The degree and significance of wildlife displacement resulting from 

 all preexploration activities are impossible to predict or quantify. 

 The point where noise and human presence may change temporary and 

 partial displacement to permanent and complete displacement is 

 unknown, but this factor should be considered during all phases of 

 activities since it extends the effects of the project beyond the 

 boundaries. 



Key attribute alterations 



The alteration which leads to the most significant impacts on the 

 ecosystem is the creation of depressions in the land surface. 

 Although long-term effects on vegetation types may result from 

 changes in waterflow regimes, the areal extent and impact on con- 

 sumers are minimal. As discussed above, direct vegetation removal 

 may be beneficial in some instances. 



Gravity preexploration . 



1. Activity sequence 



Gravity surveys may involve the placement of a relatively smal 

 equipment on the marsh surface. This unit (the gravity meter) 

 carried to stations by marsh buggy, vessel, or foot. Survey c 

 not required since data need not come from predetermined locat 

 is necessary only to plot the locations of the data-collection 

 on a map. A small amount of vegetation is trampled during the 

 of the gravity meter. Several minutes are required for data c 

 the unit is then packed and carried to the next station. The 

 stations required for a gravity-meter survey is less than the 

 shot holes necessary for a seismic survey. Two men with adequ 

 sportation can efficiently conduct a gravity-meter survey. 



1 piece of 

 may be 

 rews are 

 ions. It 

 stations 

 placement 

 ollection; 

 number of 

 number of 

 ate tran- 



2. Primary ecological alterations 



2.1 Creation of ruts or depressions in the land surface 



2.2 Trampling and crushing of vegetation at the station locations 



2.3 Localized change in direction of water flow 



2.4 Possible creation of pathway for increased rate of flow of runoff 



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