for National Geographic News
Great white sharks may be the poster child of marine predators. Yet scientists know surprisingly little about Carcharodon carcharias.
To map their movements and chart a course for the protection of great whites, one research team is getting up close and personal with the sea's top predator.
For three years Ramón Bonfil, a conservation scientist and shark specialist with the Bronx-based Wildlife Conservation Society, has been hand-fitting South Africa's great whites with dorsal-fin satellite tags. The tags reveal the sharks' day-to-day and long-term movements.
Bonfil's capture technique includes a heart-pumping face-to-face meeting with the king of the ocean food chain.
"It's a potentially dangerous situation, but we try to minimize the risk for both the scientists and the sharks," Bonfil said. "We don't want to kill a shark by mistake while studying it. Accidents can happen, so we're careful to work on nice flat water without risking more than we should."
Great white sharks can grow up to 20 feet (6 meters) long and weigh up to 5,000 pounds (2,270 kilograms).
Wildlife Conservation Society researchers began their shark-tagging project with "small" great whites, which still measured an impressive six to seven feet (two meters). The team has subsequently fitted animals measuring nearly 13 feet (4 meters) and weighing 1,650 pounds (750 kilograms).
The sharks are caught on a hook and line, and then maneuvered into a specially designed metal "cradle," which lifts them out of the water for three to seven minutes.
While researchers fix a satellite tag in the animal's dorsal fin, veterinarians pump seawater through the mouth and gills of the great white and inject drugs and vitamins that help the shark to recover from capture stress.
The entire process, from hookup to release, lasts about 15 adrenaline-filled minutes.
"When we did the first shark, we were very nervous, because we thought it would be thrashing and trying to bite everybody," Bonfil said. "But amazingly, when we took it out of the water, it was quiet and calm."
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