SUMMARY 



1. The most abundant fouling species at ambient water sites (WP, FI, BP, GN) were Balanus crenatus, 

 Codium fragile, Cryptosula pallasiana, Botryllus schlosseri, Laminaria saccharina and Balanus eburneus 

 while the most abundant fouling species at EF (effluent site) were Balanus improvisus and Mytilus 

 edulis. Balanus eburneus, a wann water barnacle, was consistently more abundant at EF than at the 

 ambient water sites, and L. saccharina was never collected at the EF site. The identity and abundance 

 of these fouling species did not affect abundance of woodborers. 



2. Characteristics of the EF community which were related to temperature included enhanced primary 

 cover, temporal shifts in peak abundance of individual species and total primary cover, absence of 

 cold water species, and the unique occurrence of a warm water shipworm, Teredo bartschi. 



3. Teredo bartschi recruited into EF panels after August with their largest populations occurring in panels 

 collected in February. There is evidence to suggest that this species has a minimum setting temperature 

 of approximately 22 "C. 



4. Teredo navalis was most abundant at GN in May-Nov, while Limnoria spp. and Chelura terebrans 

 were most abundant at WP in May-Nov. The low abundance of T. navalis at EF from 1979-1986 

 was caused by panel location. A second rack and frame assembly of panels will be relocated 0.2 m 

 from the bottom in shallow water to further evaluate the vertical distribution of woodborers at EF. 



5. The occurrence of T. bartschi at 100, 500 and 1000 m from the MNPS effluent discharge point was 

 monitored. A reproductive population of T. bartschi was collected from panels at 100 m, after six 

 months exposure. 



6. Our data describe a consistent decrease in panel recruitment of T. navalis from 601 at 100 m to 388 

 at 1000 m. This trend may indicate that recruitment of T. navalis is enhanced in the effluent mixing 

 zone. 



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