Something Alarming Is Happening To Gray Whales Off California's Coast

CALIFORNIA — Something alarming is happening to the gray whales that migrate along the coast of California.

A concerning number of eastern North Pacific gray whales are dying again after showing signs of recovery following a die-off or “unusual mortality event” between 2018 and 2023.

As of Saturday, at least 80 whales have died since the start of the year in Mexico, according to Regina Lobo Barrera, a researcher with Gray Whale Research in Mexico. All of the strandings have been reported in the Pacific side of the Baja California peninsula and the Gulf of California.

Additionally, three gray whales recently died in San Francisco Bay during their northbound migration.

“We’re talking about a relatively small number of whales in California. I wouldn't call that a big spike in mortality,” marine biologist Alisa Schulman-Janiger told Patch earlier this week when the number of reported strandings in Mexico totaled 70. “However, the 70 in Mexico is a lot. It’s more than they had last year and we still have months to go.”

A Grueling Migration

Gray whales make one of the longest annual migrations of any mammal.

Eastern North Pacific gray whales travel roughly 12,000 miles round trip between the summer feeding grounds in the Arctic and the warmer waters of Mexico, where the animals breed, give birth and nurse.

The mammals migrate close to shore along the West Coast, moving south from November to mid-February before they begin their journey north, which continues through May, according to the National Oceanic and Atmospheric Administration. During this time, researchers with organizations like Gray Whale Research in Mexico conduct monitoring surveys and research to support the conservation of the species.

Researchers count and record the number of whales and calves, as well as the behavior and condition of the animals. In addition to the large number of gray whale deaths this year in Mexico, researchers identified only eight mother-calf pairs in San Ignacio Lagoon, a sanctuary where most of the wintering whales tend to gather, Lobo Barrera said.

Although Gray Whale Research in Mexico has not yet released its 2025 report, that’s the lowest number of mothers and calves ever recorded in the lagoon, Lobo Barrera confirmed to Patch.

Counts of mothers with calves in San Ignacio Lagoon remained low throughout the 2024 winter season ranging from two to nine pairs in January and February, with the highest number of 15 pairs counted on March 14, according to the organization’s 2024 report. At the time, the total of 22 mother-calf pairs was the lowest number of pairs ever recorded in the lagoon since the surveys started.

Troubling Numbers

Researchers in California who track the gray whale migration have also seen record-low numbers of gray whales.

Also see: Something 'Unprecedented' Is Happening With Orcas Off The CA Coast

Schulman-Janiger is the director and coordinator of the Los Angeles chapter of the American Cetacean Society’s Gray Whale Census and Behavior Project. Schulman-Janiger, who founded the project in 1984, spots, tracks and records gray whales with citizen scientists from the patio of the Point Vicente Interpretive Center in Rancho Palos Verdes.

“Our numbers are extremely low compared to any other year,” she said.

As of April 6, Schulman-Janiger and her volunteers have counted 121 southbound gray whales with no calves and 364 northbound gray whales, including two calves. At the same time last year, the team had counted 224 southbound whales, including 22 calves, which was the lowest on record, as well as 531 northbound whales, including 16 calves.

“Our whale counts are very low,” Schulman-Janiger said. “We didn’t have a single southbound calf. That’s never happened in 41 seasons.”

Whale watching companies have also spotted fewer whales.

Donna Kalez, chief operating officer of Oceanside Adventures, said her team hasn't seen as many mothers and calves this year.

Jessica Rodriguez, education and communications manager for Newport Landing & Davey’s Locker Whale Watching, said her company overall has "definitely seen significantly less gray whales moving through the area" compared to the past few years. Whale watching boat captains working this past winter and spring have reported far fewer gray whale sightings, she said.

“Often, they are seeing one or two here and there. I remember several years ago, before the unusual mortality event, it wasn’t unheard of to see over 40 whales in one day,” said Rodriguez, who has been with the company since 2013. “We’re just trying to put the puzzle pieces together at this point and surmise what may be happening, but it is really hard to say with certainty what is truly happening.”

An Unusual Mortality Event

This isn’t the first time in recent history that large numbers of gray whales have died.

NOAA Fisheries declared an unusual mortality event for eastern North Pacific gray whales amid a surge of gray whale strandings several years ago. The population estimates declined from a peak of around 27,000 whales in 2016 to approximately 14,500 in 2023.

The mortality event took place from Dec. 17, 2018 through Nov. 9, 2023, with peak strandings happening between Dec. 17, 2018 and Dec. 31, 2020, according to NOAA. It involved 690 dead gray whales that washed ashore from Alaska to Mexico, including 347 in the U.S., 316 in Mexico and 27 in Canada.

NOAA researchers said the mortality event was due to ecosystem changes in the northern Bering and Chukchi seas off Alaska, which changed access to and quality of prey.

“These changes contributed to the poor nutritional condition observed in live whales in the wintering areas of Mexico and dead stranded gray whales in all three countries,” the agency said on its website. “This malnutrition led to increased mortality during the whales’ annual northward migration (from Mexico to Alaska) and decreased production of calves. This resulted in an overall decline in population abundance.”

The mortality event was closed in 2023 after stranding rates returned back to expected levels, and the prevalence of thin live or dead whales decreased, according to NOAA.

Seeing ‘Skinny’ Whales

Although experts can't say for certain why the whales are dying now, lack of food could once again be a factor based on the emaciated condition of some of the animals.

Lobo Barrera has been working with the Gray Whale Research in Mexico team since 2022. She has been in charge of evaluating the body condition of the gray whales in San Ignacio Lagoon for the past two years, where she said the number of “skinny” whales doubled from last season to this season.

“This is visible to the naked eye, when they present a poor body condition — skinny — you can see their scapular bones, their backbones and sometimes the ribcage, which is not normal,” she said. “This is a problem because they do not eat when they are in the breeding grounds, they live off their body fat for at least three months. In order to survive this period, they need to arrive with as much fat in their body as possible."

During the unusual mortality event, necropsy findings from some of the dead whales supported malnutrition as a common cause of death, Lobo Barrera noted.

“One of the main theories is that there has been changes in their feeding areas, and the decrease of food availability due to climate change," she said. "We believe that it is the same reason why they are dying this year.”

Schulman-Janiger said La Niña ocean conditions could have contributed to lower counts so far this year. Some gray whales migrated farther south in search of warmer waters, so perhaps, the whales are just late.

Still, she and her team have also spotted skinny whales off the coast of Southern California.

On April 7, Schulman-Janiger observed 11 gray whales in less than three hours and captured 706 pictures to document their condition. Of those 11 whales, she said six were “noticeably skinny” from shore.

“We’ve seen so many skinny whales and some have been emaciated, basically swimming skeletons,” Schulman-Janiger said.

"Skinny whales is a bad sign, low calves is a bad sign, and also, lower counts," she added. "There’s lots of warning signs that something isn’t right."

Three Dead Whales In One Week

Three gray whales recently died within one week in the San Francisco Bay Area, and at least one of them was described as emaciated.

Just days after a gray whale washed ashore March 30 at a beach in the Marin Headlands, two more dead whales were found April 2 and April 4 in San Francisco Bay.

The causes of death were still being reviewed by pathology teams, according to Julia O’Hern, associate director of cetacean conservation biology at The Marine Mammal Center in Sausalito. Experts, however, noted that the first whale was in emaciated body condition and there was no initial evidence of blunt force trauma.

"I think it is certainly a reason for us to pay attention," O’Hern told Patch. "We don't necessarily know the causes of death for each stranding, but we do know that there are a number of whales inside the bay, so it's very important for boaters to be vigilant and slow their vessel speeds where possible."

The deaths come after there have been a significant number of gray whale sightings in the area as the animals continue their northern migration to Alaska.

In recent years, whales have been seen feeding in areas such as San Francisco Bay and the Port of Los Angeles, which may be linked to changes in food availability in the Arctic.

"Gray whales entering San Francisco Bay are a little unusual but becoming increasingly common," O’Hern said. "We are still investigating why these whales have started entering the bay in more regular numbers, however, one possible explanation is that they are looking for a place to stop along the migration route and forage. They may also just be looking for protected waters where they can rest."

Another group of about 200 or so eastern North Pacific gray whales, called the Pacific Coast Feeding Group, stops along the coast between Northern California and British Columbia to feed rather than continue the journey to the feeding grounds in the Arctic.

Research from Oregon State University's Marine Mammal Institute found that the group has developed shorter body lengths, as well as smaller skulls and tails than other eastern North Pacific gray whales.

A Remarkable Recovery

Gray whales have made a remarkable recovery before.

The eastern North Pacific gray whales were nearly hunted to extinction by commercial whaling, but became the first marine mammal to be removed from the endangered species list in 1994 after the population rebounded due to protections from the Endangered Species Act.

“It is a very disheartening thought to think that gray whales are struggling knowing that they are one of the first marine mammals to be removed from the endangered species list,” Rodriguez said.

“These whales are extremely resilient,” she added. “We’re very hopeful that they will be able to figure it out and this is just one of those natural cycles that we’re unfortunately having to witness.”

As of Tuesday, there had been eight gray whales stranded so far this year on the West Coast of the U.S., according to Michael Milstein, a spokesperson for NOAA Fisheries’ West Coast region. Last year, there were 31 strandings.

Another dead gray whale washed up Friday near the Huntington Beach Pier, according to multiple reports. Personnel from the Pacific Marine Mammal Center in Laguna Beach responded Saturday to perform a necropsy, the OC Register reported.

“There are warning signs there that we’ve seen before," Schulman-Janiger said.

“I’m not afraid of gray whales going extinct, but I do believe that when the population recovers — and I do believe it will recover — I don't think it will necessarily get up to 27,000 again," she said. "If we have a continually warmer environment it may not support the food that they're used to eating. We may end up with less and less calves."