6-59 



suggests either an improvement in water quality or, more likely, a random 

 increase rather than a plant impact. 



DiveY'Siltij 



Because the summer has been identified as the period of 

 greatest stress for the benthic infauna in New Haven Harbor, power 

 station effects on diversity should be most evident in the summer. To 

 evaluate the possibility of reduced diversities in the inner harbor due 

 to station operation, a series of paired t-tests was run on the Shannon- 

 Weaver diversity values for the six stations closest to the discharge 

 (4, 7, 8, 8N, 5, 9) and six control stations from Morris Cove. A matrix 

 of comparisons for each location over all years was constructed (Table 

 6-12) from the results. 



For all comparisons except one, there is no significant dif- 

 ference between the mean diversity at the selected stations for pre- 

 operational vs. postoperational years. The single exception is for 1974 

 compared with 1976 at Morris Cove, where diversities were significantly 

 greater in 1976 (p < .05) . This isolated observation is of no general 

 significance and the observed pattern of minimal changes in diversity 

 supports the conclusion of no apparent impact on benthic macrofaunal 

 diversity due to station operation. 



SUMMARY 



A composite list generated by the NAI (1973-1977) and R & M 

 (1974-1978) benthic studies in New Haven Harbor consists of over 300 

 taxa. Species richness values did not have consistent seasonal patterns 

 but were higher at Morris Cove than in the inner harbor. Faunal diversity 

 in the inner harbor was typically low; values of 0.0 were common. 

 Diversities were higher in Morris Cove than in the inner harbor. A 

 slight trend of increasing diversity was observed over the course of the 



