• Habitats which make up the 

 wetland complex should be contiguous 

 with one another. If development is 

 proposed between segments of the 

 wetland complex, it is advisable to 

 leave a corridor for animal movements 

 between the larger areas. 



• The wetland needs to be buffered 

 from adjacent developments by both 

 fencing (to exclude dogs) and 

 vegetation (to reduce noise and 

 visual disturbances) . The width of 

 the buffer would depend on the 

 species using the wetland, since 

 sensitivities may differ. More 

 information is needed to determine 

 the buffer requirements necessary for 

 various birds. In general, wetlands 

 surrounded by bluffs could have 

 narrower buffers than wetlands 

 surrounded by flat topography, where 

 wildlife would be more aware of 

 nearby activities. 



• Buildings constructed near 

 wetlands could provide a skyline that 

 slopes toward the wetland, so that 

 birds will have wider flight paths. 



Developers should be made aware of 

 the positive aspects of wetlands, so their 

 natural features can be used to advantage, 

 rather than ignored. The upper floors of 

 hotels, motels and apartment buildings 

 could focus on the wetland; restaurants 

 could provide windows and other 

 visitor-serving structures to promote 

 their proximity to wildlife habitats and 

 incorporate educational information into 

 their decor. Where attempts to improve 

 public awareness and understanding of 

 wetland resources are made, it may be 

 desirable to provide an opening in the 

 buffer for direct viewing. Disturbances 

 to wildlife may be offset by greater 

 support for wildlife conservation. 



Other educational efforts, e.g. 

 viewing telescopes, interpretive signs, 

 etc., could be placed near other parking 

 lots, to minimize the area paved. 



Reduced Tidal Circulation 



Filling of wetland habitats to build 

 roadbeds or buildings reduces the tidal 

 prism and increases the probability of 

 sand bar formation at the ocean 

 connection, as discussed in Chapter 1. 

 Following closure, channel water becomes 

 stagnant, heating up, losing oxygen, 

 fostering algal blooms, and ultimately 

 causing fish kills and reducing foods for 

 carnivorous birds. Closed lagoons pose 

 management problems because nearby 

 residents complain about bad smells and 

 insects (midges and mosquitos) which breed 

 in quiet water. 



If, as discussed in Chapter 2, there 

 are also local species extinctions (such 

 as Spartina foliosa and associated clapper 

 rails), closed lagoons may become less 

 useful for the preservation of endangered 

 species. For all of these reasons, 

 managers and biologists have agreed that 

 tidally flushed wetlands are preferable to 

 frequently or persistently closed lagoons 

 (e.g. discussions of Los Penasquitos in 

 Metz 1978). 



Furthermore, closed ocean connections 

 prevent movement of accumulated sediments 

 out of lagoons. With development of steep 

 slopes upstream, southern California's 

 highly erodible soils readily move toward 

 the coast. In planning to protect Los 

 Penasquitos Lagoon from further 

 sedimentation while still allowing 

 construction north of San Diego, the San 

 Diego Association of Governments has 

 called for the opening of its inlet, and 

 further studies to determine if continuous 

 or only periodical opening is desirable 

 (Huff 1981). 



A variety of techniques are available 

 for dredging sediments and cutting through 

 sand bars, from hand shovelling to use of 

 bulldozers. A sand fluidizing system has 

 been developed recently by Inman and 

 Nordstrom (1977). Although only 

 moderately successful in the Penasquitos 

 Lagoon mouth, where cobbles slowed the 

 movement of materials to 30 m /hr, the 

 system should transport up to 100 m /hr of 

 pure sand. 



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