RESULTS 

 Fouling Species 



Primary Cover. The surfaces of the panels were covered with two types of marine fouling, that which 

 was alive and that which had died prior to collection. These two components comprise the total primary 

 cover. At WP, FI and GN total primary covers were largest during Feb-Aug, and at EF during Nov-May. 

 At WP, FI and GN covers were lowest in Aug-Feb, and at EF in Feb-Aug (Fig. 4). The average primary 

 cover on EF panels was 51%, while the combined average cover for the other sites was 29%. 



Of the live organisms, 6 plants and 24 animals were considered dominant. The criterion for determining 

 this dominance was whether a species appeared among the five most abundant at any site during any 

 exposure period. After averaging primary covers from 1979-1986 by exposure period, the dominant foulers 

 accounted for 88-100% of the living cover on panels (Table 2). The most dominant organisms at ambient 

 water sites were Balanus crenatus, Codium fragile, Cryptosula pallasiana, Botryllus schlosseri, Laminaria 

 saccharina, and B. ehurneus. The most dominant organisms at EF were B. improvisus and Mytilus edulis. 



As a taxonomic group, barnacles represented the most common genus on our exposure panels. 

 Balanus crenatus, B. improvisus, B. eburneus and Balanus juveniles accounted for large primary covers 

 throughout the study (Fig. 5). Balanus amphitrite, although collected at every site, was generally responsible 

 for less than 1% of the total primary cover and, for this reason, it was not included in Figure 5. In 

 Nov-May collections, these four barnacles contributed from 33% (EF) to 100% (FI) of the live cover at 

 all sites and in Aug-Feb they contributed 76% of the live cover at EF. Balanus crenatus was abundant 

 at all sites during Nov-May, the coldest exposure period. Balanus eburneus was most dominant at all sites 

 during the warmest exposure period, May-Nov. Balanus juveniles were most abundant on panels collected 

 in May and November, indicating that these two months are within the peak setting periods for barnacles 

 in the Millstone Bight. 



Numerical Abundance. Six fouling species were monitored by counting the number of individuals 

 attached to our exposure panels: Balanus amphitrite, B. crenatus, B. improvisus, B. ehurneus, Balanus 

 juveniles and Mytilus edulis (Table 3). The temporal and spatial trends in numerical abundance were 

 generally similar to those discussed for primary cover data. Balanus amphitrite settled on panels in very 



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