Suspects Named in San Diego’s Dead Fin Whale Case: Killer Whales

Scientists believe the dead teenage fin whale that washed up on a popular San Diego beach last week was fleeing its greater foe, the killer whale. 

First responders presumed the teeth marks that raked across the whale’s iconic shrunken dorsal and sides were the dirty work of sharks. Whale experts revealed the wounds match the jawline of the ocean’s tuxedoed top predator – the fin whales’ only real predator aside from humans.  

Marks on dead fin whale that washed ashore on a San Diego beach on Dec. 10, 2023. / Courtesy of NOAA. Note: Photos taken under stranding network permit.

But why would the whale make a break for the beach?  

“When they get attacked, they’re terrified,” said Bob Pitman, a marine ecologist at the Marine Mammal Institute at Oregon State University. “Large whales, if they’re in coastal areas, go toward shore rather than stay out in open water and deal with a killer whale.” 

Pitman recently published a paper reviewing fatal killer whale attacks on fin whales. Many of those cases occurred off Baja California, like in 2011 when fishermen near Coronado Island watched a group of killer whales attack a fin whale for over two hours. And in 2019, a fin whale beached itself after a long pursuit by killer whales in the Gulf of California.  

Michael Milstein, a spokesman for the National Oceanic and Atmospheric Administration or NOAA, said while rarely seen in Southern California, these orcas are making a flashy reappearance along the coastline.  

Orcas were spotted punting dolphins into the air off the San Diego coastline earlier this week. A whale watching crew spotted an orca pod last week off Torrey Pines and again on Monday, CBS 8 reported. Another crew spotted a pod playing off Palos Verdes Peninsula in Los Angeles Saturday.  

“I think they may be coming into our area to go dolphin hunting,” said Alisa Schulman-Janiger, lead research biologist for the California Killer Whale Project. “Ones that eat dolphin are known to go after fish and fin whales too.” 

Schulman-Janiger said this particular group of orcas have visited San Diego since 2018 and they’re extremely interactive with their human onlookers and surf along the bows of boats.  

After the San Diego fin whale washed up along Pacific Beach, lifeguards towed it back out to sea where she dropped below the water line a mile offshore. Gasses built up in her body cavity as she began to decompose, causing her to float back to the surface. Milstein said San Diego lifeguards spotted the carcass floating later that week toward the shoreline at Bird Rock in La Jolla.  

The lifeguards towed the body out to sea again, this time a full 20 nautical miles because it’s not great to have a floating buffet of meat drifting and attracting sharks along a heavily human-populated coastline. 

A whale watching crew caught footage of the tow; though it’s a sorrowful sight. Her once sleek, steel-colored body, which makes her fastest and second-largest whale species on Earth, had started to pinken and bloat. 

She is now adrift. 

NOAA attached a buoy to track her body as it travels. Her last known location Tuesday morning was 50 nautical miles off Rosarito, Mexico. 

About the ‘Killers’ 

When I first covered this story, I could only guess what might have killed the 52-foot mammal that favors the open seas and can live to 90 years old. I suspected humans were to blame, since whalers almost decimated the fin whale population at the turn of the 19th Century and modern ocean hazards like ship strikes, marine noise, plastics and entanglements with fishing gear still threaten the species.  

(NOAA encountered a humpback whale entangled in fishing gear off the coast of San Diego just a few days ago that they were unable to free.) 

In fact, it appears this was a “circle of life” kind of moment in nature. But I did learn a lot about killer whales (synonymous with orcas) in the process – who I now think of as the mob bosses of the ocean.  

For killer whales, everything stays in the family. But instead of a godfather, it’s the matriarchs – the mothers and grandmothers – that call the shots. Children stay with their mothers their entire lives. They share food. Groups don’t interbreed with each other. No Corleone mixing with Barzini.   

Scientists sometimes define orcas by what they eat, which often corresponds to where they live geographically. The endangered Southern Resident killer whale specializes in eating salmon; 80 percent of their diet is Chinook or King salmon which aren’t doing so hot due to climate change and development. (California is blowing open a whole dam on the Klamath River to restore the population, as CalMatters reported.)  

Other orcas are shark eaters. Others are mammal eaters, dining on everything from sea lions to large baleen whales. Some are generalists, scavenger types.  

Killer whales targeting food sources off Baja seem to prey on mammals, Pitman said. Fin whales are not so great at defending themselves in shallower waters. They’re built for speed but they aren’t typically powerful enough to ward off orcas. Some whales move toward shore to gain an advantage on the orcas who would otherwise attack from all sides.  

Another way to identify whether orcas were the culprit killers: If the victim whale’s tongue has been ripped out – not to keep them from squealing, but the organ is very rich and can feed quite a few orcas. Pitman said orcas can remove a tongue with little damage to the whale’s external cavity. One paper showed a killer whale inside the mouth of a blue whale extracting its tongue.  

Gore aside, killer whales are the ultimate apex predator and even hunt great white sharks. Lucky for us, they haven’t developed a taste for humans. The matriarch of the family passes down prey selection and hunting skills wisdom developed over generations.  

As the ocean warms due to climate change, scientists are seeing more killer whales from the tropics travel northward. Those spotted off San Diego’s coastline recently are eastern tropical pacific killer whales. So, they may become a more common sight in San Diego.  

Clarification: This story has been clarified to reflect that San Diego lifeguards spotted and towed the whale both times.