Tagging a Great White Shark

Predator — Greg Skomal/Div. Marine Fisheries

On Labor Day weekend 2009, scientists from the Massachusetts Division of Marine Fisheries tagged five great white sharks which had been spotted off Cape Cod beaches. It was the first successful tagging of sharks in the Atlantic.

Summer at Cape Cod

Several species of shark migrate to New England waters during summer months. Oceanic species like the blue, mako, thresher and basking shark swim onto the continental shelf to feed and reproduce. Other coastal species like the sandbar shark and sand tiger invade near-shore waters.

Trapped

In Fall 2004, a 14-foot-long great white became trapped in the shallow waters of a coastal embayment within the Elizabeth Islands off southern Massachusetts.

Tag - You're It

Scientists attached a tag to the trapped shark and spent several days steering the animal towards open water. The electronic tags use satellite-based technology to track the sharks' movements to reveal more about the creatures' migratory habits.

Great White

The tag on the great white detached prematurely, however, missing the opportunity to learn more about the creature's movements.

Retreat

On Labor Day weekend 2009, several great whites were spotted along the shoreline of Cape Cod, prompting beach closings. Massachusetts represents the northernmost reaches of great whites, who are drawn to feed on the seals making their summer home there. (Left: A shark encroaches upon the hundreds of seals off Chatham.)

Grey Seals

Grey seals are seen hugging the sand bar off Lighthouse Beach in Chatham, Mass.

Tracking

On Saturday, Sept. 5, 2009, a harpooner working with a state shark expert followed sharks off Chatham. Here Nick Chaprales maneuvers his boat the "EZYDUZIT" into position while keeping an eye on the shark.

Sighted

A spotter flying overhead helped guide the boat towards the sharks off the shores of Monomoy Island.

Watchers

Grey seals observe activity from the shallow waters off Monomoy Island.

Ready ... Aim ...

Captain Bill Chaprales deploys a PSAT tag off Monomoy Island. The tag would record depth, temperature, and light-level data while being carried by the shark before releasing itself at a specified date. The tag then floats to the surface and transmits information.

Bulls-Eye

The harpoonist is on-target. By the end of the day two sharks were tagged. "We had an incredible day today, and one I would never have anticipated," said biologist Greg Skomal, who heads the state's shark research program.

Five in All

Three more sharks were tagged on Tuesday off Monomy Island, near Chatham, with the largest shark being about 15 feet long.

By CBSNews.com producer David Morgan