Whale survived strike believed to have killed mother


Photo of Aria’s flukes taken April 25 by whale watcher Ferd Bergholz, who named Aria’s mother, Fran, before the elder whale died in an apparent ship strike. (Photo courtesy of Happywhale)

Whale conservationists in Mexico and the United States were overjoyed to learn last month that Aria, an orphaned humpback whale calf, lives.

Aria was between eight and nine months old when she disappeared last August following the death of her mother Fran, a much-photographed “celebrity whale” in California and the Pacific coast of Mexico.

Fran, so named by her legions of followers along the humpback’s migratory route, had washed up dead that month on a California beach, the apparent victim of a ship strike.

The ensuing surge of concern illustrated the extent to which technology is helping build public interest in the tracking of individual whales through the electronic parsing of shared photos that show the distinctive markings of their flukes. (See "Death of Fran has major ripple effect" —EcoAméricas, September 2022.)

Following the discovery of Fran’s carcass last August, scientists and whale enthusiasts in California, Mexico and beyond wondered whether the accident had also killed Aria. Since humpback whales spend their first year close to their mothers, experts feared the worst.

But in April, news spread that Aria had been sighted in Monterey Bay, California, having grown to an estimated length of 30-35 feet and a weight of 12-15 tons.

“When I found out that Aria had survived her first winter without her mom, I was walking on air for a week,” says Katherina Audley, founder and director of Whales of Guerrero, an environmental organization located in the Mexican state of Guerrero. “Fran was a special whale to so many of us....and was the first whale we ever [photo] matched between Guerrero and the U.S. West Coast.”

Confirmation came from the nonprofit organization Happywhale, which uses algorithms and image-analysis technology to parse whale photos submitted by researchers and members of the public worldwide, displaying the movements of individual whales online.

Ted Cheeseman, cofounder and director of the Happywhale website, says a naturalist sent him a photo of a whale she suspected was Fran’s orphan, and subsequent analysis revealed that the markings on its flukes matched those shown in other, earlier images of Aria.

“Oh my god, I was ecstatic,” Cheeseman recalled in an interview for this article. “Honestly, I thought she was probably killed by the same [ship] strike, or didn’t

Cheeseman says that Aria was spotted at least six times in Monterey Bay from April 16 to May 3, including by Ferd Bergholz, the whale enthusiast who had originally named Fran after his late wife.

“When I identified Fran from the photos of her on the beach back in August, I felt it my responsibility to call Ferd and tell him,” Cheeseman says. “So it was an enormous delight to be able to share with him this good news [about Aria]. Then he got to see [Aria] live.”

Fatal vessel traffic

Acknowledging “real surprise” at Aria’s fortunes, Mexican biologist Astrid Frisch says the humpback’s survival is “another example” of the strength and resiliency of animals. Aria is also lucky, having survived an attack by orcas when Fran was alive, Frisch says. Yet to the dismay of Frisch and other experts, whales continue to be struck and killed by vessels along the Pacific Coast of North America.

California’s Marine Mammal Center reported the deaths of two gray whales that washed ashore near San Francisco in early May. One was a well-known whale that had registered a record stay in San Francisco Bay of 75 days. Its carcass exhibited signs of a vessel strike.

The deaths occurred amid what the U.S. National Oceanic and Atmospheric Administration (NOAA) terms an Unusual Mortality Event (UME), or elevated strandings, involving the gray whale (Eschrichtius robustus).

According to NOAA, 665 gray whales were reported stranded, or washed up dead, in North America from January 1, 2019 to May 22, 2023, with 2019 and 2020 being the peak years. Of the strandings, 324 were registered in the United States, 314 in Mexico and 27 in Canada.

Like humpbacks, gray whales migrate through Mexican, U.S. and Canadian waters. In early 2021, NOAA estimated the gray whale population at 20,580, down from a 2016 survey that counted 26,960 of the animals. A 1999-2000 UME for gray whales registered a similar decline followed by a population rebound.

Cheeseman and international colleagues are currently completing a study of the North Pacific humpback population, the first comprehensive estimate since 2004-06.

While all whales face vessel-traffic hazards, calves are especially vulnerable, Frisch says, as was evidenced on April 21 when the carcass of a humpback calf washed up in Los Cabos, Mexico.

Taking stock

Frisch’s group, Ecology and Conservation of Whales of Puerto Vallarta, reviewed 9,000 whale photos taken in nearby Banderas Bay between 1996 and 2021 and found 16 whales with fresh wounds indicating a vessel strike. Three of the victims were adult females, two were adult males, and 11 were calves, including one that died instantly and another that failed to complete the annual migration to the whales’ customary feeding grounds.

According to Frisch, no whales were reported struck in Banderas Bay during 2022 and only one collision, which caused a superficial wound, has been documented so far this year. She says a resurgence of tourism in Banderas Bay and greater private-vessel traffic will require ongoing work to educate boat operators about whale-friendly speeds.

Human dangers faced by whales include the heavy volumen of large ships in commercial sea lanes and the proliferation of other craft used for tourism or recreation around resort centers such as Los Cabos and Puerto Vallarta.

Conservationists in Mexico and the U.S. continue campaigning for vessels of all sizes to reduce their speeds or modify their courses. Says Audley of Whales of Guerrero: “We can’t do more for Fran, but we can do it for Aria.”

- Kent Paterson

In the index: Aria and her mother Fran before the latter was killed in what scientists believe was a collision with a ship. (Photo courtesy of Happywhale)

Katherina Audley
Whales of Guerrero
Barra de Potosí, Mexico
Tel: (415) 847-7295
Email: katherina@whalesinmexico.com
Ted Cheeseman
Co-founder and Director
Santa Cruz, California
Tel: (408) 315-2267
Email: ted@happywhale.com
Website: happywhale.com/
Astrid Frisch Jordán
Ecology and Conservation of Whales (Ecobac) and National Whale Disentanglement Network (Raben)
Puerto Vallarta, Jalisco, Mexico
Tel: +(52 322) 293-7851
Email: fibbcatalogo@yahoo.com