Captain Brett McBride streams seawater over the gills of a nearly 15-foot, 2,292-pound great white shark on the research vessel Ocearch in the Atlantic Ocean off the coast of Chatham, Mass. A crew of researchers and fishermen are tagging great white sharks off Cape Cod in an unorthodox way.

Associated Press

Ocearch expedition leader Chris Fischer steps onto a small sport fishing boat to check chum locations for signs of great white shark activity in the Atlantic Ocean off the coast of Chatham, Mass. The Ocearch team baits the fish and leads them onto a lift, tagging and taking blood, tissue and semen samples up close from the world's most feared predator. The real-time satellite tag tracks the shark each time its dorsal fin breaks the surface, plotting its location on a map.

Associated Press

Ocearch crew members drop chum to the bottom of the Atlantic Ocean off the coast of Chatham, Mass. The team aims to attract great white sharks with whale blubber placed inside the cage.

Associated Press

Scientists collect blood and tissue samples from a female great white shark on the research vessel Ocearch in the Atlantic Ocean off the coast of Chatham, Mass. Before release, the nearly 15-foot, 2,292-pound shark was named Genie for famed shark researcher Eugenie Clark.

Associated Press