Impingement 



The number of winter flounder impinged on the traveling screens of MNPS from October 1972 

 through September 1985 was estimated using techniques described in the Fish Ecology section of this 

 report. The chronology of impingement sampling at MNPS was also given there. Meteorological data 

 were obtained from MNPS operating records to examine certain specific instances of high impingement, 

 length-frequency data offish impinged from 1976-77 through 1984-85 were also examined. The sex and 

 reproductive condition of impinged winter flounder taken just prior to and during the spawning 1982 and 

 1983 seasons were recorded using methods and criteria described previously. 



Details regarding studies leading to the construction, installation, and operation of a fish return 

 sluiceway at MNPS Unit 1 were summarized in the Fish Ecology section. Data and fmdings pertinent to 

 the winter flounder will be discussed in this section. Additional information may be found in NUSCo 

 (1981b, 1986b). 



Cntrainment 



Winter flounder larvae entrained at MNPS were collected at station EN (Fig. 3). Sampling has been 

 conducted since April 1973 as part of a general ichthyoplankton sampling entrainment program. Because 

 of sampling problems, data collected through June 1975 were not used to estimate entrainment numbers, 

 but were the basis for the sampling design beginning in July 1975. Entrairmient samples from the 1976-85 

 larval winter flounder seasons (primarily March through May) provided the longest time-series of data for 

 which annual comparisons could be made. The only changes in sampling design were sampling frequency 

 and replication. For 1976-82, three replicates were collected day and night on 3 d each week. In 1983, 

 sampling frequency was changed to one sample during the day and night on 4 d per week. Sampling 

 alternated weekly at the discharge of Units 1 and 2, whenever plant operations permitted. Approximately 

 400 m'' of water were filtered through a 1.0-m diameter, 3.6-m long, 333-nm mesh conical plankton net. 

 Laboratory processing methods and some data analyses were described previously in this report. Additional 

 details may be found in the Fish Ecology section, including the method used to estimate annual entrainment 

 numbers. 



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