Plankton samples were split using a NOAA-Bourne splitter (Botelho 

 and Donnelly, 1978) and sorted for ichthyoplankton using dissecting 

 microscopes. Samples were sorted for fish eggs and larvae during April 

 through September. During all other months, egg abundance was low and 

 samples were sorted only for larvae. Fish eggs and larvae were 

 identified to the lowest practical taxon. The eggs of Tautoglabrus 

 adspersus and Tautoga onitis were differentiated weekly using the 

 criterion of bimodality of egg diameters (Williams 1967). 



Impingement sampling 



Finfish impinged on the traveling screens of Millstone Units 1 and 

 2 were sampled after each of three 24-h periods a week, usually on 

 Tuesday, Wednesday and Friday. Organisms washed from the screens were 

 collected in a metal basket measuring 1.5 x 0.8 x 1.75 m with 2.5-cm 

 perforations. Screen washes were initiated manually at least once every 

 8 hours. During periods of heavy debris loading (e.g., storms), either 

 automatic sensors started screen washes or the system was placed in 

 continuous operation. Fish were sorted from the debris, identified to 

 the lowest practical taxon, counted and measured to the nearest mm of 

 total length. 



Analytical Methods 



The data collected from the programs described above were processed 

 and analyzed in different ways depending on the type of data. When 

 having a complete seasonal cycle was desirable, such as in species 

 composition or spectral analysis described below, a "year" was 

 considered to run from October through September. For instance, 1983 

 included data from October through December 1982 and January through 

 September 1983. The data from all programs were standardized to some 

 unit effort. The trawl data were reported as catch per 0.69-km tow; the 

 seine data as catch per 30-m haul; the plankton data as number per 500 

 m ; and impingement data as count per 24 h. Percent species composition 

 was computed by summing the total catch (corrected for variations in 



