Killer Whale Teaches Other Orcas To Attack Yacht After Being 'Traumatized' By Boat Collision

A killer whale that suffered from trauma due to a "moment of agony" is teaching gangs of orcas to attack other vessels and yachts around Gibraltar, scientists said.

Researchers believe that the ringleader among the killer whales, a female orca they call White Gladis, suffered a "critical moment of agony," possibly a collision with a boat or entrapment during illegal fishing, that left it traumatized and made it aggressive toward boats, The Telegraph reported.

"That traumatized orca is the one that started this behavior of physical contact with the boat," Alfredo López Fernandez, a biologist at the University of Aveiro in Portugal and representative of the Grupo de Trabajo Orca Atlántica, or Atlantic Orca Working Group, told LiveScience.

Gladis' actions are being copied by other killer whales in nearby areas, according to Fernandez. To date, the orcas have already struck three boats, and two of those sunk underwater.

The researcher said Gladis' behavior was not revenge but a behavior learned "as a reaction and precaution."

With the matriarch showing other killer whales how to effectively ram boats, sailors fear the prospect of future orca attacks.

On May 2, six orcas reportedly circled a Bavaria 46 cruiser yacht on the Strait of Gibraltar and rammed its hull. Skipper Greg Blackburn was already facing challenges in sailing, including "heavy weather," strong winds and a rolling swell of between six to 10 feet, when the whales hit the rudder of his boat.

"We were like, 'There's definitely something down there,'" Blackburn told 9News. "After that was when we got the first sighting of them."

"After reading reports and knowing what has been going on, I just thought we were in for a ride now," he added.

After about an hour, the orcas lost interest in the boat and swam away, leaving the sailors and the skipper unharmed. However, the ambush left a British couple who was on board for a sailing course shocked and confused.

The couple, identified as Janet Morris and Stephen Bidwell, both 58, were alerted to the attack by the cry of orcas.

Bidwell said to The Telegraph that it was "an experience I will never forget."

"I kept reminding myself we had a 22-ton boat made of steel, but seeing three of them coming at once, quickly and at pace with their fins out of the water was daunting," he added.

Bidwell noticed that a larger killer whale "was definitely around and was almost supervising" the coordinated attack and speculated that it was the notorious White Gladis.

"I couldn't believe it when I saw them," Morris added. "We were sitting ducks."

The killer whales caused thousands of pounds' worth of damage to the boat.

The attack in the Straits followed a similar incident in November last year off the coast of Portugal.

Orcas are known to be sociable creatures and can learn easily from one another. Other scientists suggested that the attacks may just be their way of playing or them being territorial.