6-53 



The community occupying the deeper portions of Morris Cove is 

 similar to the Nephtys incisa-Yoldia limatula community of Long Island 

 Sound described by Sanders (1956) , and the Nephtys-Nucula proxiim 

 community of Buzzards Bay (Sanders, 1960). The primary difference 

 between these communities and the assemblage at New Haven is that the 

 latter has a lower species richness and faunal density than Long Island 

 Sound or Buzzards Bay- The Morris Cove community also has a greater 

 number of opportunistic species. 



Reference to the literature and other areas in Long Island 

 Sound indicates that the benthic fauna of New Haven Harbor is generally 

 characteristic of a polluted estuary. Some faunal components of Morris 

 Cove, however, correspond to those of less polluted areas, reflecting 

 better water quality conditions in Morris Cove than in the inner harbor. 



ANALYSIS OF IMPACTS 



Power generating stations utilizing once-through cooling 

 systems impact the marine benthic environment in a number of ways. The 

 direct impact of the heated effluent may be sufficient to elevate temp- 

 eratures in the receiving body of water to a point which is detrimental 

 to the survival of some of the resident species. This type of impact 

 may affect adults, juveniles, or larvae of benthic infauna. Further, 

 heat may alter competitive advantages or behavior, indirectly producing 

 mortality. Although the direct effects of heat on marine communities 

 have received considerable attention from the pxiblic, they have been 

 shown in many cases to be one of the least objectionable impacts of 

 generating stations, and due to the buoyant nature of the discharge are 

 not likely to impact benthic populations. There have been no measurable 

 changes in bottom temperature at any benthic stations in New Haven Harbor. 

 Further, as discussed in the physical-chemical section of this report 

 (Section 3) , there is no evidence to suggest that dissolved oxygen 

 values in New Haven Harbor have decreased by any measurable amount due 

 to the operation of New Haven Harbor Station. 



