1915 



1925 



1936 



1946 



1965 



1975 



1985 



Figure 4. Louisiana oil and gas 

 production (Costanza and Cleveland 1984). 



beneficial effect of the Mississippi River 

 water and nutrients on aquatic 

 productivity was generally understood 

 (Gunter 1938; Viosca 1927; Riley 1937). 

 Also during this decade articles devoted 

 specifically to marsh plants were 

 published (Brown 1936; Penfound and 

 Hathaway 1936). These were soon followed 

 by articles that focused on the relation 

 of environmental factors, particularly 

 salinity and inundation, to plant 

 occurrence (Hathaway and Penfound 1936; 

 Penfound and Hathaway 1938; Brown 1944; 

 Walker 1940). 



Since that time the focus of biotic 

 research has shifted to the processes that 

 control the distribution and abundance of 

 organisms and to analyses of whole 

 communities and ecosystems. While this 

 was a national trend, on the Louisiana 

 coast it was seen in a series of studies 

 funded by the Louisiana Sea Grant program 

 in the early 1970' s. 



WETLAND 

 EXTENT 



DEFINITIONS, TYPES, LOCATION, AND 



Avifauna of Louisiana" in 1900, a classic 

 description. A.B. Langlois collected 



1,200 plants near Plaquemine in the late 

 1800's; Riddill, Hale, and Carpenter 

 collaborated between 1839 and 1859 to 

 publish a list of 1,800 names of Louisiana 

 plants, excluding grasses and sedges. 

 Cocks (1907) stated that Langlois' collec- 

 tion was shipped to St. Louis University 

 and that most of the Riddel 1 et al . 

 collection was lost. Cocks incorporated 

 their lists into his own list of the flora 

 of the Gulf Biologic Station at Cameron, 

 Louisiana. This station also published 

 pioneering studies on oysters (Kellogg 

 1905; Cary 1907) and shrimp (Spaulding 

 1908) during this period. 



The 1930' s brought a sudden wealth of 

 publications. Noteworthy are a series of 

 bulletins published by the Louisiana 

 Department of Conservation on birds, fur 

 animals and fishes (La. Dept. of 

 Conservation 1931; Gowanloch 1933) that 

 sumnarized the available knowledge on 

 these topics. By the late 1930' s the 

 general life history pattern of the 

 commercially valuable estuarine organisms 

 of the delta had been described, and the 



The marshes considered in this 

 monograph are classified by Cowardin et 

 al. (1979) as persistent or nonpersistent 

 emergent wetlands. Most of them lie 

 within the estuarine intertidal or 

 palustrine systems of this classification 

 scheme, although some could be construed 

 to be riverine, particularly where the 

 Mississippi and Atchafalaya river flows 

 are not confined by levees. In Louisiana 

 these marshes are further subdivided as 

 freshwater, intermediate, brackish, or 

 salt, based on vegetation associations 

 established by Penfound and Hathaway 

 (1938) and Chabreck (1972), rather than on 

 salinity per se. However, the salinity 

 ranges for these associations have been 

 determined by various investigators (Table 

 1). They correspond fairly closely with 

 the salinity modifiers - fresh, oligoha- 

 line, mesosaline and polysaline - of 

 Cowardin et al . (1979) as shown in Table 

 2. This table also shows the area of 

 each marsh type in the Mississippi Delta 

 region. 



In both Figure 5, a map of the delta 

 marshes, and in Table 2 the region is 

 divided into drainage basins, the natural 

 ecosystem units of the delta (Costanza et 



