Spain warns of orca attacks as whale sinks boat

Spanish authorities are advising small vessels to stick to the coastline around the Strait of Gibraltar after an orca rammed a boat, causing it to sink.

Two people on a 15-metre boat in Moroccan waters put out a call for help on Sunday after an orca had knocked into the vessel, damaging the rudder and causing a leak.

The people were picked up by a passing oil tanker, but their boat late sank.

Spain’s ministries for transport and the environment, along with its merchant marines, issued warnings on Tuesday urging both sailing boats and small motorboats to beware of orcas between May and August in the area between the Strait of Gibraltar and the Gulf of Cadiz.

A pod of orcas disrupted a sailing race last year when a boat travelling from the Netherlands to Italy had a 15-minute encounter with the animals.

The crew had to drop the yacht's sails and raise a clatter to fend them off.

There have been no reports of attacks against swimmers and the interactions on boats seem to stop once the vessel becomes immobilised.

The Atlantic Orca Working Group, a team of Spanish and Portuguese marine life researchers who study killer whales near the Iberia Peninsula, said there were 197 such interactions reported in 2021 and another 207 in 2022.

Why do orcas attack boats?

Scientists have suggested that orca attacks likely stem from the animals having had traumatic experiences with boats.

In May last year there were concerns that a "vengeful" whale had been teaching members of its pod how to ram into boats off the coast of Gibraltar.

A female orca, known as White Gladis, was thought to be behind the spate of incidents after being traumatised by her own collision with a boat, researchers said at the time.

In 2022, local researchers conducted a study on the attacks, revealing that they typically happen in daylight, mainly around noon, and last between half an hour and two hours.

“It is increasingly likely that an animal has started this behavior after an incident with a boat,” Alfredo López Fernandez, an adjunct researcher at the University of Aveiro in Portugal said.

He pointed to the history of White Gladis as evidence: “She is the only adult who started in 2020 with the interactions along with seven other juveniles.”

Orcas are very matriarchal and the younger animals look up to the older females in the pod.

"The juveniles are copying their behaviours because they believe that if these very important individuals do something, they have to do the same to ensure their own survival,” Mr González said.

The orcas usually approach the boat silently, swimming beneath it, lightly touching it and then - in the most extreme cases - going for the rudder.

The average size of the vessels approached by the whales is about 12.2 metres.

The orcas off the Iberian coast average between five and six and a half metres in length, compared to orcas in Antarctica that reach nine metres.

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