A local harpooner working with a state biologist placed electronic tags on two great white sharks today off the coast of Chatham.
"He did it in one shot,'' said state biologist Greg Skomal, referring to harpooner Bill Chaprales, a fisherman from Marstons Mills who tagged the sharks. "We don't swing the bat unless it's a strike."
The tags, which will use satellite-based technology to record the sharks' travels, should give scientists information to help them better understand their migratory patterns.
Skomal and his team set out to identify the species of five sharks reported off the waters of Monomy Island Thursday and determined that at least one was a great white shark then. Today, they identified two more great white sharks.
Skomal, who heads the Division of Marine Fisheries shark research program, said Chaprales tagged the first great white around 9 a.m. near the southern tip of Monomoy Island and the second about a mile north of there at about 3:30 p.m. Chaprales estimated that the sharks weighed about 1,000 pounds apiece.
White sharks are not uncommon off the Massachusetts coasts, state officials said, and they urged swimmers and boaters to use caution.
Although 300 to 400 people flocked to the beach in Chatham today many did not go in the water, said Dan Tobin, the town's director of Parks and Recreation.
Many species of fish, including sharks, migrate to New Englandís coastal and open ocean waters in the summer months, state officials said.
At least a dozen shark species migrate in and out of New England waters annually, officials said.
Massachusetts represents the northernmost range for several species of sharks and is an important area for monitoring the health and distribution of shark populations, the officials.
Although relatively rare in New England, great white sharks, are known to visit local waters, where they are sometimes seen feeding near seal colonies.
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