5 months at a time, their abimdance aJid the favoralile teniperature of the 

 water justify rating the attack as very heavy. 



2. Limnoria . Limnoria occurred to a very slight extent during 

 this "brief test, which was not long enough to indicate the destructiveness 

 of this particular marine torer. On the control panels, only 5 tunnels 

 were recorded, and these were on the last panel. In the test panels, they 

 occurred only on the first 2 and the last 2 of the 8 boards, the largest 

 number on any panel being 15 to 20. The severity of attack thus rated 

 a mere tarace, but no panel was left aubmerge'd for longer than 3 months. 



A28.014. Fouling Agents 



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

 panels of both the control and test series. 



2. Algae . Green algae occurred on 5 of the 8 panels in each series, 

 the growths ranging from traces to light. 



5. Invertebrate animal phyla . 



a. Coelenterata (hydrolds ). Bydroids occurred on all except 

 one of the 8 panels in each series, rating as traces on the control 

 panels and as traces or light on the test panels. 



b. Bryozoa (filamentous ). Filamentous Bryozoa occurred on k 

 of the 8 control peinels and on 5 of the same number of test panels,, 

 generally being fairly numerous. 



c. Annelida (annelid worms ). Serpulid ( Serpula ) tubes occurred 

 abundantly on k of the 8 panels in each series, the first 2 of each being 

 encrusted with them. 



d. Arthropoda (crustaceajas ) . BsLlanus (barnacles) occurred on 

 5 of the 8 panels in each series, ranging from a few to numerous. MELXimum 

 diameters of 6 mm were recorded on the control panels and of 15 mm on a test 

 panel after having been submerged for 5 months. 



e. Chorda ta (tunica tes ) . Tunlcates were numerous on a single 

 test panel submerged for 3 months. 



A28.05 Summary and Conclusions 



1. Installation . A test board of the panel type was operated at 

 the U. S, Naval Operating Base at Casablanca, French Morocco, from July 8, 

 19^14- until its discontinuance on June 1, 19^5, to determine the identity and 

 prevalence of marine borers and fouling organisms occurring at this location. 



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