What's with the recent surge in shark attacks?

Fear usually wins when shark attacks dominate the news, but a team at Ocearch wants to change that perception.

Last Sunday, a 12-year-old and 16-year-old lost their left arms in North Carolina from separate shark attacks. Then a 10-year-old was attacked Wednesday off Daytona Beach shores in Florida.

"It's very common this time of year between Florida and the Carolinas to have these sorts of incidents. We're at the peak of abundance. In the Carolinas, there's the maximum amount of bait, maximum amount of game fish there, which brings the predators in," Ocearch founder Chris Fischer said Friday on "CBS This Morning."

What's unusual in those North Carolina incidents, however, is that it wasn't a "grab-and-release," which researchers see up to 50 incidents each year, Fischer said.

"This was clearly a little bit different, more traumatic for the families who are in our thoughts, where an actual, maybe a little bit larger shark, probably a bull shark, actually removed a limb, and that's the real difference here," Fischer said.

With the grab-and-release incidents, Fischer said the sharks "realize they've got a hold of the wrong thing," and people are fine after a few stitches.

California lifeguards use drones to monitor sharks

Fischer said he "absolutely" does not think the same shark attacked the two youths in North Carolina. His co-captain Brett McBride said there's no evidence to suggest that happened.

Both Fischer and McBride said they don't think the sharks are "going after" humans.

"There's more chance of interaction when there's a lot of people in the water and there's that much bait, and there's probably going to be more sharks tight to the beach," McBride said.

"You have people fishing in the same area where people are swimming," Fischer added. "A lot of what we talked about last time we were here, in Southern California, when you had fishermen fishing for sharks in the same area where people are swimming, that doesn't really pass the common sense test. So you got a lot of life, a little bit of user conflict going on, and then bad things happen."

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In 2012, "CBS This Morning" first reported on the story of fishermen and scientists from Ocearch, making history when Ocearch caught a 2,000-pound great white shark and put a satellite-enabled spot tag on its dorsal fin. Then the sharks can be tracked for five years.

Mary Lee the shark, named after Fischer's mother, garnered particular attention and has over 79,000 followers on Twitter.

Fischer said Mary Lee has made "massive" migrations, covering 20,000 miles in less than three years from Cape Cod down to the southeastern part of the U.S., swinging up into Newfoundland and now back down to Florida.

"This is three years since we starting working with you all on this story, and our goal at that time was to figure out where these giant mature shark go. Where do they give birth? Where do they mate? And Mary Lee is coming up on completing that first full migratory cycle, and if she returns to Cape Cod this fall, it will really put the pieces of the puzzle together on mating and so forth," Fischer said.