A weeks-old sea otter is getting round-the-clock care from Vancouver Aquarium staff after being found swimming alone in open water off northern Vancouver Island.

The tiny male, estimated to be between two and four weeks old, was found by boaters on Sunday, the aquarium said.

Staff at the aquarium's Marine Mammal Rescue Centre were told that the pup had approached the boat, then followed it "while vocalizing." Seeing no adult sea otters in the area, they brought it into their boat.

They brought the otter to Port Hardy, where officers from Fisheries and Oceans Canada (DFO) arranged to transfer him to the rescue centre.

The sea otter is now receiving 24-hour care at the centre, with staff and volunteers working shifts to feed, bath and groom him. While the pup appears to be healthy, he is still fully dependent because of his age. Without a mother to nurse, groom and teach him to forage, "he would not survive on his own," rescue centre manager Lindsaye Akhurst said in a news release.

Baby otters typically spend their first six months at their mother's side, so the pup is at a disadvantage being on his own.

It is not yet known whether he will be released, or will live at the rescue facility. The decision will be made by DFO.

While the boaters were well intentioned, staff at DFO and the non-profit said the they should have reported the sighting, rather than removing the otter from the area.

"Once they're removed from the wild it's impossible to determine if the mother is alive and if they could have been reunited, or if bringing him in was the appropriate action," Akhurst said.

The last few months have been busy for the aquarium's rescue centre, where staff have also cared for a California sea lion, a Steller sea lion pup and 29 harbour seals.

DFO used the otter's "rescue" as an opportunity to remind the public that touching or capturing wild marine mammals is illegal. The ministry advises that people keep their distance and do not try to move animals, even if they appear to be alone.

Those who spot a marine mammal who appears to be in distress are asked to contact the ministry at 1-800-465-4336, or the aquarium rescue centre at 604-258-7325 (SEAL). Sightings south of the border can be reported to the National Oceanic and Atmospheric Administration's fisheries department at 1-800-853-1964.

Sea otter pup