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Fishery Bulletin 97(2), 1999 



Apalachee Bay 



Indian Pass 



St. Vincent Island 



Florida 



Study Area 



Figure 1 



Map of the study area in northwest Florida near latitude 30"00'N and longitude 85'35'W illus- 

 trating the major sampling areas (o) and the two areas (•) in which sandbar sharks were 

 captured from October 1992 to October 1997. 



The eastern part of this area has an irregular coast- 

 line, few beaches and enclosed bay systems, and has 

 large amounts of submergent (Thalassia spp. and 

 Halodule spp.) and emergent vegetation (Spartina 

 spp. and Juncus spp I. The western part has numer- 

 ous barrier islands and sand beaches and is composed 

 of semi-enclosed bays. Tidal amplitude in the bays is 

 highest in Apalachee Bay and generally decreases 

 toward the west. 



St. Andrew Bay consists of several embayments 

 (average range 1.9-5.7 m deep) and has low fresh- 

 water inflow, low turbidities, and high percentages 

 of sand in the substrate. Salinity ranges from 13 to 

 32 ppt and tidal amplitude averages 0.48 m. The sys- 

 tem exchanges water with the Gulf of Mexico through 

 two passes, a natural pass at the east end and a man- 

 made pass at the west end. 



St. Andrew Sound is a small semi-enclosed marine 

 lagoon with expanses of submergent vegetation. It 

 is about 14.5 km long and 0.2-2.0 km wide and has 

 water depths from 3.5 to 4.5 m deep (mean high tide). 

 Salinity ranges from 25 to 36 ppt and tidal ampli- 



tude averages 0.42 m. The sound exchanges water 

 with the Gulf of Mexico through a pass (=0.5-2.0 km 

 wide) that was created near the center of Crooked 

 Island by Hurricane Eloise in 1975. 



Indian Pass is located at the western end of the 

 Apalachicola Bay system. This area is about 2-3 km 

 south of St. Vincent Island in the Gulf of Mexico 

 where the average range of water depth is 5—10 m. 

 The bay system surrounding this area is largely a 

 line of barrier islands fronting the intersection of the 

 Apalachicola delta and is the only bay system in 

 Florida in which a large river system drains. As a 

 result of river discharge, there is little submergent 

 vegetation due to high turbidity. Salinity fluctuates 

 from 15 to 35 ppt and tidal range is 0.66 m. 



Apalachee Bay is an open ocean bay without bar- 

 rier islands separating the area from the open Gulf 

 of Mexico. The bay is broad, shallow (average 3 m), 

 and extends about 15 km offshore. Salinity ranges 

 from 22 to 36 ppt and tidal amplitude averages 1.0 m. 

 Wave energy is low and the area has large expanses 

 of submerged vegetation. 



