done for preservation of a particular habitat type or for the preservation of any type of vegetated 

 wetlands. Semi-impoundment may preserve a certain habitat type for a while, but as we discussed 

 earlier, problems of waterlogging, sediment starvation, and poor drainage after tropical storms may 

 make managed succession a viable alternative. 



By managed succession, we mean management actions employed to facilitate wetland succession 

 which is already taking place while minimizing net wetland loss. In the park, for example, there 

 has been a succession of fresh to intermediate and brackish marshes. Given the environmental 

 setting of the park (gradual salinity increase and altered hydrology), we believe that actions can 

 be taken to minimize wetland loss. These include a variety of actions (described above and in the 

 next section) designed to improve hydrology and increase sediment input to the park. In general, 

 we suggest that the ideas of managed succession be investigated more thoroughly to determine its 

 utility in coastal Louisiana. 



Suggested Management Pilot Studies 



The results of this research and experiences in wetland management from other areas suggest 

 that a coordinated management plan is necessary for the Jean Lafitte National Park. The plan 

 includes a number of measures designed to reduce wetland erosion, restore a more natural 

 hydrologic regime, increase sediment input to the park, and enhance productivity (Figure 12). The 

 plan also identifies areas of further research necessary to address critical information needs. 



(1) Shoreline Protection Along Lake Salvador 



Lakeside erosion is one of the most critical problems facing the park. To arrest further erosion, 

 some type of shore protection must be implemented. Shore protection as used by the Dutch in 

 the Wadden Sea (Kams 1962; DeGlopper 1965; Boumans et al. 1987) could be coupled with 

 wetland formation. 



(2) Small Scale Lakeside Flotant Conversion Experiment 



We suggest choosing a floating marsh site with potential access to lake suspended sediments 

 (Figure 12). The objectives of this experiment are to determine the feasibility of increasing bulk 

 density of soils of a floating marsh, increasing the overall health and productivity of the area, and, 

 ultimately promoting the succession of floating marsh to stable marsh. 



The design of this pilot project is as follows. A break would be created in a spoil bank adjacent 

 to an area of lakeside floating marsh to allow direct input of resuspended lake sediments to the 

 marsh surface. A low level sill structure should be installed at the spoil break to ensure that the 

 incoming lake water does not cut a crevasse and lead to erosion of the flotant. A wire mesh 

 screen should be stretched across the break to insure that the mat does not float out of the area. 

 Vegetation, soil characteristics, and accretion rates should be monitored every six months for several 

 years to determine the success of the experiment and its practical application to other sites in the 

 park. 



(3) Structural Suggestions 



Several structural measures are necessary to achieve the objectives of the management plan. 

 These include breaching or eliminating some spoil banks along major waterways and installing some 

 ' weirs. Rollover weirs would allow small boat access to the park while dampening water level 

 fluctuations. A slotted weir could be used to allow the marshes and canals to draw down, but 

 prevent rapid water level fluctuations. Slotted weirs would allow access to migratory marine 

 organisms. Other possible weir types include rock weirs and flap-gated weirs. Rock weirs allow 



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