The number of Bigg’s killer whales in the Salish Sea has reached an all-time annual high.
There were 1,271 “unique” sightings of Bigg’s orcas through to Oct. 31 — more than the previous annual record of 1,220 unique sightings for all of last year, according to data from the Orca Behavior Institute and the Pacific Whale Watch Association.
A unique sighting is a sighting of a distinct group of Bigg’s killer whales on a particular day, according to the institute, based in Washington state.
While the same group of whales may be reported by multiple sources, the institute said it does not include duplicate sightings in the official count, making the volume of Bigg’s sightings this year all the more impressive.
The Orca Behavior Institute says it compiles whale-sighting reports from professional whale-watchers, regional sightings groups and community scientists throughout the Salish Sea in B.C. and Washington. The reports are confirmed with photographs.
Monika Wieland Shields, director of the institute, said this is the ninth year out of the last 10 that the record has been broken. Only 2020 showed a slight dip, probably due to decreased observation by whale-watching groups and scientists on the water due to the COVID-19 pandemic.
A decade ago, the group was only getting 15% of the latest sightings, Shields said.
Scientists believe the increase in orcas is related to large populations of seals, which Bigg’s killer whales feed on, along with sea lions and porpoises.
Sea lions and harbour seals were once the targets of a government-funded bounty program in British Columbia to protect local fisheries, but those programs ended in the early 1970s, and pinnipeds, along with all marine mammals, are now protected in the province.
Since then, populations of seals and sea lions have rebounded in the Salish Sea, luring Bigg’s killer whales into local waters.
“What’s happening with Bigg’s killer whales right now is truly remarkable to witness,” said Erin Gless, executive director of the Pacific Whale Watch Association, which represents 30 professional ecotourism companies.
“People once referred to them as transient killer whales because sightings were so rare, but now we’re seeing them almost daily, and we have their food to thank for that.”
Gless said Wednesday that Bigg’s killer whales have been seen in different places in the Salish Sea for the past 240 days in a row, calling it “quite the streak.”
When it comes to the region’s other killer whales, the news isn’t so good, however.
The salmon-eating southern resident killer whales, which are down to 73 animals in J-, K- and L-pods, haven’t been spotted much at all this year.
And on Wednesday, the Center for Whale Research in Friday Harbour, Washington said one of the few remaining southern resident orcas, the 22-year-old male K34, dubbed Cali, has not been seen since early July.
The centre said that since this summer’s census of the southern resident population, it has had three encounters with members of K-Pod, all of which were identified except K34.
The male orca was last seen July 7, when it “appeared somewhat skinny, potentially indicating poor condition,” the centre said.
Scientists said K34’s matriline, the K13s, has lost several individuals in recent years, including K34’s older brother K25, and mother K13. The orca K34 is also the uncle of the youngest member of K pod, K45.
Whales that are missing from encounters with their associates three times or more are likely to be deceased, the Center for Whale Research said in a statement. “However it’s always possible that K34 shows up again.”
The Center for Whale Research, which reports on demographic changes in the southern resident population twice a year, on July 1 and Dec. 31, says it will be able to make a more complete statement on the status of K34 and others in the population as part of its early 2024 population update.
The Seattle-based Orca Conservancy said that given the state of K34’s condition when he was last seen, and the fact that he hasn’t been seen since the summer, he will likely be declared deceased on the next population update.
The conservancy said despite the addition of new calves, the loss of established and breeding members is keeping the southern resident population in the low 70s when it should be much higher.
The whales also face issues with lack of genetic diversity, so losing another breeding member will only add to the problem, the conservancy said.
Shields said there haven’t been many sightings of southern resident pods this year, noting it will be the second-lowest year for their presence in the Salish Sea on record, with only 2021 coming in with fewer days.
Shields said Chinook salmon, the preferred prey of the endangered southern residents, have declined in both size and abundance over recent decades, threatened by rising ocean temperatures, loss of spawning habitat, chemical pollution and predation from dozens of natural predators, including humans.
She said major salmon runs, particularly on the Fraser River, have to improve or the southern residents will continue to spend more time on the outer coast, where they have the chance to encounter a wider variety of salmon runs from different river systems.