California researchers encounter unusually large group of orcas

June 9 (UPI) -- Marine researchers in California were treated to a unique experience when they came across an unusually large pod of orcas composed of up to 24 killer whales.

Michael Pierson of the Oceanic Society said he and his fellow researchers set out on a whale-watching tour near the Farallon Islands and decided to deviate from their usual route, so they approached the islands from the south.

Pierson said the group spotted a blue whale and a pod of humpbacks before he spotted an orca's dorsal fin poking out from the top of the water.

The researchers were soon shocked to be surrounded by up to 24 orcas, including several mother and child pairs and multiple adult males.

"Just seeing them is always really exciting, but seeing such a large grouping was what made it a one-of-a-kind experience," Pierson told SFGate.

Alisa Schulman-Janiger, lead research biologist with the California Killer Whale Project and Monterey Bay Whale Watch, identified the whales spotted from the boat. She said at least six different families were represented.

"It was such a fascinating encounter in that it was such an unusually high number and an unusual mix," Schulman-Janiger said. "If you see one of those families, you'd think another family would come up, but it was a real mix of whales that were unrelated and are typically not seen with each other at all."

She said it is difficult to determine what caused the unusual grouping of orcas to come together on the day of the tour. She said they may have been preparing to hunt, investigating something unusual or merely socializing.

"We know they form long-term friendships and associations, but there's no way for us to know what they're getting out of it," she said.