Orca-nised Crime - why are killer whale attacks on boats increasing?

Could a single matriarch - White Gladis - be the driving force behind them?

Photo credit - Nitesh Jain@Unsplash

The Atlantic waters around the Strait of Gibraltar are home to the small and critically endangered population of the Iberian orca. Reaching a maximum length of 6.5 meters, this subspecies is much smaller than its Pacific relatives, and feeds exclusively on fish.

Although these animals are usually friendly towards people and boats, encounters along the Spanish and Portuguese coasts have taken on a threatening tone over the past three years, with the animals displaying aggressive behaviour towards smaller vessels in a rapidly increasing number of incidents.

On May 4th a group of the cetaceans targeted a yacht and damaged it so severely that it sank – bringing up the toll of sunken sailboats to three and the number of disruptive interactions to approximately 503.

Data collected by the Cruising Association (CA) for 2022 shows that over 70% of the boats were damaged, with roughly 22% requiring a tow. These incidents tend to follow a pattern, according to records kept by the Atlantic Orca Working Group (GTOA) and the CA: a small group of killer whales will approach and ram a boat of about 15 meters, strategically targeting the rudder, often causing extensive damage and immobilizing the vessel. In most cases, the animals lose interest after about 40 minutes and swim away.\_1sPbyyP0

However, in a recent case on May 24th, the orcas continued to follow a sailboat as it was towed back to shore after being damaged to the point of leaking, as experienced sailor April Boyes describes in a blog post. It is not yet certain whether this event marks a new shift in the orcas’ abnormal behaviour.

The motives behind the attacks remain unclear. While some witnesses find it “hard to say whether they were playing or not”, others state that the orcas “were clearly intent on doing damage”. Scientists of the GTOA support these observations and suggest that the interactions are either self-induced playful behavior or precautionary behavior triggered by an “aversive incident”, perhaps a traumatic experience with a sailboat or larger vessel.

After three years of studying these encounters, the GTOA has identified a group of around 15 orcas out of a local population of less than 50 as responsible for the damage done. An adult female dubbed White Gladis is said to be the mastermind behind the incidents, influencing her entire pod’s attitude towards these vessels, as her behaviour vertically spreads to the juvenile animals that imitate her.

As Ulrich Karlowski from the German Foundation for Marine Conservation (Deutsche Stiftung Meeresschutz) points out, the change in behaviour is most likely a cultural development, “a culture that consists of stopping certain boats [] It is an amazing and fascinating feat of intelligence and at the same time a dilemma.”

Photo credit - NOAA@Unsplash

The tabloids have done their best to portray this series of events as a vendetta, luridly describing scenes reminiscent of Jaws or Melville’s classic Moby Dick, with White Gladis in the thankless role of the vengeful anti-hero. Others describe her as an animal anti-capitalist sinking the yachts of the wealthy. But whatever her agenda, experts warn against anthropomorphising and demonizing the orcas, which can lead to an inaccurate understanding of their behaviour.

As Rocío Espada of the Seville Marine Institute told The Guardian in 2020, stress could be a more probable cause of the attacks. Living in the middle of a major shipping route, which is passed by around 300 container ships and hundreds of private boats every day, the animals are often injured by rudders, propellers, fishing lines or nets. Pollution is another consequence of the increased traffic that the animals must endure.

Moreover, Atlantic bluefin tuna – the main prey of the Iberian orca – is being overfished, making it increasingly difficult for the orcas to feed themselves. As a result, the morbidity rate of the orcas' calves in this area is tragically high. Another theory, therefore, is that the animals see the boats as a form of competition for food.

Marking the first such interaction outside of the Iberian orca’s habitat, on June 19th, a yacht was harassed by a single orca in the Scottish waters around Lerwick. The boat appears to have suffered no major damage and was able to continue its course, with the 72-year-old Dutchman Wim Rutten, who was sailing alone, escaping with a scare.

Whether this event is purely coincidental or in fact related to the ones around the Iberian coast, indicating a spreading of the aggressive behaviour, is not yet known. However, as Dr Conor Ryan of the Hebridean Whale and Dolphin Trust told The Guardian, it is a possibility that this behaviour is “leapfrogging through the various pods/communities” as there are pods that are “highly mobile” and able to communicate this behaviour over such distances.

While the idea that more members of the Iberian orca pods – and, in the light of the most recent events in Scotland, also other populations of orcas – will adopt this change in behaviour is worrying, one must acknowledge how this learning pattern testifies to the orcas’ intelligence and capability of communication.

It has long been recognised that this fascinating species possesses extremely high levels of emotional and social intelligence, possibly exceeding that of humans due to their complex brain structure.

Consistent with Espada’s suspicion that the cause of the incidents may be stress, Napier Marten, founder of the Mirthquake Foundation, a pioneering organization that is ​​involved with the culture and welfare of cetaceans, says:

“It is hardly surprising, given the phenomenal intelligence of the largest of dolphins, that the matriarch of her dwindling and diminished family of orcas, wish to express their frustration and fury over constant noise, disregard of their culture, pollution and overfishing that she will express herself in the only way she knows - attacking boats.”

The GTOA and the CA have developed an emergency protocol for sailors in the case of an orca encounter. Sprinkling sand around the rudder has also proved to be an effective method, as it confuses their sonar. But as their records show, many sailboats do not follow the protocol. And with the number of incidents on the rise, conservationists are concerned that sailors are equipping their yachts with shotguns.

With White Gladis in the media spotlight, the matriarch could quickly become the target of self-proclaimed Captain Ahabs. Anthropomorphising White Gladis is not the answer to this problem. She is neither a villain nor a matriarchal guerrilla waging war on yachts (however tempting it might be to see her as the latter). She is a highly intelligent individual whose habitat and entire population are at risk due to human influence, and she is in desperate need of our protection. Napier Marten warns:

“Until we realize cetaceans embody the great minds and consciousness of the oceans, we are doomed to stay on our track of destruction and desecration of their homes and ultimately ours too on the land.”