control panels, and only In those panels submerged from the middle of 

 Decem'ber to the middle of Jane. In the test panels, they occurred in 19 of 

 the 57 "but mostly in very small numhers. The attack rated oiily a trace 

 most of the time "but attained peak ratings of slight in 19^6 and 19^7* 



AJl.Oll- Fouling Ajiients 



1. Silt . Silt occurred on all except k of the 37 control panels 

 and on all except 2 of the 57 test panels. Hie deposits ranged from traces 

 to ligjht on the control panels, and from traces to light, or rarely moderate, 

 on the test panels. 



2. Algae . Traces of algae occurred on only 2 of the test panels. 



3. Invertebrate animal phyla . 



a. Coelenterata (hydroids ). Hydroids occurred on 9 control 

 panels and on 23 test psjiels. None was identified. 



b. Annelida (marine vorms ). Serpiilid ( Serpula ) tubes occurred 

 on only one test pajiel. 



o. Arthropoda (crustaceans ). Balanus (barnacles) occurred on 

 7 of the 57 test panels. Maximum diameters recorded were 8 mm on the 

 control panels and 19 mm on the test panels after a submergence of 7 

 months. One of the control panels was 10^ covered, and Ik of the test 

 panels were from 50^ to Q% covered. 



A3I.O5 Summary and Conclusions 



1. Installation . A test board of the panel type installed July 

 15* 19^^; at the U. S. Naval Operating Base at Adak, Alaska, to determine 

 the identity and prevalence of marine borers ajid fouling organisms at this 

 location, is still being operated. The results of this test have been 

 sunimarlzed to the end of 19^7 • 



2. Test Results . 



a* Borers . Teredlnldae occiured to a very limited extent at 

 this location In 19^6 and 19^7; no specimens were recorded In 19kh or 

 1945, The attack rated only slight on 19l<-6 and only a trace In 19^+7. The 

 breeding season at this location appears to extend from the middle of March 

 through September. Limnorla also showed more or less activity In 19^6 and 

 19^7> "but no activity In 19¥»- or 19''<-5 except for 3 tunnels recorded on a 

 single control panel In 19^? • The attack rated only a trace most of the 

 time but attained a peak rating of slight In 19^6 and 19'4-7. 



138 



