Crabtree and Bullock: Life history of Mycteroperca bonaci 
751 
V) 
O 
Month 
Figure I 3 
Gonadosomatic indices (GSI, *) and medians (+ and lines) for sexually mature female 
and male black grouper, Mycteroperca bonaci , plotted by month. 
Conclusions 
The status of black grouper stocks is unclear. Our 
sample contained many old and large grouper, most 
of which came from the commercial longline fishery. 
Large grouper are apparently still abundant in some 
areas, and their continuing presence in the commer- 
cial fishery could reflect the expansion of fishing ef- 
fort into deeper and more remote areas. In the shal- 
low waters adjacent to the Florida Keys, large and 
old black grouper were rare, probably a consequence 
of fishing mortality. The current minimum size does 
not protect sexually mature females, and the fishery 
could substantially reduce spawning success in black 
grouper. In addition, size-selective fishing mortality 
may selectively remove males from the population. 
Sex ratios are currently skewed towards females, and 
it is unknown if populations can compensate by re- 
ducing the size of transition as males are selectively 
removed. Finally, additional research is needed to 
document the existence of black grouper spawning 
aggregations in the eastern Gulf of Mexico and in 
the waters off the Florida Keys and to evaluate the 
extent to which these aggregations have been affected 
by fishing mortality. 
Acknowledgments 
We thank D. BeMaria and K. DeMaria for collecting 
black grouper from the Florida Keys. We also thank 
C. Boniface and M. Puig for their assistance in sam- 
pling in the Keys. Many commercial fishermen coop- 
erated by providing ungutted black grouper, and 
Dick’s Seafood, Madeira Beach Seafood, and 
Captain’s Finest Seafood allowed sampling of grou- 
per during their busy schedules. Captains C. 
Sullivan, B. Banks, and G. Haring deserve special 
thanks for saving gonads with their catch. We ac- 
knowledge the following FMRI personnel for their 
assistance: M. Cladas, L. French, G. Gerdeman, D. 
Harshany, M. Norris, D. Merryman, H. Patterson, T. 
Sminkey, F. Stengard, and C. Stevens. A. Collins, 
NMFS, Panama City, FL, provided samples from the 
