A shark native to frigid Arctic waters has rattled marine researchers by appearing about 3,500 south of its preferred range — in a coral reef off the Central America nation of Belize.
The discovery of a Greenland shark in the Caribbean is credited to Florida International University Ph.D. candidate Devanshi Kasana, according to a July 26 news release from the Mote Marine Laboratory & Aquarium in Sarasota, Florida.
Kasana says the large shark was caught at night on April 22, as she “was working with local Belizean fishermen to tag tiger sharks.” Belize is about 800 miles southwest of Miami.
“At first, I was sure it was something else, like a six gill shark that are well known from deep waters off coral reefs,” Kasana said in the release.
“I knew it was something unusual and so did the fishers, who hadn’t ever seen anything quite like it in all their combined years of fishing.”
Closer inspection convinced her it was not one of the known native species.
The shark was about 11 feet long, “sluggish” and had an “ancient” appearance — “more like an elongated, smooth stone that had sprung to life.”
“It had a blunt snout and small pale bluish colored eyes. All together, these clues led scientists to think it was a member of the sleeper shark family,” Mote Marine reports.
Greenland sharks — also known as sleeper sharks — grow to 23 feet and 1.5 tons, and can reach 400 years of age, making them the “world’s longest living vertebrate,” according to National Geographic.
Little is known about the species, so nothing about their lifestyle can be ruled out, experts say. This includes the possibility Greenland sharks travel the world undetected at “greater depths, where they can find their preferred low temperatures,” Mote Marine says.
The shark was caught near the Glover’s Reef Marine Reserve World Heritage Site and quickly released for its safety — without invasive samples being taken, officials said. That means researchers can’t be sure of its age or gender.
“While the exact species could not be confirmed, it is most likely a Greenland shark (Somniosus microcephalus) or a hybrid between the Greenland shark and the Pacific sleeper shark,” Kasana wrote in her research paper.
“This is the first record of a sleeper shark in the western Caribbean region and further supports the hypothesis that these sharks, best known from polar and subpolar latitudes, occur at depth in tropical regions.”
Glover’s Reef Atoll sits near “a steep slope that drops from 1,600 feet to 9,500 feet deep, which means there is cold water needed for a Greenland shark to thrive,” Mote Marine reports.
Among the Kasana experts consulted to help identify the shark was Demian Chapman, her Ph.D. advisor and Director of Sharks & Rays Conservation Research at Mote Marine.
The laboratory is now taking steps in anticipation of more Greenland shark encounters, including acquiring special satellite tags that can be attached to the sharks for tracking.
“That way, if lightning does strike twice, they’ll be ready — and one step closer to finding how these sharks live in the tropics,” Mote Marine reported.