On December 9, 19k-6, the Shipyard advised tliat extensive dredging 

 operations had been in progress in the area between the Shipbuilding 

 Ways and the west boundary since May Ik, 19h6, and that these operations 

 had caused considerable turbidity in the water because of a large amount 

 of suspended silt. At that time, pollution tests showed Bacillus coll 

 heavy at the Receiving Station Pier and medium at the other two locations. 

 This extensive dredging continued until the end of 19^6, and dredging 

 continued in the vicinity of the Receiving Station Rler until the end 

 of March 19^7, when heavy pier construction in this area continued to 

 keep the water somewhat turbid as late as the middle of August 19^7. 



The following record of temperature of the water in degrees F, 

 from readings made about the middle of each month, shows the general 

 range throughout the year at each location. 



A57 • 03 Marine Borers 



1. Tered . inldae . Teredlnidae (Bankia setacea) were very active at 

 all three locations throughout the period covered by the tests. On March 

 27, 19^7^ the Shipyard advised that panels on the test boards were more 

 or less completely eaten away because of the activity of these borers, ajid 

 it was requested that the panels on these boards be removed and new boards 



165 



