50 

 45 

 40 



35 



30- 



25- 



20 



15 



10 



5 



OH 



76 77 78 79 80 81 82 83 

 YEAR (JANUARY-DECEMBER) 



84 



85 



86 



Fig. 5. Annual 8-mean CI'UE (±2 standard errors) for winter flounder taken by the trawl monitoring 

 program (TMP) from January 1976 through December 1987. 



about 5 fish a tow (Fig. 6). This was in contrast 

 to the large fluctuations in abundance seen within 

 the river. 



Catch of juveniles (< 15 cm) in winter and 

 early spring also fluctuated less outside than inside 

 the river. As the number of small fish in the river 

 declined to low levels in 1986 and 1987, the num- 

 ber outside increased in respect to 1984 and 1985 

 and was at levels of abundance seen from 1976 

 through 1982 (Fig. 7). This was an important 

 finding, as the very low abundance of juvenile 

 fish in the river in recent years seemingly pointed 

 towards continued declines in an already reduced 

 adult stock. However, the greater catches in the 

 much larger area outside of the river suggested 

 that the year-class strength for 1986 and 1987 in 

 the general area may not have been as low as 

 catches during the winter flounder survey would 

 have indicated, assuming that many of these fish 

 were produced in the Niantic River. The differ- 

 ential distribution and abundance of juveniles 

 during the trawl surveys has made it difficult to 



predict future adult population size in the Mill- 

 stone area. 



Regional and historical trends in 

 abundance 



The abundances of winter flounder for the 

 Niantic River population surveys and from the 

 trawl monitoring program was compared to other 

 regional indices (Table 7). With a few exceptions, 

 most indices were significantly correlated and thus 

 described real trends in abundance that occurred 

 throughout Southern New England. One excep- 

 tion was the previously mentioned lack of corre- 

 spondence between the two Millstone series. 

 However, the Niantic River adult median CPUE 

 was significantly correlated with several other 

 measures of adult stock size. These included two 

 commercial fishing CPUE indices for Rhode Is- 

 land and one for Connecticut (Fig. 8) In addition, 

 the Niantic River annual medians were correlated 

 with the URI trawl survey annual 5-mean, lagged 



164 



