Scientists baffled over apparent coordinated attack by killer whales on boats

A pod of killer whales repeatedly rammed a yacht in the Strait of Gibraltar this week, damaging it enough to require Spanish rescuers to come to the aid of its four crew members.

It was the latest episode in a perplexing trend in the behavior of orcas populating the Atlantic coast of the Iberian Peninsula that has left researchers searching for a cause.

Spain’s Maritime Rescue service said that killer whales repeatedly ran into the Mustique, a 20-meter (65-foot) vessel sailing under a U.K. flag, late on Wednesday, rendering its rudder inoperative and cracking its hull. Spanish rescuers needed to pump out seawater before towing her to safety.

The alert reached the Spanish service via their British counterparts, who had relayed on the distress call, the Spanish service said. A helicopter and a rescue boat were deployed to help the damaged boat to dock in Barbate.

Speaking to Live Science, Lopez Fernandez said that the behavior has spread to younger orcas.

"We do not interpret that the orcas are teaching the young, although the behavior has spread to the young vertically, simply by imitation, and later horizontally among them, because they consider it something important in their lives," Lopez Fernandez said.

Storyful licensed footage of an aggressive orca encounter with a boat in October 2021.

According to Matt Johnston, who captured the clip, a pod of orcas circled and rammed into his boat near Sines, Portugal, breaking off pieces of the vessel.

Johnston told Storyful that "the larger pair in the orca pod would batter the boat with their heads, turning it 90 degrees, while the younger pair would attack the rudder."

After calling the maritime police to scare the orcas off, Johnston said he had to have his disabled boat towed into the nearest port.

Storyful contributed to this report.