Arctic ice melt explains narwhals’ presence in Cambridge Bay

This map shows the normal range of narwhals, which usually don’t go anywhere near Cambridge Bay, where they were spotted recently.

Increased sea ice melt could be responsible for the recent appearance of narwhals in Cambridge Bay, says a marine biologist with the federal department of fisheries and oceans.

“As we see less ice, it could become more common,” said Steve Ferguson, who works with the DFO in Winnipeg. “It fits the pattern that we’re losing sea ice and marine mammals are extending their range into the High Arctic archipelago.”

Narwhals and belugas have been spotted more frequently in the High Arctic islands, with belugas, for example, moving closer to Resolute Bay where hunters used to travel south from Cornwallis Island to Southampton Island to hunt these whales.

The narwhals which turned up in Cambridge Bay “most likely” came from Baffin Bay, Ferguson said.

The narwhals, numbering 50 or more, seen in Cambridge Bay may also have been chased by killer whales west to Victoria Island.

If killer whales were chasing the narwhals, that usually stay east of Boothia Bay, the narwhals may have sought out the more ice-filled waters of the Northwest Passage, south of Gjoa Haven to escape them, Ferguson said.

That’s because killer whales, which have a fin on their backs, try to avoid ice that can catch on to this fin, causing injuries.

Im any event, narwhals appear to be moving west — or even over the top of the pole— as there have also been sightings in the Beaufort region and in Alaska, Ferguson said.

To date, hunters have provided the most detailed information about narwhal sightings, he said.

But to track narwhal movements, the DFO has tagged narwhals in Eclipse Sound — and one tagged narwhal wintered over last year in Steensby Inlet in Foxe Basin, a place which has been considered to be less suitable for deep-diving narwhals to feed.

But that could be changing, Ferguson said: due to reduced ice cover in Baffin Bay, Foxe Basin could be “the next best bay” for narwhals.

Changes in the marine mammal population have also seen in Cumberland Sound, where Ferguson said harp seals now outnumber ring seals 50 to 1.

The ring seals are likely drawn there by the capelin, whose numbers are also increasing in the Cumberland Sound as the capelin stock travels north.