276 
Fishery Bulletin 107(3) 
A 
ABCDEFGH I J 
Scenario 
c 
o 
ABCDEFGH I J 
Scenario 
B 
ABCDEFGH I J 
Scenario 
D 
ABCDEFGH I J 
Scenario 
0.8 - 
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0.6 - 
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0.4 - 
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Figure 11 
Box plots of the estimates of F SSB40 ( A), Fssb2s(®L ^cur / ^o.issb4o(^') > anc ^ -^'cur^o.issb25 
for scenarios incorporating the uncertainty in total mortality (Z), natural mortality (M), and 
age at first capture it c ) for female sailfish (Istiophorus platypterus ) in the waters off eastern 
Taiwan. The center line represents the median and the box represents the quartiles. The 
whiskers extend 1.5 times the interquartile range. Open circles are outliers. Horizontal dashed 
lines indicate the levels of reference points at base case. 
study is needed before we can confidently recommend 
increasing t c as a measure to prevent overfishing. 
In summary, sex-specific per-recruit modeling coupled 
with Monte Carlo simulation analyses are effective in 
evaluating the stock status of billfish because of the 
sexual dimorphism and uncertainty in key life history 
and fishery parameters of these species. This study 
reveals that sailfish in the waters off eastern Taiwan 
appear to be moderately exploited and have relative low 
risk of being overfished. However, in view of the recent 
rapid increase in fishing effort, it is evident that the 
stock status and development of the fishery need to be 
closely monitored. 
Acknowledgments 
We would like to thank two reviewers, Michael H. 
Prager, NMFS Southeast Fisheries Science Center, and 
Gerard DiNardo, NMFS Pacific Islands Fisheries Science 
Center, and one anonymous reviewer for their valuable 
and constructive comments. We thank Michael Prager 
for proposing the modified catch-curve method. This 
study was partially financially supported by the Fisher- 
ies Agency, Council of Agriculture, Taiwan, through the 
grant 93AS-9.1.1-FA-F1(2) to Chi-Lu Sun. 
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