when compared to the total area of salt marsh. Consumers that 

 depend upon smooth cordgrass and its epiphytes for food and/or cover 

 may ultimately increase or decrease. 



The amount of detritus exported to the adjacent estuarine system is 

 directly proportional to the standing crop of smooth cordgrass. If 

 the affected area is close to the estuary, the frequency of inunda- 

 tion and detritus export may remain unchanged. However the depres- 

 sions allow faster movement of water in both directions. This 

 results in an increase of turbidity and a decrease in the efficiency 

 of the detritus-filtering mechanism of the salt marsh. Thus, a net 

 increase of exported detritus could result. Net amounts of nutri- 

 ents and sediment probably would not change significantly. 



If the affected area is further removed from the estuary where 

 isolated ponds may exist, intramarsh circulation could be affected. 

 Depressions could connect individual water bodies and increase the 

 intermixing of their contents. Waterfowl and wading bird use would 

 be expected to increase in these new depressions with standing water. 

 At the ecosystem level, however, this increase is slight. 



Additional destruction of vegetation and consumers is expected if 

 spoil levees/piles and dikes are leveled. The planting of vegeta- 

 tion in newly exposed areas, however, would requite these losses. 



The increases in suspended sediments associated with disassembly 

 operations (at marine sites) and filling of depressions (canals, 

 ditches, pits) are transient and affect a relatively small area, 

 especially if plugs are first placed at the mouths of the depres- 

 sions. Reestablishment of vegetation will help prevent long-term 

 erosion problems. Filling canals, ditches, borrow pits, and other 

 depressions eliminates these artificial pathways for inundation and 

 runoff that have existed for many years. The impacts (if any) 

 resulting from the original physical changes have already occurred. 

 The effects and desirability of filling these depressions must be 

 assessed on a site-by-site basis while considering the objectives of 

 a particular refuge system. Especially important are the induced 

 vegetation effects resulting from changes in frequency of inundation 

 and runoff rates. Perhaps of less importance are the losses of 

 phytoplankton and aquatic organisms associated with these depressions. 



Small amounts of toxic materials may enter the soil and/or water 

 systems during disassembly, removal, and cleanup of equipment and 

 pipelines. As emphasized in the section of this report on spills 

 and cleanup, the magnitude of effects depends on the composition of 

 the spilled material, the amount of material, and the area covered 

 by the material. The latter factor is strongly influenced by the 

 amount of surface water present. Both the short-term and long-term 

 effects are site specific and cannot be predicted. 



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