32 



similar to those in Santa Monica Bay, averaging 55,5°F, and 

 the range from 150 feet to the surface was about 3°. True 

 isothermal conditions extended below 50 feet, where a tendency 

 toward a therraocline occurred » At or slightly below this 

 depth, several masses of warm water were noted. On February 

 12, these subsurface inversion layers were distinct and more 

 or less continuous for two miles north of the outfall area 

 (Figure 11) „ 



During March the surface water temperatures rose to a 

 maximum of 580F„ Subsurface temperatures were still more or 

 less isothermal in the vicinity of the Orange County and the 

 Hyperion outfalls » Near Whites Point, however, there was a 

 range of from 7 to 8°, from 150 feet to the surface, and 

 maximiim surface temperatures were slightly lower (57,20F). 

 In April, maximum surface temperatures reached 630, In the 

 vicinity of the two shallower outfalls the subsurface tempera- 

 ture range averaged 8®, and the greatest range was lO^F. At 

 the Whites Point outfall, a range of 10^ was common and 11 and 

 120 frequent o 



In the latter part of May, when increased numbers of 

 plankton began to occur in the waters, surface temperatures 

 remained at approximately 63°, but the temperature spread 

 from 55 feet and from 150 feet increased sharply. In June 

 the maximum surface temperature was 65°. In the vicinity of 

 the two shallower outfalls, temperatures at the bottom began 

 to rise so that again more or less isothermal conditions 

 existed. At Whites Point, on the other hand, an increased 

 spread was noted from that of the other months. For example. 



