in turbid harbors.^ The sharp cutoff of green algal growth, 

 where shaded by the curvature of the hull, indicates 

 SQUAW was near the critical depth for photosynthesis. 

 Red algae normally can flourish at lower light intensities 

 than green algae. This could explain the growth of red 

 algae on the mooring chain, part of which probably extended 

 outside the shadow zone of the hull. The hull and its asso- 

 ciated fauna possibly attracted noise-producing fishes, 

 thereby raising the ambient sound level in the area. 



Previous studies^ have shown that even within harbors 

 distinct assemblages of fouling organisms can be correlated 

 with water transparency. The history of SQUAW indicates 

 the type of fouling communities to be expected on struc- 

 tures in clear, oceanic waters. 



CONCLUSIONS 



1. Antifouling-treated structures moored in the 

 deep sea environment for long time periods will experience 

 light to moderate fouling. 



2. The types of fouling organisms will differ from 

 those occurring in harbors and productive shallow waters 

 adjacent to shore. 



3. The organisms growing on such structures will 

 occupy niches similar to those of the natural environment. 



4. A variation in light appears to be the primary 

 factor governing their distribution. 



5. Sufficient light is present at a 200-foot depth to 

 support photosynthesis in this area of the ocean. 



6. All of the fouling animals on SQUAW were filter 

 feeders, which indicates a high organic content of water at 



21 



