Table 20. (Concluded.) 



Number Biomass per % Domi ri- 

 per sample (q, ance (by 

 Station sample dry weight) numbers) Dominant species 



Marqalef 

 richness 



I— 4A 13.0 



— 5 



UPPER - 

 (EAST) BAY 



5A 



— 58 



12.2 



13.7 



6.8 



— 5C 12.5 



I— 6 45.8 



SIKE'S CUT IB 10.0 



B. INVERTEBRATES (continued) 



CALLINECTES SAPIDUS 

 PORTUNUS GIRBESI 

 ACETES AMERICANUS 



but in July, the highest concentrations of 

 the sand seatrout are found at the mouth 

 of the Apalachicola River. Distribution 

 usually remains relatively unchanged 

 during August and September. The 

 remaining fish, dwindling in numbers 

 during the fall months, soread out 

 throughout East Bay and northern 

 Apalachicola Bay. By winter or early 

 spring, as noted above, no sand seatrout 

 are taken. 



Spot have a different pattern of 

 distribution (Figure 32). As they move 

 into the estuary in Jaunary, spot tend to 

 congregate in upper East Bay and around 

 Nick's Hole drainage off St. George 

 Island. This distribution broadens 

 throughout eastern portions of East Bay 

 and Apalachicola Bay during February and 

 March. Concentrations of spot appear in 

 areas of the bay that receive freshwater 



runoff from upland areas. East Bay is a 

 particularly important nursery area for 

 this species. By summer, remnants of the 

 population are found off St. Georae 

 Island. 



The spatial distribution of 

 postlarval penaeid shrimp in the 

 Apalachicola estuary illustrates the 

 summer and fall dominance of these species 

 (Figure 33). During early summer, they 

 are concentrated in East Bay. However, 

 during July and August, high numbers of 

 penaeids are located at the mouth of the 

 Apalachicola River. By fall, although 

 still concentrated in East Bay, they tend 

 to be more evenly distributed throughout 

 the estuary as they move into the open 

 gul^ to spawn. Few shrimp are taken 

 during the winter months. As with other 

 dominant (and commercially important) 

 species in the bay, the penaeids appear to 



68 



