content, and biological activity. This information is essential in evaluating changes 
in the materials exposed on the ocean floor, especially the corrosion of metals. The 
environment at both Test Site | and Test Site II is presented in Table |. 
Test Site | was selected because the area provides a nominal 6,000-foot depth 
reasonably representative of the open-sea conditions in the eastern part of the Pacific 
Ocean. It is located approximately 80 nautical miles southwest of Port Hueneme, 
California. 
Because the rate of corrosion of certain metals and alloys are greatly influenced 
by the amount of dissolved oxygen concentration in seawater, it was desired to investi- 
gate the effects of the minimum oxygen zone upon these materials. Test Site II was 
selected because at this site at a depth of about 2,500 feet, the dissolved oxygen con- 
tent in seawater falls to a relatively low value and is known as "the minimum oxygen 
zone." Below and above this depth, the dissolved oxygen content increases. The 
underlying causes of the minimum oxygen zone are still imperfectly understood. 
Biological Activity 
When the Laboratory first decided to place STU I-1 on the ocean floor at Test 
Site | in March 1962, it was not known what kind of deep-sea creatures would be 
encountered, nor was the topography of the ocean bottom known. In order to obtain 
some information, a deep-sea camera was lowered from the stern of a vessel (YFU) 
while at the same time STU I-1 was being lowered to the ocean floor from the bow 
of the vessel. Numerous photographs were taken of the ocean floor close to where 
STU I-1 was placed. 
The photographs revealed that the topography of the ocean floor in the vicinity 
of STU I-1 was generally flat except for numerous small mounds built by mud-dwelling 
animals, The presence of these mounds indicates that there is considerable biological 
activity at the test site. During the course of photographing the ocean floor, a 5- to 
6-foot-long sharklike fish with a large dorsal fin came into view of the camera and 
was photographed apparently drifting near the ocean floor in 5,300 feet of water 
(Figure 3). 
Rock Samples. Rock specimens were desired from this area to study fouling 
organisms attached to the rocks, since they 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 across the area of Test Site | at a depth of 6,000 feet, and various- 
sized rocks were collected. 
A variety of organisms were attached to the rocks (Figure 4). These are listed 
in Table II. 
