SUMMARY 



The Millstone Nuclear Power Station (MNPS) is located on the north shore of Lxing Island Sound 

 (LIS) in Waterford, Connecticut. The station consists of three operating units: Millstone Unit 1 

 commenced commercial operation in 1970, Unit 2 in 1975 and Unit 3 in 1986. 



Extensive studies of the potential impacts of MNPS on local marine flora and fauna have been 

 conducted since 1968. During this period studies have consistently been reviewed and updated to assure 

 that the best available methods were used. This report summarizes data from all monitoring programs 

 performed at MNPS during 2-unit operation and is intended to provide information which will establish 

 the baseline for all impact assessment studies during 3-unit operating conditions. 



ROCKY INTERTIDAL STUDIES 



Attached plant and animal species on local rocky shores were identified, temporal and spatial 

 patterns of occurrence and abundance of these benthic species were examined, and physical and biological 

 factors that induce variability were identified. Qualitative algal collections, quantitative studies of intertidal 

 organisms, recolonization studies, and Ascophyllum nodosum studies were performed to assess impact 

 and are summarized below. 



ITie local flora, as characterized by qualitative algal collections, has shown consistent spatial and 

 temporal patterns of distribution during Unit 1 and 2 operation. Overall, 158 algal species have been 

 identified since the inception of the monitoring program in 1979, consisting of 73 reds, 40 browns, and 

 45 greens. Several of these species were site-specific, and others were seasonally important. The greatest 

 number of algal species recorded from a single collection usually occurred in spring-eady summer for 

 all stations. The most species collected in any month was 117 in July and the fewest (101) in March. 

 The most species collected at any station was 131 at Bay Point and the least was 109 at both Seaside 

 Exposed and Twotree Island. Yearly, the greatest species number generally occurred at White Point. 



The proportions of reds, browns, and greens are similar throughout the area and independent of 

 species number when analyzed by month and station. Annual percentages of species in each division 



