MANAGEMENT ISSUES 



There are conflicting demands on 

 the wetlands and waters of the MDPR. The 

 region produces a major portion of both 

 the nation's petroleum resources and its 

 recreational and commercial fisheries. 

 It occupies a strategic location for 

 navigation and commerce. During the 

 last several decades the human popula- 

 tion and industry and commerce have 

 greatly increased, resulting in signif- 

 icant alteration and apparent degrada- 

 tion of the natural system. 



The MDPR has served as a waste re- 

 pository for domestic and industrial 

 discharges and agricultural drainage. 

 Extensive channelization and spoil dis- 

 posal have degraded wetlands. There has 

 been an enormous net loss of wetlands. 

 Some of the problems in the Louisiana 

 coastal zone were recently documented by 

 Malone et al. (1980). These include 

 pollution, wetland loss, salt water 

 intrusion, and others. These problems 

 will probably intensify over time 

 because of population and industrial ex- 

 pansion, and because of synergistic and 

 cumulative effects of existing coastal 

 modifications. Wetland loss-rates 

 throughout the United States generally 

 occur in proportion to population den- 

 sity and degree of industrial develop- 

 ment (Gosselink and Baumann 1980). 



Energy-related activities, because 

 of their importance to the national 

 economy, are favored by permitting agen- 

 cies over the preservation of undis- 

 turbed wetland resources. The habitat 

 base supporting renewable natural 

 resource productivity is constantly di- 

 minishing. An unanswered management 

 question is "What is the quantitative 

 impact of continuing wetland altera- 

 tion?" The maintenance of current 

 levels of fishery production may very 

 possibly depend on the present wetland 

 area (Turner 1977, 1979, Lindall et al. 

 1979). 



WETLAND LOSS 



The MDPR is a large area of dynamic 

 geomorphic change. Since sea level 



stabilized after the last glaciation, 

 sediments from the Mississippi River 

 have formed a broad, coastal plain of 

 over 3.4 million ha (8.4 million acres). 

 About 50% is inland water such as bays, 

 lakes, and bayous; about 40% is swamp 

 and marsh; and the remainder is upland 

 (primarily natural levee ridges adjacent 

 to Mississippi River distributaries) . 



There has been an overall gradual 

 net land gain in the MDPR during the 

 last 7,000 years. Within this time 

 there have been cycles of gain and loss 

 (see THE PHYSICAL SETTING). Since sea 

 level rise levelled off about 4,500 

 years ago, the Mississippi River has oc- 

 cupied seven major courses and many 

 minor ones and built seven major deltaic 

 lobes. The river is now in the early 

 stages of the eighth deltaic lobe, 

 forming in the area of Atchafalaya Bay. 

 The growth phase of a delta lobe is 

 characterized by rapid progradation of 

 land at the mouth of the channel. Land 

 is also built by overbank flooding and 

 filling in of older deteriorating 

 marshes. As the channel lengthens and 

 the hydrologic gradient becomes smaller, 

 the river seeks a new, shorter course to 

 the gulf. When a lobe is abandoned, 

 local land-building ceases and wetland 

 loss commences because of erosion and 

 subsidence. The historical pattern 

 throughout the MDPR, until recently, has 

 been land gain in part of the region, 

 and loss in the remainder, with an over- 

 all net gain. 



Now the pattern has been inter- 

 rupted. Cheap, abundant fossil fuel has 

 given man the power to override some 

 natural processes, especially the flow 

 of the Mississippi River. The lower 

 river is totally leveed, it is not being 

 allowed to change course, and it now 

 discharges into very deep water at the 

 edge of the Continental Shelf, where 

 sediments cannot contribute to land 

 building. A description of the ongoing 

 change (loss) in wetlands in the MDPR 

 thus requires a discussion of the inter- 

 actions among natural and cultural 

 phenomena. 



Craig et al. (1979) defined wetland 

 loss as "the substantial removal of 

 wetland from its ecologic role under 



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