1-18 



The monitoring program for operational impacts in New Haven 

 Harbor is based on a series of facts and assumptions that are important 

 to understanding the approach utilized for the analysis of impacts in 

 this report: 



1. The harbor has an apparent (though untested) high ex- 

 change rate with Long Island Sound. This is deduced from 

 the large tidal prism (43% of harbor volume at MSL) , and 

 the general LIS net flow pattern past the harbor mouth 

 (EBASCO, 1971) . 



2. The cooling water flow of New Haven Harbor Station is 

 only 0.7% of the average tidal flow rate. 



These two facts are the basis for the assumption that even 

 under the worst conditions of total mortality of entrained organisms, 

 exchange with Long Island Sound waters and associated plankton popu- 

 lations would override any potential plant-operationally induced 

 reduction in population abundances. 



Study of plankton populations was geared toward detection of 

 any shifts in dominance or abundance levels, particularly by consider- 

 ation of spatial differences. Sampling was performed throughout the 

 harbor. The generating station impact on plankton populations was 

 considered to be within acceptable limits provided that species compo- 

 sition, abundance levels and the relationship of species distribution 

 between stations remained similar throughout preoperational and operational 

 periods. Any observed qualitative changes would need to be examined in 

 detail, their potential ecological importance considered, as well as 

 their spatial extent and longevity. 



"Analysis of Impacts" in each section of this report provides 

 a comprehensive description of mechanisms of potential impact, considers 

 the potential of available data to evaluate the impacts, and proceeds to 

 examine the data for plant effects. Where possible changes in standing 



