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/ CBS News
A lifeguard in Maine said he "started swimming like hell" when a shark grabbed onto his buoy and pulled him underwater off the coast of Scarborough Beach on Saturday.
Greg Wilfert said he initially thought he was caught in the propeller of a boat.
"'Cause that's the only thing I could think of until I realized there was no boat," he said.
Wilfert said he was pulled about 5 feet underwater before he was able to get free and emerge on shore unharmed.
"It was frightening," he said. "I'm not going to deny that."
More shark sightings
Officials along the East Coast say there are more sharks closer to shore in areas where they don't usually go.
Since last week, at least a dozen sharks have been spotted close to popular beaches in the area of Wilfert's encounter, according to Scarborough's marine resources officer Daryen Granata.
"Usually we'll see one or two here and there. This is a large volume, larger than I've seen, and I've worked this area for 30-plus years," Granata said.
The trend is happening as conservation efforts have led to an increase in marine life populations in recent years, experts say.
"We're gonna see more of everything, including more sharks," OCEARCH founder Chris Fischer explained.
His nonprofit studies sharks by catching, tagging and collecting data before releasing them back into the ocean.
"It means just try to be a little bit more aware of what's going on in the environment around you. You see a lot of life, steer clear of that," he warned.
Still, shark encounters remain rare. Last year, the International Shark Attack File reported 25 unprovoked bites.
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