140 



Fishery Bulletin 102(1) 



We believe the wide type and wide, wedge subtypes are 

 often over-aged, and the thick type and thick, wedge sub- 

 types are occasionally under-aged and further propose that 

 readers be made aware that a hyaline zone typically forms 

 in the winter, but that it is not uncommon for a second 

 mark to form in the summer. 



Another, less desirable approach, would be for age read- 

 ers to record the morphological type of otolith as a routine 

 part of aging. Users of the data could then incorporate this 

 information into their studies by using a correction factor 

 for fish likely to be under-aged and for fish likely to be 

 over-aged. This factor could be in the form of an aging error 

 matrix as suggested by Heifetz et al. ( 1999 ). This approach 

 may not be practical until more data are available on the 

 true effect on ages for the morphological types described 

 in this study, including how many years would need to be 

 added or subtracted for each type. Finally, a more complete 

 description of the morphological types would be needed to 

 assist the age readers. 



Acknowledgments 



We would like to express our gratitude to Delsa Anderl 

 (Alaska Fisheries Science Center), Kristin Munk (Alaska 

 Department of Fish and Game), Shayne MacLellan (Pacific 

 Biological Station, Canadian Department of Fisheries and 

 Oceans), and Bruce Pederson (Oregon Department of Fish 

 and Wildlife) for participating in the otolith blind reading 

 component of this paper. We would also like to thank Dan 

 Kimura and Craig Kastelle of the Alaska Fisheries Science 

 Center for their assistance in developing the design of this 

 study. We would like to thank Michael Mohr (Southwest 

 Fisheries Science Center, Santa Cruz, CA) for his valuable 

 contribution to the statistical analyses used in this study 

 This study could not have been completed without the sup- 

 port of Gary Stauffer (Alaska Fisheries Science Center) 

 who provided funding for the recovery of the sablefish. 

 Additionally, this study would never have been completed 

 without the assistance of numerous commercial market 

 samplers, port biologists, commercial fishermen, and deal- 

 ers who were responsible for collecting and processing the 

 sablefish when they were caught. And finally, we would 

 like to thank William Lenarz (Southwest Fisheries Science 

 Center, retired) for his support of this study. 



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