JUPITER -- If you’re an avid, advanced scuba diver, you might want to drop whatever plan you made for Thursday or the next few days and head to Jupiter.
This is the peak of the annual spawning aggregation of Goliath grouper at several artificial and natural reefs from 60 to 130 feet deep off the Palm Beach County town. You may get to swim with up to 100 of the mottled brown, gentle fish that grow to the size of Mini Coopers and were once in danger of extinction. Try to contain your excitement and avoid chasing them underwater. They’ll just boom at you — it sounds like a muffled bass drum — and swim away.
Best viewing is at Hole in the Wall — a deep, natural cavern — also the “wreck trek” that consists of the Zion Train, Miss Jenny and Esso Bonaire, and at individual wrecks such as the Sun Mariner tug and the MG111. If you don’t have a boat, several local dive operators will be happy to escort you.
“You can’t see fish that large and that many anywhere else in the world,” said Chris Koenig, a retired FSU research professor who has studied Goliath grouper for more than two decades.
Goliath grouper are found off both Florida coasts, as well as the Caribbean and off West Africa. But there’s nothing like the Jupiter aggregation in late summer where fish travel from as far as Northeast Florida’s St. Mary’s River and the Gulf of Mexico off Fort Myers to meet and reproduce on the wrecks and reefs. Most are gone by mid-October, but a few remain in the area year round. They can range in size from about 100 pounds to 800 pounds.
“Like a VW bus — just hanging there,” said Hollywood scuba diver Patti Hanley.
The huge grouper, nearly wiped out by overfishing in the 1970s and ’80s, have made a comeback since their harvest was banned in 1990. Recreational anglers complain they gobble hooked snook, permit, and other fish before they can be brought into the boat. Commercial fishers blame Goliaths for decimating other fish populations.
Many want the fishery re-opened to harvest.
But dive operators like captain Randy Jordan of Emerald Charters in Jupiter want Goliaths to remain a protected species.
“The important thing is to monetize Goliath grouper to show they’re worth a lot more money to eco-tourism than they are dead,” Jordan said. “People come from all over the world. They rent scuba gear. They charter a boat. It seems to me one Goliath could be worth a million dollars.”
There may be a way to satisfy both sides, according to Koenig.
“Both the recreational fishing and diving ecotourism industries can have what they want, but it has to be done cautiously,” Koenig said.
While the giant groupers are showing up in greater numbers, they also have suffered some recent setbacks, the scientist said. For one thing, mangrove habitats that shelter them as juveniles — through about age 5 — are disappearing. And the two-week deep freeze in early 2010 killed many young fish that were too small to make it to deeper, warmer waters. Koenig says it will be 2015 before scientists can gauge the species’ recovery.
In the meantime, he said, there’s no scientific baseline to establish the stock size before Goliaths were nearly wiped out more than two decades ago — no information on abundance or catch rates for comparisons today. Previous stock assessments were rejected under peer review, he said, because they amounted to “guessing.”
Koenig said he’s preparing a research paper arguing that Goliath grouper should be managed in a similar way to marine mammals. Among the recommendations for the future: maintaining the harvest ban on spawning aggregations; setting a recreational slot limit that prevents harvest of the largest spawners; and establishing a tag program similar to tarpon where an angler would have to pay a premium to keep one fish per year.
“This is how you manage an extremely vulnerable fish,” Koenig said. “It would be a great system if people would do it and not get greedy. Give everyone a piece of the pie but without doing damage to the population of these fish.”