e. MolluBca (nonborlng mollusks ). Miscellaneous mollusks 

 occurred more or less frequently on the panels at "both locations. MytHus 

 (missels) occurred on ih of 56 control panels and on 55 of the 56 test 

 panels at location No. 1, and on ik of the 56 control panels and 33 of the 

 56 test panels at location No. 2. The maximum length recorded on a 

 control panel suhmerged for one month was 22 mm, while that recorded on 



a test panel was 65 mm on one submerged for 8 months, Anomia ( Jingle- 

 shells) occurred rather abundantly on 2 of the 36 control panels and on 

 17 of the 36 test panels at location No. 1, and on 17 of the 36 panels 

 at location No. 2. The largest number recorded on any one panel was 60j 

 the maximum diameter attained was 9 nm. Mya (clams) occurred as a trace 

 on a single test panel at location No. 1, the specimens being Juvenile, 

 Saxicava occurred as a trace on a single test panel at each location. 



f . Chordata (tunicates ), Tunicates occurred more or less 

 abundantly on 3 of the 36 control panels and on 26 of the 36 test panels 

 at the location No, 1, and on 2 of the 36 control panels and 2lt- of the 

 36 test panels at location No. 2. Most of these tunicates were 

 Botryllus schlosseri and Molgu-]^ sp . 



A6.05 Summary and Conclusions 



1. Installation . Two test boards of the panel type were in- 

 stalled at different locations at the Portsmouth Naval Shipyard, 

 Portsmouth, New Hfunpshire, on June 12 and Ik, 19kh, and are still being 

 operated. The results of these tests have been summarized to the eiid 

 of 19l^7. 



2. Test Be suits . 



a. Borers . At location No. 1, no Teredinidae were recorded 

 in 19kk and 19*^5, and the attack rated only a trace in 19k6 and slight 

 in 19i»-7. At location No. 2, no Teredini dae were recorded in 19kh, and 

 the attack rated only a trace in 19^5 and slight in 191*6 and 19^^. 



Limnoria were present at both locations practically throughout 

 the entire test period, the attacks in general rating from traces to 

 slight, but attaining a maximum of moderate at location No. 1 late in 

 19I4.5 and at location No. 2 late in 19^^. 



b. Fouling Organisms . Silt, algae, and Invertebrate 

 animals belonginig to o phyla contributed to fouling of the panels. The 

 latter included hydroids, encrusting and filamentous Bjryozoa, marine 

 worms, barnacles, ajitphipods and isopods, and nonboring mollusks, which 

 included mussels, j ingle -^he lis, clams and Saxicava , and tunicates. 

 Bydroids occurred the most frequently and consistently; encrusting 

 Bryozoa, barnacles, and tunicates occurred somewhat less often, and 

 mussels and Jingle-shells still less often. The occurrence of the other 

 forms mentioned was merely sporadic. 



36 



