Goliath Groupers / Marine Life

GOLIATH SUMMER – DIVING GOLIATH GROUPER SPAWNING SEASON

As the summer season reaches its zenith, a spectacle takes places off the Coast of Palm Beach County that divers and underwater photographers will not experience anywhere else in the world - congregations of 40 to 90 plus mammoth size groupers massed together on a particular handful of wreck sites. Typically the end of July, first of August marks the beginning of Goliath Grouper spawning season. Like the fish, it is a goliath event.

Diver with large Goliath Grouper

Goliath groupers (Epinephelus itajara) are the largest predatory, reef-dwelling boney fish in the Tropical Atlantic and Caribbean. A fully mature goliath can weigh as much as 500 pounds/158 to 226 kilos. Getting close to a fish of this size is a memory most will never forget. Getting a photo of a diver with one of these fish makes for a jaw-dropping image.

In most popular dive destinations, these big fish are rare or non-existent. Not so in the waters of Palm Beach County, where at any time of the year it is quite common to see at least one or two of these big animals lurking on a wreck or within an undercut on a ledge. But spawning season is something different, as the area's resident population of goliaths are joined by fish from as far as 350 miles/560 kilometers away. These gatherings are the start of a two-month romance that currently takes place at six key sites. Five of those sites lay within easy reach of dive charters between Jupiter and Boca Raton. While one site called the Hole-in-the-wall is a bit deep for most (depth profile 120 – 140 feet/36-42 metres), three sites— the MG-111, Zion Train Wrecks and Mizpah Wrecks—sit at depths of less than 90 feet/27 metres, and another, the Castor Wreck, sits in 110 feet/34 metres, and rises to 70 feet/21 metres.

Goliath Groupers gathered around the main entrance of the Hole-in-the-wall at a depth of 131 feet/40 metres. 

A Marathon Romance

In comparison to most other species of grouper, the goliath's path to romance is more marathon than sprint. Some of the spawning fish that end up in Palm Beach waters begin their journey from considerable distances, and start moving as early as mid July. By August, the bulk of the migrating fish have completed their journey, swelling the ranks on the aggregation site from a handful of behemoths to aquatic herds of 50 or more.

During the summers of 2011 and 2012, the Zion Train/Esso Bonaire wreck site peaked with 90-plus individuals, while neighboring spawning sites at the MG-111 and Hole-in-the-wall each attracted about 40 individuals. More recently, in the summers of 2013 and 2014, the Castor Wreck off Boynton Beach (the most southern spawning site known off Florida’s east coast) received the lion’s share with 100 plus fish. The shift in preferred locations may have been influenced by a string of cold-water upwelling that plagued the first half of the 2013 season, pushing a number of fish farther south than normal. Goliaths are not fans of cold water.

Unlike one of their closer kin, the Nassau grouper (Epinephelus striatus), which typically spawn in mass under a full moon in winter, the actual mating ritual for goliaths is still somewhat of a mystery. This creates considerable frustration for both fishery biologists and underwater photographers, as no one has yet been able to document the actual spawning event. Much of what we do know about the spawn has come from methods such as collecting fertilized eggs down current of spawning sites, and deploying hydrophones to listen to the fish vocalizes their booms and grunts. These methods have helped determine that that spawning takes place shortly after sunset during a six to seven night period centered on the new moon cycles of August, September to even October.

What divers typically see during daylight hours on any given spawning aggregation site are a collection of colossal-size groupers either formed up in a single group, or a collection of subgroups hanging close to one another, with the fish milling about idly as if saying, “O.K., we’re all here, now what?”  When divers encounter these groups of goliath, there is little to be afraid of, as the fish are no more territorial during spawning season than they are any other time of the year.

Despite their formidable size and somewhat dense demeanor, goliaths are not the ferocious brutes some spear-fishermen would like you believe. For the most part, they can be big babies. When threatened, they sound off with a short series of loud booms accompanied with a brief body shake that makes the fish look like its having a mild seizure. But this posturing is almost all bark and no bite, as they will typically retreat to a safer distance or disappear in a deep hole in the reef or wreck the moment they feel their bluff has been called. Even a large group of 20 or more groupers will not stand in your way should you advance into their space, and will often break to one side or the other like a group of park pigeons.

Not all fish move away however, and there are some that local underwater photographers refer to as the “super models,” as they will hold position while the diver fires off shot after shot. Where the fish are this compliant, you can do almost anything short of giving it a bear huge. If you happen to meet one of these fish, there are a few simple rules to follow:

1. Don’t put your hands in front of its face as it could result in the fish biting you.

2. Keep your movements slow and deliberate, as they also don’t like being surprised.

3. Don’t chase the fish. Your best results will come by following rule #2.

Having the opportunity to get incredibly close to a really big goliath, or perhaps two or three at time can be a heady experience. Seeing an entire spawning aggregation when underwater visibly is good (60-100 feet/18-30 metres), is a spectacle that sometimes defies words. It's also one hell of a photo opportunity.

Something else to consider when witnessing these encounters is that you are seeing something that was once quite common, but now rare. The historical range for this fish once spanned the entire Central and South American coast down to Brazil, including the Bahamas and Caribbean, as well as the West African coast in the Gulf of Guinea. Due to relentless fishing pressure throughout their range, the goliath species sits on the edge of being wiped out, which is why the IUCN has them “Red Listed” as a critically endangered species. Currently, Florida is the only region where stocks have returned from a state of collapse. This makes Florida's spawning critically important to the survival of the species.

As to why they have chosen the sites off the Palm Beach County over the rest of Florida’s East Coast all the way down to the Florida Keys, perhaps the presences of the Gulf Stream has something to do with it. Or it could be they simply like our reefs and wrecks, as even perhaps our company.

No matter how you look at it, our Goliath Summer is a one-of-a-kind event that should not be missed.