Record numbers of killer whales


RECORD NUMBERS of killer whales (Orcinus orca) have been recorded feeding on shoals of mackerel in Irish waters in recent weeks.

The killer whales came to the attention of the Naval Service, which was monitoring fishing vessels off Tory Island. Consistent estimates from Naval personnel and fishermen suggested more than 100 killer whales have been feeding off the Irish coast.

Irish Whale and Dolphin Group (IWDG) Sightings co-ordinator Pádraig Whooley said the average number of confirmed sightings in Irish waters annually was generally about a dozen.

He believes the whales have followed migrating mackerel and are likely to have come from Scotland. “Killer whales, like other dolphins, have what is called home range and they can easily travel five, six hundred miles,” he said.

While there have never been as many killer whales recorded in Irish waters at one time, Mr Whooley cannot be certain that this is not a regular occurrence. “It is just the first time that we have recorded it. It’s one event; you can never interpret too much into a single event,” Mr Whooley said.

“Although these animals were spread out over a wide area in a loose feeding aggregation, such large numbers have thus far never been documented in Irish waters. That said, similar feeding activity has in recent years been reported by the mackerel fleet off Shetland and the North Sea.”

Captain of the Irish naval ship LE NiamhLt Cdr Paddy Harkin contacted the IWDG about the “significant numbers” of killer whales close to a fishing fleet.

During a recent patrol of the northwest coast of Ireland, Capt Harkin reported sightings of a number of pods of killer whales, including a dozen whales within 200 metres of the LE Niamh.

Capt Harkin told the IWDG that on January 27th and 28th “we observed a significant number of killer whales approximately 30 miles west of Tory Island”.

“In one of our photographs upwards of eight killer whales can be observed; an estimate of 10 whales being visible at any one time is on the conservative side. On one occasion, at least a dozen killer whales were within 200 metres of the ship,” he said.

“The killer whales were among large shoals of mackerel and there were approximately 25 vessels in the area mackerel fishing.” The killer whales are believed to have stayed with the fishing fleet for up to two weeks.

The IWDG has validated 162 sightings of killer whales in Irish waters, with an average group size of three to four animals per sighting. Despite their name, killer whales are the largest member of the dolphin family.