low numbers. The maximum recruitment for this species was 12 individuals per panel during Feb- Aug. 

 Balanus crenatus settled in larger numbers than any of the other four barnacles and did so during the 

 coldest period of the year, Nov-May. Balanus eburneus consistently settled in low numbers on panels at 

 all sites during Feb- Aug and May- Nov. This species was also a dominant fouler at EF in Aug- Feb. 

 Balanus improvisus, like B. eburneus, was most commonly collected at EF and had 3 to 19 times more 

 larvae settling and surviving at EF than at any other site. Juvenile barnacles, which represent the pre-adults 

 of the above four barnacles, had strong recruitment onto panel surfaces throughout the study. The largest 

 numbers of juveniles settled during Nov-May, when B. crenatus was most abundant. Peak settlement of 

 Mytilus edulis occurred during Aug-Feb and Nov-May, and recruitment was largest at EF (Table 2). In 

 contrast, M. edulis was absent at EF in the Feb-Aug collections, while it was generally present in small 

 numbers at the ambient water sites. 



Wood-boring species 



Percentage of wood lost. Wood-loss of exposure panels was based on either direct inspection of each 

 panel (1979) or the visual assessment of panel radiographs (1980-1986). These types of estimates were 

 not as quantitative as that based on the actual weight loss of panels, but the precision of visual method 

 as compared to the weight method was very good (R = 0.98). Using a second-order polynomial 

 regression model (Fig. 6), the following equation was provided to predict the percentage of wood lost by 

 weight (WT) from that estimated by visual assessment of radiographs (V): 



%WT loss = 6.668 + 0.4204 (%V loss) + 0.0032 (%V lossf 



Wood-loss (V) was highest in May-Nov (average > 25%) and was primarily caused by Teredo navalis 

 (Fig. 7). Wood-loss during the Feb-Aug exposure period was < 5%, and ca. 10% during Aug-Feb. 

 Wood-loss from Nov-May was negligible, as T. navalis did not recruit during this period. The wood-loss 

 caused by T. bartschi at EF and juvenile teredinids at all sites did not exceed 1%. Among stations, 

 wood-loss has been greatest at GN and least at EF since 1979. At WP and FI, wood-loss has been similar 

 during all exposure periods except May-Nov, when wood-loss was nearly three times larger at WP than 

 at FI. 



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