tenance dredging of the harbor entrance was carried out from 26 January to 20 

 February 1976 using a hydraulic pipeline. The dredged material was placed along 

 a 213-meter section of beach between the harbor's protective breakwater and an 

 abandoned wharf. Observations of three subtidal regions were made before, dur- 

 ing, and after the completion of dredging using scuba equipment. The breakwater, 

 abandoned wharf, and nearshore bottom between these two structures were observed. 

 Turbidity, sedimentation, mortality, and behavioral effects of dredging on 

 organisms were observed. Only the inner areas of the breakwater showed signs of 

 sedimentation and no behavioral effects or mortalities were observed due to its 

 presence. Sedimentation in this area had little effect on the settling of lar- 

 val invertebrates or the growth of new algae. It was assumed that all sediment on 

 the breakwater would disperse over time and all effects were short-term, as no 

 sediment was found prior to the 1976 dredging. 



153. SMITH, R.W., et al., "Hydrographic and Ecological Effects of Enlargement 

 of the Chesapeake and Delaware Canal, Appendix IX, Delaware Fish Migra- 

 tion," Final Report, University of Maryland, National Resources Institute, 

 Solomons, Md., 1973. 



Tag and recapture data are given in the different fish species that used 

 the Chesapeake and Delaware Canal in migrations and movement during the period 

 1971 to 1973. 



154. SNYDER, G.R., "Effects of Dredging on Aquatic Organisms with Special 

 Application to Areas Adjacent to the Northeastern Pacific Ocean," 

 Marine Fisheries Review, Vol. 38, No. 11, Nov. 1976, pp. 34-38. 



Dredging can be accomplished by using one of three processes of dredging: 

 hydraulic, mechanical, or a combination of the two. Several types of impacts 

 on aquatic organisms from these three dredging processes are discussed, includ- 

 ing the mechanical effects, turbidity, and other miscellaneous effects. 



155. SOLLITT, C.K. , and CRANE, S.D., "Physical Changes in Estuarine Sediments 

 Accompanying Channel Dredging," Proceedings of the 14th Conference on 

 Coastal Engineering, American Society of Civil Engineers, Vol. 2, June 1974, 

 pp. 1289-1303. 



The physical characteristics of estuarine sediments provide useful informa- 

 tion about sediment sources, the nature of bottom surface stresses, and sediment 

 transport mechanisms. Changes in sediment composition and state are also useful 

 indicators for estimating the effects of unnatural stresses on dependent chemical 

 and biological activities. In this study, the changes in several sediment prop- 

 erties have been monitored for an isolated estuarine dredging project. 



156. SOLOMON, D.J., "Migration of Smolts of Atlantic Salmon {Salmo salar L.) 

 and Sea Trout {Salmo truta L.) in a Chalkstream," Environmental Biology 

 of Fishes, Vol. 3, No. 2, June 1978, pp. 223-229. 



The migration of smolts in the River Piddle, Dorset, was studied over 3 

 years in relation to factors that could influence downstream movement. The 

 river originates mostly from ground-water springs, resulting in stable flows 

 and low turbidity, except in rainy weather. Fish were intercepted at the tidal 

 limit in a fixed trap-net and measurements of water temperature, discharge, 

 turbidity, barometric pressure, rainfall, and solar radiation were taken nearby. 

 The slightly increased turbidity and discharge following heavy rain initiated 

 major movements during 2 (nights) of the 55 days studied. At other times large- 

 scale movements took place during sunny, warm afternoons. Both solar radiation 



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