Killer whales have sunk three boats in southern Europe in the past year, scientists say
Hours after traveling to Portugal from Morocco, the crew of a 14m sailing cruiser noticed something was wrong with the rudder. Then someone called what they saw cutting through the choppy waves, “Orcas! Orcas!”
The orcas kept pace with the boat, slamming into its side and chewing the rudder, according to the skipper, an onboard photographer and video of the encounter. For about an hour, the crew signaled their predicament to the Spanish Coast Guard and tried to remain calm.
“We couldn’t do anything,” said Stephen Bidwell, the photographer, who was two days into a week-long sailing course with his partner when the ramming started. “You are impressed and nervous at the same time.”
The skipper, Gregory Blackburn, said he struggled for control of the boat when the orcas crashed into it and interfered with the rudder. “It’s a reminder of where we are in the food chain and the natural world,” he said.
Finally, the boat managed to motor back to Tangier, Morocco. But marine scientists took note of the May 2 episode and said it continued a puzzling pattern of behavior among a small group of killer whales off the west coast of the Iberian Peninsula. The orcas have sunk three boats since last summer and disrupted the journeys of dozens more, according to the researchers.
Wild killer whales, although apex predators that hunt sharks and whales, are generally not considered dangerous to humans. The animals, the largest of the dolphin family, are known to touch, bump and follow boats, but ramming them is unusual, marine scientists say. A small group of killer whales, numbering about 15, began assaulting boats around Spain in 2020, with researchers calling the behavior unusual and the motivation unclear.
“We know it’s a complex behavior that has nothing to do with aggression,” said Alfredo López Fernandez, a biologist at the University of Aveiro in Portugal who worked on A study published on this topic last June. The orcas show no sign of wanting to hurt humans, he said.
In most sightings, the orcas do not change their behavior or make physical contact, the Atlantic Orca Working Groupwhich started tracking direct interactions – as well as observations – in 2020.
Since a first wave that year, killer whales have been documented about 500 times to approach or interact with ships, causing physical damage about 20 percent of the time, in the heavily trafficked seas near Morocco, Portugal and Spain, the group said.
The killer whales off the Iberian coast are being considered an endangered population: The group arrives in waters near the Strait of Gibraltar each spring from deeper waters and further north along the coast to hunt tuna. But while they’re a common sight, scientists don’t know how to stop the small group’s recent behavior, which they do worried the sailors on safety and ship damage, and which has attracted the attention of the Spanish and Portuguese authorities.
“There’s an incident every week,” said Bruno Díaz López, a biologist and director of the Bottlenose Dolphin Research Institute, who was not involved in last year’s study. “We really don’t know what the reason is.”
In the most recent example, killer whales struck a sailboat off the coast of Spain, causing it to sink in the early hours of May 5. The Spanish authorities were quickly on the scene and the four people on board were rescued “in good spirits”, Christoph Winterhalter said. , the president of the Swiss company that operated the boat, Hoz Hochseezentrum International.
University of Aveiro biologist Dr López Fernandez said it was possible the three boats sank in the past year because they were vulnerable to leaks or were not equipped to withstand the damage. (“The condition of the boat was very good,” Mr. Winterhalter said of the boat his company chartered.)
According to dr. López Fernandez was the small group of killer whales, including only two adults, responsible for the majority of boat interactions, some 200 per year and ranging from the North African coast to France.
Researchers don’t know what’s behind the behavior. Some have speculated that it is an “aversive behavior” that could have started after an incident between an animal and a boat, such as an entanglement in a fishing line, or an invented behavior of young killer whales that is repeated.
Those remain just theories, though Dr. López Fernandez said it appeared the behavior could be transferred between local animals.
“We know that killer whales share their culture with their young and with their peers,” he said, adding they learned of imitation. But because the behavior has only been observed in this specific subpopulation of killer whales, he said it was unlikely to spread to different killer whale groups that populate waters around the world.
Given the lack of evidence and the presence of young killer whales in the group, other scientists were skeptical that the behavior stemmed from a boating incident and believed the animals were simply playing.
“They get some sort of reward or thrill out of it,” said Erich Holt, an orca expert and research fellow at Whale and Dolphin Conservation, a wildlife charity. “Playing is part of being a predator.”
Scientists say that aside from sailors avoiding the area, they don’t know how to prevent killer whales from harassing sailboats, which are typically quieter than most craft and therefore more attractive to the animals.
It has also left conservationists concerned about how humans will treat the killer whale population, especially as sailors in the region express growing frustration with the animals.
“I hope they stop doing it as quickly as they started because it actually puts themselves at risk,” said Hanne Strager, a marine biologist and the author of “The Killer Whale Diaries”, adding that it was straining an already vulnerable species.
Mr Bidwell, the photographer, said the episode would not deter him and his partner from booking another sailing trip in June, albeit with some changes perhaps. “Maybe we’re not going the same route,” he said.