The world's oldest known killer whale, thought to be aged over 100, is missing and presumed dead, researchers have said.
Ken Balcomb, executive director and principal investigator at the Washington-based Center for Whale Research, wrote that he last saw the whale, known as Granny, on October 12 in Haro Strait, between the San Juans and Vancouver Island, as she swam north far ahead of the other whales in her pod.
"Perhaps other dedicated whale-watchers have seen her since then, but by year's end she is officially missing from the Southern Resident Killer Whale population," he wrote on the Center for Whale Research website. "And with regret we now consider her deceased."
Estimated to be over 100 years old, the orca's official name was J2.
Balcomb said he first observed Granny in 1976, when killer whales were taken from the Salish Sea to supply marine parks.
Granny avoided being sold then because she was considered too old to be shipped off.
The whale went on to lead a pod of orcas for another half century.
The population of the endangered Southern Resident Killer Whale was estimated to be 78 as of December 31, 2016, according to the research center.
(Story adapted from Xinhua News Agency)