IV-143 



TABLE IV. 2. 9 

 Annual Harbor and Channel Dredging and Maintenance Costs 



REFERENCE: THE NATIONAL ESTUARINE INVENTORY 

 DATA SOURCE: U. S. ARMY CORPS OF ENGINEERS 



barrier for Hi lo Bay in Hawaii were conducted by the Corps of 

 Engn§eers but no construction has taken place. 



Major modifications of estuarine areas by land fill or marsh and wet- 

 land reclamation have occurred throughout the Nation. The area 

 reclaimed is generally the highly productive tidal marsh wfcich is so 

 important to estuarine ecology. As an example, 80 percent of the 



