1.75- 



I 1.50 



^ 1.25 



S 1.00 



° 0.75 



3 0.50 



^ 0.25 



^ 0.00 



g -0.25 



^ -0.50 



[d -0.75 



> -1.00 



^ -1.25 



m -1-50 



UJ 



U. -1.751 



-2.00 



-2.25 



31 82 83 84 85 86 87 



YEAR 



Fig. 17. Annual February water temperature deviations Trom the long-term mean from 1976 tlirough 1987 

 as determined from MNPS operating records. 



Larval studies 

 Abundance and distribution 



Larval winter flounder abundance in 1986 and 

 1987 was examined in the Niantic River (stations 

 A, B, and C combined) and Bay (stations EN 

 and NB combined) using estimated abundance 

 curves from the Gompertz function (Fig. 18). In 

 the river, larvae were much more abundant in 

 1987 and in both years maximum densities oc- 

 curred during late February through mid- March. 

 The highest densities in the bay occurred later in 

 April and the difference in abundance in the bay 



between the 2 years was not as great as it was in 

 the river. This suggested that greater larval mor- 

 tality may have occurred in 1987 compared to 

 1986 and that the mortality occurred early in the 

 season while a majority of the larvae were in the 

 river. A comparison of the abundances in 1986 

 and 1987 to 1983-85 was based on the a parameter 

 from the Gompertz function, which was used as 

 an index of abundance (Table 11). This parameter 

 is actually an estimate of the area under the abun- 

 dance curves presented above (Fig. 18). The 

 Gompertz function fitted the cumulative abun- 

 dance data well with R values exceeding 0.98. 



TABLE 11. Larval winter flounder abundances and 9.'5"(i confidence intervals for the Niantic River 

 and Bay as estimated by the a parameter from the Gompertz function. 



Year 



Niantic River 



Niantic Bay 



1983 

 1984 

 1985 

 1986 

 1987 



1814 (1748-1879) 



5077 (4940-5215) 



11715 (11558-11871) 



1677 (1629-1726) 



5066 (4870-5262) " 



2911 (2873-2950) 



1823 (1742-1904) 



1604 (1548-1660) 



881 (843-920) 



1279 (1234-1324) 



Winter Flounder Studies 



177 



