and provide ready access for interpretive 

 activities. Several of the estuary's habitats 

 will be created within the excavation, 

 including tidal creek, mudflat, lower-to- 

 upper marsh, and transition to upland. It is 

 likely that the public will join in the habitat 

 creation projects, much as volunteers have 

 participated in planting and weeding the 

 coastal scrub vegetation that landscapes the 

 Visitor Center site. 



The third feature is the widening of 

 Oneonta Slough where a buried hard pan 

 prevents inland migration of the channel. 

 Unless the hard substrates are removed, tidal 

 flows would eventually be pinched off as the 

 dune gradually encroaches from the west. 

 Maintaining Oneonta Slough as the tidal access 

 for the north arm of the estuary will make it 

 unnecessary to cut a new channel south of the 

 tidal ponds, thus preserving the transitional 

 wetland-upland habitats that occur there. 



Figure 6.5. The 20-acre experimental marsh 

 is the largest component of the first phase of 

 the Tidal Restoration Plan. The importance of 

 tidal creek networks will be tested by com- 

 paring ecosystem development in areas with 

 and without such topographic heterogeneity. 



6.4.3 The 495-Acre Project 



It is expected that the 495-acre 

 excavation (Figure 6.6) will be implemented 

 over two or more decades, since the project 

 will be costly and funds are not currently 

 available for the work. An innovative, 

 modular approach will accomplish two 

 adaptive management objectives. First, it 

 will be possible to match each funding 

 opportunity with the restoration of one or 

 more habitat modules. Rather than proceeding 

 in a piecemeal fashion, the restoration will be 

 completed in modules to make up the 495- 

 acre program. Second, monitoring and 

 research on each completed module will 

 improve the next. As problems are identified, 

 corrective measures can be built into later 

 construction plans. As restoration methods 

 are improved or new ideas developed, they can 

 be incorporated into subsequent modules. The 

 essence of adaptive management is a dynamic 

 plan that can improve as knowledge 

 accumulates and restoration science 

 progresses. 



6.4.4 Restoration Research Needs 



Several questions remain about how to 

 conduct the sediment removal program: How 

 should the negative impacts of dredging be 

 mitigated? Where should dredge spoils be 

 deposited? How can river floods be diverted 

 away from the restoration area to prevent 

 further sediment deposition? How can the 

 dunes be stabilized to prevent sedimentation of 

 adjacent channels? How can we salvage 

 vegetation that will be damaged during 

 excavation? How should new marsh habitats 

 be created to speed their development toward a 

 fully functional wetland? How can the 

 movements of undocumented aliens be diverted 

 away from restored and other critical 

 habitats? 



In response to these needs the restoration 

 plan (Entrix et al. 1991) details 

 experimental projects, points out alternative 

 restoration measures, and calls for 

 supplemental impact analysis once choices 

 are made. Four of the unresolved issues are 

 discussed below: 



135 



