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piling at Port Costa driven prior to 1870 was untouched by Teredo 

 prior to the recent outbreak, although several periods of low rainfall 

 similar to the recent one have intervened, which might have permitted 

 an outbreak. 



Teredo navalis lives in a wide range of salinities in San Francisco 

 Bay and is subject, therefore, to considerable variation, which does not, 

 however, obliterate its specific identity with the European species, 

 T. navalis. 



The fact that this notorious pest of marine piling in European 

 waters has established itself in San Francisco and San Diego Bays, 

 where it repeats its history of destruction of marine piling elsewhere, 

 is indicative of the possibility of its invasion of other regions. Hence 

 engineers in charge of the construction and maintenance of marine 

 structures in marine and brackish waters at present free from Teredo 

 navalis should be on guard against its occurrence and provide against 

 its destructive activities by suitable protective or preventive measures. 



FUTURE WORK 



The scope of the work now contemplated by this Committee will 

 be sufficiently clear from the reports on the several phases of the work. 

 No statement will therefore be repeated here. The considerations 

 which indicate the necessity of a continuation of the work, it is believed, 

 will also have been made clear. The Committee feels that they are 

 of urgent weight. It therefore desires to recommend to the Associa- 

 tion, in the strongest manner possible, the granting of its authority 

 for such a continuance. 



For the San Francisco Bay Marine Piling Committee, 



(Signed) F. D. MATTOS, 

 A. A. BROWN, 

 W. C. BALL, 

 C. A. KOFOID, 

 L. D. JURS, 

 C. E. CORTES, 

 H. H. HALL, 

 C. L. HILL, Chairman, 



Executive Committee 



