Killer whale calf stopped breathing, British Columbia biologist says

The latest calf expected to boost southern British Columbia’s resident killer whale population was found off the southern tip of Vancouver Island, emaciated and breathing heavily, according to the Center for Whale Research in Washington state.

On October 5, one of the center’s biologists, Mark Malleson, received a report that J Pod had been seen in Admiralty Inlet that morning. He jumped into a boat and left Victoria Harbor hoping to reunite the mother and calf – known as L90 and L128 respectively – with the rest of the clan.

“At 12:22 p.m., as Mark approached the eastern edge of Swiftsure Bank, he spotted his first dorsal fin amid the flurry of seabirds and humpback whales,” the center noted in the encounter’s description.

Malleson saw several whales feeding when half a dozen individuals approached him, including “a very small calf hidden next to them.”

Center staff had photographed L128 several weeks earlier off San Juan Island on the U.S. side of the international border. The small, emaciated calf appeared “lumpy and skinny.”

As the mother approached the boat, she supported the calf with her head.

“Mark’s heart sank – he was sure the calf had stopped breathing,” the account of the encounter says.

Another whale shook the calf as if desperately trying to revive it, and as it passed the stern of the boat, Malleson thought he saw the calf taking a weak breath.

An hour after the encounter, Malleson turned the boat around and, “emotionally exhausted,” began the 60 nautical mile journey back to Victoria Harbor.

Peter Ross, a marine mammal toxicologist at the Raincoast Conservation Foundation who has been studying killer whales for nearly 30 years, says the discovery of a calf in such distress is a good reminder of the threats facing the southern resident killer whale population.

“Of course, it is deeply disturbing when we hear of a calf in distress while an endangered population is in trouble,” Ross said.

However, Ross cautioned against placing too much emphasis on the deteriorating health of an individual whale. He said about a quarter of newborn whales die in their first year of life.

“Is this an isolated incident? Is that Mother Nature? “Is it a genetic anomaly,” Ross said. “It’s a tough time. It’s a tough world. They must be born armed and ready for the ocean, and that is exacerbated by human disruption.”

The number of residents in the South, which stretches from California to B.C., has stagnated at around 75 people for decades.

The genetically diverse population was listed as endangered in Canada under the Species at Risk Act in 2003. As of July 1, 2024, researchers had counted 73 whales in three groups, including 25 in J Pod, 15 in K Pod and 33 in L Pod.

Some studies have found high levels of toxins from wildfires and fossil fuels in the fat layers of southern populations. Research has also looked at the impact of different whaling strategies and how underwater noise from industrial activity and boat traffic could affect navigation.

One of the most active areas of current research is assessing whether the whales are getting enough Chinook salmon – the preferred food of southern residents.

Food shortages could occur outside of summer or further south

The encounter comes as scientists released a study this week analyzing the food availability – particularly Chinook salmon – of southern resident killer whales.

In a study published in the journal PLOS One Thursday, researchers Burak Saygili and Andrew Trites of the University of British Columbia surveyed fishermen and whale-watching groups to find Chinook whale feeding hotspots.

In the summer of 2020, they used sonar to estimate fish densities in both the southern resident and their northern cousins.

The researchers found that Chinook salmon are twice as abundant in southern population hotspots as in northern populations – although the latter are consistently reported to be healthier and more abundant.

The result, the study says, is that southern resident killer whales have greater access to Chinook salmon during the summer months and that food shortages occur at other times of the year or outside the Salish Sea, such as on the coasts of Oregon and California .

Another possibility is that southern residents may have difficulty accessing these feeding sites due to acoustic or physical interference from ships, even if Chinook are plentiful there.

Ross, who was not involved in the research, said despite the Chinook’s relative density, the overall population has seen a dramatic decline in recent years.

“If the mother has difficulty finding enough nutrition, she will have difficulty providing enough milk,” he said.

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