It is notable that in a closeby area (Station 3) with very little higher 

 dissolved oxygen (between 2-3 ppm. for much of the year) both Limnoria 

 tripunctata and Teredo di egensis are present. The region of maximal 

 activity (Station D or Zone 6 among the derelict areas) is both close by 

 and highly polluted. 



Of the remaining borers of the harbor, Limnoria quadr ipun c t ata is found 

 only in Fish Harbor of the zones of heavy pollution. While the major 

 pollution here is of animal origin, lacking the toxicants of Inner Harbor 

 pollution, and while flushing action from the Outer Harbor is probably 

 strong and effective, the fact that this species of Limnoria is a cooler 

 virater species probably means that it would not in any case thrive in the 

 warmer waters of the Inner Harbor, Therefore, the observations on dis- 

 tribution in Los Angeles-Long Beach Harbors cannot be taken necessarily 

 to indicate a low tolerance for pollution. For the boring amphipod, 

 Chelura ter ebrans , the same may be true although ive believe that this is 

 a generally less adaptable animal than our two Limnorias , It appears 

 to be restricted to the waters of the Outer Harbor and the Naval Base. 

 Bankia setacea , the larger, coldwater ehipworm, has been more difficult 

 to spot as its swimming young (veligers) are released only in the cold- 

 est months in our 'larbor,. The one flourishing center we know about is 

 by the lighthouse at the entrance to the break'A'ater, the coldest area 

 in the harbors. Other centers have been active, but all in cold v/aters. 

 Therefore, the fact that these are also clean waters may not be signifi- 

 cant and one cannot conclude from these observations that Bankia setacea 

 cannot thrive under conditi --ns of pollution. 



Council studies of fouling organisms have been carried far enough to shoAr 

 population patterns for the bryozosns, h^'^droids and tunicates. Of these 

 the- hardiest is the small colonial hydroid, Obelia d ichotoma , v/hich appears 

 from time to time in small niombers even at Station C where all borers are 

 absent. Like Ljmnoria tripunctata and Teredo diegensis it flourishes in 

 derelict Zone 6 where industrial toxicants are a little less than maximal, 



SWMARY 



1. Surveys of the effects of pollution in Los Angeles-Long Beach Harbors 

 have been made by means of orange-peel bucket sampling of the bottom 

 and by standard block samplers for boring and fouling organisms. 



2. Pollution in restricted areas of Los Angeles-Long Beach Harbors has 

 for extended periods reached concentrations stopping all borer and 

 fouling activity. 



3. Lethal concentrations for borers have occurred only in parts of the 

 harbor in which tidal flushing appears to be reduced. 



ii. Bottom life (benthos) appears to be first affected and recovers 

 slowly so that there are large derelict areas about the principal 

 concentrations of pollution. 



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