Ulva Zone 



The sea lettuce, Ulva sv. , was the only fouling 

 organism observed in this zone. The mat of dried algae 

 was approximately § inch thick over the entire area (fig. 1). 

 This growth was sharply terminated vertically at the point 

 where light would be reduced by the curvature of the hull. 

 It is difficult to state how much of the upper zone was 

 covered with this growth before emergence, but the polar- 

 oid pictures of the hull immediately after recovery show 

 what could be Ul va covering the upper surfaces. 



Free Zone 



The 2 -to- 3 -foot- wide strip, immediately below the 

 Ulva zone, was completely devoid of macroscopic fouling. 

 This strip was continuous around the entire hull except for 

 the area at the rounded stern (fig. 1). Here the Ulva con- 

 tinued downward and blended into the lower zone fouling. 

 Since this zone continues along the tapered flanks of the 

 hull, it was very probably not caused by rubbing alongside 

 piers. 



Lower Zone 



The lower zone of SQUAW was 100 percent fouled. 

 Comprising roughly 85 percent of this fouling was the 

 colonial tube worm Phyl lochaeto pt erus prolifica. 

 These worms grew in a sinusoidal fashion close to the sub- 

 strate, then projected from the substrate at their distal 

 ends. Individuals became heavily entwined with one another 

 to form a mat-like structure that covered the entire bottom 

 (fig. 5). Branches of dried hydroids were interspersed 

 with these worms and their condition made identification 

 difficult. Dried colonies of crustose and arborescent 

 bryozoans round out the major fouling in this zone. These 

 latter organisms were concentrated along the keel. 



15 



