FIGURES 



Number Page 



la The study area (South Atlantic Bight) extends from Cape 



Fear, North Carolina, to Cape Canaveral, Florida 2 



lb Tidal characteristics of the Atlantic and Gulf of Mexico 



coasts 2 



2 Sedimentary regions of estuary 6 



3 A comparison of primary productivity for different kinds 



of ecosystems 9 



4 Model of energy flow in the Georgia salt marshes 12 



5 Trophic spectrum of an estuarine community (Lake 

 Pontchartrain Estuary, Louisiana) 15 



6 The distribution of Crassostrea virqinica 19 



7 Anatomy of the oyster ( Crassostrea virqinica ) and diagram 

 showing the correct method of measuring the height, length, 



and width of oyster shells 21 



8 Transverse section of the dorsal part of an adult 

 Crassostrea virginica 22 



9 A schematic representation of the rhythmic nature of the 

 feeding process and extracellular and intracellular 

 digestive mechanisms in oysters 25 



10 Effects of turbidity on pumping rate 27 



11 Effects of crude oil extract on Mytilus edulis carbon 

 budgets calculated for 100-mg mussels held at 31 /oo 

 salinity under summer conditions (15° C,215 ug C/liter). . . 31 



12 Summary of energy flow through intertidal reef oysters ... 35 



13 Diagrammatic section through oyster reef illustrating 

 relative elevation with respect to mean tidal levels and 

 corresponding fouling pattern on piling 38 



14 Several generations of oysters (£. virqinica ) growing 

 vertically on muddy bottom of Altamaha Sound, Georgia ... 39 



15 Seasonal oxygen consumption of reef community 49 



16 Seasonal energy partitioning estimates for the entire 



reef community 52 



17 Typical distribution of oyster reefs in small tidal 



creeks 60 



18 Comparison of two systems of concentrated consumers whose 

 survival depends on strong flows that bring in fuels and 

 oxygen and outflow wastes: (a) reef of oysters and 

 other marine animals characteristic of many estuaries; 



(b) industrialized city 66 



19 Three hierarchical levels of oyster reef organization. ... 67 



20 Reef distribution in a single drainage basin, the Half 



Moon River Estuary, Wilmington Island, Georgia . 68 



21 Recent and historical reef distribution in the Duplin River 

 Estuary, Sapelo Island, Georgia 69 



22 Regional level conceptual model and explanation of 



symbols 72 



23 Drainage unit level conceptual model 73 



24 Reef organization conceptual model 75 



vii 



