A group of killer whales that appeared to be freed from an icy prison in Hudson Bay after winds shifted overnight now face a 1,000-kilometre maze of deadly ice floes in order to reach the open Atlantic Ocean, says one expert.

The dozen or so orcas were first spotted this week by residents of the nearby village of Inukjuak, Que., who recorded a video of the whales coming up for air in a small hole in the ice. Their plight made headlines around the world on Wednesday, but by Thursday morning, locals reported that the whales were gone after the ice had opened up following a shift in wind direction.

Inukjuak's town manager, Johnny Williams, suspects shifting winds overnight may have pushed the ice, allowing the whales to escape.

After some local residents feared the whales were still trapped, the community hired an aerial search of the area.

Searchers did not spot the orcas, but they did see large areas of water with no ice, Mark O'Connor of the regional marine wildlife board said.

"So as far as I could tell, the emergency, for sure, is averted," said O'Connor, the board's director of wildlife management.

"Whether the whales have found a passage all the way to the Hudson Strait, we probably will never know."

And while it appears the whales are out of imminent danger, many challenges remain, said Pete Ewins, a senior Arctic species officer with WWF Canada.

"Anyone who looks at the satellite image today of sea ice coverage sees that the entire Hudson Bay system is frozen in -- as it is this time of year, mid-winter," Ewins told CTV News Channel.

"The wind has moved a little bit of ice around so that these whales are perhaps 10 or 20 kilometres further on ... but they're trapped essentially in that big Hudson Bay ice system for the winter. Normally they'd be out in the middle of the Atlantic for the winter."

From where the whales were originally spotted near Inukjuak, the whales would have to travel more than 1,000 kilometres -- through Hudson Bay, then out the Hudson Strait -- to reach the North Atlantic Ocean.

Ewins said it's unlikely that the whales will be able to reach open water any time soon. "So the question is are they going to find enough of these tiny holes to allow them to survive until May or June, when the ice starts melting?"

Inukjuak villagers requested that the Canadian Coast Guard send an icebreaker to the area Wednesday to clear a channel to open water, but were told that was not an option because there were none in the area

Ewins said there are few options available to anyone wanting to help.

It's possible the whales could be airlifted by helicopter to open water, but it would be an expensive, dangerous and difficult operation, he said. And bringing in an ice breaker wouldn't necessarily help either, since the noise and vibrations could easily send the whales further under the ice.

The whales could be simply left alone to allow nature to take its course or destroyed to spare them further suffering, Ewins said.

"This isn't the bulk of the population; these are the unfortunate losers that didn't quite get their navigation right as the ice formed at the end of October," said Ewins. "And that's just the way nature works ... nature is very powerful and sometimes very cruel."

Typically, killer whales only show up in Hudson Bay during the summer in order to prey on seals and other wildlife, and then migrate to other areas in winter.

But David Kirby, a journalist and marine life expert who has written extensively about orcas, said climate change has affected sea ice patterns in the area, and the whales' normal seasonal behaviour has been disrupted.

"The bay did not freeze over early this year; it was open water as recently as Christmas. The whales got in and then there was a cold snap, the ice came in and the whales got trapped, so this is an anomaly and a terrible tragedy and unfortunately, I'm not sure they're going to be able to make it," he told CTV's Canada AM.

Tommy Palliser, a local government official who got a good look at the whales said their energy seemed to have waned as of late Wednesday,

Still, villagers were not ready to give up and they planned a rescue operation Thursday. Some had said they would try to make the existing breathing hole large and cut a second hole with chainsaws and drills.

Inukjuak is located about 1,600 kilometres north of Montreal, located on Hudson Bay's east coast.

With a report from The Associated Press