Tourists Spot Rare Group of Killer Whales Off San Francisco Coast

A whale-watching tour near the coast of San Francisco caught a glimpse of an unusually large group of about two dozen orcas, or killer whales, swimming in a pod last month, a rare occurrence for the Bay Area.

According to the Associated Press, it is likely the orcas had gathered to "celebrate" a successful hunt for seals or sea lions, which are native to the area. 

The whales were spotted on May 7. While killer whales are often seen by the Monterey Bay, these were seen by the Farallon Islands, about 28 miles from San Francisco. 

“I screamed ‘orca!’” said Michael Pierson, who led the tour that spotted the whales. In an interview with the AP, Pierson added that he noticed “those distinct dorsal finds poking out of the water.”

Individual killer whales are often identified by the unique shape and markings of the dorsal fin.

According to the Los Angeles Times, the California Killer Whale Project has used photos to identify orcas that travel off the state's coast, even following one family for four generations. Photos are taken during encounters to aid researchers in studying individual orcas without troubling or disrupting them.

Pierson shared that the spotting came after he and his boat’s captain, Jared Davis, decided to try a different route on the May 7 boat tour, with the aim of going over deeper water.

“It really worked in our favor,” Pierson told the LA Times.

Meanwhile, a series of orca sightings thousands of miles away in the Atlantic Ocean near the coasts of Spain and Morocco have marine biologists puzzled over the animals' aggressive actions. According to reports from several separate incidents, the orcas appeared to gang up to attack sailboats and other smaller vessels, in some cases sinking them.

Some experts believe there's a single "traumatized" orca teaching the behavior to others