ARCHIVED - Sailors and fishermen warned to be vigilant as orcas are sighted off the coast of Galicia

Image: Archive. Orcas in the wild.

A group of large orcas has been sighted close to boats near the city of A Coruña

Spain’s maritime rescue services have issued a killer whale warning off the coast of A Coruña in the far north-west of the country, after a group of large specimens was sighted worryingly close to the bay.

Last year there was a spate of incidents in which killer whales, or orcas, were responsible for a series of attacks on the rudders of boats off the coast of the region of Galicia, and although on this occasion no collision has occurred Salvamento Marítimo are urging sailors to exercise caution and be vigilant.

It is known that orca sightings have become more frequent off Galicia in recent years, and scientists investigating the animals have used video footage to identify individual specimens: each orca has a uniquely shaped pale grey patch behind its dorsal fin and from the surface this can be used as an orca “fingerprint”!

Last year’s incidents mostly involved three individuals, young juvenile males who became known as the "three Gladis"; black Gladis, white Gladis and grey Gladis, and it is known that killer whales live, hunt and move in very closely connected family pods. These are tightly knit groups led by a matriarch, and families usually stick closely together with grandmothers helping to raise the young and to teach them to hunt.

The problems last year arose when the three young individuals were engaged in several "ramming" incidents, generally targeting the rudder of the mainly leisure vessels. Although there were no injuries to members of the public, the boats were all disabled by the incidents, and had to be towed into port; in one incident a rescue boat was itself attacked.

There have been reports before of young males "playing" with boats, but one of the males identified as being a "repeat offender" in these incidents last year, had a large gash on his head, which is believed to have been caused  by a propellor.

Orcas are inquisitive, highly intelligent, playful, but can also represent a severe danger to shipping as their sheer size and power is capable of causing significant damage to, and even sinking, a vessel. Orcas sometimes hunt other whales as a pack, ramming the soft underbelly of large specimens with their heads, and it is not unheard of for boats to be sunk by hunting orcas.

The orca are in this area in pursuit of tuna, which travel along this coastline in large shoals, as do other members of the tuna family at this time of year.

It is not known if any of the individuals sighted are the same orca that were in the area last year.