Rarely Seen Shark Spotted by Paul Allen’s RV Petrel

While exploring a World War II ship wreckage in the Philippines earlier this month, crew members of Paul Allen’s research vessel (R/V) Petrel were caught by surprise when they spotted a large shark swimming out of the darkness. Using cameras on their remotely operated submersible vehicle, her crew zoomed in to catch a better look and were able to identify the species–a bluntnose sixgill shark.

Reaching up to 15 feet long, the bluntnose sixgill shark (Hexanchus griseus) is one of the largest sharks in the world, but uncommon in the area. Reflecting primitive characteristics from the Triassic period, the sixgill shark has more extinct relatives than alive.

While the Philippines has nearly 200 kinds of sharks and rays, local researchers say this species of shark has never been documented alive in the country’s waters until this expedition.

“This is remarkable footage of the bluntnose sixgill shark, a rare and deep-dwelling species of shark,” said Gonzalo Araujo, Executive Director of the Large Marine Vertebrates Research Institute Philippines (LAMAVE). “This, to our knowledge, is the first live encounter with the species in the Philippines, with only a few records known from fisheries. It highlights the rich marine biodiversity of the country and the need to sustainably manage it.”

Sixgill sharks serve an important ecological role in many deep-sea and shelf slope habitats. Little is known about this species of shark, as they live so close to the ocean floor and are rarely surveyed by scientists.

“We still know so little about deep sea ecosystems around the world, and sightings like this one provide exciting glimpses of these important species and habitats,” said Dr. Mike Heithaus, co-lead principal investigator for Global FinPrint and Florida International University marine scientist.

Allen launched Global FinPrint in summer 2015 to bring together collaborators around the world to fill a critical information gap – tracking the diminishing number of sharks, rays and other types of marine life. Global FinPrint aims to aid in management and conservation efforts for life on coral reefs.

In 2016, Allen purchased the R/V Petrel, a 250-foot research and exploration vessel. Petrel’s advanced underwater equipment and technology make it one of the few ships on the planet capable of exploring to 6,000 meters. Following a 2017 retrofit, Petrel and its crew use state-of-the-art underwater technology for deep-sea expeditions.