A northern fur seal pup rescued off Vancouver Island earlier this year has finally returned to the ocean and is expected to help researchers learn more about the species.

According to a post shared on Ocean Wise's Twitter page Monday, Mo was spotted swimming in an unusual way near Hardwicke Island back in January.

She was floating sideways and seemed to be unable to dive," the post said, adding that staff at the Vancouver Aquarium's Marine Mammal Rescue Centre "estimated her to be about seven months old, but severely underweight."

After five months of rehabilitation at the aquarium, Mo was released on a beach on Vancouver Island's outer coast.

"Without so much as a parting glance at her caregivers, she rushed into the water at Big Beach and bolted for the open ocean," Ocean Wise said.

The seal was equipped with a satellite transmitter on top of her head that will her allow scientists to track her for several weeks.

“We never know how successful each pup’s recovery will be, but our objective is always a full rehabilitation and return to the ocean,” said MMRC manager Lindsaye Akhurst.

“Mo is an energetic and spirited animal, which served her well as she recuperated and will help her thrive now that she’s back in the ocean.”

According to the organization, researchers are especially interested in northern fur seals as pup production in the species' main breeding ground in the Bering Sea has declined by 50 per cent since the 1970s and continues to drop.

The species is listed as "vulnerable" in the U.S. and "threatened" in Canada, Ocean Wise said.

"Ocean Wise scientists are participating in an international research program to determine the causes of the decline," the post read. "Mo may well provide these scientists with some insights."

Members of the public can track Mo's satellite location through a website set up by the Vancouver Aquarium.