DISCUSSION 



As would be expected, the fouling of SQUAW was 

 relatively light in contrast to similarly treated structures 

 submerged for equal time periods in coastal waters. 

 However, considering the location, depth, and treatment 

 of the hull, the degree of fouling is considerable. Several 

 phenomena are of interest. 



The sparse settling of barnacles on the hull may be 

 an indication of the effectiveness of the antifouling treat- 

 ment against balinoid cerripeds. On the other hand, bar- 

 nacle fouling may be lighter at these depths. Barnacles 

 were only found on the superstructure, inside ballast tanks, 

 and on brass valves. 



The growth of jingles on the upper surfaces is strik- 

 ingly similar to the location of thick stacks of another 

 bivalve growing on the upper surface of a siltstone reef at 

 a depth of 35 feet off Corona Del Mar, California.^ Appar- 

 ently hard, calcareous foulers can be anticipated on the 

 upper surfaces of deep-moored platforms. 



The tube worms fouling the lower sides and bottom 

 of the hull were growing in a similar ecological situation 

 to that found in the littoral zone of northern California, 

 where their membranous tubes mat large areas of vertical, 

 or slightly overhanging, rock faces. Such growth will 

 probably foul the light restricted regions of similarly 

 moored platforms. 



While algal growth may have been accelerated during 

 the time the hull was confined in the shallow waters of the 

 bay, the pattern of distribution, and the observations by 

 the salvage officer, clearly indicate that the majority of 

 plant growth had taken place in situ. Minimum light 

 intensity of about one percent of noon sunlight is required 

 for sufficient photosynthesis to support the growth of green 

 plants. In clear oceanic waters this could correspond to a 

 depth of about 330 feet, equivalent to a depth of only 3 feet 



20 



