The forceful interactions between orcas and yachts have become a widely publicized phenomenon in recent years. Scientists are actively studying these encounters to understand their underlying causes, presenting a challenge for marine researchers and mariners alike.
A Pattern of Targeted Encounters
Since 2020, a pattern of interactions has emerged, concentrated primarily in the Strait of Gibraltar and extending along the Atlantic coasts of Portugal and Spain. These incidents involve the Iberian orcas, a specific subpopulation, targeting sailboats and catamarans. The orcas focus on the rudders, and sometimes the keels or hulls.
The orcas approach these vessels, often from the stern, engaging in ramming, nudging, and biting. Over 500 interactions were reported between 2020 and 2023, attributed to roughly fifteen individual orcas within this population. While many encounters result in only minor contact, more than 250 boats have sustained damage, and a few vessels have even sunk due to rudder destruction.
Exploring the Motives Behind the Encounters
Scientists are exploring several hypotheses to explain this unique behavior, largely ruling out intentional aggression toward humans. One leading theory suggests the interactions are a form of play or a social fad that has spread through the orca pod. Orcas are intelligent and social animals, known to develop and share new behaviors. This playful engagement might be reinforced by increased availability of prey, allowing more time for non-foraging activities.
Another hypothesis considers a defensive reaction, perhaps stemming from a traumatic event involving one orca, often referred to as “White Gladis.” This theory posits that an initial negative encounter with a vessel, such as a collision or injury, could have led an individual to develop a protective response, which then spread through social learning to others in the pod. Scientists do not consider these interactions to be malicious acts of revenge.
Environmental stressors are also being considered as contributing factors. The Strait of Gibraltar is a busy maritime passage, and increased vessel traffic, along with associated noise pollution, could be causing agitation among the orcas. Additionally, competition with human fisheries for bluefin tuna, their primary food source, might contribute to stress within the critically endangered Iberian orca population. These pressures could manifest in unusual behaviors directed at vessels.
Recommended Protocols for Mariners
In response to these interactions, Spanish and Portuguese maritime authorities, in collaboration with research groups, have issued specific safety protocols for mariners. If orcas are sighted or begin to interact with a vessel, the first recommendation is to stop the boat immediately by taking down sails and turning off the engine and autopilot. It is also advised to keep hands off the steering wheel to prevent injury from sudden movements.
Mariners should contact authorities via phone on 112 or VHF channel 16 to report the interaction and their position. During the encounter, it is important to minimize noise, avoid shouting, and refrain from touching the animals or throwing objects at them, as these actions could escalate the interaction. The rationale behind stopping the vessel and keeping the rudder loose is to make the boat less interesting to the orcas, often leading them to lose interest and move away.
A Uniquely Localized Behavior
This phenomenon of orcas interacting forcefully with vessels is a localized behavior, confined to the small and critically endangered Iberian orca subpopulation. This distinct group, numbering fewer than 40 individuals, migrates along the coasts of Spain, Portugal, and Morocco. While this behavior has gained significant public attention, it is important to understand its limited geographic and population scope.
Orcas in other parts of the world, such as the Pacific Northwest or Antarctica, engage in countless interactions with human vessels without exhibiting this type of targeted contact. This contrast highlights that the Iberian incidents are not a global trend in orca behavior. The localized nature of these interactions underscores the need for specific regional research and management strategies rather than generalized alarm.