65. HENEGAN, D.L., and HARMON, K.W., "A Review of References to Channelization 

 and Its Environmental Impact," Stream Channelization; A Symposinmj Special 

 Publication No. 2, American Fisheries Society, Dec. 1971, pp. 79-83. 



References to stream channelization and its environmental impacts are not 

 easy to locate. Few such studies find their way into the formal literature. 

 This report provides the references that are available. 



66. HERBICH, J.B., "Environmental Effects of Dredging," Proceedings of the 

 Fifth World Dredging Conference, June 1973, pp. 699-719. 



This paper summarizes the present state-of-the-art of the effects of dredg- 

 ing on the environment. The possible advantageous effects include: removal of 

 polluted bottom sediment for storage or treatment, change in flow patterns, 

 reoxygenation of sediments and the water columns, and resuspension of nutrients. I 

 The possible deleterious effects include: removal or burial of habitats, 

 change in the flow pattern, resuspension of polluted bottom sediments, and 

 a possible barrier to the movement of marine life. 



67. HILLMAN, R.E., "Effects of Dredging on Marine Ecology," World Dredging and 

 Marine Construction, Vol. 7, No. 7, June 1971, pp. 25-27. 



Several techniques for collecting samples for the assessment of the impact 

 of dredging on the environment are discussed. Techniques for data sampling 

 before, during, and after dredging will pinpoint the ecological effects of dredg- 

 ing on aquatic organisms. These techniques are utilized with the goal of pro- 

 ducing data suitable for use in constructing mathematical models that stimulate 

 events occurring in nature and give the models predictive capability. 



68. HIRSCH, N.D., DiSALVO, L.H. , and PEDDICORD, R., "Effects of Dredging and 

 Disposal on Aquatic Organisms ,"Vicksburg, Miss., Technical Report DS-78-5. 

 Dredged Material Research Program, U.S. Army Engineer Waterways Experiment 

 Station, Vicksburg, Miss., 1978. 



This report synthesizes data from the U.S. Army, Corps of Engineers' Dredged 

 Material Research Program (Task ID) that investigated the direct and indirect 

 effects of dredging and the disposal of dredged material on aquatic organisms. 

 Direct effects of dredging and disposal are restricted to the immediate area of 

 operation. They include the removal of organisms at dredging sites and the 

 burial of organisms at disposal sites. Data indicate that the recovery of dis- 

 turbed sites occurs over periods of weeks, months, or years. Possible mecha- 

 nisms of recolonization include lateral and vertical migration of organisms and 

 larval recruitment. Disturbed sites may be recolonized by opportunistic species, 

 which are not normally the dominant species occurring at nearby undisturbed sites, 



Most organisms studied were relatively insensitive to the effects of sedi- 

 ment suspension in the water. Dredging- induced turbidity is probably not of 

 major environmental concern in most cases, but may be an esthetic problem. 

 The formation of fluid mud due to dredging and disposal is a poorly understood 

 process and is of probable environmental concern. Available data indicate 

 that suspensions of highly contaminated sediments have a greater potential for 

 adverse effects than uncontaminated or lightly contaminated sediments. 



Bioavailability of sediment-absorbed heavy metals is low. The release of 



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