The death of a four-year-old bowhead whale near Tuktoyaktuk last summer continues to puzzle scientists, but they say the whale's young age offers a big clue.

In August, scientists with Fisheries and Oceans Canada and members of the Tuktoyaktuk Hunters and Trappers Committee helicoptered to the whale's carcass and found it lying on its back with its stomach torn open.

While bowhead whales can live as long as 200 years, scientists say the death of the young whale isn't out of the ordinary, since it was likely growing its filter-feeding bristles, known as baleen.

"It was quite a young whale and this is the life stage when they are developing their baleen and so they are more susceptible to mortality," said Ellen Lea, a biologist with the Department of Fisheries and Oceans in Inuvik.

"We have no reason to believe that it is suspicious in any way," Lea said.

bowhead whale Tuktoyaktuk

The sampling crew from Fisheries and Oceans Canada and the Tuktoyaktuk Hunters and Trappers Committee measure the total length of the whale in August. (Ellen Lea/Fisheries and Oceans Canada)

Other researchers agree the death rates for the sea mammals tend to be quite high around the age of four, when they stop nursing.

Craig George, an Alaskan wildlife biologist, suspects that young bowhead whales spend so much energy developing their teeth and baleen that they might not eat enough.

"I guess starving is a little bit of a strong term — but basically they're dropping weight through that period," said George, who has studied the animals for 35 years.

"They are basically trying to build large baleen in order to feed effectively."

Bowheads also face the threat of disease early on life, as well as predators such as killer whales and humans.

Scientists took samples of the whale's skin, muscles, baleen and its eye in August. The samples were sent to an Alaskan lab for testing.