Wetzel et a!.: The effect of reduced data on monitoring overfished fish stocks 
201 
Full data 
Reduced data 
B 
Eliminated data 
C 
i -1-1-1-r 
50 74 98 122 146 
1-1-1-1-T 
50 74 98 122 146 
1-1-T 
98 122 146 
5 
0 - 
-5 
BBT 
-EM 
~i-1-1-1-r 
50 74 98 122 146 
1-1-1-1-T 
50 74 98 122 146 
Assessment year 
o 
n-1-1-1-r~ 
50 74 98 122 146 
100% 
F 50% 
0 % 
Figure 6 
Relative error (RE) of estimated spawning biomass (SB) and relative SB, estimates of 
steepness, size at maximum selectivity, and the width of at maximum selectivity in 
each assessment year for the time-varying case and all 3 data scenarios (full data, re¬ 
duced data, and eliminated data) for all simulations used to examine the effect of data 
availability on the ability to monitor rebuilding of an overfished stock of rockfish spe¬ 
cies. The eliminated data scenario in the absence of composition data had selectivity 
fixed at the asymptotic assumption and hence did not estimate the width at maximum 
selectivity parameter. The percentage of stocks that had rebuilt to the target biomass 
during the management period within the operating model (OM, solid black line) and 
with the estimation method (EM, dashed black line) is shown in the bottom panels. 
Data collection consequently returned to historical levels when the EM determined 
that the stock was rebuilt. The black lines in the gray boxes denote the median of 
the estimates, the gray boxes cover the 25-75% simulation interval, and the boxplot 
whiskers cover the 95% simulation interval for each assessment year 
