which were sulMerged for one, 2, and 5 months, respectively, were 

 covered. A few Corophium were recorded on the first test panels and the 

 accompanying control panel. 



f. Mollusca (nonhoring mollusks ). Oetrea (oysters) occurred 

 on one control panel and on 12 test panelsj "the maximum numher recorded on 

 any panel was 25, and the mariTtiHTn length recorded was 20 mm on a pajiel 

 submerged for 5 months. Traces of Anomia (jingle-shells) occurred on 2 



of the control panels and on one of the test panels. A trace of Pinctada 

 radiata occurred on 2 test panels, and a single specimen of Musculus 

 lateral-is was recorded on another. 



g. Chorda ta (tunicates ). Tunicates, occurred on 5 control pajiels. 

 and on ;9. test panels. The first panel in "both the control and test series 

 was covejred, "but on the other panels the number of colonies ranged from 



one to 25 forms. Most of these tunicates were identified as Botryllus 

 schlosseri . 



A25.05 Summflry and Conclusions 



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

 the U. S. Naval Submarine Base at Erum Bay, St. Thomas, Virgin Islands, 

 frata Jiily 1, 19^ until its discontinuance at the end of April 19^7, in 

 order to determine the identity and prevalence of marine "borers .and fouling 

 organisms at this location. 



2. Test Eesults . 



a. Borers . Teredinidae , while showing little activity during 

 the last half of 19^^* were active for periods of varying length and season 

 throughout most of the period covered by the test. The "breeding season at 

 this location appears to "be more or less continuous "but is chiefly from 

 March through Octo"ber. Wo great numbers of these "borers were recorded in 

 any one panel, and the severity of the attack was rated as moderate. 

 Limnoria occuired with great regularity throughout the test and were far 

 more numerous and destructive than the Teredinidae . The attack soon 

 rated very heavy in the test panels and continued to "be severe mitil 

 the termination of the test. Chelizra were numerous, along with the 

 Limnoria , in 19^5 and 19^6. No Pholadidae were recorded at this location. 



"b. Fouling Organisms . Silt, algae, and irivertehrate animals 

 "belonging to 7 phyla contri"buted to fouling of the panels. The latter 

 included encrusting sponges, hydroids, encrusting and filamentous Bryozoa, 

 serpulid worms, "barnacles and Corophium , miscellaneous non"boring mollusks, 

 and tunicates. Of the latter organisms, hydroids and encrusting Bryozoa 

 occurred with great regularity, "barnacles occurred with less regularity, 

 while the occurrence of the others was merely sporadic or occasional. 



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