Hulson et al.: Distribution of sampling effort for age composition of multiple species 
341 
bution of sample size across species, should be under- 
taken with more complex simulation analyses than the 
scope of this article allows. 
We have attempted to synthesize the use of sam- 
pling theory with SCAA model simulation analyses to 
address 2 primary questions: 1) how to distribute age- 
composition sample sizes across species, and 2) what is 
the effect on SCAA model uncertainty by increasing or 
decreasing age-composition sample size for species with 
different life histories. In addressing the first question, 
if a goal of sampling is to obtain age compositions with 
a similar degree of uncertainty across species, the sam- 
ple sizes should be distributed on the basis of life-his- 
tory characteristics, in particular growth rates. In ad- 
dressing question 2, at the same time one should keep 
in mind that the relationship between age-composition 
sample size and resulting SCAA model uncertainty can 
be disproportionate because of species-specific charac- 
teristics, and is related to the recruitment variability 
and survey index uncertainty of the species modeled. 
We had to make several simplifying assumptions be- 
cause of the breadth of the topic of optimal distribution 
of age-composition sample size across species. It is due 
to these simplifying assumptions that we are reluctant 
to suggest absolute ranges of age sample sizes for each 
species, but we do contend that there are life-history 
characteristics, in particular growth, that can be con- 
sidered when discussing the distribution of sample 
size. Optimal allocation of sample size has historically 
been an extremely important topic, although not one 
that has received attention in the literature. As fisher- 
ies research resources appear to be shifting away from 
traditional survey and stock assessments toward pro- 
cess studies, government agencies will continue to seek 
guidance for current allocation strategies. We suggest 
that future developments be focused on developing both 
sampling theory to take into account various aspects of 
sampling that currently are not considered and more 
sophisticated simulation analyses with SCAA models to 
place the discussion of sample size distribution across 
species in terms of risk of overfishing, accuracy of re- 
sults, and value to managers and stakeholders. 
Acknowledgments 
We would like to thank P. Malecha, J. Heifetz, and 
P. Spencer for helpful comments and advice. We also 
thank J. Short for providing the reader-tester data 
to determine aging error. Three anonymous reviews 
also helped make substantial improvements to this 
manuscript. 
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