PHYTOPLANKTON - Phytoplankton, as primary producers, were considered to be an important 

 component of the marine ecosystem to study in early power plant impact assessments. Thus, various 

 studies were completed at MNPS from 1970 to 1982 to monitor and assess the impact of entrairunent on 

 phytoplankton community composition and abundance. The phytoplankton community in the vicinity 

 of Millstone was found to be similar to that of Long Island Sound and to that near Cape Cod (NUSCo 

 1983b). Carpenter (1975) found that the higher discharge temperature depressed productivity only during 

 warmer periods at Millstone. Chlorination had the greatest impact on phytoplankton, but during chlori- 

 nation the predicted 5-10% decrease in productivity and biomass Ln the effluent mixing zone at Millstone 

 could not be detected (Carpenter et al. 1974a). This result was not unexpected because NUSCo (1979a) 

 estimated that, assuming total mortality of entrained phytoplankton and using published growth rates, the 

 phytoplankton populations in the vicinity of MNPS could recover to preentrainment levels in 1 to 9 h. 

 Because it became apparent that power plant operation had a negligible impact on the phytoplankton 

 community, the phytoplankton program was discontinued in 1982 (NUSCo 1983a). 



ZOOPLANKTON - Zooplankton densities in the Millstone area and potential entrainment losses 

 were also examined as part of the long term monitoring program because of the importance of zooplankton 

 to the marine ecosystem. Zooplankton studies were conducted from 1970 through 1983 and included, 

 estimates of zooplankton densities at several nearshore stations in and around Niantic Bay, estimates of 

 entrained zooplankton, and studies of entrainment-related zooplankton mortalities (NUSCo 1983a). Car- 

 penter et al. (1974b) found that entrainment resulted in zooplankton mortality but significant changes in 

 the zooplankton community near MNPS were not observed. Only a small percentage of the community 

 was directly influenced by power plant operation (4% of the average volume of the Niantic Bay tidal 

 exchange (NUSCo 1976b) and the densities and species composition were typical of greater LIS. Because 

 it was unlikely that detectable changes in zooplankton species composition or abundance would occur 

 during Unit 3 operation, the zooplankton monitoring programs were discontinued in 1983 (NUSCo 1983c). 



OSPRFY - The osprey {Pandion haliaetus) is a pisciverous raptor found in many estuarine areas along 

 the east coast of North America. The area around MNPS is an established breeding ground for osprey; 

 both .fordan Cove and the Niantic River provide abundant food. Because the population in the northeast 

 declined during the 1950's and 1960's as a result of egg shell thinning from the ingestion of DDT, federal 

 officials placed the osprey on the list of threatened species. To assist the recovery of osprey populations 

 after the ban on DDT, NUSCo erected nesting platforms on MNPS property between 1967 and 1985 



