153 



A detailed survey in the area of Redondo Canyon on June 

 7 and 8, 1956 o gave surface values of 0o3 ;ug-a/L of phosphate- 

 phosphorus and 4„0 iiig-a/L of silicate-silicon offshore. These 

 values increased toward shore to maxima 0„5 and 6.0 jug-a/L, 

 respectivelyo An attempt was made to determine ammonia, but 

 the method was not sensitive enough to detect the small amounts 

 present in offshore water (0 to 0,5 jjg-a/L >„ On the north side 

 of the head of Redondo Canyon measurable amounts (between 0.5 

 and 1.0 lag-a/L ) began to appear. Phosphate , silicate, and 

 oxygen values ia the surface water were considerably higher 

 than on the previous cruise in January. Throughout the area 

 no oxygen values below 95% saturation were found, and a number 

 of stations indicated a s-apersatmration of up to 7%. 

 Conditions at the HTperion Outfall 



In the vicinity of the Hyperion outfall the nutrient salts 

 were concentrated considerably over the values found in sur- 

 rounding shelf waters. A detailed traverse parallel to the 

 coast was made both north and south of the boil on January 12 

 and 13 p 1956. The dispersal pattern of the nutrients in the 

 effluent was found to be different than at either Orange County 

 or Whites Point. It is believed that this difference is 

 associated with differences in oceaji ©graphic conditions and 

 with differences in the character of the effluents. The higher 

 concentrations of nitrate and silicate and, to a degree, phos- 

 phate were found in the subsurface and bottom layers with an 

 intermediate layer of lower concentration at a depth of 20 feet. 

 On the other hand, ammonia-nitrogen decreased from a relatively 

 high value in surface water to a depth of 15 feet, where it 



