The Gulf grouper’s large size has made it a popular target for recreational fishing and for local fisheries, and the species is also caught as bycatch by shrimp trawlers in the Gulf of California (1) (2). However, as with many groupers, the long life span, slow growth, late maturity and unusual life history of the Gulf grouper, together with its small geographical range and its tendency to come together in large spawning aggregations, all increase its vulnerability to overfishing (1) (6) (7) (8). The population of this once abundant fish is believed to have declined severely, more than halving in the last 30 years (1) (6) and, even more alarmingly, may have declined by over 99 percent since the 1940s (1). In the Gulf of Mexico, the sex ratio of the population is currently skewed, with significantly fewer males than females. Sadly, increased coastal development in the northern Gulf of California, and greater investment in recreational fisheries, look set to increase reef habitat destruction and intensify fishing pressure on the Gulf grouper in the future (1).