Something fishy is going on along the southeast coast of the US. Researchers are excited and confused to report that an unusually large cluster of great white sharks have gathered in the Atlantic near South Carolina shores.

OCEARCH, an ocean research group that tracks great white sharks and other large marine species, posted a screenshot of their shark tracker over the weekend, showing a collection of great whites congregating near the North and South Carolina border. Stranger still, the rest of the coastline appears to have been devoid of any other sharks at the time.

"What do you think could be causing this big gap in where white sharks are pinging right now. There are pings in the Gulf of Mexico and then a big grouping in North Carolina/South Carolina but none in the middle," OCEARCH said in a Facebook post on February 8.

As of February 12, the tracker shows at least 16 tagged great whites near the North and South Carolina border, with some others lurking around the states. Among them are some of OCEARCH’s largest sharks, including a 4.36-meter (14.3-foot) adult male called “Murdoch” and another 3.8-meter (12.5-foot) guy named "Vimy”. Coincidentally, Vimy was also documented last year with two giant bite marks on his head.

Courtesy of OCEARCH

Bear in mind, the tracker does contain some delays, with the tags often not “pinging" their location for weeks. Nevertheless, the gathering is still something of an event.

So, what's going on?

Great white sharks (Carcharodon carcharias) can be found in many waters across the globe, with notable concentrations in the US (northeast coast and California), South Africa, Japan, Chile, and the Meditteranean. They are generally considered solitary creatures, but they are known to congregate in certain circumstances, such as the emergence of fatty food to eat.

"One of the really unique aspects off the North Carolina coastline, we have thousands and thousands of shipwrecks. So when sharks come in, there's big fish, small fish, this whole food chain that now exists on all these wrecks," Brian Dorn, associate director of North Carolina Aquarium at Fort Fisher, told CBS News. "I do believe we're seeing more sharks come back because of protections that are in place. So it's a conservation success story."

Many researchers over the decades have also noticed that a huge number of great white sharks make a regular pilgrimage to the middle of the Pacific halfway between Baja California and Hawaii, an area that’s been dubbed the White Shark Café.