sewage into the sea, and was an added inducement to the stiidy 

 of this problem. During the warm months of 1955 (July, August, 

 and September) many areas having yellow-green discoloration were 

 noted south of El Segundo. The patches, extending two to three 

 miles seaward, were sampled on several occasions. Phytoplankton 

 numbers were high and consisted chiefly of Ceratium f urea , 

 although many other dinoflagellates as well as diatoms were 

 present. However, the water was not nearly as intensely colored, 

 nor populations as high as in the waters north of El Segundo 

 between Venice and Santa Monica. Along the latter shore and 

 extending from 0.5 to 1.0 mile from the coast was a reddish- 

 brown discoloration which persisted for periods of 10-20 days,, 

 This water contained the same organisms in about the same 

 ratios, but in numbers many times greater. The normal path 

 of the effluent-enriched waters during these months is north 

 from the outfall, striking the shore in the Venice area, the 

 same area of abundant plankton. 



THE NUTRIENT SALTS 



Phosphate, nitrate, silicate, and iron are among the most 

 important of the various compounds dissolved in sea water, as 

 limiting factors in phytoplankton growth. Many experiments 

 have been conducted under laboratory conditions on pure cultures 

 to determine the reactions and requirements of plankton for 

 nutrients (Harvey, 1955). Few experiments have been conducted 

 using more than one type of organism or with other than sterile 

 sea water. None have approached the multitude of complexities 

 involved in the sea with a vast variety of plankton using and 



