Department of Fisheries and Oceans scientists are sharing a video of something they say has never been captured before — narwhal using their tusks to hunt cod.

The film shows narwhal in Nunavut's Tremblay Sound using their tusks as spears, stabbing at the cod.

Narwhals are mammals that live in Arctic waters in Nunavut, west Greenland and the European Arctic, according to the Fisheries Department. In Canada they summer in waters near Baffin Bay and Hudson Bay.

There are approximately 158,000 narwhal living near Baffin Bay, and 12,500 in the Hudson Bay.

"We need to pursue [this] further to see if they use this kind of behaviour often, or if it's just unique to Tremblay Sound where it was filmed," explained Marianne Marcoux, a research scientist with the Fisheries Department.

"Is it important for them?" she said. "Do they just do it a few days a year or do they do it the whole summer and it's a big part of their diet?"

Inuit traditional knowledge speaks about the uses of the narwhal's tusk.

Narwhal are known to use their tusks to spear and hunt other sea animals but using them to hunt fish is unusual, explained Paniloo Sangoya, an elder from Pond Inlet, Nunavut, the community closest to Tremblay Sound.

"There was a hunter who has caught one with something on its tusk," Sangoya said in Inuktitut. "But I have never seen narwhal stinging fish."