Photo by Rita Mexia, a passenger on a boat in the Algarve approached by orcas back in 2021
Photo by Rita Mexia, a passenger on a boat in the Algarve approached by orcas back in 2021

Orcas’ sailboat ‘atttacks’: Aveiro scientist offers explanation

Traumatic event “may have triggered change in behaviour in one orca” that others are now imitating

At least three yachts have sunk since orcas (killer whales) began harassing relatively small sailing boats along the Iberian coast in 2020. Now, after years of study, a marine biologist working out of Aveiro university believes the explanation lies in whatever happened to one traumatised orca, named by researchers as White Gladis.

According to Alfredo López Fernandes, who is part of the Atlantic Orca Working Group, White Gladis must have suffered “a critical moment of agony” – a collision with a boat, or entrapment during illegal fishing – that flipped a behavioural switch.

That orca is the one that started this behaviour of physical contact with the boat”, López Fernandes has explained to Live Science, whose story now has been picked up by various international outlets.

“The orcas are doing this on purpose, of course, we don’t know the origin or the motivation, but defensive behavior based on trauma, as the origin of all this, gains more strength for us every day,” he said.

Researchers do not go as far as saying the orcas are teaching their young to immobilise sailboats (the modus operandi always being ‘going for the rudder’, usually until it is destroyed), just that the “behaviour has spread to the young vertically, simply by imitation, and later horizontally among them because they consider it something important in their lives”.

The bottom line of scientists’ research, however, is that their explanation does not offer any kind of solution.

Reports of interactions between orcas and sailboats “have been continuous since 2020 in places where orcas are found, either in Galicia, or the Strait” (of Gibraltar, or in between the two points, meaning along the Algarve and Portuguese west coast). Most encounters “have been harmless”, Fernandes told Live Science (meaning, they have damaged the boats – leading them often to require towing into the nearest port, for extensive repairs, but not destroyed them – nor harmed the people inside).

In more than 500 interaction events recorded since 2020 there are three sunken ships. We estimate that killer whales only touch one ship out of every hundred that sail through a location,” he said.

That is cold comfort for the boats that have been touched, worse for the craft that have sunk to the bottom of the sea

Says Live Science: “As the number of incidents grows, there is increased concern both for sailors and for the Iberian orca subpopulation, which is listed as critically endangered by the IUCN Red List. The last census, in 2011, recorded just 39 Iberian orcas, according to the 2022 study. “If this situation continues or intensifies, it could become a real concern for the mariners’ safety and a conservation issue for this endangered subpopulation of killer whales.”

In many ways, the scientists are saying now what they said, without the benefit of study, in the early days of this phenomenon – and there is already increased concern for sailors’ safety. Various social media groups have formed with a view to keeping the sailing community safe and in touch with one an other when they embark on trips that are now fraught with these unpredictable dangers, beyond those that are habitually posed by the sea.

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