Chelura (crustacean borers) as shown in Figure 9. 



Surface Rack 



The replicate test specimens in a titanium rack exposed at the 

 surface of the water in Port Hueneme Harbor was covered with a 

 moderately dense growth of fouling - considerably more than the 

 rack which had been exposed in bottom sediments. Large mussels, 

 barnacles, encrusting and branching bryozoans, tubeworms and kelps 

 were the major fouling growths found attached to the plastic panels 

 and rope specimens (Figure 10). Compared to the severely deteri- 

 orated condition of the cotton and manila ropes exposed at the 

 bottom, the cotton and manila rope specimens exposed at the surface 

 were in relatively good condition. As soon as the visual inspection 

 was completed, the rack with the test specimens was immediately 

 submerged in the harbor water for continued testing. 



CONCLUSIONS 



Biodeterioration of materials such as cotton and manila ropes 

 (natural fibers), and wood placed exposed on the bottom sediment 

 were severe and rapid due to the activity of microorganisms and 

 wood borers. The synthetic fiber ropes (nylon, polypropylene, and 

 polyester) were not affected by marine organisms but were affected 

 by seawater in an anaerobic environment resulting in decreased 

 tensile strength. A natural rubber electrical insulating material 

 exposed in the bottom sediment experienced severe surface cracking, 

 probably due to the effect of both hydrogen sulfide and microorganisms, 

 Other insulating materials such as neoprene rubber, PVC, polyethylene, 

 and TFE were not affected. Except for the 6 x 12 inch phenolic 

 laminate and nylon panels, the majority of the 6 x 12 inch plastic 

 panels were not affected significantly by the seawater - hydrogen 

 sulfide environment found in the bottom sediments of Port Hueneme 

 Harbor. The principal fouling organisms found attached to the test 

 materials exposed at the bottom were encrusting bryozoans (several 

 species), calcareous tubeworms and rock oysters. 



FUTURE PLANS 



The second titanium rack with replicate test panels as above, is 

 undergoing continued exposure testing in the bottom sediment at the 

 same location. It will be recovered after two years of exposure 

 and the materials will be examined and evaluated for fouling attach- 

 ment, biodeterioration, and other changes which may occur during this 



