VI-57 



in any case. A species sensitive to sediments, therefore, would not 

 normally be present in turbid waters. Generally, then, natural 

 sedimentation cannot be considered highly damaging to estuarine biota. 



Man-induced sedimentation is unfortunately another story. Denuding 

 an area of earth releases to the hydrologic system an exponentially 

 large amount of sediments. Rainfall washing over these bare areas 

 carries sediment loads in slugs into the surface water drainage 

 system, disturbing the ecosystem with unaccustomed turbidity. It is 

 frequently when these streams reach sea level --the estuaries--that the 

 water's momentum is slowed sufficiently to permit the sedimentation 

 process to take place. The ecosystem is disturbed not only by excess 

 turbidity, but also by an excess sedimentary covering which coat? the 

 bottom, smothering many life forms and changing the basic configuration 

 of the estuary. 



Sediment loads in rivers are transient phenomena related to sudden 

 increases in flow and other climatological conditions. Understanding and 

 mastering the problems of sedimentation pollution in estuaries requires 

 a much broader data base than is now available. Much of the necessary 

 data can be obtained through consistent sediment load and bottom con- 

 dition monitoring throughout the estuarine zone. 



USES AND USE DAMAGES 



A body of water may be littered with floating debris, it may be turbid 

 and foul-smelling , and to all intents and purposes, dead, yet proving 



