SpainA cruise ship sailing through the Strait of Gibraltar recently sank after being attacked by a pod of killer whales, marking the latest in a series of encounters with the animals.
Robert Powell and two others on the yacht Bonhomie William had to be rescued by the Spanish coast guard on July 24 after killer whales damaged the ship’s rudder, causing the vehicle to shake violently, according to Newsweek. He believes they were not playing around, but rather a well-coordinated and organised attack. However, Volker Deecke, professor of wildlife conservation at the University of Cumbria, said there was no evidence of aggressive behaviour or that the killer whales had deliberately tried to sink the boats they encountered.
According to a spokesman for the Spanish Coast Guard, on the evening of July 24, the Bonhomme William yacht, 3.2 km from Cape Camarinal between Tarifa and Barbate, reported that it needed to be pulled ashore because its steering system was not working after interacting with a killer whale.
Powell and two crew members initially contacted Spanish authorities for a tow, as the initial attack by the killer whales had damaged their rudder. Spanish authorities began preparing the Salvamar Enif lifeboat, but the crew of the Bonhomme William later reported that the killer whales had returned and that their ship was taking on water. When the Salvamar Enif arrived, the Bonhomme William had sunk below the surface, and the crew was forced to use life rafts, but were unharmed. Spanish authorities collected samples of the contaminated fluid, radio, life raft, and other items before transporting Powell’s party to Barbate.
The incident comes just three months after a similar incident in the Strait of Gibraltar, where a pod of killer whales also blocked and sank a cruise ship in Moroccan waters. The two crew members on board were rescued by a passing tanker.
Scientists, including biologist Alfredo López Fernández of the University of Santiago, theorize that the boat-targeting behavior may stem from a traumatic event that changes the behavior of the killer whales and that other members of the group follow suit. Fernández speculates that a killer whale injured by a boat may prompt its family to retaliate.
“When we examined underwater footage of killer whales interacting with boats, we did not see the behaviour that is typically seen in aggressive encounters. The killer whales appeared to be extremely calm and relaxed, with no signs of agitation. Therefore, we avoid using the word attack. There was no evidence of retaliation or negative reactions. We assume that this was a playful activity and that younger individuals tend to exhibit this behaviour,” said Professor Volker Deecke.
According to Deecke’s observations, killer whales that interact with boats are usually 3-15 years old, rather than very young calves. Their engines seem to be aimed at the rudders of boats. When the rudders fail, they abandon the boats.
However, Deecke stressed that killer whales do not actively seek out boats to interact with. They only approach when boats are passing through their territory. Killer whales do not venture outside their usual feeding grounds to find and intercept boats. Interactions are essentially opportunistic rather than targeted.
Killer whales also show preferences for the type of boat they interact with and the timing of their interactions. They often target sailboats, likely due to their speed. Many motorboats are too fast for killer whales to follow, while sailboats move slowly at speeds they can keep up with.
Accidents are rare in winter, possibly because there are fewer boats on the water, according to Deecke. Attack activity increases in May around the northern tip of Spain in Galicia, followed by clashes along the Portuguese coast. The highest frequency of incidents in the Strait of Gibraltar usually occurs between July and September.
The above pattern is closely linked to the movements of bluefin tuna, the main prey of killer whales. The tuna swim into the Mediterranean Sea to spawn, then migrate past Gibraltar in midsummer, the timing and location of killer whale interactions coincide with the movements of the tuna.