Killer whales are no strangers to Canadian waters. In fact, orcas are living in every ocean on earth. The highest densities of killer whales are in the northeast Atlantic around the Norwegian coast, in the north Pacific along the Aleutian Islands, the Gulf of Alaska and in the Southern Ocean off much of the coast of Antarctica. They are also common in the eastern Pacific along the coasts of British Columbia, Washington and Oregon, in the North Atlantic Ocean around Iceland and the Faroe Islands. It isn't unheard of to spot some in Baffin Bay. At this time of year, however, it is unusual for them to be gathered near Inukjuak, Quebec in Hudson Bay. They often visit arctic water in more temperate weather, but rarely come near an ice pack. Recently a group of up to 18 of them were trapped under the ice in this location. Their presence in this spot is what is cryptic.
While there is rapid Arctic sea ice decline in the Hudson Strait, it is still unlikely that killer whales would come into the bay in the winter. Average December and January temperature onshore is -15C, with an average low nearly -30C. The latest ice charts for the area show not only normal ice present, but significantly lower temperatures just east of the Hudson Straight, and the whales would have had to have passed through there to get to their current location. While ice coverage is still below normal historically, there is about twice as much ice there this year as there was just two years ago.
Occasionally, killer whales swim into freshwater rivers. Beluga whales, native to the area, winter in the open waters of the Hudson Straight and in the spring return to the larger rivers nearby for calving. Belugas are typically gone from the Bay itself by the time the ice gets just a couple of inches thick. The freshwater river that flows into the bay at this area is full of rapids, and not nearly deep enough to house killer whales, even for a short time. As the ice builds along the shore and into the river, the tide action pushes it up creating a very ragged terrain of solid ice. For most of the winter, this ice is very thick which would make it difficult for the air-breathing orcas to surface. In the past few days, the wind and tides have been slowly closing the pickup truck sized hole the whales were using for breathing.
Winds shifted overnight, however, and today the whales appear to have escaped to open water. Will they come back?
Inujjuamiut Foraging Strategies: Evolutionary Ecology of Arctic Hunting Economy By Eric Alden Smith