Chelsea Stanley and her colleagues from the Pacific Biological Station in Nanaimo, B.C. got a call earlier this week about some sort of mammal found on a nearby beach. When they got a closer look, they were quite shocked.

"I was taken aback definitely," says Stanley. "We thought it was going to be a stellar sea lion which is more common around here."

What they actually found is much rarer -- a northern elephant seal.

"It's the largest piniped, so the largest sea or sea lion in the North Pacific," says University of British Columbia marine mammal researcher Andrew Trites.

For scientists the discovery of the two-tonne, 13-foot adult elephant seal goes beyond the wow factor. The extraordinary find has marine biologists across the country buzzing.

"The elephant seals breed in Mexico and they breed in California, they don't breed in British Columbia," says Trites. "The animals do make an annual migration up to Alaska, but they don't stop off in the Georgia Strait, so to find one here -- particularly this age and size -- it's really rare."

"I've never seen or even heard of it before," he says.  

The discovery of the seal is somewhat of a mystery. Scientists aren't sure if the animal is simply a wayward seal that lost its way or a sign that a species nearly hunted to extinction is making a comeback on the west coast.

They won't know for sure until they examine the seal and perform a necropsy later this week.

But with such a unique opportunity, scientists hope to unravel the mystery of this giant specimen and what its presence here means for the B.C. marine ecosystem.

With a report from CTV British Columbia's Stephen Smart