An orca moves along a rudder of the Team JAJO entry in The Ocean Race. Photo / AP
Killer whales have developed a taste for the ultimate quarry: pleasure yachts.
Marine scientists in Spain were surprised to see that a pod of unruly orcas may be teaching others bad habits. The whales have been blamed for sinking three small boats in south west Europe, around Spain and Portugal - with the cases of “orca attacks” growing from 52 incidents to 207 last year.
More alarmingly the behaviour has spread from the Mediterranean to the North Sea, with The Guardian reporting an incident off the Scottish Shetland islands in June.
One CBS report said it was as if the animals were “seeking revenge”, over a montage of the 500 or so recorded incidents from the past three years. In many parts of the world including southern Europe, the animals are deemed critically endangered.
Dr Renaud de Stephanis, a researcher for Spain’s Conservación, Información y Estudio sobre Cetáceos (CIRCE) has a more prosaic explanation for the new behaviour. He says boredom could be to blame.
“It’s only a game. It isn’t revenge, it isn’t climate change, it’s just a game and that’s it,” Dr de Stephanis told the BBC.
The highly sociable creatures learn habits from one another. The whales, which have the most diverse habitats of any cetacean, are able to live and hunt in the waters from Antarctica to the tropical zones of Indonesia and the Caribbean. This huge range requires orca pods to be able to learn and teach techniques and behaviours to adapt.
This can be useful habits like hunting manta rays or arctic fur seals, or unhelpful ones like attacking boat rudders.
There is a growing concern both for sailors and for the 49 orca who are known to live in the area.
“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,” researchers for conservation body IUCN wrote, last year.
Sailors have had to adapt to the new behaviour, so as to not harm their vessels or the animals. One orca incident disrupted racing near Gibraltar, in June, forcing teams to stop
“We took down the sails and slowed down the boat as quick as possible. Luckily after a few attacks, they went away,” said skipper Jelmer van Beek of Team JAJO, who were participating in The Ocean Race.
The orca, the crew and the boat were unharmed, said a team press release.
Fewer than 200 individual killer whales have been recorded as living in the waters around New Zealand. Fortunately none appear to have adopted this fad.
Mike Ogle, a technical adviser for DoC’s marine species team, says no incidents of similar behaviour have been reported.
“Orca are predators with quite a reputation, but no records exist of deliberate fatal attacks on humans,” says the Department of Conservation’s advice on marine mammals.
“It still pays, however, to show respect around these animals.”