13-22 



None of the species collected in the New Haven Harbor samples 

 depends primarily on the Harbor for successful spawning and rearing of 

 young. Consequently, the impact of entrainment on resident species' 

 ecology in New Haven Harbor is moderated by the ability of Long Island 

 Sound to provide recruited larvae and juveniles to replace those des- 

 troyed by the generating station. No changes in the adult or juvenile 

 finfish assemblages have been observed which could be attributed to 

 entrainment mortality of ichthyoplankton. 



Impingement at the New Haven Harbor Station intake was notable 

 for only two species: a resident species, winter flounder, and a summer 

 migrant, menhaden. Although impingement mortality of approximately 

 27,000 juvenile winter flounder per year is high compared to other Long 

 Island Soiind generating stations, this number is not significant compared 

 to the natural and fishing mortality of the species. High winter 

 flounder impingement rates reflect the large numbers of small winter 

 flounder present in New Haven Harbor. No reduction of the harborwide 

 winter flo\inder population based on our catch statistics was observed 

 following peak impingement in the winters of 1976 and 1977. Menhaden 

 were impinged in relatively large numbers in the spring and fall of 

 1976, concurrent with observed mass mortalities of this species sug- 

 gesting that dead and disabled fish accounted for a large proportion of 

 the observed impingement (D. Damer, pers. obser.); no similar impinge- 

 ment occurred in 1975 or 1977. An occurrence of siibstantial juvenile 

 weakfish impingement was observed in late November-early December 1977, 

 after completion of the study. For all other species, impingement 

 mortality was small compared to abundance and assumed natural mortality. 



Most species including cunner, scup, alewives, bluebacks, 

 shad, mackerel, striped bass and smelt show little or no population 

 change. Other species such as winter flounder, summer flounder, Atlantic 

 herring, menhaden, bay anchovies and weakfish show higher operational 

 than preoperational abiundances. The only species with a mean opera- 

 tional abiindance below the preoperational range for two or more months 

 was the windowpane in January and February. Unusually cold winters in 



