Table 9. Total annual net productivity and net input to the Apalachicola estuary (East 

 Bay, Apalachicola Bay, St. Vincent Sound) and the Apalachicola Bay system (Aoalachicola 

 estuary, St. George Sound, Alligator Harbor). Productivity includes (metric tons) 

 organic carbon produced by the Apalachicola River wetlands, coastal marshes, phyto- 

 plankton, and seagrass beds. 



Vegetation 



Apalachicola estuary Apalachicola Bay system 



Net in situ Net input Net in situ Net input 

 productivity mt C yr~l productivity mt C yr"l 

 mt C yr~l mt C yr~^ 



Season of 

 maximum input 



Freshwater 

 wetlands 



Coastal 

 marshes 



Phyto- 

 plankton 



Seagrass 

 beds 



360,000 

 37,714 



103,080 

 8,953 



30,000 



360,000 



30,000 



37,714(?) 46,905 



103,080 



8,953 27,213 



27,213 



winter/spring 



46,905(?) late summer, 



fall(?) 



233,284(?) 233,284(?) spring and 



fall 



summer-fal 1 



A review of the phytoplankton ecologv 

 of the Apalachicola estuary (Estabrook 

 1973; Livingston et al. 1974, lQ76a; Myers 

 and Iverson 1977) indicates that ohyto- 

 plankton productivity is relatively 

 restricted to conditions of optimum 

 temperature and ample (available) 

 nutrients. Such conditions occur 



princioally in the spring, summer, and 

 fall. Multiple regression analysis (Myers 

 and Iverson 1977) indicated that river 

 discharge explained 209S-50^ of the 

 variability of chlorophyll _a and phvto- 

 plankton productivity. Nutrients were 

 positively correlated with river 

 discharge. Temperature accounted for 26^ 

 to 49% of the variability in phytoplankton 

 productivity. Water temperature was also 

 positively correlated with phytoplankton 

 productivity. Wind speed was positively 

 correlated with suspended sediments and 

 phosphate concentrations, increases in 

 which were followed by increases in ohyto- 

 plankton productivity. Nutrient 



enrichment experiments indicated that 

 nutrients are limiting only during summer 

 and fall (Estabrook 1^73) and that 

 phosphate is the primary nutrient that 

 limits phytoplankton productivity in East 

 Bay and Apalachicola Bay (Myers and 



Iverson 1*^77), although both nitrates and 

 phosphates may be limiting in summer 

 (Livingston et al. l^^a). 





2 



< 



N D 



J F M A 



MONTH 



Figure 24. Monthly averages of daily 



litterfall on intensive transect plots 



across the Apalachicola wetlands (after 

 Elder and Cairns 1982). 



38 



