Ault et a I.: A multispecies assessment of coral reef fish stocks 
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Figure 4 (continued} 
restricted to shallower depths for safety reasons. 
Thus, large hogfish that inhabit depths below safe 
diving limits are available to only the headboat fleet. 
In shallow water, divers are more likely to see small 
hogfish because they are more abundant and because 
large hogfish are more likely to be selectively depleted 
by spearfishing. The increased average size in both 
data sets since the mid-1980s (Fig. 4G) is most likely 
the result of increased spearfishing regulation, im- 
posed recreational bag limits, and initiation of mini- 
mum size limits. 
The average size of barracuda diverged in visual 
samples and headboat landings since the early 1980s 
(Fig. 4H). This pattern is likely the result of the pro- 
motion and expansion of catch-and-release fishing 
for barracuda during that time period. Decreased 
fishing mortality resulting from more released bar- 
racuda would increase the average size of fish in the 
exploitable phase and be detected in visual samples. 
Headboat landings, however, could trend toward 
smaller fish because more large barracuda increase 
the frequency of angler “breakoffs” (i.e. fish biting 
through lines or leaders) and the proportion of re- 
leases because only small barracuda are normally 
retained for human consumption. Large barracuda 
are avoided because they carry greater risk of 
ciguatera poisoning, which can result in convulsions 
and death for humans (de Sylva, 1994). 
The trend in average size for grouper, snapper, and 
grunt stocks was relatively flat over the past 18 years 
and close to the minimum exploitable length (Fig. 4). 
The flatness is explained by considering expected L 
from a modeled range of F in an analytical model, 
given knowledge about current values of F. The slope 
of L on F was very shallow in the range of the ana- 
lytical model (Fig. 9), corroborating the empirical 
estimates in Figure 4. Some stocks appear to have 
been chronically overfished since the late 1970s. We 
