and Wildlife Service 1976). Habitat 

 quality and quantity for other marsh 

 birds will also be reduced by contin- 

 ued wetland deterioration. Nutria 

 comprised roughly 70 percent of 

 Louisiana's total fur harvest between 

 1970 and 1975 (O'Neil and Linscombe 

 1975). Palmisano (1973) reported 

 that nutria catch per acre is highest 

 in fresh marsh, declining progres- 

 sively in the intermediate, brackish, 

 and saline marsh types. Alligator 

 populations also reach peak levels 

 in fresh to intermediate marshes 

 (Palmisano et al. 1973). Accord- 

 ingly, continued wetland deteriora- 

 tion can be expected to result in 

 declines in fur harvest and alligator 

 populations, especially as land loss 

 and salinity intrusion reduce fresher 

 marsh acreage. 



DISCUSSION OF MEASURES TO 



REDUCE WETLAND DETERIORATION 



Except for regulation of devel- 

 opment, the primary measures investi- 

 gated to date for control of wetland 

 deterioration in the LCR have in- 

 volved diversion of Mississippi River 

 water into adjacent marshes and estu- 

 arine areas for salinity control and 

 creation of new subdeltas. A plan 

 for introduction of Mississippi River 

 water into the subdelta marshes of 

 southeast Louisiana was submitted by 

 the U.S. Fish and Wildlife Service 

 to the U.S. Army Corps of Engineers 

 in 1959 (U.S. Fish and Wildlife Ser- 

 vice 1959). This plan included a 

 recommendation for the construction 

 of four water control structures, 

 having a combined discharge capacity 

 of 24,000 cubic feet per second 

 (cfs), to divert Mississippi River 

 water for salinity control. The 

 structures would have benefitted an 

 estimated 264,500 acres (107,043 ha) 

 of marsh and estuarine waters. The 

 annual benefits of this plan in in- 



creased oyster yields, furbearer har- 

 vest, and waterfowl utilization were 

 estimated at $841,600, exceeding 

 costs by 62 percent. Recognizing 

 that the project was necessary to 

 partially rectify wetland degradation 

 brought about by the construction of 

 federally financed Mississippi River 

 mainline levees, the U.S. Fish and 

 Wildlife Service (1959) recommended 

 that the Mississippi River and Trib- 

 utaries Project authorized by the 

 Flood Control Act of 1928 be amended 

 to recognize fish and wildlife as a 

 project purpose and to include the 

 service's freshwater introduction 

 plan as an integral feature. That 

 plan, now known as the "Mississippi 

 Delta Region, Louisiana," project, 

 was authorized by Public Law 89-298 

 on October 27, 1965. Detailed plan- 

 ning of one of the four authorized 

 diversion structures was initiated in 

 1969, but was suspended when local 

 interests failed to furnish economic 

 justification for their requested 

 change in the location of that 

 structure (U.S. Army Corps of Engi- 

 neers 1975). It should be noted that, 

 despite the obvious need for the pro- 

 ject to mitigate the adverse effects 

 of the Mississippi River mainline 

 levees, the project is classified as 

 "enhancement," making local interests 

 responsible for 25 percent of the 

 project costs. This has been cited 

 by local interests as one reason for 

 their reluctance to participate in 

 the project. 



The most comprehensive treat- 

 ment of measures for arresting land 

 loss and salinity intrusion in the 

 LCR is contained in a report prepared 

 by Gagliano et al. (1973b) under 

 contract to the U.S. Army Corps of 

 Engineers. That study was conducted 

 in conjunction with a broad evalua- 

 tion of the LCR by an ad hoc in- 

 teragency group and evaluated two 

 primary measures for addressing wet- 

 land deterioration, including: 



393 



