The potential impact of MNPS on LIS biota has been the focus of study since 1968. The early 

 biological investigations included exposure panel monitoring of woodboring and fouling communities, and 

 surveys of the intertidal sand, rocky shore and shore-zone fish communities. The program scope increased 

 considerably between 1970 and 1973 with the addition of heavy metal analyses of seawater and mollusc 

 tissue, studies of impingement, pelagic and demersal fishes, plankton, subtidal benthos, and lobster and 

 Niantic River winter flounder population studies (Battelle - W.F. Clapp Laboratories 1975; NUSCo 1975). 

 A bibliography of all Millstone-related studies is provided at the end of this introduction; results of these 

 studies are on file at NULL. 



Studies of entrained plankton began in 1970 when Unit 1 became operational (Carpenter 1975); studies 

 at Unit 2 began in 1975. To date, the routine monitoring and special investigations have covered nearly 

 all components of the plankton, including ichthyoplankton, phyto plankton, and zooplai\kton. Effects of 

 chlorination and increased temperature on entrained phytoplankton were addressed and latent mortality 

 of 7,ooplankton after condenser passage was determined (Carpenter et al. 1972b, 1974b) L^ter, emphasis 

 was placed on entrained ichthyoplankton and the relative impact of entrainment on fish populations in 

 surrounding waters (NUSCo 1976b, 1984a). 



Impingement monitoring began at Unit 1 in 1971 and at Unit 2 in 1975. The scope has varied from 

 a complete census of all impinged organisms (1972-1976) to the current program of counting those 

 organisms impinged during a 24 h period on several days per week. Special studies have evaluated the 

 effectiveness of several fish deterrent systems at the intakes, including acoustics, underwater lighting and a 

 surface and bottom barrier (NUSCo 1976b, 1980a, 1981a). In December 1983, a fish return system 

 (sluiceway) began operating at Unit 1 reducing impingement related impacts on fish and shellfish populations 

 (NUSCo 1981b, 1986b). 



The potential effect of three-unit operation on selected species was also considered. Mathematical 

 population dynamics models were developed for the Niantic River winter flounder population (Hess et al. 

 1975, Saila 1976) and for the regional menhaden population (NUSCo 1976b, 1983c). These models 

 estimated the effect of predicted entrainment and impingement losses to populations over the life of the 

 power station. 



