B. Colonial Hydroids 



Site 1 hydroid data for 1956-57 and 1957-58 were similar. 

 Initial monthly hydroid set for Site 1 occurred in June- July and reached 

 a peak in August-September, after which no set occurred until the 

 following June-July (Fig 23). Site 2 hydroid set started a month 

 earlier than Site 1 set, continued through November-December or 3 

 months longer than Site 1, but did not occur from December- January 

 to Febraury-March (Fig 23). Most panels were analyzed in the labor- 

 atory after drying; consequently, no significance can be placed on 

 hydroid length measurements. In some panels, area coverage data are 

 suspected even though the data were checked against photographs 

 taken immediately after panel removal. 



Figure 24 presents cumulative percent coverage hydroid data for 

 Sites 1 and 2, for 1 through 12 months, and for Site 4 for 1 through 6 

 months. Set, growth, and decay were typical for Site 1, with growth 

 stopping after October-November, then slow decay to February-March, 

 and a more abrupt fall in March-April. Site 2 cumulative hydroid 

 coverage for 1957.-58 and 1958-59 is erratic when compared to Site 1. 

 It is possible that this irregularity can be attributed in part to new set 

 occurring through mid-December (Fig 23). The coverage of the 9-month 

 panels far exceeds all others, showing winter growth, the effect of a 

 longer set period, and the possibility of considerable decay in late 

 autumn and early winter along with the late set. Site 4 data indicate 

 initial hydroid fouling in May-June with the possibility of an even 

 earlier beginning (Fig 24). The increase in coverage is much more 

 abrupt than shown in Sites 1 and 2 data, and a slight drop is indicated 

 after August-September. It is not known whether this drop is just an 

 irregularity such as at Site 2 or if it is the actual onset of decay. 



50 



40 



sj 30 



S 20 



z 











I 























— «•— - SITE 1 1956-1958 

 .— O—. SITE 2 1957-1959 

















































A 





























4 



A 



v 



*»°«~ 



s»Q 













o 







y 



4 



/ 





K 







V 







-p— 



r 

 • 



-»Q 



f 



APR. MAY JUN. JUL. AUG. SEP. OCT. NOV. DEC. JAN. FEB. MAR. APR. MAY JUN. 

 FIGURE 23 HYDROID FOULING, MONTHLY. 



26 



