Researchers from the University of Aveiro in Portugal have documented a rise in reports of encounters with aggressive killer whales along the Iberian coastline. The study, published in the journal Marine Mammal Science, highlights a notable shift in patterns of interaction between orcas and seafaring vessels.
In a notable incident, a trio of killer whales targeted a yacht in the Strait of Gibraltar, near the southern coast of Spain, damaging the vessel’s steering mechanism during a late-night encounter.
Witnesses described two smaller orcas pushing at the rudder from the stern while a larger individual repeatedly rammed the hull from the side, as recounted to a German-language edition of a maritime publication by Captain Werner Schaufelberger.
Researchers note that reports of aggressive orca interactions along the Iberian coast began to appear in 2020 and have become more frequent over time. The behavior appears to be predominantly directed at sail-powered boats, with a discernible sequence: the orcas approach from the stern to strike the helm, briefly pause, and then depart after disrupting the vessel’s course.
Experts describe this escalation as a new and troubling development in killer whale behavior. They suggest that a traumatic experience affecting a single individual could be learned and reinforced within the group, giving rise to a broader pattern of imitation among others in the population.
Scientists emphasize that the intent behind the actions remains unknown, noting that deliberate aggression toward boats is likely purposeful, though the exact triggers are not yet clear. The accumulating evidence points to trauma-linked responses as a contributing factor, with the implications spreading as more orcas observe and imitate the tactic.
The researchers identified a female killer whale nicknamed White Gladys as a possible catalyst for the observed behavior. They speculate that this individual may have survived a close call with a vessel or a poaching attempt, which could have shaped her subsequent perception of boats as threats. Mimicry by other members of the group could be reinforcing the spread of this behavior.
Since these unusual interactions began, several individuals within the aggressive Iberian subpopulation have died. While those deaths cannot be directly tied to boat encounters, the pattern raises concerns about the safety of seafarers and the well-being of the orcas themselves. Maritime incidents involving orcas remain relatively rare, yet the trend appears persistent, with a meaningful portion of observed episodes resulting in vessel disruption or damage. These dynamics underscore the need for continued monitoring and collaboration between researchers, sailors, and coastal communities to understand and mitigate potential risks in shared waters. [citation: University of Aveiro study; Marine Mammal Science publication]