Wood Specimens 



A total of 26 wood test panels including pine, fir, ash, maple, oak, and redwood 

 were exposed to determine the effects of deep-ocean animals on different woods. None 

 of the woods were immune from borer attack — including redwood (Figure B-21), which 

 is considered very resistant to insect attack, such as by termites, as well as to decay. 



A majority of the borers had concentrated their attack in large numbers along 

 the inside edge next to the laminated plastic sheet to which the panels were attached. 

 The panels had become saturated with sea water and had warped, producing a thin 

 crevice between the wood and the plastic sheet. Such an area in the crevice would 

 be ideal for borer activity because it would be protected from the slightest amount 

 of sea currents, which the borers seem to dislike. 



Very little borer attack occurred on the surface of the 2- by 6-inch wood panels 

 exposed about 3 feet above the sediment, probably because of the presence of currents. 

 The surfaces of only two fir panels and an oak panel facing the sea water were attacked 

 by borers. These panels were exposed at the sediment-water interface and were 

 attached behind the plastic sheet where there was very little current. There was an 

 average of 25 borers per square inch of surface on these panels. Deterioration of the 

 panels was more pronounced where the borers had attacked, in large numbers, over 

 a narrow area along the edges of the panels (Figure B-22). The majority of the borers 

 were 1/16 inch in diameter and had penetrated over 3/16 inch into the wood. 



The largest borers were found boring into the ends of a large fir wood bait piece 

 fitted over plastic rods and tubes (Figure B-23). Some of the borers were 1/8 inch in 

 diameter and had penetrated approximately 5/16 inch into the wood. When finally 

 matured, the shells of these borers will grow to about 3/4 inch in diameter. The borers 

 were also present throughout the surface of the pine bait piece fitted around the plastic 

 specimens. In one area of the wood there were approximately 200 young borers in a 

 1 -square-inch area (Figure B-24). The average diameter of entry holes was 1/32 inch. 

 The borers inside the wood were 1/16 inch in diameter and had penetrated approxi- 

 mately 1/8 inch into the wood. 



The molluscan marine borers in pine test panels have been identified as 

 Xylophaga washingtona Bartsch" (Figures B-25 and B-26). 



Unaffected Materials 



The borers had failed to penetrate into the following plastics: nylon, phenolic 

 resin, polycarbonate. Teflon, polyethylene, polyvinyl chloride (pipe), and a yellow 

 vinyl. However, there were numerous small circular etched areas on the surface of 

 many of these plastics. These are areas where the borers had attempted to penetrate 

 into the plastic materials but were unable to do so, probably because of the following 

 reasons: (a) very hard surface — nylon, polyvinyl chloride pipe, polycarbonate; 

 (b) waxlike surface — Teflon, polyethylene; (c) soft, flexible, and smooth surface 

 — yellow vinyl tube (NCEL No. 387); (d) thick bacterial slime growth — vinyl tube 

 (NCELNo. 374). 



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