assumed to be reproductive whereas many of the three year old females 

 were immature. If the size of maturity of the Niantic River female 

 winter flounder is known, then all females above this size estimated to 

 have been in the Niantic River should also have been assumed to spawn 

 there. Although some females taken near the end of the spawning season 

 may have spawned elsewhere and then entered the River, it is just as 

 likely that some early spawners were not taken in the population surveys. 



Age and length samples 



Except for 1977 (9.3%), the number of winter flounder aged was 23.9 

 to 30.1% of those measured (Table 20). Considerable effort has been 

 expended since 1977 in processing the age samples in the laboratory and 

 the number aged annually ranged from 228 in 1977 to 1,287 in 1981. The 

 number of winter flounder aged within a length group was generally 

 proportional to that measured; two examples are shown in Figures 6 and 

 7. This is not surprising considering how both samples were chosen. In 

 many cases far more fish of certain sizes or ages were aged then necessary 

 to determine the age composition of the population. A more appropriate 

 method for selecting specimens for aging is a stratified subsampling 

 method (Ketchen 1950; Ricker 1975). In this method, which is most 

 reliable when a large representative length sample is available, fish 

 ate selected for aging up to a uniformly fixed number. Depending upon 

 the abundance of fish in a length group, this could be a small fraction 

 of smaller-sized fish or most of the older, scarce specimens. From the 

 percentage of each age in the aging sample, an age composition for each 

 length group of the length sample is determined, and by summation across 

 ages, an estimate of the age composition of the population. The number 



49 



