119. O'CONNOR, J.M., NEUMANN, D.A., and SHERK, J. A., Jr., "Sublethal Effects of 

 Suspended Sediments on Estuarine Fish," TP 77-3, U.S. Army, Corps of 

 Engineers, Coastal Engineering Research Center, Fort Belvoir, Va., Feb. 

 1977. 



The objective of this study was to determine the effects, if any, of sub- 

 lethal concentrations of suspended materials on the fish in estuarine systems. 

 The suspensions were of natural sediment, obtained from the Patuxent River 

 estuary, Maryland, or commercially available fuller's earth. 



120. O'CONNER, J.M., and SHERK, J. A., Jr., "The Responses of Some Estuarine 

 Organisms to Suspended Solids," Proceedings of the Seventh Dredging 

 Semivar, Center for Dredging Studies, Texas A & M University, College 

 Station, Tex., Sept. 1975, pp. 215-234. 



Potential environmental hazards from dredging may be estimated accurately 

 by knowing, prior to operation, the particle-size distribution of the material 

 to be dredged and the volume of material to be removed; the sufficient physical 

 characteristics of the area to estimate accurately the settling time and aerial 

 dilution of the finest particles to be resuspended; and the biota of the af- 

 fected area — phytoplankton, zooplankton, fish and benthos — and their ecology. 



This study shows that suspended solids have a significant effect on pri- 

 mary productivity, zooplankton feeding rates, fish survival, and the physio- 

 logical state of fishes. The effects of suspended sediments on phytoplankton 

 and zooplankton appeared to be related to particle concentrations rather than 

 to particle size. 



It was concluded that dredging and spoiling operations are capable of 

 producing suspended-solid concentrations capable of affecting the natural 

 function of organisms and ecosystems as a whole. 



121. ODUM, H.T., "Productivity Measurements in Texas Turtle Grass and the 

 Effects of Dredging an Intracoastal Channel," Publication of the Insti- 

 tute of Marine Scienoey University of Texas, Austin, Tex., Vol. 9, 1963, 

 pp. 48-53. 



Benthic chlorophyll a and diurnal oxygen productivity were measured in 

 turtlegrass beds containing Thalassia testudium and Diplanthera wrightii in 

 Redish Bay, Texas, both before and after the dredging of an intracoastal canal. 

 Moderate values of photosynthesis (2 to 8 grams of oxygen per square meter 

 per day) were observed in the spring of 1959 following a period of shading by 

 turbid dredge waters, but exceptionally high values (12 to 38 grams per square 

 meter per day) were recorded the following spring in those areas not smothered 

 with silt. Chlorophyll a averaged 0.0338 gram per square meter in 1959, but 

 increased to 0.68 gram per square meter the following summer. 



122. OLIVER, J.S., and SLATTERY, P.N., "Effects of Dredging and Disposal on 

 Some Benthos at Monterey Bay, California," TP 76-15, U.S. Array, Corps of 

 Engineers, Coastal Engineering Research Center, Fort Belvoir, Va., 



Oct. 1976. 



The specific objectives of this study were to document: (a) natural 

 temporal variations in benthic assemblages and changes related to substrate 



41 



