With sunglasses, beard, and red bandanna around his face to block sun and mosquitoes, Gruber looks more outlaw biker than marine biologist. Kneeling in a swirl of sandy water, he tries to lure sharks into reach by flicking bits of bait at them and crooning "Ma Chérie Amour." He swears loudly when they ignore his overtures, but then, with a pup finally in hand, he coos like an adoring mother. He shows how the young shark, when flipped on its back, slips off to a sleeplike state called tonic immobility.
Sharks bite fewer people each year than New Yorkers do, according to health department records. And you are far likelier to drown in your bathtub or be murdered by your spouse than you are to die in the jaws of a shark. Yet it's still difficult to win public support and dollars for shark research and conservation. Gruber's lab on South Bimini is clearly a duct-tape-and-string operation. Torn fishnets festoon the yard. The lab's donated truck, when it runs, fills quickly with noxious exhaust (a passenger needing air has to ride holding the door ajar). Volunteers who do most of the grunt work share a double-wide mobile home painted in loud colors. The food is off-brand, the bread soft and white, the bunking arrangements chummy. The mostly twentysomethings look sleep-deprived and hungry, but they still eagerly line up to do hands-on research in a place where sharks still thrive.
The self-described "shark geeks" spend long nights working by moon and flashlight in open stretches of Bimini's North Sound, wading along a lattice of nets, carefully untangling captured lemon sharks and rushing them to a pen to be studied and later released. Nearly every pup that moves through the sound is caught this way. Each is weighed, measured, tagged, and its dorsal fin snipped for DNA studies to help the researchers build a lemon shark family tree. More than 90 percent of the tagged sharks that survive their first year are caught again in subsequent years, their health and growth recorded for comparison. Gruber boasts about this recapture rate the way brokers brag about their rate of return. But the real credit goes to the mangrove forests, whose isolation and bounty keep generations of lemons close to home.
Gruber has been studying Bimini's lemon sharks for some 25 years, amassing a detailed database that's the largest for any shark population anywhere on Earth. His findings on how sharks affect their environment and what they need from it confirm, along with numerous other studies, the life-giving nature of mangroves—which is one reason the biologist is fighting mad about a contentious and outsize resort elbowing its way onto tiny North Bimini Island. Condos, a marina, and a casino are already under way, and plans call for a waterside golf course. Local Bahamians are worried about their shrinking access to fishing grounds as the seafloor is dredged and the land locked up in gated communities. Gruber has his own concern: the mangroves. "They'll all be wiped out if the developers have their way," he says. "The North Sound will be the 18th hole. You can have your mai tai there."