lynts' (1966) investigation of 

 Buttonwood Sound suggests a pattern 

 more directly responsive to the wet 

 and dry periods. August values 

 range from 25.3% to 28.9% responding 

 to the wet season precipitation. 

 The February data show increases in 

 salinity from 37.9% to 40.8% in 

 response to the dry season water 

 deficit. It appears that Buttonwood 

 Sound is hydrologically disconnected 

 from Florida Bay, responding primar- 

 ily to the localized precipitation/ 

 evaporation regime and the tidal 

 interflow across Key Largo (Lee and 

 Rooth 1972). 



Lynts (1966) also monitored 

 temperature, pH , and Eh of the sedi- 

 ment water interface. He concludes 

 that temperature, like salinity, 

 varies in response to climatic 

 changes. In addition to seasonal 

 changes, temperature is responsive 

 to diurnal variation in the surface 

 air temperature. Ginsburg (1956), 

 Lloyd ( 1964) , and Turney and Perkins 

 (1972) also note the sensitive na- 

 ture of temperature changes which 



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