Just off one of New York's famed Hamptons beaches, shark researcher Greg Metzger reels in one of the day's prize catches: a young but powerful sand tiger shark.

He and another marine researcher quickly lasso the tail of the sharp-toothed female to the side of the boat and hold it steady as they take tissue samples and work to attach small data collection devices.

Metzger marvels as the shark's thick, rugged skin snaps a surgical-grade scalpel.