TABLE 2. (cont'd) 



(— ) = taxon has never occurred on a panel 



(t) = trace percentage cover, < Wo of the panel's surface 



(ns) = exposure period not sampled 



Balanus improvisus was found at all sites, but was 

 abundant only at ES before 3-unit operation. 

 Other species found during both operational pe- 

 riods were consistent components of the fouling 



communities at only effluent sites (EB, ES), e.g., 

 Mytilus edulis, or at only ambient sites (WP, FI, 

 BP, GN), e.g., Cryptosula pallasiana and 

 Laminaria saccharina. Still other species had 



236 



