Scientists detect something fishy about the behavior of these sharks — and they’re looking to get to the bottom of the maritime mystery.

On Saturday, OCEARCH — a nonprofit organization that gathers data on sharks and other animals around the world by tracking and studying them — shared a map on Facebook highlighting where groups of great whites have recently been spotted.

The researchers noted an unusually large spacing between the groups.

“What do you think could be causing this big gap in where white sharks are pinging right now?” OCEARCH asked its followers. “There are pings in the Gulf of Mexico and then a big grouping in North Carolina/South Carolina but none in the middle.”

According to Raleigh, North Carolina’s News & Observer, scientists first noticed in January that tagged great white sharks were lingering off the coast of Southport, North Carolina.

Since the large great white sharks are remaining some 20 miles from the coasts, OCEARCH’s Robert Hueter told CBS News that beachgoers need not be alarmed.

Read more: People