Beach mystery: Another dead whale washes up in Pacifica

Ed Kasazza holds his granddaughter Mia Kasazza while looking at a female humpback whale that washed up on the beach in Pacifica on May 5, 2015. Ed Kasazza holds his granddaughter Mia Kasazza while looking at a female humpback whale that washed up on the beach in Pacifica on May 5, 2015. Photo: Sam Wolson / Special To The Chronicle Photo: Sam Wolson / Special To The Chronicle Image 1 of / 23 Caption Close Beach mystery: Another dead whale washes up in Pacifica 1 / 23 Back to Gallery

For the second time in three weeks, a dead whale has washed up on a Pacifica beach, and watchers of deceased whales returned to nearly the same spot to ask the same questions.

The carcass of a 32-foot-long female humpback whale washed up late Monday on Sharp Park Beach, about a quarter-mile north of the rotting carcass of a 48-foot-long sperm whale that washed up on April 14.

As they did before, passersby with bikes, kids and dogs stood somberly behind yellow caution tape while biologists studied the beached hulk for clues to its cause of death. There seemed to be fewer onlookers, however — perhaps because a second dead whale is less of a novelty.

Sue Pemberton, a curatorial assistant with the California Academy of Sciences, said the whale was lying on her back, preventing scientists from inspecting her to see if she had been struck by a ship. Scientists had not determined a cause of death.

“We can’t rule anything out,” Pemberton said.

The carcass was being buffeted by waves, each one appearing to drag it a little more out to sea. Pemberton said scientists would attempt to determine a cause of death Wednesday — providing the whale was still on the beach.

“We’re hopeful that conditions on the beach improve, allowing us to conduct a necropsy on this animal, as every stranding represents an opportunity for us to learn more about this species and our ocean environment,” said Lauren Rust, research biologist at the Marine Mammal Center.

What does it mean?

Spectators had their own ideas about the meaning of the second public whale death in 21 days. Some said they were scared, and others said it was an omen of something or other.

“Something’s going on with nature,” said Ralph Clement, who was walking his dog, Frankie. “This is kind of eerie. What are the odds of two whales in the same place? It has to mean something. Is this climate change? You can’t rule it out.”

Nicole Larson of Pacifica, a naturalist who leads whale-watching trips with the Oceanic Society, came by with her 1-year-old son, Tyler. Usually the whales she and Tyler watch are alive, she said, but any whale is a good whale.

“I’m not sad,” she said. “This is a learning opportunity. People see death and they think it’s sad, instead of something natural. When most whales die, they sink in the ocean. This is a chance to learn something.”

Courtney Patterson pedaled her bike along an embankment accompanied by her dog, Jet, to a spot where they could take in both dead whales.

“This is just not supposed to happen,” Patterson said. “It’s very unnerving. Is this caused by a lack of food, from global warming? Maybe.”

Jane Nahass said she has been walking on Pacifica beaches for 26 years and never saw two dead whales so close together.

“Something’s going on,” she said.

But Pemberton said the appearance of the second whale so close in time and place to the first was most likely “a coincidence.”

“This beach, because of its geographical features and currents, lends itself to being a huge repository of dead marine mammals,” she said. “And also trash.”

Humpback sightings

Humpback whales, which are endangered, are frequently seen off the coast of California. Strandings tend to occur more frequently in the spring and fall as the whales migrate up and down the coast. Over the past 40 years, the mammal center has responded to 21 humpback whale incidents, including in 2007 when two whales ventured into San Francisco Bay.

The back-to-back beachings appear to be a coincidence, but scientists will look into any factors that may have contributed to the events, said Laura Sherr of the Marine Mammal Center in Sausalito. Scientists from a half dozen agencies performed a necropsy on the sperm whale carcass but could not pin down a cause of death — though they did determine it was not struck by a ship. Then, two weeks later, someone tagged it with graffiti.

Steve Rubenstein and Evan Sernoffsky are San Francisco Chronicle staff writers. E-mail: srubenstein @sfchronicle. com, esernoffsky@sfchronicle.com. Twitter: @EvanSernoffsky