entrainment programs and to increase the detectability in density differ- 

 ences, a new offshore program was designed. Station 5 (mid-Niantic Bay) 

 was to be sampled with replicate day and night oblique tows using 0.333- 

 mm mesh nets weekly from April through August and biweekly from September 

 through March. Station 5 was determined to be the most representative 

 offshore station in comparison to the discharge. In addition, weekly 

 oblique tows were made during the day at Niantic River station 2 from 

 March through May to cover the winter flounder larval season. Other 

 offshore stations were deleted after 1978 since the number of samples 

 and data were generally insufficient for analyses. 



During 1979, more winter flounder larvae were again found at the 

 discharge than at station 5. An examination of the length frequency 

 distributions of larvae showed an increase of larvae larger than 6 mm at 

 the discharge at night. It was concluded that these larger larvae had 

 been undersampled by the short tow time in the bottom strata of the 

 sawtooth oblique tows made heretofore. Beginning in 1980, the offshore 

 plankton tows were made using a stepwise oblique towpath with equal 

 duration across surface, mid, and bottom stata to better estimate 

 abundance throughout the water column. 



Analyses were conducted to see if the additional sampling at station 

 5 increased the power to detect differences in density between there and 

 the discharge. The probability of detecting an annual mean density 

 difference of 0.25 (log transformed units) was about 0.85 in 1979 

 (NUSCo 1980). The probability of detecting a 0.15 difference in mean 

 annual abundance (log.. transformed) among years at the discharge was 

 0.61. Thus the previous changes in sampling schemes had increased 



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