Tautog larvae ranked fifth at NB and seventh at EN and the annual cumulative larval densities were 

 usually greater at NB than at EN (Fig. 22). Although tautog egg abundance was relatively stable throughout 

 the study period, larval abundance was not. Larval densities were considerably lower in 1978 and 1984 

 than in any other year (Tables 10 and 12). In July 1984 a large decline in the abundance of other plankton 

 (including larval anchovies and cunner) was noted. The reasons for this 1984 decrease, which was observed 

 in other parts of eastern LIS (Richards, per. comm.), were not known, but during July 1984, ctenophores, 

 a plankton predator (Denson and Smayda 1982) were unusually abundant; a similar phenomenon may 

 have occurred in 1978. 



Juvenile and adult tautog were present throughout the year in both impingement and trawl collections 

 but catches were higher May through October. Even though tautog prefer rocky shores such as those 

 surrounding MNPS intakes, they were not impinged in large numbers and contributed less than 1% to 

 the estimated impingement total (Table 8). Annual impingement estimates varied an order of magnitude, 

 from 122 in 1985 to more than 1,500 in both 1982 and 1983; the low estimate in 1985 may have been 

 related to a Unit 2 shut-down in June. More tautog were taken by trawl at nearshore stations (JC, IN 

 and NR) than at mid-bay (NB) and offshore (TT, BR) stations. Juveniles (fish smaller than 80 mm) 

 were taken by trawl primarily at NR (Fig. 23), which was an ideal nursery area (P. Briggs, per. comm.). 

 Smaller adult tautog probably stayed near the rocks and shoreline and thus were more susceptible to 

 impingement (Fig. 23). For similar reasons, these smaller fish were also abundant at JC. Because larger 

 tautog move to open water to feed, these individuals would be more likely to be taken by trawl at BR, 

 IN, NB and IT. 



Because the numbers of tautog caught in trawl and seine samples were generally low and not 

 representative of their temporal distribution, the indices of egg and larval density were used for impact 

 assessment. Time-series models were fitted to the egg and larval data from the NUSCo plankton program. 

 All models had R^ values larger than 0.80 and included an annual cycle. The 1984 decline in larval 

 abundance is now a feature of the two-unit operational baseline models for both EN and NB. Summaries 

 of these models are presented in Appendices XXIV and XXV. 



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