whatever) and allow species to spread 

 from this source than to attempt to 

 create a community which is absent at 

 or near the site. 



* Where two or more areas of high 

 resource value occur within the 

 degraded area, plans for enhancement 

 should link the areas with a 

 "corridor" of wetland habitat, rather 

 than surrounding each area with 

 development. Observations near the 

 San Diego River suggest that birds 

 moving back and forth between the 

 river mudflat and Famosa Slough 

 utilize a narrow connecting channel 

 in preference to developed 

 properties, even though the channel 

 route is longer (Wetland Evaluation 

 Class 1981). 



» A modified wetland with no 

 special features to enhance will 

 provide more leeway in designing 

 alterations. Determinations of the 

 most desirable habitats to include 

 should be made with both local and 

 regional objectives in mind, as 

 discussed in the previous section. 



Techniques for achieving 

 objectives include: 



specific 



* Where tidal flushing is impaired, 

 breaching barriers are the usual 

 first suggestion. Without tidal 

 flushing for at least part of the 

 year, the marsh would not develop its 

 normal range of intertidal habitats 

 nor support its full potential of 

 plant and animal species. With tidal 

 flushing, a variety of habitats, 

 identifiable by elevation and 

 substrate type but characterized by 

 different degrees of submergence and 

 salinity, becomes available for 

 colonization. 



In addition to creating the variety 

 of habitats, tides also provide many 

 colonizers. Seeds of marsh plants, spores 

 and colonies of algae, larvae and eggs of 

 fish and invertebrates all disperse with 

 the aid of tides. The earliest natural 



colonizers will be "opportunistic" 

 species — species which usually have many 

 seeds, eggs or larvae available for 

 dispersal. Ubiquitous bacteria, fungi and 

 protozoa, all tiny, rapidly dividing and 

 readily floating individuals^will flourish 

 first by feeding on the organic matter of 

 the sediments. Algae species which grow 

 well both in shallow water and on 

 sediments will probably be the first 

 producers to invade the new habitat. 

 Among the marsh halophytes, pickleweed 

 ( Salicornia virginica ) , sea-blite ( Suaeda 

 californica ) , and perhaps annual 

 pickleweed ( Salicornia bigelovii ) will 

 arrive and begin growth, especially if the 

 restoration site is near a 

 well-established marsh. Species which are 

 poorly dispersed or which are not well 

 adapted to establish on bare substrates 

 will be slow to invade. Artificial 

 establishment may be desirable to speed 

 their development. 



* Where artificial marsh 

 establishment is judged to be 

 desirable, plantings can be 

 undertaken, but environmental 

 characteristics and sources of plants 

 are both restrictive. 



Elsewhere in the United States, marsh 

 establishment has proven successful 

 (Garbisch 1977, Environmental Laboratory 

 1978), although the value of the 

 artificial marshes for wildlife takes much 

 longer to determine. In southern 

 California, guidelines are being developed 

 for marsh establishment (Zedler in prep.), 

 but no large-scale projects have been 

 implemented. 



A major consideration for large-scale 

 artificial marsh establishment is where to 

 obtain the plants. Many of the natural 

 marsh habitats are protected from 

 collecting, and the rest should be. As 

 described here, the marshes are endangered 

 ecosystems, and unnatural disturbances of 

 all types should be carefully controlled. 

 Two alternate sources, which should be 

 explored first are: (1) other projects 

 involving destruction of wetland 

 vegetation, which can then be salvaged for 



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