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Grouper baby booms can spawn regulatory cuts

BATON ROUGE — Fish baby booms, though great for replenishing stocks, throw monkey wrenches into fishery management.

Take 2004, when red grouper supposedly were reeling from unsustainable fishing pressure.

Catches took a big jump, so regulators shut down commercial fishing for two years and slashed the recreational bag limit. Tourists hankering for grouper sandwiches switched to landlubber's specials.

As it turned out, the restrictions were probably unnecessary.

The latest scientific studies now indicate that the red grouper bonanza of 2004 was partly triggered by two unexpected baby booms that had quietly reached maturity.

Big landings that appeared to signal perilous overfishing were actually the first stirring of a revitalizing stock.

Now fishermen from Bradenton to Apalachicola worry that a gag baby boom massing in grass flats and bays will force fishing shutdowns a few years from now, just like the red grouper boom did in 2004.

"We are going to be catching gag at an explosive rate," said Martin Fisher, who owns two boats and runs a seafood stall at St. Petersburg's Saturday market. "We are going to get hammered" by regulators.

The Gulf of Mexico Fishery Management Council, which sets the rules in federal waters, was scheduled to impose a 45 percent cutback in gag landings last week at its meeting in Louisiana. That's because a "stock assessment" indicated that gag — the gulf's second most popular grouper — were being fished too heavily.

The council is now taking a closer look at that data, and may soften its cuts. Still, recreational and commercial fishermen can expect some kind of gag quota, probably beginning in 2009 and lasting at least through 2011.

Signs of a boom

Gag grouper spawn offshore, sometimes 100 miles out in the gulf. Current and wind carry eggs into coastal estuaries, where baby gag begin their lives.

By their first birthday, they might be a foot long and starting to move into deeper waters.

At about 4, they approach 2 feet in length, big enough to catch and old enough to join the "spawning stock," the critical reproducing population that fishing managers track.

Though some grouper might live 25 years, mortality shreds the spawning stock every year. A fifth of the population can easily die, from natural causes or well-placed hooks.

Baby booms, as big as four times the norm, can swell the spawning stock and jack up landings.

Fisherman believe we're in midst of such a boom, saying inshore waters are crawling with baby gag.

"You go down to the dock with a spinning rod, and you will catch one after another," said Bobby Spaeth, who owns a Madeira Beach seafood house. "I've never seen them as abundant as this."

Jim Clement, a commercial fisherman from Carabelle, said small gag are clogging stone crab traps in the Big Bend area, looking for easy meals.

Dennis O'Hern, a diver and recreational fishing advocate, speculates that a big Red Tide bloom in 2005 wiped out trout and snook in the estuaries. Baby gags born since had fewer predators to escape.

These anecdotal reports are supported by recent reports from the Florida Fish and Wildlife Research Institute. Since 1996, state researchers have been counting juvenile gag in lower Tampa Bay, Charlotte Harbor and Apalachicola.

Though the data are preliminary, the counts show a minor juvenile uptick in 2006 followed by a whopper 2007, with counts quadrupling the previous year.

"This is going to impact spawning for the next few years," said Luiz Barbieri, a supervising biologist at the institute. "Whatever happened, they seem to be on the rebound."

That's good news for the fish, but a thorny problem for managers and fishermen.

What to measure

The gulf management council bases its fishing rules on "stock assessments," complicated computer models that try to measure current fish populations and predict how they will fare in the future.

They can track the impact of old baby booms by counting today's legal-sized fish of different ages. But they can't account for a baby boom under way because they only measure fish older than about 4.

The gag assessment, created by the National Marine Fisheries Service science center in Miami, was completed in 2006, using data through 2004. The last baby boom it could have tracked would have occurred in 2001.

State research shows a big spike in juveniles born in 2001 and 2002. Two years later, recreational fisherman caught, discarded and killed tons of undersized gags, a key reason the stock assessment concluded that the species was under too much pressure.

Florida's juvenile gag studies might have reassured managers that the discard binge of 2004 was partly due to the natural outgrowth of a 2002 baby boom, but federal scientists and independent reviewers considered Florida's data too small in scope to include in the model, Barbieri said.

The gulf management council now wants its scientific advisers to examine Florida's juvenile data and other direct measurements of the gag population, while re-evaluating the 2006 stock assessment.

It's a good thing, because the Florida research shows that Tampa Bay and Apalachicola experienced a huge gag boom in 2007, fish that will join the catchable stock in 2010 or so.

No matter what quotas managers set, a big baby boom might lead to huge catches and broken quotas. Having good information about juveniles will help managers make decisions with open eyes.

"There's no two ways about it. This is a strong showing. It's consistent with the little gag everybody is catching in the bay," Barbieri said. "Last year, we probably had a very good spawn. The fishery is about to explode."

Grouper baby booms can spawn regulatory cuts 04/12/08 [Last modified: Wednesday, April 16, 2008 2:19pm]

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