PLANKTON AND ASSCTIATED NUTRIENTS IN THE WATERS 

 SURROUNDING THREE SEWER OUTFALLS IN SOUTHERN CALIFORNIA 



INTRODUCTION 



The discharge of sewage through ocean outfalls has been 

 investigated as to its possible role in causing an increase 

 of phytoplankton production in the coastal waters of the Los 

 Angeles region. The frequent amber -colored water off the Playa 

 del Rey-Santa Monica shoreline has been quite apparent to local 

 residents during the past decade, and has given rise to the 

 colloquial terminology of "beer-colored breakers". Laymen have 

 attributed this discoloration directly to the sewage effluent, 

 apparently unaware of its more likely origin from plankton 

 blooms o The "red water" is, of course, objectionable to those 

 who frequent the shore, mainly because of the supposed origin, 

 but also due to the distastefulness of swimming and bathing in 

 water that is not "clean and blue". 



Of greater significance is the possibility of the parti- 

 culate organic matter contributed by plankton acting as "sanc- 

 tuaries" for coliform bacteria and allowing the bacteria to 

 persist in the marine environment for periods of time longer 

 than normal. Such a possibility would have little importance 

 if the plankton populations were normal in abundance and occurred 

 in a natural cycle. However, with a constant inflow of avail- 

 able nutrients in proportions many times greater than normal, 

 significant numbers of phytoplankton could conceivably exist 

 throughout the year even though visible blooms are infrequent. 



