Orcas attacking yachts off Spain may be after revenge for injuries

A GROUP of scientists investigating a spate of attacks by orcas on yachts off the coast of Spain in recent months has said their unprecedented behaviour may be a form of revenge by the whales after being injured by humans.

Members of the international working group for Atlantic orcas say they have been able to confirm that three juvenile killer whales from the same pod are responsible for the ramming attacks that have damaged boats.

Of the three orcas – which the scientists have collectively named Gladys – a study of photographs has revealed that two sustained injuries to their flanks, which is not the kind of habitual damage the animals’ dorsal fins sustain by accidental brushes with fishing gear.

The injuries to white Gladys and black Gladys, so named due to differences in their dorsal fin colouration, appeared between June 20 and Aug 3. The vast majority of the incidents took place after this period, leading researchers to suspect that the orcas are retaliating aggressively for the pain they endured.

“Since that event a series of behaviours have been triggered when the orcas are in the presence of yachts, which culminate in a preventive action to stop it moving by manipulating [the rudder],” the scientists’ report reads.

“We cannot rule out that a sailboat could have been involved in the aversive incident.”

Sailors have reported “coordinated attacks” by a group of orcas, lasting up to an hour, in which the animals take turns to ram the hulls of yachts, bite the rudder and make boats spin around.

The researchers have confirmed that the Gladys trio took part in 61 per cent of the 33 incidents reported since late July.

Six attacks took place in the Strait of Gibraltar, five in Portuguese waters and 22 off the coast of the north-western Spanish region of Galicia, where yachting was banned off a stretch of coastline to avoid further confrontations.