the midfifties and an abundance of sea urchins, may be responsible for 

 the kelp reduction. The kelp beds of California, however, are not 

 obliterated by any means. The kelp industry harvests annually 100,000 

 to 120,000 tons of this important resource. 



The general conclusion of all studies in Santa Monica Bay is that in 

 the 20 years of continuous discharges by the Hyperion Plant, with the 

 exception of the kelp, remarkably little damage has been done to the 

 marine environment. 



b. San Diego . The rate of accumulation of digested sludge discharged 

 by an ocean outfall located 2 miles off the San Diego shore in 200 feet 

 of water, has been reported by Orlob (1965) . 



In this study, the sludge accumulation rate was estimated at 0.1 

 inch per year near the outfall, with 40 percent of the solids settling at 

 such slow rates that their accumulation within a radius of 5 miles could be 

 considered neglible. Grease and floatables were identified as a potent- 

 ial problem, but were not defined quantitatively. The study did not con- 

 sider the effects or destination of the solids which are carried away 

 from the discharge area. 



6. San Francisco Bay 



About 8 million cubic yards of material is dredged annually from San 

 Francisco Bay. Most of the dredge spoil is disposed of outside the Bay 

 on the San Francisco Bar, but part of it has been dumped inside the Bay 

 near Alcatraz Island. 



To determine the effects of dredging and spoil disposal on fish and 

 wildlife environment within certain areas of San Francisco and- San Pablo 

 Bays, the Corps of Engineers funded a study by the U. S. Fish and Wild- 

 life Service (National Marine Fisheries Service). Due to rapidly 

 fluctuating environmental variables, this study did not determine any 

 apparent adverse effects in the deep channel areas (U. S. Fish and 

 Wildlife, 1970). In the other areas, however, the study indicated a 

 significant reduction of numbers and species composition of benthic 

 organisms and demersal fish. Although certain species reestablished 

 themselves in the affected areas within a short time, the species diver- 

 sity index did not return to its previous level during the study period. 

 The study did not show that turbidity had a major effect on marine life. 

 Furthermore, turbidity within the Bay, at least in the shallow areas, 

 appears to be a naturally occurring phenomenon. According to the Civil 

 Engineering Department of the University of California at Davis (Krone, 

 1972, informal communication) which has conducted studies of the water- 

 ways circulation system in San Francisco Bay for more than a decade, 

 present and past dredging activities are in significant in terms of 

 total distribution of sediment being put to circulation by natural pro- 

 cesses. According to these studies, the amount of bottom sediment 

 agitated into suspension in 5-foot depths by wave action of 10-knot 

 winds blowing from less than 5 square miles of the Bay, exceeds the 



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