Dolphins are often seen as playful, gentle creatures, a perception reinforced by popular media. However, these intelligent marine mammals are wild animals. While encounters are generally peaceful, instances of dolphin aggression towards humans do occur. These rare but documented incidents remind us that dolphins possess complex behaviors, including defensive or assertive actions. Understanding the natural instincts and triggers behind such events is important for safe coexistence.
Reasons for Dolphin Aggression
Dolphins may exhibit aggressive behaviors when they perceive a threat to themselves or their social group. A mother dolphin, for instance, will fiercely protect her calf and may lash out if she feels it is in danger from nearby swimmers or boats.
Hormonal changes, particularly during mating season, can contribute to male dolphins becoming more aggressive or dominant. Solitary male dolphins, lacking conspecific social interaction, may direct mating-related behaviors, including biting or pushing, towards humans. Dolphins accustomed to human feeding can also grow agitated if food is not provided, leading to aggressive demands. Illness, injury, or frustration from disturbances in their habitat can also cause uncharacteristic and aggressive behavior.
Documented Incidents and Behaviors
While infrequent, documented dolphin attacks can result in significant injuries. Aggressive actions often involve ramming with their powerful rostrums (snouts), causing blunt-force trauma, including broken bones or internal injuries. Biting is another form of aggression, and dolphins have also been observed attempting to drag people underwater. For example, a woman in Hawaii was bitten by a dolphin, sustaining spinal fractures, broken ribs, and a damaged lung.
Dolphin aggression is not exclusive to humans; these animals are known to display aggressive behaviors towards other marine species. Bottlenose dolphins, for instance, have been observed attacking porpoises, sometimes for reasons unrelated to feeding. This behavior underscores that aggression, including what might appear as “play” to humans, is a natural part of their complex social dynamics and predatory instincts within the marine ecosystem.
Safety Around Wild Dolphins
Observing wild dolphins from a respectful distance is a primary safety measure. Federal regulations, such as the Marine Mammal Protection Act, prohibit feeding or harassing wild marine mammals, including dolphins. NOAA Fisheries recommends maintaining a distance of at least 50 yards (approximately 45 meters) from wild dolphins to ensure both human safety and the animals’ well-being. Violations of these regulations can lead to substantial fines, up to $100,000, and even imprisonment.
Never attempt to feed wild dolphins, as this alters their natural foraging behaviors and can make them dependent on humans for food. Such conditioning can lead dolphins to approach boats more closely, increasing their risk of injury from propellers or entanglement in fishing gear. It is also important to be especially cautious and provide extra space when dolphin calves are present, as mothers are highly protective. If a dolphin approaches you, remain calm, avoid sudden movements, and refrain from direct eye contact, which can be perceived as a challenge.