The period of biological attachment extends from April to December 

 ■with maximum activity occurring from July to October. 



The gross appearance of the test panels reveals relatively large 

 differences from month to month as the season progresses. Biological 

 activity is practically nil from the latter part of December to the latter 

 part of April. 



Detailed analysis of the various organisms occurring on the panels 

 indicate the following attachment periods: 



Encrusting bryozoans - April to November 



Barnacles - April to November 



Tubeworms - June to October 



Hydroids (colonial) - July to September 



Jingle shells - July to November 



The growth of tubeworms, as indicated by average length of tubes 

 and of jingle shells as indicated by average diameter of shell, show 

 a relatively smooth, progressive increase with increase in exposure 

 during the growing period. These two organisms offer a possibility 

 for determining the length of time an object to which they have attached 

 has been in place on the bottom. Figure 21 shows a closeup view of 

 some of these common fouling organisms. Further study and more 

 detailed statistical measuring procedure are required to establish 

 definite growth curves for these and other forms such as barnacles, 

 bryozoans, and hydroids. These studies will be continued as the project 

 moves into its second year. 



The information obtained from the study during the first year of 

 operation has already demonstrated some important applications to 

 various harbor activities. The results of this study demonstrate 

 the advisibility and feasibility of initiating similar fouling studies in 

 all major harbor areas. 



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