Goliath grouper (Epinephelus itajara) is the largest member of the grouper family and the bane of offshore anglers and spearfishermen on Florida's west coast. Protected since 1990, these massive bottom dwellers can grow to be more than 7 feet long and weigh more than 800 pounds. Goliath grouper swim slowly, except when there is an injured fish in sight, then these monsters of the deep can move with astonishing speed. Many recreational anglers and divers blame these opportunistic predators for the downturn in local gag and red grouper stocks, and they want the goliath population culled. But it is unlikely federal fishery managers will open the season any time soon for this often-maligned and misunderstood species.
Twenty years ago goliath numbers crashed, causing federal officials to step in and ban the taking of these large grouper.
Spearfishermen were lucky to see one or two of these behemoths during the course a dive back then. But years of protection has helped the species rebound, and it is not uncommon to see as many as a dozen of these fish on some of the more popular shipwrecks off Tampa Bay, such as the Mexican Pride and the Gunsmoke.
Goliath grouper are now found throughout subtropical and tropical waters of the Gulf of Mexico, Atlantic Ocean and Caribbean Sea.
In some areas, including Boca Grande Pass where a deep channel runs close to shore, large goliath grouper can be found hanging around shallow-water docks and pilings. The juvenile of the species are frequently caught by inshore anglers, especially in remote areas such as the Florida Everglades.
Goliath grouper are opportunistic feeders that ambush prey. These fish can open and close their mouths rapidly, causing a change in water pressure, which allows them to literally suck in unsuspecting victims.
These sedentary lords of the deep feed primarily on crustaceans, stingrays and a variety of slow-moving finfish such as toadfish, filefish and catfish. Researchers say there is no evidence to suggest that these lumbering beasts will actively hunt and capture faster moving species.
But goliath grouper will eat what they can, including a hooked gag or snapper, even if it is just a few feet below the surface. On some of the more heavily visited wrecks, the sound of a spear gun being cocked will attract inquisitive goliath grouper.
Goliath grouper live a relatively long time. Individual specimens have been documented at 37 years old, but it is suspected these fish may live well into their 40s. Goliath grouper aggregate when spawning, which makes them vulnerable to overfishing.
The species was decimated by overfishing in the 1980s, which prompted U.S. officials to protect the goliath grouper in 1990. Other governments around the Caribbean soon followed the United States' lead.
In the years that followed, goliath numbers improved dramatically. In 2006, a status report showed a "significant increase" in goliath grouper stocks, and as a result, the National Marine Fisheries Service removed the species from its species of concern list.
State researchers have also found the number of young goliath grouper found in nearshore waters has also increased, which is another sign of recovery.
But because goliath grouper remain a federally protected species, fishery managers cannot look at landings data to gauge the health of the fishery. Several research projects are currently under way by the NMFS, the Florida Fish and Wildlife Conservation Commission, the University of Florida and USF.
In the waters off Tampa Bay, independent contractors are diving local wrecks, ledges and artificial reefs to get an accurate picture of the goliath grouper population.
The project, led by Angela Collins of the FWC's Fish and Wildlife Research Institute in St. Petersburg, uses underwater video and lasers to assess the size and numbers of both individual fish and the overall grouper population.
When possible, individual fish are fitted with external identification tags that allows researchers to track their movement. Information gathered during this project will help fishery managers put together a stock assessment, due in 2013, which will determine whether these tackle busters will someday become fair game.
Sources: The National Marine Fisheries Service, Florida Fish and Wildlife Conservation Commission, Angela Collins of the FWC's Fish and Wildlife Research Institute