It certainly seemed like it was a long way from home.
A mysterious shark that is typically found in the waters of the Arctic was spotted cruising around a coral reef near Belize. The half-blind animal was discovered by researchers in the area.
Devanshi Kasana, a Ph.D. candidate at Florida International University, was in Belize tagging tiger sharks as part of a long-term shark and ray monitoring project.
“But, on the other end of one of the lines was something unexpected. It looked old—ancient,” Kasana tells Treehugger.
Originally, she thought it might be a sixgill shark, which are known for frequenting deep waters off coral reefs.
“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,” Kasana says.
But after they consulted with experts, they determined it was in the sleeper shark family. Named for their reportedly sluggish personalities, sleeper sharks are found mostly in polar and subpolar areas. They were once thought to be only bottom-dwellers but more recent research has found that they move continuously after a variety of prey and spend little time on the sea floor.
Researchers thought that because it was so large, it was probably a Greenland shark (Somniosus microcephalus) or a hybrid of the Greenland shark and Pacific sleeper shark (Somniosus pacificus).
They believed it was the first time a shark like this was found in western Caribbean waters off the barrier reef.
The findings were published in the journal Marine Biology.
Elusive Sharks Are Hard to Study
Researchers don’t know much about the Greenland shark. They live in such deep depths that they are very difficult to study, Kasana says.
Scientists know they seem to prefer the icy cold waters of the Arctic and North Atlantic oceans. And they are estimated to live 400 years or more, which makes them the longest-living vertebrate known to science.
But because so little is known about them, they could be anywhere and it could’ve been a Greenland shark spotted off Belize.
“Sleeper sharks, like Greenland sharks, can tolerate very cold waters which tell us that their preferred habitat and distribution range are potentially unlimited throughout the deep sea,” Kasana says. “However, at this time, we don’t have a lot of actual records to support this hypothesis. Therefore, our finding provides evidence that sleeper sharks could be circumglobal and present at greater depths throughout the tropics.”
This time around, researchers weren’t able to collect much information on the rare visitor. For the shark’s safety, they were only able to take a photo. But they’re prepared if they ever spot a Greeland shark again, “would be like winning the lotto,” Kasana says.
One of the world’s top experts on the species, University of Windsor Associate Professor of Biology Nigel Hussey, gave them four satellite tracking tags in case they see one again.
Kasana’s project includes a network of researchers, fishers, and the Belize Fisheries Department. The goal is to do research that will translate into conservation, in order to help guide policy decisions that can better protect sharks and rays.
“Great discoveries and conservation can happen when fisherman, scientists, and the government work together,” Beverly Wade, director of the Blue Bond and Finance Permanence Unit conservation group in the Office of the Prime Minister of Belize, said in a statement.
“We can really enhance what we can do individually, while also doing some great conservation work and making fantastic discoveries, like this one.”
