The bluntnose sixgill shark, Hexanchus griseus, the deep sea’s largest predator, has six gill slits instead of the usual five. Although this ancient shark hasn’t changed much since the age of dinosaurs, little is known about the apex predator because it spends most of its time at depths of up to 4,500 feet. The International Union for Conservation of Nature lists the bluntnose sixgill as near-threatened.
OceanX is an ocean exploration and media initiative established by Ray Dalio and his son Mark Dalio. On June 3 an OceanX team on their research vessel, OceanXplorer, a 286-foot-long former oil drilling support vessel equipped with two submersibles, a remotely operated vehicle, and a research vessel outfitted with equipment that can scan the water column and map the seabed embarked on an expedition off the Azores in the North Atlantic Ocean, to attach satellite and camera tags to the large population of bluntnose sixgills that live among the underwater canyons and seamounts surrounding the islands.
Inside one of the submersible are the pilot Lee Frey, and marine scientists Jorge Fontes and Melissa Cristina Márquez (see SRI newsletter Summer 2020). They hope to outfit as many bluntnose sixgill sharks as they can with two types of tags. One is a satellite tag with a nine-month life span that will document the shark’s vertical movements, and the other is a camera tag that can not only film the shark over an eight-to-12-hour period but also track its location, speed, depth, and surrounding temperature.
The Atlantic Ocean projected to warm by at least 2.7°F by 2050. Comparing data from these tags with data from colleagues in other parts of the world may allow us to understand what impacts climate change and ocean warming might have on the distribution of these animals, and eventually their prey says Fontes, who’s studied sharks for over 15 years.
The sixgill research will be featured in the six-part National Geographic series OceanXplorers, executive produced by James Cameron, BBC Studios’ Natural History Unit, and OceanX. Read more here.