BIOLOGICAL ACTIVITY 



Deep-sea photographs show that the surface of the ocean floor at Test 

 Site 1 is very irregular with numerous mounds built by benthic mud-dwelling 

 animals. This indicates that considerable biological activity is occurring 

 at this site. Also, a 5- to 6-foot-long shark-like fish was photographed 

 at the test site drifting near the ocean floor. 



Rock Samples 



Rock specimens were desired from these areas to study any fouling 

 organisms attached to the rocks since these fouling organisms could be 

 expected to attach themselves to other materials placed there. A 10-inch- 

 diameter by 36-inch-long steel pipe with retaining rods welded across the 

 lower end of the pipe was employed for collecting rocks from the ocean floor. 

 The pipe dredge was lowered to the ocean floor from an oceanographic vessel, 

 USNS DAVIS, and the area dredged for rock specimens. Several passes were 

 made over Test Site, 2 but no rock specimens could be obtained. However, 

 numerous large and small rock samples were obtained near Test Site 1 at a 

 depth of 6,000 feet. Various species of bryozoa, tube worms, Foraminifera , 

 and a specie of chiton were found on these rocks. Some rocks had holes 

 made by Pholads, a rock boring mollusk. 



Sediment Samples 



Sediment samples for bacteriological and biological analysis were 

 obtained with: 



1. A gravity core sampler, which takes cores up to 4 feet long. 



2. NCEL's scoop-type bottom sampler which collects about 225 cubic 

 inches of sediment from a soft bottom. 



3. A modified ZoBell bacteriological sampler was used to collect a 

 mixture of sea water and sediment. The sampler consists of a 100-ml rubber 

 bulb (deflated) connected with a rubber tube to a glass tube (sealed at one 

 end). The sterilized unit is attached to the side of an NCEL bottom sampler 

 with the glass tube protruding below the scoop sampler. When the heavy 

 sampler touches bottom, the glass tube shatters and the rubber bulb expands, 

 drawing in the surface layer of the bottom sediment and sea water. 



Marine bacteria are one of the major biological agents in the deteriora- 

 tion and fouling of various materials and equipment submerged in the sea. 

 To determine the type and activity of bacteria in the deep ocean, sediment 

 samples were obtained with the above samplers and analyzed in the laboratory 

 using standard microbiological methods. 



Approximately 1,500,000 aerobic and 5,000 anaerobic bacteria were found 

 in a gram of sediment (wet weight) collected at the sediment-sea water inter- 

 face. Sulfate-reducing bacteria were also present in the sediment samples. 



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