EXPOSURE PANEL PROGRAM 



INTRODUCTION 



The exposure panel program monitors the abundance of fouling and wood-boring organisms in the 

 vicinity of the Millstone Nuclear Power Station (MNPS). Since 1975, when the subtropical shipworm, 

 Teredo bartschi, was first collected in the MNPS effluent, the primary focus of this program has been the 

 monitoring of shipworms. Marine woodborers and specifically shipworms are primarily responsible for 

 the decomposition of wood in marine and estuarine waters. In the last 25 years, as industrial warm water 

 effluents increased in number, several investigators reported increased growth and fecundity of shipworms 

 within these thermally enhanced environments (Naylor 1965; Board 1973; Turner 1973; NUSCo 1982). 

 For example, T. bartschi and 7". furdfera caused extensive damage to marinas in the vicinity of the Oyster 

 Creek Nuclear Generating Station, New Jersey in 1971 (Turner 1973; Hoagland and Turner 1980; Hoagland 

 1981). Teredo bartschi primarily occurs south of Cape Fear, North Carolina and in the coastal waters of 

 the Gulf of Mexico. Although this species has not been collected beyond the influence of the undiluted 

 effluent at MNPS, we have conducted special studies between 1981 and 1985, and established that T. 

 bartschi can survive winter water temperatures in the Millstone Point area and reproduce at local summer 

 temperatures (report in preparation). 



Fouling organisms, plants and animals that colonize new substrata, are also important in the exposure 

 panel program, for two reasons. First, some fouling species are sensitive to thermal stresses (Naylor 1965; 

 Cravens 1981) and the survival and growth of their sessile adult stages are influenced by the water quality 

 suiTounding the substratum to which they attach (Hillman 1975, 1977). Second, their abundance may 

 affect the recruitment of wood-boring species (Weiss 1948). 



Artificial substrata have been used to study community structure and temporal variability of fouling 

 and wood-boring organisms (Turner 1947; Cairns 1982; Manyak 1982). Materials such as glass, plexiglass, 

 ceramic tiles, asbestos-cement and various types of wood have been used as zirtificial substrata. Although 

 the type of substratum, length of exposure period, and deployment strategies influence the patterns of 

 community colonization (Grave 1928; Zobell and Allen 1935; Schoener 1974; Shafto 1974; Osman 1977; 



