insulations; (3) marine borers, Xylophaga washingtona, had penetrated the surfaces of 

 various plastic specimens in an area where the plastic was in contact with wood bait 

 pieces; (4) marine organisms found in mud samples collected at both test sites were 

 sulfate-reducing bacteria, aerobic and anaerobic bacteria, amphipods, annelid worms, 

 cumacean, ophiuroids, bivalve molluscs, and Foraminifera tests. Similarity in effect 

 on specimens was as follows: (1) the borers and microorganisms inflicted severe 

 damage to manila rope specimens which were exposed on or right above the sediment 

 layer; (2) identical rope specimens which were exposed 3 to 4 feet above the sedi- 

 ment layer were moderately damaged; (3) marine microorganisms were responsible for 

 the deterioration of cotton rope and burlap specimens; and (4) marine bacteria had 

 deteriorated the surfaces of the wood panels. 



Factors Found Only at Test Site I 



The following marine organisms were found only at Test Site I: (1) A white 

 lobsterlike crustacean was found on a test panel; (2) marine borers, Xylophaga 

 washingtona and Xylophaga duplicata, were found in wood panels (only species of 

 Xylophaga duplicata were found in greenheart, a tropical wood noted for its 

 resistance to marine borers); (3) numerous stalked organisms (hydroids), possibly a 

 Tubularia specie, were found on metallic as well as nonmetallic test panels; (4) on 

 numerous large and small rock specimens collected from the sea floor (largest, 500 

 pounds) were found species of bryozoa (erect and colonial forms), tubeworms, gorgo- 

 nians, Foraminifera, solitary coral, chiton, brittle stars, glass sponges, and egg cases 

 of unknown animals; (5) small white starfish, limpets and species of deep sea sponges 

 were found on test materials; (6) a nemertean (round worm) and a holothurian (sea 

 cucumber) were the other mud-dwelling animals found in sediment samples; and 

 (7) marine fungi which were found on wood panels had deteriorated the surface of 

 the wood. 



Factors Found Only at Test Site II 



The following marine organisms were found at Test Site II: (1) spider crabs 

 and snails; (2) only Xylophaga washingtona were found in wood panels including 

 tropical woods such as greenheart, Afambeau , and Antidesma (the activity of this 

 specie seems much more pronounced than at deeper depths); and (3) the sediment 

 at this site seems to contain more sulfate-reducing bacteria than in sediments found 

 in the vicinity of Test Site I. 



Since the sulfate-reducing bacteria are usually found in an anaerobic environ- 

 ment, the seawater at Test Site II could be expected to contain very little dissolved 

 oxygen, and therefore, the seawater could be slightly stagnant in the mud zone or 

 at the mud-seawater interface. It is anticipated that considerable detrimental effects 

 will be experienced by certain types of metallic as well as nonmetallic materials 

 exposed in such environments. 



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