(Bishop and Sheppard 1973), it nevertheless remains the most useful 

 method of population estimation (Southwood 1978) . 



Use of the Jolly method requires that certain assumptions be made. 

 A summary of these is provided by Begon (1979) and below each is listed 

 followed by a brief evaluation regarding the adequacy of the Niantic 

 River winter flounder population surveys in meeting them. 

 Assumption 1 

 1. Marks are easily recognized, are not lost, and do not cause mortalites. 



The methods of fin clipping (1975, 1976) and freeze branding (1977 

 to present) were chosen to increase the reliability and ease in marking 

 winter flounder. Adult fish marked by both means have been held in the 

 laboratory in several experiments and little mortality has been observed 

 from handling or marking. 



In 1981, fish as small as 6.5 cm were branded. If successfully 

 marked, the Jolly technique could be extended to estimate a large proportion 

 of the 1 year old winter flounder as well as the older fish. Unfortunately, 

 experiments to estimate branding mortality were not successful due to 

 holding problems. Personal observations indicated that branding and 

 handling mortality of small (less than 10 cm) winter flounder may 

 have been considerable at times. The proportion of winter flounder 

 smaller than 15 cm recaptured in 1981 (4.4%) was significantly less 

 (test of equality of percentages, Sokal and Rohlf 1969) than that for 

 winter flounder larger than 15 cm (8.7%), indicating either differential 

 marking mortality or susceptibility to recapture or both. Therefore the 

 method of population estimation of small fish by the proportional catch 

 method is probably preferable than using a mark-recapture technique 

 since the number of recaptures becomes less important. 



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