ATLANTIC GOLIATH GROUPER
The Atlantic goliath grouper (Scientific name: Epinephelus itajara) can weigh as much as 362 kilograms (800 pounds) and reach the length of 2.7 meters (9 feet). Scientist have found whole sea turtles in their stomachs and divers have been rammed by them and knocked unconscious. The head and shoulders of a navy diver was once swallowed by one but the diver managed to pull himself out. As a rule, however, these fish generally hang out in caves and usually flee when they come into contact with divers. [Source: Walter A. Stark II, National Geographic. December 1972]
The goliath grouper is the largest grouper species in the Atlantic Ocean. It is found primarily in shallow tropical waters among coral and artificial reefs. Its range includes the Gulf of Mexico and Florida Keys in the United States, the Bahamas, most of the Caribbean, and most of the Brazilian coast. On some occasions, goliath grouper have been caught off the coast of New England in Massachusetts and Maine. In the eastern Atlantic Ocean, goliath grouper are found off the coast of Africa from the Congo to Senegal. They can live over 30 years,
Goliath groupers can be quite noisy. Jennifer S. Holland wrote in National Geographic: “Off the coast of southwest Florida, a hundred feet below the water’s surface, a whump rolls through the sea. Another whump follows, like the boom of distant fireworks. It’s coming from the carcass of a drowned ship. Packed into the cracked-open belly of the wreck are a dozen very big — and very audible — fish. These Atlantic goliath groupers gather on shipwrecks and reefs to eat and socialize. They sport jutting jaws and giant palm fronds for fins and are mottled and spotted in earth tones. They announce their presence to encroaching creatures by squeezing their swim bladders, the air sacs that help keep them afloat. Whump. Whump. WHUMP! [Source: Jennifer S. Holland, National Geographic, July 2014]
Chris Koenig of Florida State University has found that the only time goliaths really move far is for spawning. “When it comes time to mate, they will travel great distances to get to spawning sites, nearly 300 miles in some cases,” says Koenig. “They might cover 25 miles a day in a beeline.” Fish from far and wide, maybe from the entire Atlantic seaboard, congregate offshore near shipwrecks and reefs, sidling together in bullet-shaped masses, bumping and nuzzling and sounding off in the dark of night as they send up sperm and eggs to build the next generation.
Websites and Resources: Animal Diversity Web (ADW) animaldiversity.org; National Oceanic and Atmospheric Administration (NOAA) noaa.gov; Fishbase fishbase.se ; Encyclopedia of Life eol.org ; Smithsonian Oceans Portal ocean.si.edu/ocean-life-ecosystems ; Woods Hole Oceanographic Institute whoi.edu ; Cousteau Society cousteau.org ; Monterey Bay Aquarium montereybayaquarium.org ; MarineBio marinebio.org/oceans/creatures
Endangered Atlantic Goliath Groupers
Atlantic goliath groupers were once so overfished in the southeastern United States, they were considered for listing under the Endangered Species Act.Jennifer S. Holland wrote in National Geographic: Atlantic goliaths used to be numerous and widespread, inhabiting the waters of the southern United States, the Caribbean, and Brazil by the tens of thousands. But after years of being speared and hooked by the boatload, their numbers dwindled to an unknown low, perhaps below a thousand. [Source: Jennifer S. Holland, National Geographic, July 2014]
“The goliath’s own behavior contributed to its population drop. “Ordinarily these fish don’t move a whit; they are glued to the reef,” where food and shelter are plentiful” Koenig says: “That makes them easy targets. “We used to shoot goliaths all the time,” says 86-year-old Frank Hammett, who spent much of his 20s with speargun in hand. “In Palm Beach you could see them sitting on the bottom in a hundred feet of water. The reefs were covered with them. There might be a hundred in one spot or a wall of them — something you don’t forget! I’d shoot one or two, get eight cents a pound for them. Did that for 15 years or more.”
“For a while the grouper’s commercial appeal was regional — in the Florida Keys goliath grouper with black beans and rice was a delicacy — but when other fish stocks waned in the early 1980s, goliaths landed on menus everywhere. They were also a recreational favorite; sportsmen loved overpowering the giants. Many thousands died as trophies. Long-lived and slow to mature, the species simply couldn’t keep up with the slaughter. It teetered on the edge of extinction. But it didn’t fall.
And their numbers have rebounded. But “a return to historic high numbers may be just a dream for the big fish. Koenig says exposure to mercury is having “an insidious toxic impact” on the animals. “The adults have actual pathologies — lesions in the liver — from the levels of mercury,” he says. Not only might that be partly to blame for the fish’s decline, but also it means we shouldn’t be eating these things. “If you were to catch anything over about four feet long,” says Don DeMaria, a former commercial fisherman who assists with conservation efforts, “you would have to throw it back anyway.” The mercury, he says, “makes it inedible.”
“The future of goliaths is also tied up in those mangrove nurseries, where the fish live around the trees’ tangled roots until they are about five years old. Coastal development, agriculture, and pollutants threaten these shallow-water habitats. The current trajectory suggests 20 percent losses of remaining U.S. mangroves in the next 50 years — devastating for young, developing goliaths, which are already reeling from unusually cold winters that took out thousands of the fish from their juvenile habitat throughout South Florida.
Return of Atlantic Goliath Groupers
Jennifer S. Holland wrote in National Geographic: The Florida population of Atlantic goliaths is now rebounding, and fishermen, biologists, and local officials are raising their voices over whether the animals have recovered enough to shed their legal protection from people wielding spearguns and fishing lines. [Source: Jennifer S. Holland, National Geographic, July 2014]
“Chris Koenig of Florida State University has been catching goliaths for decades, but not to bring them home as fillets or trophies. With the help of some strong assistants, he hooks goliaths and wrestles them on board a small boat to measure them, remove a cartilaginous fin ray for DNA and age tests, sample the stomach contents for diet studies, and check reproductive organs for signs of spawning. Each fish gets a tag beneath its skin before the scientists slide the animal back into the sea. Tracking his catch-and-release fish, Koenig has been able to pile up information on where and when they show up and how healthy each one is. He and his wife and colleague, Felicia Coleman, who helps manage the slew of data, hope to get a handle on the current status of the species, Epinephelus itajara.
In 1990 the goliath, identified as endangered, received legal protection in the southeastern U.S. The fish have been slowly rebuilding their population ever since — and attracting scuba divers, who delight in swimming with the immense but nonthreatening fish. The biggest recovery — perhaps as many as thousands of fish — has been off southwest Florida where the mangrove forests, the home of the juveniles, remain thick.
“As often happens in the world of conservation, there are two distinct sides on the issue of goliaths. Still considered critically endangered in much of their range, goliaths in Florida remain legally off-limits. “The political pendulum has swung so far toward protection that you can’t even touch or look at one,” says Key West City Commissioner Tony Yaniz. “You’re better off getting caught with bales of marijuana than with one of these fish.”
“Yet many fishermen insist the animal has returned in droves. And they complain that the big fish interfere with business. “We have goliaths taking legal grouper and snapper right off our lines, over and over,” says commercial fisherman and guide Jim Thomas. “Lobsters too. It’s such a waste.” He is one of many who want to be able to fish for goliaths — even just a few annually — to thin out the alleged thieves. It doesn’t have to be a one-sided benefit, Yaniz adds. Why not have the fishermen contribute to answering the conservation questions by providing data on numbers and sizes of fish? “They’re the ones out there every day, with eyes on the water. They can really help us figure out where the species stands.”
“Conservationists think the fishing community is off base. Koenig and other non-fishermen with “eyes on the water” strongly dispute the claim that groupers are sucking up fishermen’s haul. Studies have repeatedly shown that the lumbering goliaths feed almost exclusively on small, slow targets (crabs, not lobsters, make up more than half their diet).
“Koenig says that giving permission to fish for goliaths in Florida where numbers are up could hamper overall recovery. These fish mostly stick close to the same shallow reefs, rocky ledges, and wrecked ships. “As homebodies,” he explains, “goliaths are already reluctant to relocate.” So if you thin out the most crowded areas, the remaining goliaths have even less reason to recolonize places where the species has died out. And that means recovery won’t be as widespread as it could be.
Yellowfin grouper (Scientific name: Mycteroperca venenosa). are also known as Arigua, Grouper and Rock grouper. Yellowfin grouper are native to the western Atlantic Ocean and found from Florida in the north and Brazil in the south as well as in the Gulf of Mexico and the Caribbean Sea. They live in tropical, saltwater, marine environments in reefs, coastal areas and on or near the sea bottom at depths from two to 198 meters 6.6 to 650 feet). Their lifespan in the wild is typically 12 to 15 years.[Source: Ellen Huether and Lyndee Logan, Animal Diversity Web (ADW) /=]
Adult yellowfin grouper are often found out to the continental shelf break while juveniles favor shallow turtle grass beds. Adults are regularly found in waters from two to 137 meters deep, and are most common at depths of 5-35 meters. Yellowfin grouper areas that offer this shelter, such as offshore reefs, irregular rock formations, and sunken shipwrecks. They are considered a “secretive” species, as their habitat is thought to be dictated by their need for shelter as opposed to the availability of prey.
Yellowfin grouper are pelagic (open ocean) and reef hunters, feeding mainly on coral reef fishes; as well as crustaceans and squid. These fish may forage over long distances. They often use their mouths to burrow into the sand, waiting for prey. Their slender bodies and explosive swimming speed make them nimble ambush hunters. They usually swallow prey whole. Yellowfin grouper are large, top-level predators and so are mainly only preyed upon as juveniles. They use reefs, wrecks, caves, and other structures as shelter from potential predators. As adults, they are susceptible to predation by sharks and humans, especially during spawning aggregations. Their main known predators are Caribbean reef sharks, tiger sharks, lemon sharks and humans
The firm, white flesh of the yellowfin grouper makes it a popular restaurant fish. They are also highly prized in game fishing and are popular in public and private aquariums There have been some reports of ciguatera poisoning — a dangerous sometimes fatal condition — from consumption of yellowfin grouper.
Yellowfin grouper are classified as "near-threatened" by the IUCN. They are vulnerable to overfishing, particularly when they aggregate to spawn. In the Caribbean, about a third of spawning aggregations have completely disappeared due to over-fishing. From 1998 to 2013, the spawning aggregation in Belize declined 80 percent. Data from Bermuda and the Caribbean include evidence of diminishing stocks and declines in weight as much as 15 fold between the years 1979-1981, due to unregulated exploitation. Spawning sites in Belize, Cuba and Mexico are declining and are subject to commercial exploitation.
Yellowfin Grouper Physical Characteristics
Yellowfin grouper weigh up 18.5 kilograms (40.75 pounds) and range in length from 46 to 100 centimeters (18 to 40 inches). Sexual Dimorphism (differences between males and females) occurs: Males are larger than females. sexes colored or patterned differently. Males are distinguished by a yellow blotch on either side of the lower jaw. Females have a reddish lower jaw. [Source: Ellen Huether and Lyndee Logan, Animal Diversity Web (ADW) /=]
According to Animal Diversity Web (ADW): Yellowfin grouper have a fusiform (cylindrical and tapering) body shape, and are strong and agile swimmers. Yellowfin grouper have distinctive dark blotches in oval-shaped groups on their heads and bodies, wide, brilliant yellow margins on their pectoral fins, and yellow-edged mouths. Their bellies are pink in color. The caudal fin is slightly truncated. The dorsal fin has 11 spines and 15-16 rays. Indivduals up to 100 centimeters have been found, although average lengths are around 50 centimeters.
Their body coloration is highly variable, as these fish are able to use chromatophores to rapidly change color and shade in response to their environments. Most typically, they are a pale olive green to brown, but may range to gray or even black. Specimens taken from depths exceeding 35 meters are often red in color, with darker red blotches; body color is usually more brownish in specimens inhabiting shallower waters. Coloration change, from lighter or reddish to a darker, more drab color, tends to occur as a fish ages and moves to deeper water. Other changes in coloration observed include a dark phase, in which the fish is completely dark with no blotches (also observed when a fish is hiding); a bicolor phase,in which the fish is dark gray dorsally, contrasting with a light ventral coloration; and a white-headed phase, seen during interactions with conspecifics, including during breeding.
Yellowfin Grouper Behavior and Communication
Yellowfin groupers are crepuscular (active at dawn and dusk), motile (move around as opposed to being stationary), nomadic (move from place to place, generally within a well-defined range), migratory (make seasonal movements between regions, such as between breeding and wintering grounds) and solitary. Whether this species maintains a well-defined home range or territory is unknown.[Source: Ellen Huether and Lyndee Logan, Animal Diversity Web (ADW) /=]
Except for congregating to spawn, groupers are solitary and do not socialize. Yellowfin groupers aggregate at breeding sites. One of the primary aggregation sites is the Grammanik Bank, a narrow shelf (100 meters in length) at a depth of 25 meters, located south of St. Thomas, U.S. Virgin Islands
Yellowfin grouper communicate with vision, touch, sound and chemicals usually detected by smelling. They also use vibrations to communicate and sense using vision, touch, sound, vibrations and chemicals usually detected with smelling or smelling-like senses. They have the ability to change body color when changing habitat and communicate reproductive readiness using visual color variation cues and sounds. These fish have lateral line systems, which perceive changes in water pressure and movement, as well as olfactory nares that can detect dissolved chemicals in the water.
Yellowfin Grouper Mating, Reproduction and Offspring
Yellowfin grouper are oviparous (young are hatched from eggs), and iteroparous (offspring are produced in groups. They are sequential hermaphrodites in which individuals change their sex at some point in their lives and typically produces eggs and sperm at different stages their lives and tend to be protogynous ( hermaphrodites that have female organs and eggs before male organs and sperm). [Source: Ellen Huether and Lyndee Logan, Animal Diversity Web (ADW) /=]
Yellowfin grouper engage in seasonal breeding. Reproduction is external, meaning the male’s sperm fertilizes the female’s egg outside her body. They are polygynandrous (promiscuous), with both males and females having multiple partners, and employ broadcast (group) spawning, the main mode of reproduction in the sea. It involves the release of both eggs and sperm into the water and contact between sperm and egg and fertilization occur externally. On average females reach sexual or reproductive maturity at age four years. Males reach sexual or reproductive maturity at eight to nine years.
Yellowfin grouper release gametes multiple times over an annual breeding season, which is during the winter months, with the average number of offspring being 1.4 million. The average time to hatching is 24 hours. There is no parental involvement in the raising of offspring. /=\
Yellowfin grouper form spawning aggregations. The size of these groups varies depending on locality, with groups of anywhere from 2-4 individuals to hundreds. Males with the white-headed color phase display to females, first positioning themselves alongside them, then turning 90° sharply above them, while twitching their bodies. Males also produce low frequency sounds in uniform pulses and variable pulse calls, to induce females to spawn.
Yellowfin grouper changes sex from female to male upon reaching approximately 65 centimeters in length. The sex change may be also cued by social interactions. Males in the Florida Keys are reported to reach maturity at approximately 54 centimeters in length, while females off the coast of Cuba reportedly reach maturity at 51 centimeters.
Yellowfin grouper females release eggs at a variety of developmental stages and sizes in up to 7-8 batches when in a spawning aggregation. Spawning is thought to be linked to lunar cycles. Breeding season varies by location and typically lasts three months. In the Bahamas, the spawning season is January through March, beginning during a full moon and continuing for 12-14 days each month when the water is coldest. In southern regions, the season changes accordingly, e.g. from June to August in the waters off of Sao Paolo, Brazil. Eggs and larvae are planktonic and larvae settle anywhere from one week to two or three months after hatching. Fry are red with light blotches that become darker as they age.
Red Groupers (Scientific name: Epinephelus morio) are also known as grouper, cherna americana, negre. A popular food fish found in the western Atlantic Ocean from Massachusetts through the Gulf of Mexico and south to Brazil they have dark red bodies, white spots and some pink shading, and a large mouth. They play a significant role in their underwater environment by acting as “marine engineers.” They excavate flat-bottom areas creating habitat for themselves and other commercially important species, such as spiny lobster, black grouper, red porgy, and vermilion snapper. [Source: NOAA]
Red grouper are referred to as shallow-water grouper because they’re common in waters three to 18 meters (10 to 60 feet) deep. Juveniles prefer grass beds, rock formations, and reefs in shallow, nearshore waters. They move offshore as they mature. Adults are most commonly found around ledges, crevices, and caverns of rocky limestone reefs, and also near lower-profile, live-bottom (sponges, corals and sea squirts) areas. Adults may school or move together as groups, but only for short distances.
Red grouper have robust bodies with small scales. Their head and body are dark reddish brown, shading pink or reddish below with occasional white spots on the sides and black spots on the cheeks. They have large mouths with a lower jaw that often projects slightly beyond their upper jaw, with bands of slender, sharp teeth, and usually a few stout, fixed canines. Their large mouths allow them to eat their prey whole.
Red grouper grow slowly. The reach the length of 1.27 meters (four feet two inches) and can weigh more than 23 kilograms (50 pounds). The oldest recorded red grouper in the South Atlantic was 26 years old and the oldest recorded in the Gulf of Mexico was 29 years old. They are protogynous hermaphrodites — they begin life as females and sexually mature when they reach 4 to 6 years of age. Some later transform into males, most often between the ages of 7 and 15. The proportion of males in the population increases with age. They spawn frequently, close to 26 times a year, in shallow waters from February through June.
Red grouper feed on a wide variety of fish, octopus, and crustaceans, including shrimp, lobsters, and mantis shrimp. They are among the top predators in reef community food webs and may control some aspects of community balance in reef systems. Red grouper are unspecialized and opportunistic feeders — they eat any convenient prey. They engulf prey whole by opening their large mouths, dilating their gill covers, rapidly drawing in a current of water, and inhaling the food. Smaller grouper are preyed on by the same predators that eat snappers, including jacks, other groupers, sharks, barracudas, and morays. Large sharks and carnivorous marine mammals prey on adult red grouper.
Red Grouper Fishing
Although some populations are below target levels, U.S. wild-caught red grouper are regarded as a smart seafood choice because it is sustainably managed and responsibly harvested under U.S. regulations. Above target population levels are found in the Gulf of Mexico. Significantly below target population level exist in the South Atlantic. A rebuilding plan is in place for the South Atlantic stock.[Source: NOAA]
In 2020, commercial landings of red grouper totaled 2.8 million pounds and were valued at approximately $12 million, according to the NOAA Fisheries commercial fishing landings database. Commercial fishermen mainly use hook-and-line gear, including longlines and handlines, to harvest red grouper. Trawl gear, fish traps, and bottom longlines are prohibited in some areas to reduce bycatch. Several areas are closed to all fishing to protect snappers and groupers, including red grouper.
Red grouper is a popular fish among recreational fishermen in the South Atlantic and Gulf of Mexico. In 2020, recreational anglers landed 2.9 million pounds of red grouper, according to the NOAA Fisheries recreational fishing landings database.
There are two stocks of red grouper: the Gulf of Mexico stock and the South Atlantic stock. The Gulf of Mexico stock is not overfished (2019 stock assessment), and is not subject to overfishing based on 2020 catch data. The South Atlantic stock is overfished (2017 stock assessment), but is not subject to overfishing based on 2020 catch data.
Red Grouper Fishing Restrictions
Annual catch limits are used for red grouper in the commercial and recreational fisheries. These fisheries are closed when their annual catch limit is projected to be met. Both the commercial and recreational fisheries have size limits to reduce harvest of immature red grouper The commercial and recreational fishing seasons are closed from January through April to protect red grouper during their peak spawning period. The annual catch limit is allocated between the commercial (76 percent) and recreational (24 percent) fisheries.
Gear restrictions are used to reduce bycatch and protect habitat. There are eight deep-water marine protected areas and several spawning special management zones to protect habitats. The Oculina Experimental Closed Area is closed to fishing for and possession of all snappers and groupers to protect deepwater coral habitat and the reef fish it supports.
To reduce bycatch, there are restrictions on the type of gear fishermen may use and where they can fish. Sea turtles and other reef fishes, such as snappers and groupers, can be incidentally caught while fishing for red grouper. In certain areas, fishermen are required to use circle hooks to improve the chance of survival of any unintentionally caught fish and to reduce turtle hookings.
Commercial and charterboat/headboat reef fish fishermen must use appropriate release gear and follow handling protocols to increase the chance of survival for any incidentally caught sea turtles. Fishermen are encouraged to use venting tools or fish descenders when fish are caught showing signs of barotrauma. Barotrauma occurs when reef fish are quickly brought to the surface by hook-and-line and the gas in their swimbladders expands. Venting tools help deflate the expanded abdominal cavity, potentially reduce injury to the fish, and make it easier to return to deep water.
For sport fishermen there are annual catch limits and accountability measures and bag and size limits. In the south Atlantic The fishery is closed during the spawning season (from January through April). In the Gulf of Mexico:, the fishery is closed during the spawning season (from February 1 through March 31) in deep water to protect spawning aggregations. In the U.S. Caribbean seasonal closure from February 1 through April 30.
Image Sources: Wikimedia Commons; YouTube, Animal Diversity Web, NOAA
Text Sources: Animal Diversity Web (ADW) animaldiversity.org; National Oceanic and Atmospheric Administration (NOAA) noaa.gov; Wikipedia, National Geographic, Live Science, BBC, Smithsonian, New York Times, Washington Post, Los Angeles Times, The New Yorker, Reuters, Associated Press, Lonely Planet Guides and various books and other publications.
Last Updated June 2023