A56.0l|- Foullofi Agents 



1, Silt . Silt occurred as light deposits on all the control 

 panels and as light to moderate deposits on all the test panels. 



2. Inverte'brate ajilmaT phyla . 



a. Coelenterata (hydrolds ). Hydrolds occurred as traces 

 on all the control panels received except the last one, and as traces 

 to light growths on all of the 8 test peinels, which had heen suhmerged 

 for periods ranging from 1 to 7 months. 



h. Bryozoa (encrusting and filamentous ). Encrusting Bryozoa 

 occuired more or less ahundantly on 2 of the 6 control panels ajad on the 

 first 6 of the 8 teat panels. ELectra sp. was the only one Identified. 

 Scattered colonies of filamentous Bryozoa ( Bugula sp.) occurred on a 

 sin^e panel of "both the control and test series. 



c. Annelida (annelid worms ). Serpulld ( Serpula ) tubes 

 occuixed on the last 2 of the control peinels etnd on 2 of the test 

 panels. They were few In numher on all "but the last one of the control 

 panels, where tuhes up to 50 ™i in length covered 80^ of the surface. 



d. Arthropoda (crustaceans ). Beilanus ('barnacles) occurred 

 more or less ahundantly on k of the 6 control pajiels and on all 8 



test panels. They attained maximum diameters of 12 mm in one month 

 on a control panel and 22 mm on one of the test panels suhmerged 

 for h months. On 2 of the test panels they covered 50^ and 75^, 

 respectively, of the surface. 



e. Mbllusca (nonhoring mollusks ). ttrtilus (mussels)- 

 did not occur on any of the control panels hut developed in great 

 ahundance on 5 of the 8 test panels which had heen submerged from 



5 to nearly 7 months. The Trw-YiTninn length recorded was 22 mm on a panel 

 submerged for 5 months. On one of the test panels submerged for 6 

 months, ^0^ of the surface was covered; and on the last two, which 

 had been submerged from 6 to 7 months, 90> of the surfaces were 

 covered. 



A56.O5 SuTTgnary and Conclusions 



1. Install atlon . A test board of the panel type was operated 

 at the U. S. Na-val Operating Base at Brisbane, Avistralia, during the 

 last half of 19hh, to determine the identity and prevalence of marine 

 borers and fouling organisms occurring at this location. 



257 



