Great White Shark Tagging Expedition Sets Sail Today

Great white shark being captured and tagged — "Lydia" the great white shark aboard the OCEARCH research vessel during a tagging expedition. (Image credit: OCEARCH/Robert Snow)

How many great white sharks live off the U.S. East Coast, and how do they make a living? Researchers and fishermen set sail today (July 30) from Cape Cod, Mass., to find out, in one of the most ambitious expeditions to ever tag great white sharks.

The mission is to tag as many as 20 sharks. That would make it the largest shark-tagging mission in U.S. history, according to the nonprofit shark research group OCEARCH, which is leading the mission along with the Woods Hole Oceanographic Institution (WHOI).

"Given how much interest there is in great white sharks, we are still scientifically trying to find out the very basics," Thorrold said.

Aboard a vessel known as the M/V OCEARCH, researchers will cast lines for great white sharks, using barbless hooks designed to minimize harm to the animals, Thorrold said. After the shark is reeled in, a special platform powered by a hydraulic lift is then raised up underneath the shark, allowing scientists to attach a GPS tag to the animal's dorsal fin and perform a variety of tests on the animal, Thorrold told LiveScience's OurAmazingPlanet.

During the expedition, which runs until Aug. 29, the scientists will take blood and tissue samples from each of the sharks they catch to learn more about the animals' health and diet. The GPS tagging of great white sharks will allow scientists to see where the animals are going, as well as the temperature of the water and the depths of their dives, Thorrold said.

The data will be used in as many as a dozen studies and will help scientists understand the sharks' behaviors. For example, more and more great white sharks have been spotted off Cape Cod in recent years — a development that has coincided with the rebound of populations of gray seals, upon which the sharks feed, Thorrold said.

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Douglas Main loves the weird and wonderful world of science, digging into amazing Planet Earth discoveries and wacky animal findings (from marsupials mating themselves to death to zombie worms to tear-drinking butterflies) for Live Science. Follow Doug on Google+.