DEEP-OCEAN BIODETERIORATION OF MATERIALS-PART VI. One Year at 2,370 Feet,
 Technical Report R525, Naval Civil Engineering Laboratory, Port Hueneme, CA, by James S. Muraoka, May 1967, 55 pages.

As Part VI of a series of reports on the biological deterioration of materials in the deep ocean, this report covers the data obtained after exposing metallic and nonmetallic specimens for 13.4 months on the floor of the Pacific Ocean at a depth of 2,370 feet (Test Site 11). The specimens were attached to a Submersible Test Unit that was emplaced in April 1965 and retrieved in May 1966. Preliminary examination of the specimens was made aboard ship, and the final examination,, tests, and analyses were performed at the Naval Civil Engineering Laboratory.

On recovery, most of the plastic materials and all of the rope specimens were covered with bacterial slime. Cotton and manila ropes were severely deteriorated by marine microorganisms. Wood panels, certain plastics, and manila ropes were attacked by molluscan borers. Some of the plastics were attacked by borers directly from seawater environment without the aid of wood bait pieces. Hydroids and tubeworms were found on metal panels. Sea anemone, snails, and crabs were also found attached to various test panels. The surface of a silicone rubber electrical cable insulation was deteriorated by some marine organisms. Typical fouling organisms such as barnacles and bryozoa were not found. Glass, elastomer, and certain plastics were not adversely affected. Data from evaluation of these specimens are presented.