An orca born around Christmas Day, dubbed J60, who dazzled Salish Sea whale watchers is now presumed dead, according to researchers.
Last week, the Center for Whale Research saw the J pod of the endangered southern resident orcas traveling and socializing in San Juan Channel. The only whale missing was J60.
Survivorship among the youngest southern resident orcas is quite low, said Michael Weiss, research director of the nonprofit. It’s hard to know how low because there are likely calves that are born and die before researchers see them. Weiss estimates about half of the calves born to the southern residents don’t survive to adulthood.
J pod is one of three families within the southern resident orca population that frequents the Salish Sea. The 2022 census by the Center for Whale Research tallied just 73 orcas, one of the lowest population counts among the whales since 1974, when 71 orcas were counted after the live capture era, according to the National Oceanic and Atmospheric Administration. There are now estimated to be 74 orcas.
J42, also known as Echo, was the calf’s most likely mother, the center said. The calf was also spotted with J40, known as Suttles; J46, known as Star, was also heavily pregnant in late 2023. J60 would have been the first observed calf for any of the females.
The mortality rate among these calves is especially high in first-time mothers.
These mothers are accumulating toxics throughout their life, and studies have tracked the rising concentrations of PCBs and other persistent pollutants as they get older, Weiss said.
Researchers believe firstborn calves are getting a higher dose of the toxics than later calves. The amount of toxics these females have circulating to pass on to their children through gestation and lactation is partially dependent on their nutritional state.
Most of these toxics are lipophilic, stored in fats and blubber, and they really start circulating when mothers have less to eat, Weiss said.
A study of the orcas’ fecal samples found higher levels of PCBs in the samples amid periods of low salmon abundance.
Generally, the southern residents are struggling to survive in the face of at least three threats: pollution, lack of Chinook salmon in their foraging range and underwater noise that makes it harder for them to hunt and communicate with each other.
Researchers have found two-thirds of southern resident pregnancies end in loss because of lack of food. More recently, studies have found the southern resident females have less hunting success than their neighbors up north and that the shrinking, increasingly inbred population of southern residents could be plummeting toward extinction.
“The really sad and unfortunate fact is that this isn’t a shocking outcome for a southern resident calf that’s detected that young,” Weiss said. “They’re in a tough spot. They’re having a hard time having kids. They’re having a hard time keeping kids.”
“We can’t extract the toxins from their body,” Weiss continued. “We can’t really extract the toxins from their environment. What we can do is try to get them more fish. And they’re going to need it if we want fewer calves dying.”
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