passinq thunderstorms, wind effects, and 

 tidal actions are superimposed over basin 

 characteristics such as depth and bottom 

 morphology. These, in turn, may 

 significantly influence larqer-scale 

 conditions such as temperature, salinity, 

 and light penetration. The large-scale 

 seasonal fluctuations of important 

 climatic features, in combination with the 

 influence of local habitat distribution 

 and basin configuration, produce an array 

 of processes whereby organic matter is 

 incorporated into the estuarine food webs. 



The seasonal cycle of nutrient- 

 detritus flux in the Apalachicola estuary 

 has been well established (Livingston et 

 al . 1976a; Livingston and Loucks 1978). 

 Huring winter and spring periods of hi ah 

 river flow, dissolved nutrients and 



particulate organic matter are washed into 

 the estuary. The influx is concurrent 

 with salinity reductions. Peak levels of 

 leaf matter are present during these 

 periods. One to two months later, wood 

 debris and other forms of particulates 

 appear in the bay system. In the spring, 

 as river flow diminishes, temperature 

 increases, and the water becomes clearer, 

 phytoplankton blooms occur. As 

 principally phosphorus, become 

 during summer/fall months, 

 productivity becomes 

 wind-mixed transfers of 



the spring 

 nutrients, 

 1 imi ti ng 

 phytoplankton 

 dependent on 



nutrients from the sediments into the 

 water column. During the summer and early 

 fall, local rainfall enhances nutrient 

 enrichment. At this time, benthic 

 macrophytes begin to die off. The peak 

 levels of macrophyte organic debris and 



Table 11. Nutrient values (winter and summer) for stations in the Apalachicola estuary 

 (means ± one standard deviation of five stations) and River (Station 2) (Livingston et 

 al. 1974). 



Nutrient 



Nutrient values ( g/1) 



N03 



NH4 



P04 



Silicate (Si04) 



40 



