Smack dab in the middle of Florida’s spring break season, vacationers are being banned from some public beaches in southern portions of the state as thousands of migrating sharks pass through.

The Palm Beach Daily News reported that the beach closures might be sporadic over the next few weeks as the sharks make their journey north.

Shark Migration Causes Beach Closures in Florida

Here you can see the shadows of the sharks in aerial footage that was taken above the clear, blue water. (Image: YouTube screenshot)

“We got here this morning and they were thick, really thick,” Craig Pollock, a lifeguard supervisor, said earlier this week to the Daily News. “They were frenzied and chasing bait all the way up to shore. They were practically right on the sand.”

Watch this raw, aerial footage of the shark swarm:

Pollock continued saying that beach closures will depend on where the sharks are that day and noted the most common varieties he’s seeing are blacktips and spinners.

The Daily News reported associate professor of biology at Florida Atlantic University Stephen Kajiura saying from aerial surveys he has observed more than 15,000 sharks less than 200 yards from the shore during this time of year before.

“That’s 1,000 sharks per square kilometer. If you were a swimmer, you would probably be within 60 feet of a shark,” Kajiura said to the Daily News.

ABC News reported that the annual migration usually occurs earlier in the season than it did this year, causing spring breakers to be impacted more than usual.

Although the sharks are not likely to bite a human, ABC affiliate WEWS wrote a few precautions should be taken for people who are going in the water — regardless of the known prevalence of sharks. These recommendations include ensuring a lifeguard is on duty, not wearing jewelry and avoiding silver, yellow and gold colors.

Check out the more up close pictures of the sharks taken by Jeff Langlois on the Palm Beach Daily News here.

(H/T: Daily Mail)