2. Primary ecological alterations 



2.1 Temporary loss of producer biomass along flowlines, vegetated 

 levees, and pad sites 



2.2 Loss of consumer biomass in access canals and pipeline canals 

 due to refilling procedures 



2.3 Increase in producer biomass on formerly barren sites due to 

 revegetation 



2.4 Increase in suspended sediments and dissolved nutrient con- 

 centrations 



2.5 Alteration of modified circulation patterns as a consequence of 

 reestablishing former marsh flow regimes 



3. Attribute alterations 



Procedures which reestablish the surface contours existing prior to 

 those topographic alterations generated by canal dredging, levee and 

 pad construction, and pipeline activities are most effective in 

 restoring basic site, as well as ecosystem, integrity. Flow pat- 

 terns interrupted by levees and diversion canals are reestablished. 

 Backfilling, canal plugging, levee grading, and levee breaching 

 procedures remove or bypass such obstructions and facilitate restora- 

 tion of the original flow patterns. Inherent properties of the 

 water covering the brackish marsh, such as average water depth, 

 frequency of inundation and exposure, and duration of submergence, 

 effectively regulate the dominance of Spartina patens or Sci rpus 

 spp. and consequently determine the nature of the marsh fauna. 

 Rectification of alterations caused by diking, ditching, and channel- 

 ization help restore the balance of freshwater and saltwater inflows 

 and degree of intramarsh mixing if the system has not been irrepa- 

 rably altered. Many aquatic invertebrates and fish species, particu- 

 larly larval and juvenile forms, are dependent on certain salinity 

 regimes for optimum growth and development. Restoration helps 

 reestablish the initial salinity regime and thereby enhances the 

 continued productivity of these components. 



Reworking levees, filling in canals and pits, and removing surface 

 flowlines destroys small quantities of producer biomass that may 

 have become established on such sites during the operational life of 

 the facility. Favorable cover types for select wildlife species 

 which may have become established are also lost. Canal levees are 

 the most important in this respect. Suspended sediments associated 



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