Endangered Southern Resident Orca, A Senior Male, Feared Dead By Researchers

The death would leave the population of the southern resident killer whales at 72.

The centre in Washington state says on its website that the killer whale known as L41 was thin when researchers saw it last January.

Andrew Trites, director of the University of British Columbia’s marine mammal research unit, said the orca was born in 1977 and, at 43, is quite old because the average lifespan for a male is 30 years.

"There was some speculation that he may be coming to an end," he said.

Researchers identify the dwindling group of salmon-eating orcas as J clan and further divide the clan into three groups, or pods, known as J, K and L.

The centre said in its post: "Given his age and that he looked a little thin in our January 2019 encounter, we fear he may be gone and will consider him missing unless he shows up unexpectedly in an upcoming encounter."

Trites said L41 fathered a number of calves.

"His gene pool is well represented, perhaps over-represented, in this small population," Trites said.

"But every loss is a stab to the heart. It's not what anyone wants to hear, having lost another animal."

Males help locate prey, spread out and communicate information, Trites said.

The Department of Fisheries and Oceans announced a number of measures last year to protect the orcas off B.C.'s coast.

Those include requirements that ships stay 400 metres away from the whales, the closure of several fisheries, and supporting dwindling chinook salmon stocks — the orca's main food source — by protecting and restoring chinook habitat.

Last year three southern resident killer whales were declared dead by the Center for Whale Research.

Trites said while the loss of L41 would hurt, there is some good news as a calf born last year known as L124 is still alive, though scientists don't know whether it is a male or a female.

"But they aren't out of the woods yet," he said. "Not by a long shot."