Material and Methods 



Trawl program 



Data used for this report are from the period 

 of January 1976 through May 1987. A reporting 

 year included data collected from June of one 

 year through May of the following year; thus, the 

 report y^ar 1986-87 included data from June 1986 

 througli May 1987. A complete history offish 

 ecology programs was presented in a two-unit 

 summary report (NUSCO 1987b) using a calender 

 year (January through December). Prior to the 

 summary report, the reporting period was October 

 through September. This report period was not 

 based on biological considerations, but on the 

 timing of report requirements to regulatory agen- 

 cies. Many of our analyses used the seasonal 

 period of occurrence of a species (i.e., the period 

 when 95% of the cumulative abundance was ob- 

 served) and in some cases the seasonal abundance 

 transcended the arbitrary reporting periods of Oc- 

 tober througli September or the calender year. 

 Considering the seasonal occurrence of our abun- 

 dant species, June was the best trauvsitional period. 

 By the end of May the early life history stages of 

 the winter-spawning species were no longer sus- 

 ceptible to entrainment and summer spawners 

 were not yet abundant. Because of occasional 

 overlap in the occurrence of a species during tliis 

 May-June transitional period, species-specific 

 analyses are based on the period of occurrence of 

 each species and not absolutely constrained to 

 June 1 as the starting point. If a life history stage 

 occurred during the June- December period, only 

 the 1986 season of three-unit operation is given 

 in this report, whereas, if it occurred in the 

 January-May period, the 1986 and 1987 seasons 

 of three-unit operation are reported. The materials 

 and methods presented are for 1985-86 and 

 1986-87 reporting periods, except for impingement 

 monitoring, which was discontinued at Unit 2 on 

 December 11, 1987. Impingement data are sum- 

 marized through 1987 using a calender reporting 

 year. 



Demersal fishes were collected using a 9.1-m 

 otter trawl with a 0.6-cm codend liner. Triplicate 

 tows were made biweekly at six stations: Niantic 

 River (NR), Jordan Cove (JC), Twotree (TT), 

 Bartlett Reef (BR), Intake (IN) and Niantic Bay 

 (NB) (Fig. 1). A standard tow covered 0.69 km 

 and this distance was measured using radar. The 

 total length of up to 50 randomly selected indi- 

 viduals of each species per station was measured 

 to the nearest millimeter. Catch was expressed 

 as the number per tow. Data are reported from 

 June 1976 through May 1987. 



Seine program 



Shore-zone tishes were sampled using a 9. 1 x 

 1.2-m knotless nylon seine net of 0.6-cm mesh. 

 Triplicate 30-m tows were made parallel to the 

 shoreline at White Point (WP), Jordan Cove (JC) 

 and Ciiants Neck (GN), monthly from November 

 througli March and biweekly April through Oc- 

 tober (Fig. 1). Collections were made during the 

 period of 2 hours before to 1 hour after high tide 

 and all three stations were sampled the same day. 

 Fish in each haul were identified to the lowest 

 possible taxon, counted, and the total length of 

 up to 50 randomly selected individuals of each 

 species in each replicate was measured to the 

 nearest millimeter. Catch was expressed as the 

 number per haul. Data are reported from June 

 1976 through May 1987. 



Impingement program 



Fish impinged on the intake screens at Unit 2 

 were washed at least once ever 8 hours into a 1.5 

 X 0.8 x 1.75-m perforated collection basket. 

 Impingement sampling consisted of sorting spec- 

 imens from all material washed from the screens 

 during a 24-hour period. All were identified to 

 the lowest possible taxon, counted, and the total 

 length of up to 50 randomly selected specimens 

 of each species was measured to the nearest mil- 

 limeter. Catch was calculated as number impinged 

 per 24-hour period. Sampling effort was stratified 



256 



