grass covered) reflecting differ- 

 ences in depth, flow, and substrate. 

 Catastrophic events, such as hurri- 

 canes, are another form of a transi- 

 ent physical force temporarily or, 

 in some cases, permanently disrupt- 

 ing the typical habitats. Coupon 

 Bight represents an area character- 

 ized by various habitat forms in 

 close proximity which reflect more 

 permanent differences in depth, 

 circulation, and substrate (Howard 

 and Faulk 1968, Kissling 1968, 

 Lineback 1968). The point is that 

 the Keys' marine habitats, although 

 following a general geographic 

 scheme from shoreline to shelf 

 break, can be quite variable in 

 their pattern of occurrence. 



9.3 HABITAT PARTITIONING 

 FOR FISH AND WILDLIFE 

 PRODUCTION 



9.31 ENERGY FLOW 



The generalized flow of energy 

 through the Florida Keys system is 

 illustrated in Figure 58. The 



system is formed from three major 

 divisions of habitats including 

 terrestrial, shoreline (intertidal) , 

 and marine habitat groups. Obvi- 

 ously the delineation is not a 

 strict one as observed, for example, 

 in the overwash mangrove island 

 (e.g., Rodriquez Key) where exten- 

 sive interconnection exists between 

 seagrass, intertidal, and mangrove 

 habitats. 



In general the Keys are home 

 (or a visiting place) for a wide 

 variety of fauna. These fall into 

 two broad categories which reflect 

 the prevailing forces that drive the 

 Key's energy flow: 



(1) the opportunists such as the 

 probing shorebirds and ma- 

 rine transients. Relatively 

 high physical energy of mix- 



ing (from tides, currents, 

 and wind), the extensive 

 shallows, and the mild cli- 

 mate make the Keys an ideal 

 spot for shorebirds in 

 search of sea wrack and mud 

 flat organisms, especially 

 in the winter. The nearness 

 of the pelagic environment 

 and nearshore estuaries make 

 the keys a kind of interface 

 zone through which life his- 

 tory stages of many marine 

 species may pass; and 

 (2) the specialists such as the 

 invertebrates and fishes of 

 the coral reef. The rather 

 stable subtropical climate 

 makes the Keys home for a 

 variety of animals that 

 depend on very specific con- 

 ditions available only in 

 highly differentiated habi- 

 tats such as the coral reef 

 and the tropical hardwood 

 hammock. 



As in Florida Bay the lower 

 Everglades, detrital material serves 

 as a primary source of energy flow 

 between and within the major habitat 

 divisions. Debris formed from man- 

 grove leaf litter, as discussed in 

 Section 7.31, either accumulates to 

 form peat, or is transported via 

 tidal flushing or storm activity 

 into the nearshore waters undergoing 

 further bacterial decomposition, 

 consumption by detritivores, or 

 sedimentation (Odum et al. 1982). 

 Seagrass debris is formed by graz- 

 ing, mortality from exposure to air 

 on shallow banks, wave induced tear- 

 ing of senescent leaves, and entire 

 plant removal by storm activity 

 (Zieman 1982). Leaves of manatee 

 grass ( Syrinqodium filiforme ) and 

 turtle grass ( Thalassia testudium ) 

 are particularly important in de- 

 trital energy flow since they tend 

 to float at first, thus forming 

 mobile periphytic communities. This 



198 



