An unusual amount of hungry sharks were caught on film by a rescue helicopter off the coast of Australia, making the water bubble with their activity as they fed on bait fish.
According to the Australian, the sharks were also a bit too close for comfort to a local beach in Perth and swimmers were temporarily banned from the water as a precaution.
Watch the frenzy:
The Australian has more from experts on the large school of what was estimated at about 50 sharks:
"It's very natural behaviour that probably happens out in the ocean far more often than we know about," [Department of Fisheries' shark researcher Rory] McAuley said.
"But it is quite unusual to see it so close to shore, and it is unusual to see it within the bounds of the major metropolitan area."
He said they were fish eaters and not particularly dangerous.
"Beaches were closed, which is a sensible precaution, but people don't need to be too concerned with having these species of shark off the coastline -- they're a natural part of a healthy marine ecosystem."
Operations manager for Surf Life Saving -- the company that ran the helicopter capturing footage of the frenzy -- Chris Peck said "you usually don't see them in this number." Peck said groups of two or three are more common.