34 
Fishery Bulletin 1 10(1 ) 
ment methods. The uncertainty about the trends in 
rockfish populations may be reduced by using habitat 
modeling to account for some of the variability in the 
survey data since the current stratified abundance 
indices produce biologically unrealistic variation in 
abundance estimates among years. Thus the habitat- 
based indices may provide for stock assessment models 
a more stable alternative to current biomass estimates 
produced by the multispecies bottom trawl survey in 
the Gulf of Alaska. 
Acknowledgments 
This manuscript was improved by helpful reviews from 
P. von Szalay, D. Hanselman, D. Somerton, M. Wilkins, 
S. Lowe, and three anonymous reviewers. Additional 
data from and discussions with K. Shotwell, P. Spencer, 
J. Boldt, and P. von Szalay also improved the manu- 
script. The data were collected with the assistance of 
many scientists and volunteers at the Alaska Fisheries 
Science Center over the last 15 years. 
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