2,000-Pound Great White Shark Tagged & Tracked

"Lydia" the great white shark aboard the OCEARCH research vessel during a tagging expedition. CREDIT: OCEARCH/Robert Snow View full size image

A 2,000-pound (907 kilogram) great white shark nicknamed "Lydia" is doing deep dives after being hauled aboard a research vessel and tagged by scientists hoping to learn more about the behavior of these massive toothy fish in the wild.

Lydia is the first great white tagged and released in Florida waters, according to OCEARCH, a nonprofit that worked with Mote Marine Laboratory scientists and other researchers to corral and trap the 14-foot (4.3 meter) beast on March 3.

The tagging is part of a project aimed at better understanding the life cycles of great whites, including reproductive behavior. Little is known about how the fish mate, breed and mature, making conservation decisions difficult. Meanwhile, shark populations are declining worldwide. About 100 million sharks are killed per year due to both legal and illegal fishing, according to a recent study.

OCEARCH scientists tag sharks aboard the M/V OCEARCH, a research vessel equipped with a hydraulic lift capable of bringing sharks out of the water. Lydia and other sharks tagged in the project are kept oxygenated with a hose running seawater through their mouths and gills as scientists take blood and other samples and fit tracking devices to their fins. [See Video of the Shark Trapping & Tagging]

The researchers fitted Lydia with a satellite tag to track her movements. They also attached to her fin an accelerometer, which enables them to track every movement and tilt of a shark's body. (Smartphones use similar accelerometer technology to tell if users are holding the screens horizontal or vertical.)

Researchers tag a great white shark in Florida waters to track her movements.
CREDIT: OCEARCH/Robert Snow

View full size image

The accelerometer has already popped off the shark, allowing scientists to retrieve it and analyze the data. That analysis is just beginning, but according to OCEARCH, Lydia spent about three hours recovering after the tagging experience and then began a series of repetitive dives from the ocean surface to the bottom, which appears to be typical great white behavior.

The research team will also analyze blood and tissue samples from the shark to assess the impact of environmental pollution. Armchair scientists can track the movements of Lydia and other sharks using the Global Shark Tracker.  

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