(Contribution from the University of Southern California) 



THE REL/.TIONSHIP OF THS AR'JAS OF MARINE BORER ATTACK 

 TO POLLUTION PATTERNS IF LOS /NGELES-LONG BEACH HARBORS 



by John L, Mohr 



Los Angeles and Long Beach Harbors comprise somewhat more than 7jO0O acres 

 of -..i-ater of thirty-five foot average depth enclosed by a rock breakwater 

 from the remainder of San Pedro Lay. Terminal Island, built up from a 

 line of mud \vaddens and low islands and supporting extensive naval and 

 industrial installations, provides several enclosed anchorages opening 

 on the Outer Harbor and protects the waters of the Inner Harbor. The 

 Inner Harbor appears on the map as a six-mile arch of water v^rith approaches 

 from the Outer Harbor at east (Long Beach) and west (Los Angeles) by 

 thirt3'"-foot channels. 



Although flushing and current patterns have not been adequately studied, 

 it has been estimated that with roughly 250,000 acre feet (80 billion 

 gallons) of r/ater in the harbor, the daily tidal oj''cles move about a fifth 

 or 50,000 acre feet of v;ater in and out the break^Arater. Accordingly, it 

 might be predicted that any acute ef.i'ects of pollution would be found in 

 enclosed areas particularly of the Inner I-iarbor. 



Surveys on the effects of harbor pollution have been of two sorts. Under 

 the aegis of the Los ■''^ngeles Regional ..ater Pollution Board, a coordinating 

 agency of the State of California, some 17 agencies concerned with harbor 

 conditions carrie-d, mainly in 19^1, an investigation into the sources and 

 effects of pollution in Los Angeles-Long Beach Harbors. Fifty-five stations 

 in Los Angeles and eighteen in Long beach Harbor ivere made. An 

 abridged report of the joint agencies is in press. In this investigation 

 the study of bottom conditions made by analysis of sauplings by a small 

 orange-peel bucket was carried out by my colleagues of the Southern Cali- 

 fornia Larine Borer Council for the Department of Fish and Game. Secondly, 

 the Council has carried on studies v'ith standard Douglas fir blocks and 

 microscope slide carriers at fifteen stations ghoson to represent 

 a wide range of theriral, pollutional and other factcrs. From these specific 

 data has been obtained on borer activity and fouling in the major areas 

 of the harbor. Finally, the records of the decennial surveys of piling 

 condition in Los Angeles Harbor (the most recent being that of 19U6) have 

 bee'-; made available by Li*. C. i.i, ;.'akeman. Testing Engineer of the Los 

 Angeles Harbor Department, 



Degree of pollution in a harbor may be gauged in a number of ways. The 

 actual quantitative determination of particular pollutants :.'ould be most 

 desirable. The chemists of the joint agencies' survey found, hoxrever, 

 tl'iat with practicable survey methods it was not possible to demonstrate 

 certain deleterious substances knovm to be entering the harbor in con- 

 siderable amounts at specific points. The effects of such pollutants may 

 usually be noted by their depression of the dissolved o^qygen index, in- 



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