Killer whales attack boats off Spain and Portugal, baffling scientists: NPR

Ester Kristine Storkson was sleeping on her father’s small yacht earlier this month, sailing off the coast of France, when she was violently awakened.

Rushing to the deck, she spotted several killer whales, or killer whales, surrounding them. The steering wheel swayed wildly. At one point, the 37ft sailboat was pushed 180 degrees, steering it in the opposite direction.

They were “spurring the boat,” Storkson says. “They [hit] us several times… giving us the impression that it was a coordinated attack.”

“I said to my father, ‘I don’t think clearly, so you have to think for me,'” says the 27-year-old Norwegian medical student. “Fortunately, he is a very calm and centered person, and he made me feel safe by speaking softly about the situation.”

After about 15 minutes, the killer whales broke off, leaving father and daughter to assess the damage. They stuck a GoPro camera in the water, she says, and found that “about three quarters of [the rudder] was broken, and metal was bent.”

For any vessel, losing direction at sea is a serious problem and can be dangerous in adverse conditions and some sailboats had to be towed in the harbor after the orcas destroyed their rudders. Fortunately, the Storksons had enough rudder to get to Brest, on the French coast, for repairs. But the incident temporarily derailed their plans to reach Madeira, off northwest Africa, as part of an ambitious plan to circumnavigate the globe.

The there is no record of an orca killing a human in the wild. However, two boats were would have sunk by orcas off the coast of Portugal last month, in the worst such encounter since authorities tracked them.

The incident involving the Storksons is a outrageous, says Renaud de Stephanis, president and coordinator of CIRCE Conservación Information and Research, a cetacean research group based in Spain. It was further north – nowhere near the Strait of Gibraltar, nor the coasts of Portugal or Spain, where other such reports come from.

It’s an enigma. Until now, scientists have assumed that only a few animals were involved in these encounters and that they all belonged to the same group, de Stephanis explains.

“I really don’t understand what happened there,” he admits. “It’s too far. I mean, I don’t think [the orcas] would go up there for a few days and then come back.

These encounters – most scientists avoid the word “attack” – have captured the attention of sailors and scientists over the past two years as their frequency appears to be increasing. Sail magazines and websites wrote about the phenomenon, noting that killer whales seem to be particularly attracted to the rudder of a boat. A Facebook group, with over 13,000 members, sprung up to exchange personal reports of boat-orca encounters and speculation about evasive tactics. And, of course, there’s no shortage of drama videos published on YouTube.

Scientists don’t know the reason, but they have ideas

Scientists theorize that killer whales like the water pressure produced by a boat’s propeller. “What we think is they’re asking to have the propeller in the face,” de Stephanis said. So when they come across a sailboat whose engine isn’t running, “they get a bit frustrated and that’s why they break the rudder.”

Even so, it doesn’t fully explain an experience Martin Evans had last June when he was helping deliver a sailboat from Ramsgate, England to Greece.

About 25 miles off the coast of Spain, “just before entering the Strait of Gibraltar”, Evans and his crew were under sail, but they were also running the boat’s engine, the propeller being used to increase their speed.

While Evans was on watch, the steering wheel began to move so violently that he couldn’t hold on, he said.

“I was like, ‘Jesus, what is this?'” he recalled. “It was like a bus moving it. … I look to the side, and suddenly I could just see that familiar white and black killer whale.”

Evans noticed “chunks of rudder on the surface”.

The orca population along the Spanish and Portuguese coasts is quite small. According to Jared Towers, director of Bay Cetology, a research organization in British Columbia, scientists believe the boats are damaged by a few young males.

“There’s something about the moving parts…that seems to stimulate them,” he says. “Maybe that’s why they focus on rudders.”

If a small number of orcas are involved, they may simply outgrow the behavior, Stephanis says. As young bucks get older, they will need to help the group hunt for food and will have less time to play with sailfish.

“It’s a game,” he speculates. “When they…have their own adult life, it’ll probably stop.”

Towers points out that such “games” tend to be in and out of fashion in orc society. For example, right now, in a population he’s studying in the Pacific, “we have juvenile males that … often interact with shrimp and crab pots,” he says. “It’s just been a fad for a few years.”

In the 1990s, for some orcas in the Pacific, something else was in fashion. “They were killing fish and swimming with that fish on their heads,” Towers explains. “We don’t see that anymore.”