160 



Fishery Bulletin 94(1). 1996 



found a 1/6.5 ratio between the smallest and largest 

 year classes of widow rockfish (S. entomelas). 



Density-dependent natural mortality during the 

 benthic juvenile stage reduces interannual variation 

 in numbers but does not change the rank order of 

 abundance between years. Since year-class strength 

 ratios at the end of year one are similar to those of 



adults, we feel that year-class strength is set before 

 this period. However, by removing some of the varia- 

 tion in estimates caused by year-class strength, den- 

 sity-dependent mortality increases the relative con- 

 tribution to variation from the underlying patchi- 

 ness and reduces one's ability to distinguish between 

 different estimates (i.e. reduces statistical power). 



