Entrainment mortality studies were conducted in 1983 on larvae that had passed through the plant 

 (NUSCo 1984). A total of 135 winter flounder larvae was collected during 11 sampling sessions (Table 

 36). During the study the effluent ^T ranged from 8.0 to ILSX. Of the 24 Stage 2 larvae collected, 8 

 were alive following capture but none survived the 2- to 4-h effluent holding period. Stage 3 larvae had 

 greater survival than Stage 2 following capture and the effluent holding period, but all survivors died during 

 the first 24 h of the latent holding period. All 24 Stage 4 larvae were alive following capture, with 19 

 (79%) surviving effluent and 96-h latent holding periods. From 1983 though 1985, 11% of the larvae 

 entrained were Stage 4 and many of these most likely would have survived passage. These older larvae 

 would also have had a greater probability of recruitment to the adult stock than the younger stages. 

 Survival of larger winter flounder larvae entrained would reduce the estimated effects in previous assessments 

 (Hess et al. 1975; Saila 1976; NUSCo 1983c), which assumed 100% mortality for entrained larvae. 



Table 36. Results of larval winter flounder entrainment mortality studies. 



Total 



135 



101 



34 



19 



Impact assessment 



The potential impact of the 3-unit MNPS over its operational lifetime on the Niantic River population 

 of winter flounder has been addressed by a deterministic impact assessment model. This model was 

 developed under the direction of Dr. Saul Saila of the University of Rhode Island and has been described 

 in numerous reports to NUSCo as well as in the scientific literature (Sissenwine et al. 1973, 1974, 1975; 

 Hess et al. 1975; Vaughan et al. 1976; Saila 1976). The model is subdivided into hydrodynamic, concen- 

 tration, and population submodels and examines the entrainment of winter flounder larvae, which are 



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