Orcas have increasingly interacted with boats in recent years, drawing attention from the public and scientists. This notable phenomenon has prompted extensive research to understand its nature and underlying causes.
Describing the Interactions
These interactions primarily involve orcas (Orcinus orca), concentrated off the Iberian Peninsula, including Spain, Portugal, and Morocco. Since 2020, the Atlantic Orca Working Group has documented over 500 encounters. Orcas often approach vessels, especially medium-sized sailboats, focusing on their rudders. They ram, nudge, and bite rudders, sometimes causing significant damage or disabling steering systems. While disruptive and damaging, scientists are cautious about labeling these as deliberate “attacks.” Approximately 20% of interactions result in severe damage, and a few vessels have sunk.
Why Whales Engage with Boats
Multiple scientific hypotheses attempt to explain why orcas engage with boats, though no single theory is definitively confirmed. One prominent idea suggests the interactions stem from play and curiosity, particularly among younger orcas. Juvenile orcas might treat rudders as toys, and the behavior could escalate as they grow. This aligns with observations of other transient cultural behaviors in orcas.
Another theory proposes the behavior is a learned social activity, potentially initiated by one or more individuals and then spread through the pod. For instance, an orca named White Gladis is often cited as a potential initiator, possibly after a negative encounter with a boat, leading to a learned response adopted by others. The abundance of bluefin tuna, a primary food source, has also been suggested as a factor, leading to more time for other behaviors, including play.
Environmental factors, such as stress or irritation from human activity, noise, pollution, or fishing gear interactions, are also considered contributors. While some theories suggest a defensive response, scientists generally refute the idea of intentional aggression, noting orcas could cause far more damage if they intended to. The current scientific consensus leans towards the behavior being playful or social rather than aggressive.
Responding to Whale Encounters
Marine authorities and scientific groups have issued recommendations for boaters in affected areas. It is advised to avoid specific sailing areas where interactions are most frequent, particularly around the Strait of Gibraltar and off the coasts of Portugal and Spain. If an encounter occurs, guidelines suggest stopping the vessel, deactivating the autopilot, and remaining still, as this can cause the orcas to lose interest. Moving away slowly is another option if safe.
Boaters are encouraged to report encounters to relevant marine authorities or working groups like the Atlantic Orca Working Group (GTOA) to help track the phenomenon. The focus is on minimizing disturbance to whales and ensuring human safety. Developing and testing deterrents, such as rudder modifications or acoustic devices, are also being explored. The aim is to promote coexistence while protecting marine life and maritime activities.