To date, Teredo bartschi has been found only in panels exposed to undiluted effluent, but the 

 destructive potential of this species warranted a series of special studies, conducted from 1981 to 1985 

 (report in preparation). Teredo bartschi is a warm water immigrant, and differs from 7'. navalis in being 

 a long-term brooder instead of a short-term brooder. By brooding its veliger larvae to the pcdiveliger 

 stage before releasing them, 7'. bartschi pediveligers are able to reinfest wood near their parent populations, 

 which makes this species very destructive to a localized area after it has established a population (Hoagland 

 and Turner 1980; Turner 1973). In contrast, T. navalis veligers are released at the straight hinge stage and 

 require at least three weeks of development in the plankton before they metamorphose (Imai et al. 1950; 

 Culliney 1975). Teredo bartschi recruitment into EF panels occurred after August with the largest popu- 

 lations occuiring in the panels collected in February. However, our investigation concerning the life history 

 of this species has established that T. bartschi release pediveliger larvae throughout the year at EF tem- 

 peratures (report in preparation). This would suggest that the successful recmitment of this species requires 

 temperatures above 22 "C. 



Wood-loss data prior to 1979 indicated that the EF site consistently experienced the heaviest annual 

 shipworm infestation of any of the ambient water sites (Battelle 1978b). This contradicted the 1979-1986 

 data as presented in this report. The reason for this discrepancy is that the location of the exposure panel 

 rack at EF was changed in 1979 from just off the bottom in shallow water to 1 m below the surface in 

 about 10 m of water. The depth preference data described in this report indicates that T. navalis occurred 

 in greater abundance 1 m off the bottom than at 1 m from the surface. Others have reported that this 

 species has a strong preference for setting close to the bottom (Grave 1928; Schellema and Tinjitt 1956; 

 Turner 1966; Nair and Saraswathy 1971). In fact, its preference is so pronounced that the location of our 

 panels 1 m of the bottom probably missed their peak zone of recruitment. Therefore the 1979-1986 data 

 may underestimate the abundances of woodborers on the bottom. We will evaluate the depth response 

 of T. navalis by placing a set of panels in pre- 1979 position, i.e., just off the bottom in shallow water. 



In summary, the ambient water sites had similar fouling assemblages and trends in abundance from 

 1979-1986. Total primary cover at all sites was dominated by three barnacle species. Balanus crenatus was 

 most dominant at ambient water sites during Aug- Feb and Nov- May, and B. eburneus and B. improvisus 

 were most dominant during Feb-Aug and May-Nov. Other fouling species that consistently colonized over 

 5% of the panel surfaces at ambient sites were Cryplosula pallasiana, Botryllus schlosseri and Laminaria 

 saccharina. The primary covers of EF panels were different from those at ambient water sites; Balanus 



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