Initial 7.(i(i]->lankton irivtvsti gat ions were entrainment studies 

 conducted at MNFS Unit 1 from November 1970 through June 1975 to 

 determine zooplankton species composition, abundance and survival. 

 Zooplankton has been sampled weekly at the MNPS discharges (Units 1 and 

 2) since July 1975. Offshore zooplankton has been sampled at several 

 stations since 1973 (NUSCo 1974). In 1979 more frequent, year-round 

 samples were collected at a single offshore station in mid-Niantic Bay 

 (NUSCo 1980). 



The objectives of the current monitoring program are to provide 

 information on abundance of zooplankton around Millstone Point and in 

 the cooling waters of MNPS, and to determine whether fluctuations in 

 these populations are natural or power plant related. This report 

 presents the results of the zooplankton program from October 1975 to 

 September 1983. 



METHODS AND MATERIALS 



Zooplankton Laboratory Processing 



Zooplankton was examined from the ichthyoplankton samples collected 

 with 0.333 mm mesh plankton nets (see Methods and Materials of Finfish 

 Ecology Section). The mesh size retained only the mesozooplankton, and 

 allowed passage of smaller organisms. 



Each week, one day and one night sample was processed for 

 zooplankton from tows at the discharges (EN) and at Station 5 (NB) (Fig. 

 1). Whole samples or fractions were placed in a 6 liter reservoir, 

 mixed with a slotted piston, and subsampled with a Stempel pipette. 

 Aliquots were examined until 300 organisms were counted and identified 

 to the lowest practical taxon. 



Data Reduction and Statistical Analysis 



Year designations refer to the sampling months of October of the 

 preceding year through September of the designated year, e.g. sampling 

 year 1983 included samples from October 1982 through September 1983. 



