Number Page 



64 Nitrogen and phosphorus budgets for a Mississippi deltaic 



salt marsh 75 



65 Conceptual diagram illustrating the coupling of delta marshes to other 

 ecosystems 79 



66 Patterns of estuarine use by nektonic organisms in the Barataria 



basin, Louisiana 80 



67 The life cycle of the brown shrimp 81 



63 Major duck migration corridors to gulf coast marshes 82 



69 Seasonal use of wetlands by migratory birds, shellfish, and fish 83 



70 The increase in open water in natural and impounded wetlands. The 

 pattern of greater wetland loss in impoundments is consistent in both 

 fall, when water levels are low, and winter when impoundments are 



f 1 ooded 92 



71 Wildlife management areas in the Mississippi Delta 94 



72 A weir in the deltaic plain marshes. The strong flow of water across 

 the weir is an indication of the effectiveness of the barrier. These 

 structures are favorite sport fishing spots 95 



73 Cumulative number of days per year that ponds in the study area will 

 equal or exceed certain percentages of bottom exposure. Based on 

 depth contours of 48 ponds and 20 years of tide data on the central 

 Louisiana coast 96 



74 The percentage of different types of vegetation in impoundments in the 

 Rockefeller State Wildlife Refuge 97 



75 Habitat type, vegetative cover, and fish and wildlife values achieved 

 with water management programs operating on the Rockefeller 



Refuge 98 



XI 



