By Michael E. Miller
By Allie Conti
By David Villano
By Jose D. Duran
By Michael E. Miller
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By Kyle Swenson
By Luther Campbell
Glazer recalls releasing his first batch of 300 conch into the wild in 1993. "We didn't know what to do. We just put them out in a hard bottom area and then we came back two days later. Slaughterhouse Five," he recounts. None lived. "There was a big massacre. It looked like the killing fields," he continues. "They were out in the open, stupid as sheep when the wolves come." Glazer says the evidence -- crushed shells -- indicated the villains were puffer fish, which squeeze their prey to death.
While the strombus gigas population has declined, Glazer and his fellow researchers have made some fascinating finds. Over lunch recently at an Italian restaurant next to the Long Key lab, Glazer and Gabe Delgado, one of his assistants, discussed some bittersweet news. Styer found #13751, one of the first batch of young queen conchs Glazer raised back in 1996. Glazer, eating a chicken sandwich, says he thinks it is the first time that a hatchery conch has been recovered in the wild as an adult.
"Yeah, I think it is," agrees Delgado, who is 26 years old. He's eating a plate of conch fritters.
Conch #13751 was dead when Styer spied it in the waters off Duck Key. Glazer had released it into the wild in January 1997 with a tiny numbered metal strip wrapped around its shell with a wire. The biologists suspect a December cold snap caused its demise. Styer happened upon the hatchery-raised conch while working on another project. Although the recovery of #13751 had more emotional than scientific value, it proved at least one thing: A conch born into captivity can grow up and survive in the wild, at least for a couple of years.
Conch #13751 is also different from those that Glazer is raising these days. Now he trains the creatures to avoid one of their main predators: the Florida spiny lobster. His classrooms are the three bayside troughs behind the lab. Last year he added sand to the containers, then deposited twenty juvenile conchs there. Next he placed a small cage holding a spiny lobster near the sea snails and put another young conch in the cage. As is nature's nefarious way, the lobster eventually pecked and clawed through the puerile prisoner's still-fragile shell and devoured it. For a week Glazer staged a sacrifice each day. Finally the others wised up and buried themselves under the sand, as wild conchs would do at the spiny one's approach.
The researchers were not surprised, though. "Gastropods are supposedly the most intelligent of all the invertebrates," says Delgado, who hails from Queens, New York, and holds a bachelor of science degree in marine science from the University of Miami. "We analyzed the data statistically -- or sadistically, if you will," Glazer adds.
The analysis yielded two important facts: first, according to Glazer: "They can learn." Second, conchs exposed to the death-by-lobster routine develop thicker shells than conchs that do not witness it. Biologist Bori Olla at the University of Oregon has documented a similar phenomenon with salmon, which grow faster in the presence of their main nemesis, the lingcod. Biologists have concentrated on this aspect of predator-prey relations only in the past decade, Glazer notes.
Hatchery-raised conchs tend to survive at much higher rates when released in autumn and under a full moon. Size also makes a difference: Juveniles that are seven-centimeters in length fare better than shorter or longer ones. Glazer can't explain any of this, but he's not trying to; he simply wants his conch to survive in the wild so that he can study their habits. One day he hopes that biologists can restock the Keys with lab-hatched conch. But before introducing them on a large scale, he wants to make sure they won't be heartier than the native conchs. If that were to happen, the ocean-grown variety could disappear altogether. "We're concerned about hatchery conch taking over the wild conch," Glazer says. "So we're proceeding with caution."
Meanwhile Strombus gigas continues to struggle. From 1992 to 1997 Glazer and his colleagues reported a gradual increase in the total number of queen conch in offshore waters. But this past month Glazer calculated his latest data, from 1998, which show a disturbing 30 percent decline in three main offshore spawning areas. He's mystified by the drop, but suspects poachers might have ravaged one site. In general Glazer thinks the offshore population has stabilized, thanks to the 1985 ban.
Closer to shore, however, the situation continues to worsen, his data indicate. At one research site off Big Pine Key, Glazer estimated 13,000 juveniles (ages one to three) in 1989. Last December the figure was down to thirteen. At another site off Marathon, a conch community dropped from 2300 in 1993 to 24 last year. A third site produced similar results.
In recent weeks Glazer and Styer have again donned their wet suits to look for untagged adult conchs. Their plan is to find a few hundred of them in deep-water sites and move them across the Hawk Channel into shallow waters. They also want to do the reverse: transplant dozens of the animals from shallow areas to deeper waters. This underwater search is the first step in learning why the snails don't spawn in near-shore waters as they once did. The U.S. Fish and Wildlife Service has supplied a $48,000 grant for the endeavor. "We're going to look at their gonads when we move them back and forth," Glazer explains. But there has been an alarming glitch: There are even fewer Strombus gigas in coastal areas than the researchers previously thought. In fact they have not been able to find a large enough sample to carry out the experiment.