A great white shark has been filmed swimming beneath a fishing boat in the Florida Keys.
The footage was captured by keen diver and angler Amanda Callahan on April 15 around seven miles southwest of the American Shoal lighthouse during a day of fishing with friends. Callahan later published some of what she shot to her Aquablu Youtube channel.
"The Gulfstream was in close that day and all the right conditions were present, the right time of day, current, tide, water temp and wind which made for a lot of activity," Callahan told the Miami Herald/FLKeysnews.com.
Callahan, a professional scuba instructor from Cudjoe Key, captured some footage from her group's fishing boat, but she also dove into the water to get some incredible close-up shots.
"We don't want to encourage people to get in the water with an apex predator, and this stuff should only be done under the supervisor of professionals," she said.
Callahan, 31, estimated that the shark measured around 11 or 12 feet in length given the width of their fishing boat.
"The fishing and diving this last holiday weekend was great. We estimated the great white to be around 11 to 12 feet in length as the boat's beam [width] is around 9 feet and the shark easily exceeded that," Callahan said. "A healthy 12-foot male great white shark would weigh around 1,000 pounds."
Callahan said they knew the shark was a male because it had two claspers—an external appendage found on male sharks, skates and rays that are used to deliver sperm.
According to Callahan, the shark was not in feeding mode, and did not appear too interested in the boat or its crew.
"He wasn't feeding because we threw a dead bonito, and he wasn't interested," Callahan said. "But, it was awesome to see."
Great white sharks are found in coastal and offshore waters around the world, with concentrations near South Africa, Australia/New Zealand, the North Atlantic, and Northeastern Pacific, according to marine nonprofit Oceana.
The sharks are a migratory species that prefer cooler ocean waters although they sometimes move into warmer regions. For example, while white sharks in the North Atlantic often aggregate in northern latitudes, such as the waters around Cape Cod, Massachusetts, they are sometimes seen farther south.
Mahmood Shivji, professor at Nova Southeastern University's department of Biological Sciences and the director of the Guy Harvey Research Institute, told the Herald that the sharks "are long-distance travelers as a natural part of their life-cycle, and have been known to move through South Florida waters during their migrations."
