Researchers in pursuit of a World War II shipwreck have had to settle for observing a "once-in-a-lifetime event." The NOAA Ocean Exploration and Research team was using a remotely operated vehicle to explore 1,500 feet below the surface of the ocean off South Carolina when it spotted a shark feeding frenzy, per CNN. The sight of at least 11 sharks—specifically, two species of dogfish not typically observed in groups—feeding on the carcass of an 8-foot-long swordfish was neat enough. "This is so rare to be able to see something like this," a researcher says over live video footage. Then, "Oh, my gosh!" Suddenly, a wreckfish emerges from behind the ROV and attacks a shark, completely swallowing its head.
The wreckfish, seemingly unable to feed on the swordfish, "demonstrated the ability of large predatory fishes to feed on smaller sharks" in this "rare and startling event," writes researcher Peter Auster. Wreckfish can grow more than 6 feet long and weigh up to 220 pounds. Still, Auster says the sighting "leaves us with more questions than answers, but such is the nature of scientific exploration." Meanwhile, the search continues for the SS Bloody Marsh, a US oil tanker sunk by a German U-boat on July 2, 1943. The wreck is one of 87 identified by the NOAA as a potential pollution threat. The six-week expedition to find it wraps Friday, per Fox News. (Read more sharks stories.)