314 



Fishery Bulletin 93(2), 1995 



reduces the errors to under 2%, and a second itera- 

 tion practically eliminates the errors. 



The computational requirements of our approach 

 for obtaining a solution to the catch equation that 

 includes a plus group are small. If errors up to 12% 

 can be tolerated, the initial approximation (Equa- 

 tion 11) and the subsequent empirical correction 

 (Equation 14) can be incorporated into a single for- 

 mula. One or two additional computations from the 

 application of Newton's Method substantially reduce 

 or eliminate the biases altogether. 



Acknowledgments 



We are grateful to an anonymous reviewer for com- 

 ments that helped clarify our presentation. Support 

 for this study was provided through the Cooperative 

 Unit of Fisheries Education and Research (CUFER) 

 by National Oceanic and Atmospheric Administration 

 (NOAA) Cooperative Agreement NA90-RAH-0075. 



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