When Daniel Kriz saw a pair of orcas under his boat as he crossed the Strait of Gibraltar in April, he thought, “Not again.”
For Kriz, a veteran captain who was delivering a racing catamaran across the Atlantic, this was the second encounter in three years after a pod of orcas surrounded and damaged his boat in 2020.
“We were suddenly taken aback by what appeared to be a bad wave on the side,” he said of the recent incident. “This happened twice and the second time we realized we had two orcas under the boat, biting the rudder. They were two young girls, and the adults were swimming around, and it looked to me like they were monitoring this action.”
The four people aboard the craft were uninjured, but without full control of the boat, Kriz had to reach the nearest marina using only her engines. The whales destroyed both rudders – the submerged control surfaces that steer a boat – in what appeared to be a simplified version of the encounter that took place three years earlier.
“In 2020, the attack lasted almost an hour and was not as organized,” Kriz said. “This time we could hear them communicating under the boat. It only took about 10 to 15 minutes.”
Kriz’s experience is not isolated. For the past three years, the Strait of Gibraltar, an 13km-wide maritime corridor separating Europe from Africa, has been a hot spot of activity, with more than 500 interactions between orcas and boats.
All encounters involve some combination of the same 15 animals, which sank three boats and incapacitated dozens more, according to Mónica González, a marine biologist at the CEMMAor Coordinator for the Study of Marine Mammals, a non-governmental organization that is gathering data on orcas in the strait.
Why certain whales are becoming so interested in boats is still unclear, but experts have a few theories.
two theories
The Strait of Gibraltar is one of the busiest waterways in the world, and while orcas approach only a small fraction of passing boats, about 1 in 5 interactions result in serious damage that requires a tow, González said.
The last wreck occurred in early May, when the sailboat Alboran Champagne was attacked by three orcas and completely swamped; she was then abandoned and left adrift to sink. On June 22, two different teams participating in the annual Ocean Race event reported encounters with orcas in the strait, but neither yacht suffered damage.
The current rate of interactions is at a seasonal peak of about 20 to 25 per month: “There are more encounters in the summer because the orca’s prey, the bluefin tuna, are in the straits, so they’re waiting there,” González said. “When the summer ends, the tuna move to the north of Spain and the killer whales follow”.
Killer whales are the largest members of the dolphin family. The mighty animals are highly social marine mammals and can swim at speeds of up to 30 miles per hour, according to the National Oceanic and Atmospheric Administration. An adult can weigh up to 11 tons and reach 9.7 meters in length. Individual killer whales can live up to 90 years in the wild, and the global population is estimated to be around 50,000.
González said the total number of orcas in the strait is just 40 – a subpopulation listed as critically endangered by the International Union for Conservation of Nature – with about 15 of them approaching the boats. And among the individual offenders, there are only two adults, which may offer clues to their motivation.
“We have two theories as to why these interactions started,” she said. “The first is that the orcas are just playing around, and the other is that an animal has had an aversive moment and the orcas are trying to stop the boats to prevent this from happening again – but we don’t know exactly what happened in the first place.”
white gladis
In 2022, researchers from various local institutions and universities carried out a study about the attacks, revealing that they usually happen in daylight, mostly around noon, and last between half an hour and two hours.
The average size of boarded vessels is around 12.2 meters, and the usual pattern for an interaction involves the orcas silently approaching the boat, swimming under it, touching it lightly, and then – in the most extreme cases – heading for the rudder.
When animals attack the rudder, they can quickly turn a boat 360 degrees, causing danger and distress to its occupants. The encounter usually ends when the killer whales break the rudder or the boat comes to a complete stop.
“It is increasingly likely that an animal initiated this behavior after an incident with a boat,” said biologist Alfredo López Fernandez, an associate researcher at the University of Aveiro in Portugal and one of the authors of the study. He points to the story of a female orca known as White Gladis as evidence: “She is the only adult that started in 2020 with interactions along with seven other juveniles.”
There are clues to suggest that Gladis Branca may have become entangled in fishing gear – a common threat to orcas – either by accident or during an attempt at illegal fishing, López Fernandez said: Many boats use fishing lines on the stern, and this appears to be one of the motivating factors for the orcas to approach and investigate the rear of the vessel. Earlier this year, another killer whale in the area was spotted with a fishing line in its body, he said.
Since the supposedly traumatic event at White Gladis, two adult orcas may have started teaching the young how to approach boats to damage their rudders – which seems to go along with Kriz’s observation about the evolution of behavior between their two encounters.
“Orcas are a very matriarchal society and all the young look up to these very important females in the group; minors are copying their behavior because they believe that if these very important individuals do something, they must do the same to ensure their own survival,” said González.
The worrying thing is that interactions seem to be increasing: “From January to May we saw an increase compared to last year, but it is too early to say if this will be maintained during the rest of the season,” said López Fernandez.
No harm to people
According to Hanne Strager, marine biologist and author of “The Killer Whales Journals”although the traumatic origin of the behavior cannot be ruled out, she also believes that playing is a more viable explanation.
“They are attracted to the rudder because it is made to be mobile and they have found that if they push it to the side they can crack the hull – and this is what is believed to be the cause of some of these boats sinking,” she said.
“They might think it’s fun – like kicking a ball across the lawn to see what happens. But for the people who are experiencing this on their multi-million dollar boat, it’s no fun, no joke. It’s pretty scary.”
However, there is no evidence that whales want to harm humans, Strager added.
“I spoke to one of the crew members of one of the vessels that sank, who is also a marine biologist, and he said he never felt that there was aggression,” she said. “They didn’t care about the people and as soon as the boat sank they left.”
Kriz also ruled out any overtly hostile intent on the part of the mammals.
“I don’t think this is aggressive behavior and it is definitely not directed towards humans. They basically play with the rudders until they get them out,” he said. “They could see us – we were filming and taking pictures of them from the boat and there was no interaction from either side. They didn’t hit anywhere else on the boat. Just at the rudders.”
playful behavior
Killer whales are highly intelligent and known for playful behaviors, which can sometimes turn into cultural fads among a small group of individuals. González mentioned how in 1987, in the waters of the Pacific Northwest, an orca began carrying dead salmon on her head, and the behavior quickly spread to the rest of the pod, lasting just over a year.
“They certainly romp and play with all kinds of things,” Strager said. “I saw them swimming around with a jellyfish on their nose for a while. Several of them did this and there was no explanation other than fun. I also saw them catch small seabirds on the surface of the water, which they then didn’t eat. They also play with each other.”
Boats crossing the Straits of Gibraltar are advised to check the Atlantic Orca Working Group and download an app called GT Orcas to discover activity hot spots to avoid. In case of meeting, it is better to do nothing.
“The official recommendation is to do nothing, turn off the engine or lower the sails and be as uninteresting as possible for the orcas. Don’t scream, don’t scream, don’t scream,” advised Strager.
For critically endangered whales, getting a bad reputation can be fatal. “Some sailors are recommending that you throw chloride, diesel, fireworks or even dynamite into the water,” Strager said. “But this small, very vulnerable population of killer whales depends on our love for them. They depend on our protection.”
Kris agreed. “In short, we are in their territory,” he said.
“Perhaps we should designate some sort of corridor where boats enter or leave Gibraltar, something like sea lanes,” he added, noting that tracking the animals’ location only works to a certain extent because “they’ve been everywhere.”
Is it likely that whales will get tired of breaking rudders soon? Don’t bet on it, González said. “Personally, I don’t think they’re going to stop anytime soon,” she said. “Perhaps gradually, but not in the short term.”
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Source: CNN Brasil
Bruce Belcher is a seasoned author with over 5 years of experience in world news. He writes for online news websites and provides in-depth analysis on the world stock market. Bruce is known for his insightful perspectives and commitment to keeping the public informed.
