Opprnf.ion of the Millstone Nuclear Power Station (MNPS) creates several 

 changes in the natural environmental conditions that might induce changes 

 in the composition and abundance of Ideal benthic communities. These 

 changes include: current generated scour near the plant intake and discharge) 

 organism entrainment through the condenser cooling system, chemical and 

 heavy metal additions, and increased water temperatures associated with the 

 plant discharge. 



The objectives of the Millstone infaunal monitoring program are to: 



(1) establish the infaunal composition and abundance at subtidal and 

 intertidal stations located within and beyond the area influenced 

 by operation of the MNPS, 



(2) identify seasonal and year to year patterns in species 

 composition and abundance and establish the natural range of 

 these measures, 



(3) evaluate whether any changes in species composition and 

 abundance (both short and long-term) are due to operation of 

 MNPS. 



The following report summarizes the 1983 results of the Millstone 

 infaunal monitoring study and includes data collected in prior years for 

 comparative purposes. 



MATERIALS AND METHODS 



Benthic infaunal communities were sampled at four subtidal and three 

 intertidal stations in September and December 1982 and March and June 1983 

 (Fig. 1). The Giants Neck (GN) subtidal and intertidal stations are 

 located 5.5 km west of the plant and serve as reference stations since they 

 are located beyond any projected influence of the plant. The Intake 

 subtidal station (IN) is located 0.1 km seaward of the Millstone Unit 2 

 intake structure, while the Effluent (EF) subtidal station is located 

 approximately 0.) km offshore and adjacent to the cooling water discharge 

 into Long Island Sound. This station is positioned as close to the effluent 

 as possible given the current produced by the discharge. The Jordan Cove 

 (JC) subtidal and intertidal stations are located 0.5 km east of the plant 

 and are within the area potentially influenced by the the cooling water 



