224 
Fishery Bulletin 109(2) 
A 
Year Year 
Figure 2 
(A and B) Biomass time series for 16 selected groundfish and coastal pelagic species 
from stock assessments conducted for the Pacific Fishery Management Council on 
the west coast of the United States. In each panel the bold line with square symbols 
represents the most recent stock assessment that was completed, whereas the lighter 
lines represent biomass time series from earlier assessments. 
' 
proxy for all groundfish and coastal pelagic species 
stocks. Among all the 17 stocks listed in Table 2, only 
Pacific sardine yielded a Hessian-based “within” CV 
that is greater (41%). On average, variation among stock 
assessments was about twice that of the estimation error 
within assessments (18%). 
Our approach is empirical and we simply strive to 
quantify variation in biomass estimates from repeats 
