INTRODUCTION 



Investigations of benthic infaunal communities are frequently 

 included in ecological surveillance programs at electrical generating 

 stations that use once-through cooling systems (ConEd 1977; LILCo 1980, 

 1981; Boston Edison Co. 1981). The reasons for this are two-fold. 

 First, benthic organisms remain fairly stationary and thus are continuously 

 exposed to any physical or chemical changes in the overlying water 

 caused by plant operation. The sensitivity and response of benthic 

 communities to various environmental perturbations have been well docu- 

 mented (Boesch 1973; Reish 1973; Loi and Wilson 1979; Reish et al. 1980) 

 and this information provides a solid framework within which any man 

 induced changes in community composition and abundance may be detected 

 and their ecological significance evaluated. 



The second justification for monitoring benthic communities in 

 areas potentially impacted by man's activities is that these organisms 

 play an integral role in the function of marine ecosystems. Benthic 

 animals provide a valuable food source for demersal fish populations 

 (Longhurst 1958; Arntz 1980). Additionally, their activities (tube 

 building, burrowing, feeding) contribute to energy recycling and nutrient 

 regeneration processes essential to maintaining the high productivity 

 characteristic of estuarine and coastal ecosystems (Aller 1978a, b; 

 Goldhaber et al . 1977; Tenore 1977). 



Quantitative infaunal studies have been conducted at the Millstone 

 Nuclear Power Station since 1968, with an overall objective of assuring 

 that construction and operation of the facility results in no significant 

 changes in the ecology of local marine communities. The program has 

 been designed to detect changes in community structure that have been 



