Ault et al.: A multispecies assessment of coral reef fish stocks 
409 
A 
C 
Figure 6 
Example calculation of an analytical yield model management analysis for gray snapper: (A) 3-dimensional yield-per-recruit YPR 
surface (g) as a function of the fishing mortality rate F (per yr) and size at first capture L' (mm); (B) YPR isopleths in lifetime 
yield-per-recruit; (C) stock biomass dependent on size for several exploitation levels; and (D) spawning potential ratio (SPR) as a 
function of F and L'. REEFS model input parameter values are from Table 3. Shaded rectangles in panels A, B, and D show 
estimated range of F and L'. Darkened rectangle in panel D indicates the range of F estimates that exceed the Federal 30% SPR 
overfishing definition following Rosenberg et al. (1996). 
of grunts. Another indication of significant change 
was the explosive growth of barracuda (Fig. 4H) 
which may be explained by several factors. First, 
there is little directed commercial or recreational fish- 
ing for barracuda as food because of health concerns. 
Second, growth of catch-and-release fishing by sport 
anglers and reduced emphasis on spearfishing may 
have substantially lowered barracuda mortality. 
Third, other top predators, such as groupers, snap- 
pers, and sharks, have been intensively fished, there- 
fore probably lowering competition for food, while, 
at the same time, barracuda still retain a large and 
possibly increasing prey base of grunts and other 
small fishes. Increased abundance and biomass of a 
top predator like barracuda could be a management 
concern if barracuda substantially impact reef fish 
community dynamics. For example, excessive pre- 
dation on popular sport fishes like snappers could 
counteract potential reductions in fishing mortality 
sought by traditional management. 
An adjustment of minimum sizes of first capture 
(L 1 ) and fishing mortality rates (F) may mitigate the 
apparent growth and recruitment overfishing condi- 
tions in the fishery. This adjustment should be done 
in a multispecies context to optimize the biotic and 
fishery potential of the reef fish assemblage. How- 
ever, traditional management actions alone are un- 
likely to be sufficient because they can be circum- 
