18.05.2024

Experts puzzled: Why do killer whale attacks continue to Spain?

Killer whales have attacked again in the Strait of Gibraltar, where they sank a yacht at the end of last week, reports Euronews. A 15-meter vessel was carrying two people in Moroccan waters when an unknown number of killer whales began crashing into it, the Spanish Maritime Rescue Service reported. After a warning was issued, the pair were rescued by a nearby oil tanker and taken to Gibraltar. The yacht has sunk to the bottom of the sea.

This is the latest in a series of orca attacks that have occurred in the region in recent years. Other similar incidents were reported off the Atlantic coast of Portugal and northwestern Spain.

Last November, a Polish yacht sank in the Strait of Gibraltar after an attack. In July 2023, Portugal banned tourist boats from approaching orcas in open waters.

"Given the size of adult killer whales, which can reach a maximum length of nine meters and weigh between three and five tonnes, more intense interaction with smaller vessels used for whale watching could have more serious consequences." , the Portuguese Institute for the Conservation of Nature and Forests (INCF) said at the time.

The research group Grupo Trabajo Orca Atlántica (GTOA), which tracks populations of the Iberian orca subspecies, says there have been almost 700 interactions since an orca collision was first reported in May 2020. Experts believe it is a subpopulation of about 15 individuals. The group is called Gladys. But the motivation for the strange behavior of the predators is still a mystery.

Why are killer whales crashing into boats in southwest Europe?

According to some experts, behind the unusual behavior there may be a desire for revenge, based on the traumatic experience of a female orca called "White Gladys". According to the theory, after the initial collision several years ago, it began to exhibit "defensive behavior" against vessels. Other killer whales then start copying her.

The highly social predators usually target sailboats but do not cause much damage. Only three boats have been reported to have been sunk by killer whales since the anomaly began in May 2020. It is estimated that they attack only one in every 100 ships that sail through a given location.

Are orcas seeking revenge?

According to Alfredo López Fernández, a biologist at the University of Aveiro in Portugal and representative of the GTOA, the orcas' behavior is conscious.

"We don't know the origin or the motivation, but the theory of trauma-based defensive behavior as the origin of all of this is gaining more strength for us every day," he said.

Some researchers suspect that White Gladys suffered a "critical moment of agony" - either being hit by a boat or snared during illegal fishing - which changed her behavior.

"It was the traumatized orca that initiated this behavior of physical contact with the boat," adds López Fernández.

Other accounts have a vengeful White Gladys teaching younger killer whales to break boat rudders. But López Fernández, who co-authored a 2022 marine mammal study, thinks aggressive behavior simply spreads through imitation among animals.

Could the killer whales' visits be an attempt at social contact?

Still no one knows for sure the reason for the aggressive behavior of marine predators.

"The situation is unprecedented - a complete mystery. But these attacks are more like accidents. "After all, why would killer whales want to engage in self-destructive behavior," asks Andrew W. Traits, professor and director of marine mammal research at the University of British Columbia.

According to Traits, it could be "playful behavior that has gotten out of hand." He remembers a whale named Luca seen off the coast of Vancouver, Canada, that broke free from its pod and began chasing boats.

“Later he learned to intercept the rudders and break them to disable the boats and push them around. In his case, he was looking for social interactions. Luca learned that he could prolong interactions by disabling the boats. And then they'll have to stay with him and he'll be able to play as much as he wants," Traits explains.

He also has another explanation:

"I know of many cases where killer whales come in and almost put their noses against the propeller of the boat to feel the water wash over them. For them, it feels like being in a hot tub.”

The behavior could put mariners and whales at risk

A little "rough shoving" may seem like harmless fun to the whale. But the impact on vessels can be harmful and dangerous to mariners. And conservationists are concerned. Although their deaths cannot be directly linked to the boat attacks, four killer whales belonging to the Iberian Gladys subpopulation are known to have died since the anomaly began in 2020.

There are only 39 Iberian killer whales recorded at the last census in 2011, and this group is listed as Critically Endangered by the International Union for Conservation of Nature (IUCN) Red List.

"If this situation continues or intensifies, it could become a real problem for the safety of sailors and also for the conservation of this endangered subpopulation of killer whales," said López Fernández.

Spain's transport ministry previously urged boaters to leave the area if they notice a change in the orca's direction or speed and to report any interactions.