When the tube with the mud was examined the day following retrieval, a 

 strong hydrogen sulfide odor was detected coming from the mud. This indicated that 

 there were sulfate-reducing bacteria present which had produced hydrogen sulfide 

 gas. One or more of the reasons why the metallic and nonmetallic test specimens 

 were relatively free of various fouling organisms (although numerous deep sea 

 animals such as snails, crabs, and marine borers were found on test panels) include 

 the presence of turbid currents, low water temperature, hydrogen sulfide in the mud 

 zone, and the small amount of dissolved oxygen (minimum oxygen zone) found at 

 this test site. 



Generally, the materials placed in the plastic tube were not deteriorated as 

 severely as those materials exposed outside the tube (Figure 42). The fir panel was 

 moderately attacked by borers, with some borers measuring about 1/4 inch in diameter. 

 The fibers of cotton and manila rope specimens were slightly deteriorated by micro- 

 organisms. Borers were not found in manila rope specimens. The synthetic rope 

 specimens were in excellent condition. The various electrical cable insulations 

 (15 mils thick) on No. 16 wire were not affected. However, a large section of the 

 white polyvinyl chloride insulation had turned black after being exposed to the 

 hydrogen sulfide in the mud (Figure 43). This change occurred probably because 

 there may have been small quantities of lead in the PVC insulation, and this lead 

 had reacted with hydrogen sulfide to form lead sulfide, which is black. Small test 

 strips of white polyvinyl chloride materials such as this could probably be used to 

 detect the presence of hydrogen sulfide in an anaerobic environment, especially in 

 areas where conventional testing devices cannot be placed or used for detecting 

 hydrogen sulfide. 



FINDINGS 



1. There is considerable biological activity in the sediment at Test Site II (2,370 feet). 



2. Sulfate-reducing bacteria which produce hydrogen sulfide seem to be present in 

 large numbers in the sediment. 



3. Light slime and hydroid growth, a large sea anemone, a few tubeworms, some large 

 gastropods (snails), and crabs were found on the metal and nonmetallic specimens. 

 Typical fouling organisms such as bryozoa, barnacles, and tunicates found on submerged 

 panels in shallow water were not found on these panels. 



4. Marine microorganisms were responsible for the deterioration of cotton and manila 

 rope specimens, wood surfaces, and burlap (jute fibers). 



5. Marine borers identified as Xylophaga washingtona Bartsch were responsible for 

 the slight to heavy deterioration of the following materials: wood panels such as 

 pine, cedar, fir, oak, maple, ash, redwood, plywood, greenheart, Afgmbeau , and 



43 



