did not vary to any extent, there was 

 a progressive decline in winter low 

 temperatures over the first three 

 years with a minimum occurring during 

 January, 1977. This was followed by 

 progressively warmer winters (1978- 

 1980). Apalachicola River flow was 

 seasonal with the highest daily peaks 

 occurring during winter and spring 

 months. After moderately high flows 

 in 1975, there was a two-year period 

 of relatively low winter-spring flows 

 (1976-1977). This was followed by a 

 series of high peaks in the early 

 winter months of 1978 and spring of 

 1979 and 1980. Local rainfall peaked 

 during summer-fall periods with rela- 

 tively high rainfall in 1975. This 

 was followed by a period of low rain- 

 fall (1976 through 1978). Increased 

 precipitation was observed in 1979 

 and 1980. These data indicate 

 various phase differences in the 

 climatological features of the study 

 area as part of longer-term cycles 

 (Livingston and Duncan 1979; Meeter 

 et al. 1979). 



Analysis of the temporal varia- 

 tion of macrodetritus and microdetri- 

 tus is given in Figure 2b. A qual- 

 itative determination of the macrode- 

 trital component indicates spatial 

 differences in detrital distribution 

 (Livingston et al. 1977). Areas 

 dominated by the Apalachicola River 

 have winter peaks of wood debris and 

 leaf litter derived from wetlands 

 vegetation along the river flood 

 plain. Dominant plant forms 

 represented in the detritus include 

 oaks (Quercus spp) , cottonwood 

 (Populus deltoides) ,sweetbay (Liquid - 

 ambar styraciflua) , tupelo ( Nyssa 

 aquatica) , river birch (Betula nigra) , 

 and maples (Acer rubrum) . Detritus in 

 the outer bay stations, farthest from 

 river input, was dominated by various 

 macrophytes including seagrasses and 

 algae. Benthic macrophyte-derived 

 detritus usually peaked in late sum- 

 mer or fall, reflecting growth and 

 decay patterns of Ruppia maritima , 



Ulva lactuca , Halodule wrightii , 

 Vallisneria americana , and Gracilaria 

 spp. 



A bimodal seasonal cycle of 

 estuarine detrital peaks was super- 

 imposed over a long-term trend that 

 tended to reflect supra-annual varia- 

 tion of river flow. The first sea- 

 sonal peak of debris was absent dur- 

 ing 1980 at which time river flow 

 tended to peak later in the spring. 

 There were indications that although 

 the amount of debris in the bay tends 

 to follow river flow conditions, the 

 specific time of the year of river 

 flooding is also an important factor 

 in the amount of available detritus. 

 The long-term trends of microdetritus 

 were somewhat consistent with this 

 pattern (Figure 2b) , and the highest 

 levels of such particulate matter 

 tended to coincide with maximal 

 river peaking early in the year. 

 (January-February). Such peaks in 

 microdetritus usually were closely 

 associated with river flow peaks in 

 time whereas the macrodetritus showed 

 differential lags as explained by 

 Livingston et al. (1977). Thus, 

 there were short- and long-term asso- 

 ciations of available detritus and 

 river flow conditions (i.e., seasonal 

 peaks) that reflected qualitative 

 differences in the form of the or- 

 ganic matter as well as the seasonal 

 distribution of river peak phenomena. 

 Overall, peak detrital flows re- 

 flected seasonal river flow patterns 

 with major peaks occurring during 

 winter-spring months. Such patterns 

 of total detrital loading (flux) fol- 

 lowed detrital concentrations (mg 

 ash-free dry weight/m in the Apala- 

 chicola River. 



A linear regression of micro- 

 detritus and river flow by season 

 (Table 1, Figure 3) indicated that 

 there are seasonal differences in 

 the relationship of detrital 

 concentration and river flow. 

 During summer periods, there is no 



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