A7 . 05 Marine Borers 



1. Teredlnldae . No evidence of Teredlnidae was recorded cm any 

 of the panels of the test "boards at any of the four locatictns. 



2. Llmapria . Llmnorla vere q.uite active at all four locations, 

 hut in the control panels their occurrence was virtually limited to the 

 months from the middle of Fehruary or March to the middle of November 



or December, with the greatest period of activity largely occurring from 

 the middle of March to the middle of August. It is interesting to note 

 that at all locations the maximum nuitiber of Llmnoria tunnels occurred in 

 those control panels which were submerged from the middle of March to 

 the middle of April. The number of tunnels recorded in these particular 

 panels was 1,200 at the Navy Yard in 19k6} 880 and 990 in 19^ and 19l»-7, 

 respectively, at Pier No. 7 at the Naval Drydocks; 660 at the Lockffood 

 Basin in 19k6} and 105 at the East Jetty of the Naval Drydocks in 19^. 



In the test panels, Llmnorla occurred more or less abundantly at 

 all locations throughout the period covered by the tests except in the 

 first and third panels submerged at the Navy Yard, and in the first It- 

 panels submerged at Pier No. 7 at the Naval Drydocks. As in the control 

 panels, occurrence of the peaks of high activity coincided closely at 

 all locations, nearly all occurring from the middle of August or Septenibei 

 to the middle of December, after submergence for 8 months. The peaks of 

 attack during the latter part of tie year rated as follows: At the Navy 

 Yard, heavy in 19h-^, 19^, and 19h'J} at Pier No. 7 at the Naval Drydocks, 

 heavy in 19^5, medium heavy in 191^6, and heavy in 19^7; a-t the Lockwood 

 Basin, heavy in 19li-5, and medium heavy in 1946 and 194*7 j and at the East 

 Jetty at the Naval Drydocks, medium heavy in 19if7. Figures 1 and 2 are 

 good examples of test panels which have been subjected to heavy attack 

 by Llmnorla . 



A7.0i<- Fouling Agents 



1. Silt . Silt occurred on all the panels at all locations except 

 on one at the Navy Yard and one at Pier No. 7 at the Naval Drydocks. The 

 deposits mostly ranged from traces to light on the control panels, and 

 from traces to moderate on the test panels. 



2. Algae . A trace of green algae was recorded on only a single 

 control panel at the Navy Yard and on one at the Lockwood Basin. 



5. Invertebrate animal phyla . 



a. Porlfera (sponges ). One specimen of a sponge was recorded 

 on a single test laajiel at Pier No. 7 at the Naval Drydocks. 



h3 



