T!ie remaining derelict zones are Y/itbin the Inner Harbor vihere dead end 

 slips receive large amoiints of pollution, mainly of industrial origin, 

 but in each case including domestic sewage some part of which is often 

 ra\T or nearly so. It may be noted that next to some of the derelict zones 

 very high numbers of living animals may congregate as though areas with 

 just tolerable concentrations of pollutants are bordered by belts high in 

 food for these forms or foi" the microbes on \'irhich they depend. In such 

 beds it has been the marine worms or polychetes which have been most 

 abundant. From v;ork on the bottom faunas of Los Angeles-Long Beach, 

 Avalon, New Port and San Diego Harbors, the Council's biologists conclude 

 that the polychete v/orms provide more clear indications of conditions of 

 marine pollution than do any other groun of animals. This is consistent 

 with the findings of Prof. Francis Filice in San Francisco Bay. In 

 general the benthic arthropods and mollusks have proved to be enough more 

 sensitive to be too reduced in numbers to be useful index animals. 



Mr. C. M. Wakeman's periodic surveys have shovm that at the peak of harbor 

 activity in "fforld War II, pollution was so intense in the Inner Harbor 

 that borer activity was checked in an area which would include and join 

 Zones 3 to 7. Determinations of dissolved oxygen were frequently zero 

 for much of the area and positive sulfide readings v/ere obtained from the 

 water. "In lyhO the Industrial Hygiene Service reported Excessive absences 

 from vfork among fish cannery workers as a result of conjunctivitis caused 

 by hydrogen sulfide," Throughout the war years complaints were made by 

 military authorities about paint damage and corrosion of their harbor 

 equipment. As late as 19hQ the U. S. Corps of 3n^ineers estimated the 

 "unnecessary daniarre" to harbor installations, shipping and industry would 

 reach -,^2,000,000 annually. But by 19U8 the harbor was already less pol- 

 luted and serious borer damage T;as observed again within the Inner Harbor, 

 damage v;hich has been increasin;^ since that time. 



Conditions in the harbor during the joint agencies ' surveys and those of 

 the Borer Council may perhaps be considered to be approaching a fairly 

 stable baseline. Although pollution is high enough to raise corrosive 

 action significantly above that of ordinary seavrater, much further improve- 

 m.ent Virill be v/on only by very persuasive measures, educational or other- 

 wise. On the other hand, agencies nov; in existence aiid the balance of 

 interest along the waterfront may be counted upon to hold the line against 

 much additional pollution, 



sii'ith this background we may examine the results of the standard block sur- 

 vey,- Limnoria tripunctata and Teredo diegensis had for the most part a 

 parallel distribution in IJ^O-lP'^l arid, from spot checks, have one today. 

 In contrast ?jith "Yorld '.iar II conditions when most of the Inner Harbor was 

 free of borer activity, only Station C is now v/ithout either gribbles or 

 shipv^orms. Station C receives the runoff of Dominguez Slough, practically 

 an open sewer which drains industrial areas of Los Angeles, Vernon and 

 Torrance inter alia and numerous oil fields. In 11 of lU checks made during 

 the 19^0-1951 survey dissolved oxygen determinations were zero vj-hile in the 

 remainder the reading did not go higher than one part per million. 



1-3 



