Transcript for Researchers look at spike in shark sightings
Now we go to she's shark close encounters in both California and South Carolina. Take a look at these photos. They were taken from a hotel room in Myrtle Beach showing swimmers unaware that they are just feet away from a shark. ABC's gio Benitez is on the beach in sea bright, New Jersey. Good morning, gio. Reporter: Hey there, Michael. Good morning, yeah, she was shocked to see those sharks in the water close to those people. Why are we getting so many of these sightings? Experts say that more people are coming out to the beach. That's one but also we have these warmer waters and more sharks are coming in. A California surf competition coming to a halt after state park officials spotted this shark just off the coast captured on tape by surf line. And in South Carolina one photographer capturing these jaw-dropping photos from her hotel balcony, a shark in knee-deep water just feet away from swimmers. I thought, my goodness, I'm getting ready to catch a shark attack on camera. Reporter: And in New Jersey, a 16-foot great white feasting on a bag of bait before swimming away. The spike in close encounters is something scientists are taking seriously. When a white shark bites a person it is a mistake because it thinks that that person is a seal. Reporter: Researchers on cape cod are now zeroing in on the hunting and feeding patterns of great whites after a 26-year-old was attacked and killed last year just 30 yards offshore. Their first deadly attack there in more than 80 years. What we're looking for is patterns in behavior, patterns in activity and once you've got a solid pattern, it allows you to forecast where that activity is likely to happen. Reporter: Dr. Gregory and his team plan to attach Orange trackers to the sharks. The trackers will allow researchers to monitor a shark's movement in greater detail than before including speed, frequency of fin beats and orientation, certain, sudden movements could be a sign they're feeding on seals, information he says could help identify areas unsafe to swim in. I can't modify the shark's behavior and I can't modify the seal's behavior but people can modify theirs and I'm hoping this will introduce information that allows us to take steps in a logical way. Reporter: Here's a tip from some of these experts. They're saying don't go swimming near where people are fishing off a pier or even on a beach because you don't want to be mistaken for fish or bait. Guys, back to you. Something to keep in mind. Keep an eye on the fishermen. Coming up next on "Gma," the ABC news investigation into
This transcript has been automatically generated and may not be 100% accurate.