Florida residents who live by the coast are smart to stay out of the ocean this week. According to a report from CBS News, as many as 12,000 blacktip sharks have been spotted cruising up and down the beach by aerial photographers.

As scary as it may seem, the mass gathering of sharks is really just part of a natural migration event that happens every year. The sharks arrive off the coast of Florida to seek refuge and gorge themselves on the abundant fish before returning to the open ocean. Even though there is a low risk of being attacked while swimming with these blacktips, it is understandable for people to not want to go anywhere near the water.

Visitors to Florida’s beaches this time of year may even be treated to a view of the balcktip sharks “breaching,” or leaping out of the water like a dolphin. While marine mammals exhibit breaching behavior for a number of reasons, sharks and other fish usually jump out of the water in the hot pursuit of prey.

Blacktip sharks can grow to roughly 5.4 feet, and they mate and raise their young off the coast of the Mid-Atlantic and Southern states during the summer months. The sharks winter off the coast of Florida, creating a nearly continuous chain from Miami to Jupiter Inlet – nearly an 80-mile distance.

And according to Florida Atlantic University biologist Stephen Kajiura, the 12,000 estimate could be way off. He believes there are many more sharks among the group that are invisible to aerial cameras, but even on the low end that’s pretty impressive.

“You can literally sit on the beach and you can watch the blacktips jumping and spinning and splashing back into the water,” he said. “They’re not out to get you, you’re not part of their diet, so you may as well go to the beach and enjoy the phenomenon.”