Expedition member Whitey Evans uses a blowtorch to heat-seal plastic bolts that secure a tracking antenna to a great white's dorsal fin off Mexico in 2008.
The hi-tech tracking tags, developed by researcher Michael Domeier, are designed to transmit up to 120,000 messages and can last for up to six years.
Previously Domeier had relied on conventional satellite tracking devices that "you can just harpoon into the sharks." But, he said, "they can only track the animals for nine to ten months."
The new devices are designed to chart migration patterns, which females can take several years to complete.
Because of the bolting required by the new antennas, "we have to capture the shark," Domeier said.
(Meet the expedition crew.)