If the wood panels had been treated with wood preservatives, which are toxic 

 to shallow-water borers, it may be assumed that the panels would be free of deep 

 sea borer attack. However, future tests are needed to verify such an assumption. 



Marine bacteria and fungi were also responsible for the deterioration of the 

 wood. The surfaces of the test panels were softened by the action of bacteria and 

 fungi. Microscopic examination of the sections through the wood revealed two 

 types of deterioration of wood cells. First, irregular tiny cracks and channels in 

 the cell walls were caused by bacteria. This type of deterioration was the one most 

 commonly found on the surface of the wood. Second, wide channels in the secondary 

 cell walls of the wood were caused by marine fungi. This type of deterioration is 

 known as "soft rot" and was less commonly found on the surface of the wood. 



Brownish fungi hyphae (without the fruiting bodies) were detected in the wood. 

 An unsuccessful attempt was made in the laboratory to induce fructification by the 

 fungi for classification purposes. 



Rope Specimens. A heavy growth of slime bacteria was present over the 

 entire surfaces of cotton and manila ropes, and a light growth of slime was present 

 over the surfaces of nylon and polypropylene ropes. 



The fibers of cotton ropes were decayed severely by bacterial action (Figure 22) 

 and as a result, the fibers were easily pulled apart by one's fingers. Only a few 

 borers were found on the surface of the cotton rope and none of these had bored into 

 the rope. 



On the other hand, the 1/2 -inch-diameter manila rope specimens were 

 severely damaged by both microorganisms and borers. The 4-foot-long specimen 

 exposed near the sediment layer was completely destroyed, and only a few short 

 sections of the rope where a plastic cable clamp was located were recovered 

 (Figure 23). However, the rope specimen exposed about 3 feet above the sediment 

 layer was not as severely damaged and was recovered virtually intact. Although 

 the slime bacteria were responsible for some decay of the jute fibers, the borers 

 were responsible for severing the fibers of the rope. Numerous borers measuring 

 about 3/16 inch in diameter were found deep inside the recovered rope specimen 

 (Figure 24). 



Two microorganisms isolated from cotton and manila rope specimens which 

 were exposed at 5,640 feet (STL) 1-3) have been identified as Torulopsis versatilis 

 and Psuedomonas sp. The descriptive and biochemical data of these two microorga- 

 nisms are presented in Tables 5 and 6. 



Examination of the nylon and polypropylene ropes under a microscope showed 

 that their fibers were neither severed nor damaged by marine microorganisms or 

 borers. On the contrary, the fibers were in excellent condition (Figure 25). 

 Table 7 compares the breaking strength of rope specimens before and after the deep 

 sea exposure. There was some loss in strength in the nylon and polypropylene ropes. 



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