More than 500 narwhals have been hunted from the sea ice near Pond Inlet, Nunavut. (CBC)

A federal researcher says he hopes some satellite imagery of the area around Pond Inlet, Nunavut, will help them figure out how more than 500 narwhals became trapped in sea ice near the Baffin Island community.

As of Friday afternoon, hunters have culled 511 narwhals trapped in the ice near Bylot Island, about 17 kilometres from Pond Inlet. The number surpasses previous estimates — 500 whales — by the federal Department of Fisheries and Oceans.

Local hunters have been culling the trapped narwhals since Nov. 20, after residents found hundreds of whales crowded in small areas of open water.

Elders and fisheries officials have agreed that the whales would otherwise die from starvation and a lack of oxygen as the sea ice closes in around them.

The federal department has sent several officers to Pond Inlet to tag each narwhal as it's being hunted, as well as to gather scientific samples from the harvested animals.

Pierre Richard, a Winnipeg-based DFO research scientist, told CBC News he has requested satellite imagery to get a better look at ice conditions around Bylot Island.

"For reasons we don't know, occasionally there are herds or smaller groups of narwhal that remain in areas where they risk this kind of entrapment," he said.

"It could be food-related. It could be they didn't have access to their normal migration route for some reason."

Speaking to CBC News from Pond Inlet, local elder Gamailie Kilukishak said he does not remember seeing so many narwhals trapped at the same time.

Speaking in Inuktitut, Kilukishak said he suspects that multi-year ice has closed off Navy Board Inlet, which runs along the western side of Bylot Island.

The narwhals may have then turned around to head out toward Baffin Bay, only to find the ice had already formed on the east side of the island, he added.

Richard said he believes the whales got trapped in fast-freezing ice as they tried to reach open water.

"That ice will become solid and the holes will progressively become smaller," Richard said.

"And as animals become weaker from lack of food and from the effort of competing to breathe in these holes, they'll slowly die in the process."

Richard said that in 1927, about 600 narwhals, also trapped in the ice, were harvested at Admiralty Inlet, near the community of Arctic Bay.

There have since been other incidents involving a smaller number of entrapped whales, but Richard said the current situation involves the most whales they've discovered in recent history.

Richard said the department will review the situation once the harvest ends.