Table 15. --List of t^-values for comparison between mean days out for trap recoveries and mean days 

 out for seine recoveries. (Only releases with 10 or more seine recoveries Included.) 



n.s. Not significant. 

 * Significant at 0.05 

 ** Significant at 0.01 



level . 

 level . 



was the modification of the Chapman-Robson catch 

 curve analysis described by Paulik (1962). The weekly 

 survival rates obtained are listed in Table 16. 



The total rate of exploitation was computed for 

 each group of tagged fish by dividing the total number 

 of tags recovered from all sources by the number of 

 tagged fish released. Since neither time nor place of 

 recapture affects the estimation of total exploitation 

 rate, complete information on individual recoveries 

 was not needed. For ease in computing total exploita- 

 tion rates, the 30 stream recoveries were included in 

 the total of 7,027 recoveries used. No more than one 

 stream recovery was made for any one experiment. 



Total exploitation rates may be converted to weekly 

 exploitation rates by the following procedure when es- 

 timates of weekly survival rates are available. 



Let R, = number of recaptures in ith week, i = l,...,k, 

 Ni = number of fish released, 

 ix-p = total exploitation rate for k weeks, and 

 /i = weekly exploitation rate. 



Then the expected number of recoveries in the ith week 

 is given by the formula 



Ri = fis'-^ N. 



32 



