EXPOSURE PANEL STUDY 

 MATERIALS AND METHODS 



T'ouling and wood-boring organisms have been monitored in the vicinity of Millstone Point since 

 1968. This report summarizes data collected from 1979 to 1986, following evaluation and modification of 

 the methodology and objectives of the exposure panel program. These changes were based on the 

 recommendations from several studies that critically reviewed our program (Brown and Moore 1977; 

 Battelle 1978a, 1979; NUSCo 1983). The most important changes made were: (1) introduction of replicate 

 panels, (2) reduction of the exposure period from twelve months to six months, and (?>) restriction of data 

 collection to the wooden side of each panel. Adding replicates increased the power of our statistical 

 analyses, and reducing the exposure period decreased the likelihood that a panel would be entirely degraded, 

 and lost before collection. Since the major concern in fouling species was to determine their influence on 

 the abundance of woodborers, only data from the community that developed on wooden panels were 

 needed for our analyses. 



The present study used sets of six replicated wood panels submerged at five sites, that were grouped 

 as: treatment sites, White Point (WP) and Fox Island (Fl), where potential power plant impacts during 

 3-unit operation may occur; control sites, Black Point (BP) and Giants Neck (CjN), located well beyond 

 the area of predicted power plant influence; and one impacted site, FfTIuent (FF), which was in the 

 Millstone Quarry where panels were exposed to maximum AT's. Water temperatures at FF from 1978-1986 

 averaged 9-10 "C warmer than those recorded at the Intakes of MNPS Units 1 and 2. The Intake 

 temperatures were considered to represent ambient conditions; seawater temperatures at WP and FI did 

 not vary more than 2 °C from ambient (NUSCo 1982). Water temperatures were derived from the 

 Environmental Data Acquisition Network (FDAN), and from continuous strip chart recorders. 



Each of six exposure panels consisted of a knot-free pine board (25.4 x 9.5 x 1.9 cm) which had one 

 face covered by plexiglass. Only the uncovered wood side of each panel was processed. Sets of six 

 replicated panels were bolted to a stainless steel rack which was attached to a stainless steel frame at each 

 site (Fig. 2). The rack and frame assemblies deployed at WP, FI, BP, and GN were suspended from docks 

 by ropes in waters not exceeding 2 m in depth; the lower edge of the panels was maintained 0.2 ra off 



