A newborn orca calf has been spotted off Tofino, B.C., swimming with J Pod, an endangered population of southern resident killer whales.

John Forde and Jennifer Steven of the Tofino Whale Centre, who spotted the whale, posted photos of the baby on the company website.

"From my experience, I'm going to guess it's days old. It's bright orange. It had the fetal folds still. It's so tiny, it looked so fresh," said Steven.

According to the B.C. Cetacean Sightings Network, most killer whale calves are born with this yellow or orange colouring, and take on their stark, black-and-white colour within their first year.

Fisheries and Oceans Canada announced the birth via Twitter.

We are happy to confirm that the newborn Southern Resident <a href="https://twitter.com/hashtag/KillerWhale?src=hash&ref_src=twsrc%5Etfw">#KillerWhale</a> calf spotted in Canadian Pacific waters near <a href="https://twitter.com/hashtag/TofinoBC?src=hash&ref_src=twsrc%5Etfw">#TofinoBC</a> will be the newest member of the Salish Sea’s J-Pod. <a href="https://t.co/NN5t9g7a7A">pic.twitter.com/NN5t9g7a7A</a> —@DFO_Pacific

"Southern resident killer whales, their population is small so any birth is huge," said DFO marine mammal co-ordinator Paul Cottrell.

Only 75 southern resident killer whales remain and the population is reported to be at a 30-year low.

The southern resident killer whales are listed as a species at risk in Canada. (John Forde, Jennifer Steven)

Cottrell cautions that the mortality rate of southern resident killer whale babies is high — around 50 per cent die in the first year.

Forde and Steven said the newborn was spotted swimming with two adult females — J41 who is believed to be its mother, and elder J19.

"This is great news for them, and let's hope [the baby] survives its first year," Steven said.

They said the last time J pod was spotted near Tofino was last June on its annual migration down the coast.