Fish
Goliath Grouper
Epinephelus itajara · also called goliath grouper, atlantic goliath grouper, jewfish
The Atlantic goliath grouper is a reef giant — up to 2.5 metres and 360 kilograms — that hoovers up lobsters and fish with a sudden gulp and warns off intruders with a booming sound you feel in your chest. Fished almost to disappearance, it has clawed its way back off Florida since a 1990 ban.
Overview
Goliath groupers live in warm shallow waters of the western Atlantic, from Florida to Brazil, plus West Africa, on reefs, wrecks, and mangrove estuaries. Up to 2.5 m and 360 kg, among the largest reef bony fish, they ambush lobsters, crabs, and fish with a powerful suck of the mouth.
A sound you feel
It vibrates its swim bladder to produce a deep booming sound that carries underwater as a pressure wave, warning off divers and rival groupers.
Fished out, then protected
Easy to catch at predictable spawning sites, populations fell by 80 percent or more before a 1990 US harvest ban began a slow, decades-long recovery.
Status
The goliath grouper is Vulnerable but increasing in protected US waters, while still depleted elsewhere in its range.
Goliath Grouper: common questions
How big does the goliath grouper get?
The Atlantic goliath grouper is one of the largest bony fish found on coral reefs, with the biggest confirmed individuals reaching around 2.5 metres in length and weights of up to roughly 360 kilograms, comparable to the weight of a large motorcycle. Fish of this size are old, having taken many years to grow, and are relatively rare even in recovering populations, but goliath groupers of 100 to 200 kilograms are regularly encountered by divers on reefs and wrecks off Florida, where the species is protected, and their sheer bulk, combined with a tendency to approach divers out of apparent curiosity, makes an encounter with one memorable.
What is the booming sound a goliath grouper makes?
The goliath grouper can produce a distinctive low-pitched booming or drumming sound by rapidly contracting specialised muscles against its gas-filled swim bladder, using the bladder much like a drum to generate a pulse of low-frequency sound. This sound carries efficiently through water and can be strong enough that nearby divers feel it as a thump in their chest rather than simply hearing it. The booming is used as a territorial warning to intruders, including divers and other fish that come too close, and also appears to play a role in communication between groupers, particularly around spawning aggregations.
Why did goliath grouper populations collapse?
Several traits made the species exceptionally vulnerable to overfishing. It grows large and slowly, takes years to reach breeding age, and gathers in large numbers at the same predictable locations and times each year to spawn, so a fishery targeting those aggregations could remove a huge proportion of the breeding population in a short time. The fish are also naturally curious and unwary around people, making them easy targets for spearfishers and anglers. Combined, these factors led to declines estimated at 80 percent or more across the species' range through the middle and late 20th century, prompting fishing bans in several countries.
Has the goliath grouper recovered since it was protected?
In United States waters, where a complete harvest ban has been in place since 1990, the population, particularly off the coast of Florida, has shown a clear and sustained recovery over the following decades, with juveniles now common in mangrove nursery habitat and adults regularly seen on reefs and wrecks. This recovery was strong enough that the IUCN reassessed the species from Critically Endangered to Vulnerable in 2021. However, recovery has been uneven, and populations in parts of the Caribbean, South America, and West Africa remain depleted or are still declining where protection is weaker or absent, so the species is not considered secure range-wide.