GOLIATH CONSERVATION STORY

LONG JOURNEY BACK

Twenty-five years ago, any type of encounter with these reef giants off Florida’s East Coast was a considerable rarity. Across the State on the West Coast, the situation was not all that much different.

The number of fish I had seen in my youth gathered on some of the distant wrecks far off shore in the southern Gulf of Mexico was identical to what I am seeing today. But, by 1985, those encounters had gone away, beaten back by aggressive fishing practices to become stories of something that once was, and likely never to be again.

In 1990 the Federal Government under the Magnuson-Stevens Fisheries Act, closed the fishery on goliath grouper completely. By the time these protective measures were enacted, there were so few large goliaths left it would be some eight years (1998) before the first documented spawning aggregation would reappear in the southern Gulf of Mexico. And another three years (August 2001) before the first spawning aggregation comprised of 27 fish off Jupiter, Florida would be seen again for the first time on the east coast in nearly three decades.

During the 1950’s and 60’s, large goliaths were highly plentiful in Florida’s coastal waters. To find them seldom took more than dropping a line in from the end of a dock or pier. As fishing pressure grew, finding the big fish meant fishing further off shore, specifically on wrecks.

But appearances can be deceiving, as a major portion of the entire regional population taking part in this ritual behavior is represented between this one zone off Florida’s east coast and a key number of sites in the southern Gulf of Mexico.

Add to that the reality that at onetime, the Atlantic goliath grouper (Epinephelus itajara) were once highly abundant in not only Florida, but also along the entire Central and South American Continental Shelf as far south as the southern edge of Brazil. Their historical range even spanned the entire Bahamas and Caribbean to as far away as Western Africa in the Gulf of Guinea.

Our planet’s ever expanding human population and today’s highly efficient means to harvest fish from the oceans has made it more difficult than ever to keep fish stocks the world over from being pushed to complete collapse.

The most heavily impacted are the dominant predators of the tropical reefs – namely the groupers, with goliath grouper taking the heaviest toll.

While our own management measures may have stopped the progression of the US population of goliath grouper toward extinction, relentless fishing pressure elsewhere in their range alerted the International Union for the Conservation of Nature (IUCN) to list goliath grouper as “critically endangered.”

UNDERSTANDING BIG OLD FISH

The same year the fish was placed under it’s new protected status, the job of monitoring the recovery of this species was put into the hands of scientists at both the National Marine Fisheries Service (NMFS) and Florida State University (FSU). FSU’s Research Ecologist, Dr. Chris Koenig, and his colleagues, began a detailed study of the fish’s natural history.

Much of the process included capturing a large number of both adult and sub-adult size fish on Florida’s east and west coast. Whenever a fish is brought aboard, Koenig’s team would quickly go to work extracting fin ray samples for age determination and DNA cataloging, checking stomach contents, attaching visual tags to even implanting acoustic tags in the fish to track its movements before releasing it back into the wild. With each year, an extensive amount of new data were collected revealing even more information about this fish that challenges almost everything we previously knew about it.

REPRODUCTION AND AGE

Like most reef dwelling species, groupers are broadcast spawners where a female releases a quantity of unfertilized eggs into the water at the same time sperm is released by one or more males; the result is fertilization.

Among broadcast-spawning fish larval mortality (from egg to fry) is extremely high, as they are cast into highly variable ocean currents and preyed upon by a wide variety of fish and invertebrates. Therefore, for females in the spawning group to contribute effectively to the reproduction of the species, they must produce a great abundance of eggs. In terms of a fish’s fecundity (its production of fertilizable eggs), the older the fish, the more prolific it will be at producing viable eggs for fertilization. Unlike people and other mammals, reproductive output increases with age and size in fish.

Generally speaking, the more fertilized eggs each female can release during spawning, the better the chances a few members of that reproductive event will make it to adulthood. It’s all a numbers game when it comes down to who will survive and who will not in the ocean.

While it has been found that goliaths are a long-lived fish, the oldest documented specimen was 37 years old, which opens speculation that they could live well beyond 50, they are also a relatively slow-growing species, taking as long as 7 years to reach sexual maturity.

Here’s where things get interesting.

Most grouper species are protogynous hermaphrodites, meaning that individuals first mature as females, changing sex to become males later in life. Thus, the vast majority of large individuals in protogynous species are male. Goliaths are a bit more complicated, as they don’t exactly follow that rule. FSU researchers have found some males at small sizes–as small as the size of sexually maturity–and some at the largest sizes, but females are abundant among older age groups, a pattern unlikely to occur in typical protogenous species.

The bigger surprise is that they have found specimens that had both fully functional male and female capabilities in the same individuals. This new finding has led Dr. Koenig to surmise that these individuals are bisexual hermaphrodites, capable of functioning as a male at one time and a female at another. Talk about your gender bender.

While this new finding adds a new wrinkle to the knowledge base of this fish’s natural history it does not underscore the fact that although a goliath might technically be considered a breeder by age 7, it is significantly far off from reaching peak fecundity; which does not happen until 14 -15 years of age.

A goliath’s growth rate begins to slow after the first 8 years. From there, it may take as long as another 7 to 15 years before they actually exceed 400 pounds. This begs the question: how big does a goliath get?

Left is a photo of the largest goliath on record with the IGFA (International Gamefish Association) weighing 680-lbs that was taken by a sport fisherman in 1961 off Fernandina Beach, Florida; compared to an even larger reported 900-lb giant (right) taken in the waters of Brazil (Right), the two fish are not that much different in size.

While it does question the true weight of the Brazilian fish, it does not exclude the fact that, like the Fernadina fish, it still was of significant size.

Most text books, as well as Wikipedia describe the Atlantic goliath capable of growing to extremely large size, reaching lengths of up to 10 ft./3 m, with their ponderous girth pushing the scales past 790 lbs./360 kg in weight. While such behemoths have been reported, the most incontrovertible is the 680-lb fish landed by a sportfisherman in 1961 off Fernandina Beach, Florida. By the way, this still remains the all tackle record recognized by the IGFA (International Gamefish Association) for any grouper species taken anywhere in the world.


What is interesting is that stories persist of fish equal to or even larger than the Fernandina fish in Florida lore. Yet, Dr. Koenig and his team of researchers have yet to come across a single fish past the 500-lb mark since the study began in 1990.

But even at that size, a face-to-face encounter with a fish of that magnitude underwater would obviously be something you would never forget.

Due to the magnification created by water’s effect on a diver’s facemask, the perspective to just how big that fish is, like the one pictured left with a diver, would be greatly amplified making even a 7-foot long fish with a girth the diameter of a 55-gallon oil drum appear as big as a compact car.