tropical algae including species of 

 Caul erpa , Acetabularia , P e n i c i 1 1 u s , 

 G r a c i 1 a r i a , H a 1 i m e d a , Sargassu m, 

 Batophora , Udotea , and Dasya . These are 

 discussed at length by Zieman (in prep.). 

 Other pertinent references for mangrove 

 regions include Davis (1940), Taylor 

 (1960), Tabb and Manning (1961), and Tabb 

 et al. (1962). 



5.2 PHYT0PLANKT0N 



All aspects of phytoplankton, from 

 seasonal occurrence to productivity 

 studies, are poorly studied in mangrove 

 ecosystems. This is particularly true in 

 Florida. 



Evidence from Brazil (Teixeira et al. 

 1965, 1967, 1969; Tundisi 1969) indicates 

 that phytoplankton can be an important 

 component of the total primary production 

 in mangrove ecosystems; just how important 

 is not clear. Generally, standing crops 

 of net phytoplankton in mangrove areas are 

 low (personal observation). The nanno- 

 plankton, which have not been studied at 

 all, appear to be most important in terms 

 of total metabolism (Tundisi 1969). The 

 net plankton are usually dominated by 

 diatoms such as Thai assothri x s p p . , 

 Chaetoceras s p p . , Ni t zsc hi a s p p . , 

 Skeletonema spp., and Rhi zosol eni a spp. 

 (Mattox 1949; Wood 1965; Walsh 1967; Bacon 

 1970). At times, blooms of dinoflagel- 

 lates such as P e r i d i n i u m spp. and 

 Gymnodi ni urn spp. may dominate (personal 

 observation). In many locations, particu- 

 larly in shallow waters with some turbu- 

 lence, benthic diatoms such as Pleurosigma 

 spp., Mastogloia spp., and Disploneis may 

 be numerically important in the net plank- 

 ton (Wood 1965). 



Understanding the mangrove-associated 

 phytoplankton community is complicated by 

 the constant mixing of water masses in 

 mangrove regions. Depending upon the 

 location, the phytoplankton may be domi- 

 nated by oceanic and neritic forms, by 

 true estuarine plankton, and by freshwater 

 plankton. The pattern of dominance may 

 change daily or seasonally depending upon 

 the source of the principal water mass. 



Before we can understand the impor- 

 tance (or lack of importance) of phyto- 

 plankton in mangrove regions, some ques- 

 tions must be answered. How productive 

 are the nannoplankton? How does the daily 

 and seasonal shift in phytoplankton domi- 

 nance affect community productivity? Does 

 the generally low standing crop of phyto- 

 plankton represent low productivity or a 

 high grazing rate? 



5.3 ASSOCIATED VASCULAR PLANTS 



Four species of aquatic grasses occur 

 on bay and creek bottoms adjacent to man- 

 grove forests. Turtle grass, Thai assia 

 testudinum , and manatee grass, Syringodium 

 fi Hi forme , are two tropical sea grasses 

 which occur in waters with average salini- 

 ties above about 20 ppt. Shoal grass, 

 Hal odule wri ghti i , is found at somewhat 

 lower salinities and widgeongrass, Ruppia 

 maritima , is a freshwater grass which can 

 tolerate low salinities. These grasses 

 occur throughout south Florida, often in 

 close juxtaposition to mangroves. Zieman 

 (in prep.) presents a thorough review of 

 sea grasses along with comments about 

 possible energy flow linkages with 

 mangrove ecosystems. 



For example, along the southwest coast 

 between Flamingo and Naples, marshes are 

 scattered throughout the mangrove belt and 

 also border the mangroves on the upland 

 side. The estuarine marshes within the 

 mangrove swamps have been extensively 



eel 1 ul osa , glass wort, Sal i cornia spp., 

 Gulf cordgrass, Spartina spartinae , sea 

 purslane, Sesuvium portulacastrum , salt 

 wort, Batis maritima , and sea ox-eye, 

 B o r r i c h i a f rutescens . Farther north, 

 above Tampa on the west coast of Florida, 

 marshes populated by smooth cordgrass, 



43 



